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samba-mirror/lib/tevent/tevent.h
Stefan Metzmacher 407cda2f3b tevent: add support for TEVENT_FD_ERROR 
After 12 years we finally got TEVENT_FD_ERROR support :-)

TEVENT_FD_WRITE event handlers never get errors reported
instead the event handler is silently disabled.
There are likely callers relying on that behavior, so
we are not able to chance it.

Now TEVENT_FD_WRITE can be used together with TEVENT_FD_ERROR
in order to get errors reported without waiting for TEVENT_FD_READ.

TEVENT_FD_ERROR can also be used alone in order to detect errors
on sockets in order to cleanup resources.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2023-10-13 09:49:33 +00:00

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/*
Unix SMB/CIFS implementation.
generalised event loop handling
Copyright (C) Andrew Tridgell 2005
Copyright (C) Stefan Metzmacher 2005-2009
Copyright (C) Volker Lendecke 2008
** NOTE! The following LGPL license applies to the tevent
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __TEVENT_H__
#define __TEVENT_H__
#include <stdint.h>
#include <talloc.h>
#include <sys/time.h>
#include <sys/types.h>
#include <stdbool.h>
/* for old gcc releases that don't have the feature test macro __has_attribute */
#ifndef __has_attribute
#define __has_attribute(x) 0
#endif
#ifdef TEVENT_DEPRECATED
#ifndef _DEPRECATED_
#if __has_attribute(deprecated) || (__GNUC__ >= 3)
#define _DEPRECATED_ __attribute__ ((deprecated))
#else
#define _DEPRECATED_
#endif
#endif
#endif
struct tevent_context;
struct tevent_ops;
struct tevent_fd;
struct tevent_timer;
struct tevent_immediate;
struct tevent_signal;
struct tevent_thread_proxy;
struct tevent_threaded_context;
/**
* @defgroup tevent The tevent API
*
* The tevent low-level API
*
* This API provides the public interface to manage events in the tevent
* mainloop. Functions are provided for managing low-level events such
* as timer events, fd events and signal handling.
*
* @{
*/
/* event handler types */
/**
* Called when a file descriptor monitored by tevent has
* data to be read or written on it.
*/
typedef void (*tevent_fd_handler_t)(struct tevent_context *ev,
struct tevent_fd *fde,
uint16_t flags,
void *private_data);
/**
* Called when tevent is ceasing the monitoring of a file descriptor.
*/
typedef void (*tevent_fd_close_fn_t)(struct tevent_context *ev,
struct tevent_fd *fde,
int fd,
void *private_data);
/**
* Called when a tevent timer has fired.
*/
typedef void (*tevent_timer_handler_t)(struct tevent_context *ev,
struct tevent_timer *te,
struct timeval current_time,
void *private_data);
/**
* Called when a tevent immediate event is invoked.
*/
typedef void (*tevent_immediate_handler_t)(struct tevent_context *ctx,
struct tevent_immediate *im,
void *private_data);
/**
* Called after tevent detects the specified signal.
*/
typedef void (*tevent_signal_handler_t)(struct tevent_context *ev,
struct tevent_signal *se,
int signum,
int count,
void *siginfo,
void *private_data);
/**
* @brief Create a event_context structure.
*
* This must be the first events call, and all subsequent calls pass this
* event_context as the first element. Event handlers also receive this as
* their first argument.
*
* @param[in] mem_ctx The memory context to use.
*
* @return An allocated tevent context, NULL on error.
*
* @see tevent_context_init()
*/
struct tevent_context *tevent_context_init(TALLOC_CTX *mem_ctx);
/**
* @brief Create a event_context structure and select a specific backend.
*
* This must be the first events call, and all subsequent calls pass this
* event_context as the first element. Event handlers also receive this as
* their first argument.
*
* @param[in] mem_ctx The memory context to use.
*
* @param[in] name The name of the backend to use.
*
* @return An allocated tevent context, NULL on error.
*/
struct tevent_context *tevent_context_init_byname(TALLOC_CTX *mem_ctx, const char *name);
/**
* @brief Create a custom event context
*
* @param[in] mem_ctx The memory context to use.
* @param[in] ops The function pointer table of the backend.
* @param[in] additional_data The additional/private data to this instance
*
* @return An allocated tevent context, NULL on error.
*
*/
struct tevent_context *tevent_context_init_ops(TALLOC_CTX *mem_ctx,
const struct tevent_ops *ops,
void *additional_data);
/**
* @brief List available backends.
*
* @param[in] mem_ctx The memory context to use.
*
* @return A string vector with a terminating NULL element, NULL
* on error.
*/
const char **tevent_backend_list(TALLOC_CTX *mem_ctx);
/**
* @brief Set the default tevent backend.
*
* @param[in] backend The name of the backend to set.
*/
void tevent_set_default_backend(const char *backend);
#ifdef DOXYGEN
/**
* @brief Add a file descriptor based event.
*
* @param[in] ev The event context to work on.
*
* @param[in] mem_ctx The talloc memory context to use.
*
* @param[in] fd The file descriptor to base the event on.
*
* @param[in] flags #TEVENT_FD_READ, #TEVENT_FD_WRITE or #TEVENT_FD_ERROR.
*
* @param[in] handler The callback handler for the event.
*
* @param[in] private_data The private data passed to the callback handler.
*
* @return The file descriptor based event, NULL on error.
*
* @note To cancel the monitoring of a file descriptor, call talloc_free()
* on the object returned by this function.
*
* @note The caller should avoid closing the file descriptor before
* calling talloc_free()! Otherwise the behaviour is undefined which
* might result in crashes. See https://bugzilla.samba.org/show_bug.cgi?id=11141
* for an example.
*/
struct tevent_fd *tevent_add_fd(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
int fd,
uint16_t flags,
tevent_fd_handler_t handler,
void *private_data);
#else
struct tevent_fd *_tevent_add_fd(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
int fd,
uint16_t flags,
tevent_fd_handler_t handler,
void *private_data,
const char *handler_name,
const char *location);
#define tevent_add_fd(ev, mem_ctx, fd, flags, handler, private_data) \
_tevent_add_fd(ev, mem_ctx, fd, flags, handler, private_data, \
#handler, __location__)
#endif
/**
* @brief Associate a custom tag with the event.
*
* This tag can be then retrieved with tevent_fd_get_tag()
*
* @param[in] fde The file descriptor event.
*
* @param[in] tag Custom tag.
*/
void tevent_fd_set_tag(struct tevent_fd *fde, uint64_t tag);
/**
* @brief Get custom event tag.
*/
uint64_t tevent_fd_get_tag(const struct tevent_fd *fde);
#ifdef DOXYGEN
/**
* @brief Add a timed event
*
* @param[in] ev The event context to work on.
*
* @param[in] mem_ctx The talloc memory context to use.
*
* @param[in] next_event Timeval specifying the absolute time to fire this
* event. This is not an offset.
*
* @param[in] handler The callback handler for the event.
*
* @param[in] private_data The private data passed to the callback handler.
*
* @return The newly-created timer event, or NULL on error.
*
* @note To cancel a timer event before it fires, call talloc_free() on the
* event returned from this function. This event is automatically
* talloc_free()-ed after its event handler files, if it hasn't been freed yet.
*
* @note Unlike some mainloops, tevent timers are one-time events. To set up
* a recurring event, it is necessary to call tevent_add_timer() again during
* the handler processing.
*
* @note Due to the internal mainloop processing, a timer set to run
* immediately will do so after any other pending timers fire, but before
* any further file descriptor or signal handling events fire. Callers should
* not rely on this behavior!
*/
struct tevent_timer *tevent_add_timer(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
struct timeval next_event,
tevent_timer_handler_t handler,
void *private_data);
#else
struct tevent_timer *_tevent_add_timer(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
struct timeval next_event,
tevent_timer_handler_t handler,
void *private_data,
const char *handler_name,
const char *location);
#define tevent_add_timer(ev, mem_ctx, next_event, handler, private_data) \
_tevent_add_timer(ev, mem_ctx, next_event, handler, private_data, \
#handler, __location__)
#endif
/**
* @brief Set the time a tevent_timer fires
*
* @param[in] te The timer event to reset
*
* @param[in] next_event Timeval specifying the absolute time to fire this
* event. This is not an offset.
*/
void tevent_update_timer(struct tevent_timer *te, struct timeval next_event);
/**
* @brief Associate a custom tag with the event.
*
* This tag can be then retrieved with tevent_timer_get_tag()
*
* @param[in] te The timer event.
*
* @param[in] tag Custom tag.
*/
void tevent_timer_set_tag(struct tevent_timer *te, uint64_t tag);
/**
* @brief Get custom event tag.
*/
uint64_t tevent_timer_get_tag(const struct tevent_timer *te);
#ifdef DOXYGEN
/**
* Initialize an immediate event object
*
* This object can be used to trigger an event to occur immediately after
* returning from the current event (before any other event occurs)
*
* @param[in] mem_ctx The talloc memory context to use as the parent
*
* @return An empty tevent_immediate object. Use tevent_schedule_immediate
* to populate and use it.
*
* @note Available as of tevent 0.9.8
*/
struct tevent_immediate *tevent_create_immediate(TALLOC_CTX *mem_ctx);
#else
struct tevent_immediate *_tevent_create_immediate(TALLOC_CTX *mem_ctx,
const char *location);
#define tevent_create_immediate(mem_ctx) \
_tevent_create_immediate(mem_ctx, __location__)
#endif
#ifdef DOXYGEN
/**
* Schedule an event for immediate execution. This event will occur
* immediately after returning from the current event (before any other
* event occurs)
*
* @param[in] im The tevent_immediate object to populate and use
* @param[in] ctx The tevent_context to run this event
* @param[in] handler The event handler to run when this event fires
* @param[in] private_data Data to pass to the event handler
*/
void tevent_schedule_immediate(struct tevent_immediate *im,
struct tevent_context *ctx,
tevent_immediate_handler_t handler,
void *private_data);
#else
void _tevent_schedule_immediate(struct tevent_immediate *im,
struct tevent_context *ctx,
tevent_immediate_handler_t handler,
void *private_data,
const char *handler_name,
const char *location);
#define tevent_schedule_immediate(im, ctx, handler, private_data) \
_tevent_schedule_immediate(im, ctx, handler, private_data, \
#handler, __location__);
#endif
/**
* @brief Associate a custom tag with the event.
*
* This tag can be then retrieved with tevent_immediate_get_tag()
*
* @param[in] im The immediate event.
*
* @param[in] tag Custom tag.
*/
void tevent_immediate_set_tag(struct tevent_immediate *im, uint64_t tag);
/**
* @brief Get custom event tag.
*/
uint64_t tevent_immediate_get_tag(const struct tevent_immediate *fde);
#ifdef DOXYGEN
/**
* @brief Add a tevent signal handler
*
* tevent_add_signal() creates a new event for handling a signal the next
* time through the mainloop. It implements a very simple traditional signal
* handler whose only purpose is to add the handler event into the mainloop.
*
* @param[in] ev The event context to work on.
*
* @param[in] mem_ctx The talloc memory context to use.
*
* @param[in] signum The signal to trap
*
* @param[in] handler The callback handler for the signal.
*
* @param[in] sa_flags sigaction flags for this signal handler.
*
* @param[in] private_data The private data passed to the callback handler.
*
* @return The newly-created signal handler event, or NULL on error.
*
* @note To cancel a signal handler, call talloc_free() on the event returned
* from this function.
*
* @see tevent_num_signals, tevent_sa_info_queue_count
*/
struct tevent_signal *tevent_add_signal(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
int signum,
int sa_flags,
tevent_signal_handler_t handler,
void *private_data);
#else
struct tevent_signal *_tevent_add_signal(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
int signum,
int sa_flags,
tevent_signal_handler_t handler,
void *private_data,
const char *handler_name,
const char *location);
#define tevent_add_signal(ev, mem_ctx, signum, sa_flags, handler, private_data) \
_tevent_add_signal(ev, mem_ctx, signum, sa_flags, handler, private_data, \
#handler, __location__)
#endif
/**
* @brief Associate a custom tag with the event.
*
* This tag can be then retrieved with tevent_signal_get_tag()
*
* @param[in] fde The signal event.
*
* @param[in] tag Custom tag.
*/
void tevent_signal_set_tag(struct tevent_signal *se, uint64_t tag);
/**
* @brief Get custom event tag.
*/
uint64_t tevent_signal_get_tag(const struct tevent_signal *se);
/**
* @brief the number of supported signals
*
* This returns value of the configure time TEVENT_NUM_SIGNALS constant.
*
* The 'signum' argument of tevent_add_signal() must be less than
* TEVENT_NUM_SIGNALS.
*
* @see tevent_add_signal
*/
size_t tevent_num_signals(void);
/**
* @brief the number of pending realtime signals
*
* This returns value of TEVENT_SA_INFO_QUEUE_COUNT.
*
* The tevent internals remember the last TEVENT_SA_INFO_QUEUE_COUNT
* siginfo_t structures for SA_SIGINFO signals. If the system generates
* more some signals get lost.
*
* @see tevent_add_signal
*/
size_t tevent_sa_info_queue_count(void);
#ifdef DOXYGEN
/**
* @brief Pass a single time through the mainloop
*
* This will process any appropriate signal, immediate, fd and timer events
*
* @param[in] ev The event context to process
*
* @return Zero on success, nonzero if an internal error occurred
*/
int tevent_loop_once(struct tevent_context *ev);
#else
int _tevent_loop_once(struct tevent_context *ev, const char *location);
#define tevent_loop_once(ev) \
_tevent_loop_once(ev, __location__)
#endif
#ifdef DOXYGEN
/**
* @brief Run the mainloop
*
* The mainloop will run until there are no events remaining to be processed
*
* @param[in] ev The event context to process
*
* @return Zero if all events have been processed. Nonzero if an internal
* error occurred.
*/
int tevent_loop_wait(struct tevent_context *ev);
#else
int _tevent_loop_wait(struct tevent_context *ev, const char *location);
#define tevent_loop_wait(ev) \
_tevent_loop_wait(ev, __location__)
#endif
/**
* Assign a function to run when a tevent_fd is freed
*
* This function is a destructor for the tevent_fd. It does not automatically
* close the file descriptor. If this is the desired behavior, then it must be
* performed by the close_fn.
*
* @param[in] fde File descriptor event on which to set the destructor
* @param[in] close_fn Destructor to execute when fde is freed
*
* @note That the close_fn() on tevent_fd is *NOT* wrapped on contexts
* created by tevent_context_wrapper_create()!
*
* @see tevent_fd_set_close_fn
* @see tevent_context_wrapper_create
*/
void tevent_fd_set_close_fn(struct tevent_fd *fde,
tevent_fd_close_fn_t close_fn);
/**
* Automatically close the file descriptor when the tevent_fd is freed
*
* This function calls close(fd) internally.
*
* @param[in] fde File descriptor event to auto-close
*
* @see tevent_fd_set_close_fn
*/
void tevent_fd_set_auto_close(struct tevent_fd *fde);
/**
* Return the flags set on this file descriptor event
*
* @param[in] fde File descriptor event to query
*
* @return The flags set on the event. See #TEVENT_FD_READ,
* #TEVENT_FD_WRITE and #TEVENT_FD_ERROR
*/
uint16_t tevent_fd_get_flags(struct tevent_fd *fde);
/**
* Set flags on a file descriptor event
*
* @param[in] fde File descriptor event to set
* @param[in] flags Flags to set on the event. See #TEVENT_FD_READ,
* #TEVENT_FD_WRITE and #TEVENT_FD_ERROR
*/
void tevent_fd_set_flags(struct tevent_fd *fde, uint16_t flags);
/**
* Query whether tevent supports signal handling
*
* @param[in] ev An initialized tevent context
*
* @return True if this platform and tevent context support signal handling
*/
bool tevent_signal_support(struct tevent_context *ev);
void tevent_set_abort_fn(void (*abort_fn)(const char *reason));
/* bits for file descriptor event flags */
/**
* Monitor a file descriptor for data to be read and errors
*
* Note: we map this from/to POLLIN, POLLHUP, POLLERR and
* where available POLLRDHUP
*/
#define TEVENT_FD_READ 1
/**
* Monitor a file descriptor for writeability
*
* Note: we map this from/to POLLOUT
*/
#define TEVENT_FD_WRITE 2
/**
* Monitor a file descriptor for errors
*
* Note: we map this from/to POLLHUP, POLLERR and
* where available POLLRDHUP
*/
#define TEVENT_FD_ERROR 4
/**
* Convenience function for declaring a tevent_fd writable
*/
#define TEVENT_FD_WRITEABLE(fde) \
tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) | TEVENT_FD_WRITE)
/**
* Convenience function for declaring a tevent_fd readable
*/
#define TEVENT_FD_READABLE(fde) \
tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) | TEVENT_FD_READ)
/**
* Convenience function for declaring a tevent_fd waiting for errors
*/
#define TEVENT_FD_WANTERROR(fde) \
tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) | TEVENT_FD_ERROR)
/**
* Convenience function for declaring a tevent_fd non-writable
*/
#define TEVENT_FD_NOT_WRITEABLE(fde) \
tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) & ~TEVENT_FD_WRITE)
/**
* Convenience function for declaring a tevent_fd non-readable
*/
#define TEVENT_FD_NOT_READABLE(fde) \
tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) & ~TEVENT_FD_READ)
/**
* Convenience function for declaring a tevent_fd not waiting for errors
*/
#define TEVENT_FD_NOT_WANTERROR(fde) \
tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) & ~TEVENT_FD_ERROR)
/**
* Debug level of tevent
*/
enum tevent_debug_level {
TEVENT_DEBUG_FATAL,
TEVENT_DEBUG_ERROR,
TEVENT_DEBUG_WARNING,
TEVENT_DEBUG_TRACE
};
/**
* @brief The tevent debug callbac.
*
* @param[in] context The memory context to use.
*
* @param[in] level The debug level.
*
* @param[in] fmt The format string.
*
* @param[in] ap The arguments for the format string.
*/
typedef void (*tevent_debug_fn)(void *context,
enum tevent_debug_level level,
const char *fmt,
va_list ap) PRINTF_ATTRIBUTE(3,0);
/**
* Set destination for tevent debug messages
*
* As of version 0.15.0 the invocation of
* the debug function for individual messages
* is limited by the current max_debug_level,
* which means TEVENT_DEBUG_TRACE messages
* are not passed by default:
*
* - tevent_set_debug() with debug == NULL implies
* tevent_set_max_debug_level(ev, TEVENT_DEBUG_FATAL).
*
* - tevent_set_debug() with debug != NULL implies
* tevent_set_max_debug_level(ev, TEVENT_DEBUG_WARNING).
*
* @param[in] ev Event context to debug
* @param[in] debug Function to handle output printing
* @param[in] context The context to pass to the debug function.
*
* @return Always returns 0 as of version 0.9.8
*
* @note Default is to emit no debug messages
*
* @see tevent_set_max_debug_level()
*/
int tevent_set_debug(struct tevent_context *ev,
tevent_debug_fn debug,
void *context);
/**
* Set maximum debug level for tevent debug messages
*
* @param[in] ev Event context to debug
* @param[in] max_level Function to handle output printing
*
* @return The former max level is returned.
*
* @see tevent_set_debug()
*
* @note Available as of tevent 0.15.0
*/
enum tevent_debug_level
tevent_set_max_debug_level(struct tevent_context *ev,
enum tevent_debug_level max_level);
/**
* Designate stderr for debug message output
*
* @param[in] ev Event context to debug
*
* @note This function will only output TEVENT_DEBUG_FATAL, TEVENT_DEBUG_ERROR
* and TEVENT_DEBUG_WARNING messages. For TEVENT_DEBUG_TRACE, please define a
* function for tevent_set_debug()
*/
int tevent_set_debug_stderr(struct tevent_context *ev);
enum tevent_trace_point {
/**
* Corresponds to a trace point just before waiting
*/
TEVENT_TRACE_BEFORE_WAIT,
/**
* Corresponds to a trace point just after waiting
*/
TEVENT_TRACE_AFTER_WAIT,
#define TEVENT_HAS_LOOP_ONCE_TRACE_POINTS 1
/**
* Corresponds to a trace point just before calling
* the loop_once() backend function.
*/
TEVENT_TRACE_BEFORE_LOOP_ONCE,
/**
* Corresponds to a trace point right after the
* loop_once() backend function has returned.
*/
TEVENT_TRACE_AFTER_LOOP_ONCE,
};
typedef void (*tevent_trace_callback_t)(enum tevent_trace_point,
void *private_data);
/**
* Register a callback to be called at certain trace points
*
* @param[in] ev Event context
* @param[in] cb Trace callback
* @param[in] private_data Data to be passed to callback
*
* @note The callback will be called at trace points defined by
* tevent_trace_point. Call with NULL to reset.
*/
void tevent_set_trace_callback(struct tevent_context *ev,
tevent_trace_callback_t cb,
void *private_data);
/**
* Retrieve the current trace callback
*
* @param[in] ev Event context
* @param[out] cb Registered trace callback
* @param[out] private_data Registered data to be passed to callback
*
* @note This can be used to allow one component that wants to
* register a callback to respect the callback that another component
* has already registered.
*/
void tevent_get_trace_callback(struct tevent_context *ev,
tevent_trace_callback_t *cb,
void *private_data);
enum tevent_event_trace_point {
/**
* Corresponds to a trace point just before the event is added.
*/
TEVENT_EVENT_TRACE_ATTACH,
/**
* Corresponds to a trace point just before the event is removed.
*/
TEVENT_EVENT_TRACE_DETACH,
/**
* Corresponds to a trace point just before the event handler is called.
*/
TEVENT_EVENT_TRACE_BEFORE_HANDLER,
};
typedef void (*tevent_trace_fd_callback_t)(struct tevent_fd *fde,
enum tevent_event_trace_point,
void *private_data);
typedef void (*tevent_trace_signal_callback_t)(struct tevent_signal *se,
enum tevent_event_trace_point,
void *private_data);
typedef void (*tevent_trace_timer_callback_t)(struct tevent_timer *te,
enum tevent_event_trace_point,
void *private_data);
typedef void (*tevent_trace_immediate_callback_t)(struct tevent_immediate *im,
enum tevent_event_trace_point,
void *private_data);
/**
* Register a callback to be called at certain trace points of fd event.
*
* @param[in] ev Event context
* @param[in] cb Trace callback
* @param[in] private_data Data to be passed to callback
*
* @note The callback will be called at trace points defined by
* tevent_event_trace_point. Call with NULL to reset.
*/
void tevent_set_trace_fd_callback(struct tevent_context *ev,
tevent_trace_fd_callback_t cb,
void *private_data);
/**
* Retrieve the current trace callback of file descriptor event.
*
* @param[in] ev Event context
* @param[out] cb Registered trace callback
* @param[out] p_private_data Registered data to be passed to callback
*
* @note This can be used to allow one component that wants to
* register a callback to respect the callback that another component
* has already registered.
*/
void tevent_get_trace_fd_callback(struct tevent_context *ev,
tevent_trace_fd_callback_t *cb,
void *p_private_data);
/**
* Register a callback to be called at certain trace points of signal event.
*
* @param[in] ev Event context
* @param[in] cb Trace callback
* @param[in] private_data Data to be passed to callback
*
* @note The callback will be called at trace points defined by
* tevent_event_trace_point. Call with NULL to reset.
*/
void tevent_set_trace_signal_callback(struct tevent_context *ev,
tevent_trace_signal_callback_t cb,
void *private_data);
/**
* Retrieve the current trace callback of signal event.
*
* @param[in] ev Event context
* @param[out] cb Registered trace callback
* @param[out] p_private_data Registered data to be passed to callback
*
* @note This can be used to allow one component that wants to
* register a callback to respect the callback that another component
* has already registered.
*/
void tevent_get_trace_signal_callback(struct tevent_context *ev,
tevent_trace_signal_callback_t *cb,
void *p_private_data);
/**
* Register a callback to be called at certain trace points of timer event.
*
* @param[in] ev Event context
* @param[in] cb Trace callback
* @param[in] private_data Data to be passed to callback
*
* @note The callback will be called at trace points defined by
* tevent_event_trace_point. Call with NULL to reset.
*/
void tevent_set_trace_timer_callback(struct tevent_context *ev,
tevent_trace_timer_callback_t cb,
void *private_data);
/**
* Retrieve the current trace callback of timer event.
*
* @param[in] ev Event context
* @param[out] cb Registered trace callback
* @param[out] p_private_data Registered data to be passed to callback
*
* @note This can be used to allow one component that wants to
* register a callback to respect the callback that another component
* has already registered.
*/
void tevent_get_trace_timer_callback(struct tevent_context *ev,
tevent_trace_timer_callback_t *cb,
void *p_private_data);
/**
* Register a callback to be called at certain trace points of immediate event.
*
* @param[in] ev Event context
* @param[in] cb Trace callback
* @param[in] private_data Data to be passed to callback
*
* @note The callback will be called at trace points defined by
* tevent_event_trace_point. Call with NULL to reset.
*/
void tevent_set_trace_immediate_callback(struct tevent_context *ev,
tevent_trace_immediate_callback_t cb,
void *private_data);
/**
* Retrieve the current trace callback of immediate event.
*
* @param[in] ev Event context
* @param[out] cb Registered trace callback
* @param[out] p_private_data Registered data to be passed to callback
*
* @note This can be used to allow one component that wants to
* register a callback to respect the callback that another component
* has already registered.
*/
void tevent_get_trace_immediate_callback(struct tevent_context *ev,
tevent_trace_immediate_callback_t *cb,
void *p_private_data);
/**
* @}
*/
/**
* @defgroup tevent_request The tevent request functions.
* @ingroup tevent
*
* A tevent_req represents an asynchronous computation.
*
* The tevent_req group of API calls is the recommended way of
* programming async computations within tevent. In particular the
* file descriptor (tevent_add_fd) and timer (tevent_add_timed) events
* are considered too low-level to be used in larger computations. To
* read and write from and to sockets, Samba provides two calls on top
* of tevent_add_fd: tstream_read_packet_send/recv and tstream_writev_send/recv.
* These requests are much easier to compose than the low-level event
* handlers called from tevent_add_fd.
*
* A lot of the simplicity tevent_req has brought to the notoriously
* hairy async programming came via a set of conventions that every
* async computation programmed should follow. One central piece of
* these conventions is the naming of routines and variables.
*
* Every async computation needs a name (sensibly called "computation"
* down from here). From this name quite a few naming conventions are
* derived.
*
* Every computation that requires local state needs a
* @code
* struct computation_state {
* int local_var;
* };
* @endcode
* Even if no local variables are required, such a state struct should
* be created containing a dummy variable. Quite a few helper
* functions and macros (for example tevent_req_create()) assume such
* a state struct.
*
* An async computation is started by a computation_send
* function. When it is finished, its result can be received by a
* computation_recv function. For an example how to set up an async
* computation, see the code example in the documentation for
* tevent_req_create() and tevent_req_post(). The prototypes for _send
* and _recv functions should follow some conventions:
*
* @code
* struct tevent_req *computation_send(TALLOC_CTX *mem_ctx,
* struct tevent_context *ev,
* ... further args);
* int computation_recv(struct tevent_req *req, ... further output args);
* @endcode
*
* The "int" result of computation_recv() depends on the result the
* sync version of the function would have, "int" is just an example
* here.
*
* Another important piece of the conventions is that the program flow
* is interrupted as little as possible. Because a blocking
* sub-computation requires that the flow needs to continue in a
* separate function that is the logical sequel of some computation,
* it should lexically follow sending off the blocking
* sub-computation. Setting the callback function via
* tevent_req_set_callback() requires referencing a function lexically
* below the call to tevent_req_set_callback(), forward declarations
* are required. A lot of the async computations thus begin with a
* sequence of declarations such as
*
* @code
* static void computation_step1_done(struct tevent_req *subreq);
* static void computation_step2_done(struct tevent_req *subreq);
* static void computation_step3_done(struct tevent_req *subreq);
* @endcode
*
* It really helps readability a lot to do these forward declarations,
* because the lexically sequential program flow makes the async
* computations almost as clear to read as a normal, sync program
* flow.
*
* It is up to the user of the async computation to talloc_free it
* after it has finished. If an async computation should be aborted,
* the tevent_req structure can be talloc_free'ed. After it has
* finished, it should talloc_free'ed by the API user.
*
* tevent_req variable naming conventions:
*
* The name of the variable pointing to the tevent_req structure
* returned by a _send() function SHOULD be named differently between
* implementation and caller.
*
* From the point of view of the implementation (of the _send() and
* _recv() functions) the variable returned by tevent_req_create() is
* always called @em req.
*
* While the caller of the _send() function should use @em subreq to
* hold the result.
*
* @see tevent_req_create()
* @see tevent_req_fn()
*
* @{
*/
/**
* An async request moves from TEVENT_REQ_INIT to
* TEVENT_REQ_IN_PROGRESS. All other states are valid after a request
* has finished.
*/
enum tevent_req_state {
/**
* We are creating the request
*/
TEVENT_REQ_INIT,
/**
* We are waiting the request to complete
*/
TEVENT_REQ_IN_PROGRESS,
/**
* The request is finished successfully
*/
TEVENT_REQ_DONE,
/**
* A user error has occurred. The user error has been
* indicated by tevent_req_error(), it can be retrieved via
* tevent_req_is_error().
*/
TEVENT_REQ_USER_ERROR,
/**
* Request timed out after the timeout set by tevent_req_set_endtime.
*/
TEVENT_REQ_TIMED_OUT,
/**
* An internal allocation has failed, or tevent_req_nomem has
* been given a NULL pointer as the first argument.
*/
TEVENT_REQ_NO_MEMORY,
/**
* The request has been received by the caller. No further
* action is valid.
*/
TEVENT_REQ_RECEIVED
};
/**
* @brief An async request
*/
struct tevent_req;
/**
* @brief A tevent request callback function.
*
* @param[in] subreq The tevent async request which executed this callback.
*/
typedef void (*tevent_req_fn)(struct tevent_req *subreq);
/**
* @brief Set an async request callback.
*
* See the documentation of tevent_req_post() for an example how this
* is supposed to be used.
*
* @param[in] req The async request to set the callback.
*
* @param[in] fn The callback function to set.
*
* @param[in] pvt A pointer to private data to pass to the async request
* callback.
*/
void tevent_req_set_callback(struct tevent_req *req, tevent_req_fn fn, void *pvt);
void _tevent_req_set_callback(struct tevent_req *req,
tevent_req_fn fn,
const char *fn_name,
void *pvt);
#define tevent_req_set_callback(req, fn, pvt) \
_tevent_req_set_callback(req, fn, #fn, pvt)
#ifdef DOXYGEN
/**
* @brief Get the private data cast to the given type for a callback from
* a tevent request structure.
*
* @code
* static void computation_done(struct tevent_req *subreq) {
* struct tevent_req *req = tevent_req_callback_data(subreq, struct tevent_req);
* struct computation_state *state = tevent_req_data(req, struct computation_state);
* .... more things, eventually maybe call tevent_req_done(req);
* }
* @endcode
*
* @param[in] req The structure to get the callback data from.
*
* @param[in] type The type of the private callback data to get.
*
* @return The type casted private data set NULL if not set.
*/
void *tevent_req_callback_data(struct tevent_req *req, #type);
#else
void *_tevent_req_callback_data(struct tevent_req *req);
#define tevent_req_callback_data(_req, _type) \
talloc_get_type_abort(_tevent_req_callback_data(_req), _type)
#endif
#ifdef DOXYGEN
/**
* @brief Get the private data for a callback from a tevent request structure.
*
* @param[in] req The structure to get the callback data from.
*
* @return The private data or NULL if not set.
*/
void *tevent_req_callback_data_void(struct tevent_req *req);
#else
#define tevent_req_callback_data_void(_req) \
_tevent_req_callback_data(_req)
#endif
#ifdef DOXYGEN
/**
* @brief Get the private data from a tevent request structure.
*
* When the tevent_req has been created by tevent_req_create, the
* result of tevent_req_data() is the state variable created by
* tevent_req_create() as a child of the req.
*
* @param[in] req The structure to get the private data from.
*
* @param[in] type The type of the private data
*
* @return The private data or NULL if not set.
*/
void *tevent_req_data(struct tevent_req *req, #type);
#else
void *_tevent_req_data(struct tevent_req *req);
#define tevent_req_data(_req, _type) \
talloc_get_type_abort(_tevent_req_data(_req), _type)
#endif
/**
* @brief The print function which can be set for a tevent async request.
*
* @param[in] req The tevent async request.
*
* @param[in] ctx A talloc memory context which can be uses to allocate
* memory.
*
* @return An allocated string buffer to print.
*
* Example:
* @code
* static char *my_print(struct tevent_req *req, TALLOC_CTX *mem_ctx)
* {
* struct my_data *data = tevent_req_data(req, struct my_data);
* char *result;
*
* result = tevent_req_default_print(mem_ctx, req);
* if (result == NULL) {
* return NULL;
* }
*
* return talloc_asprintf_append_buffer(result, "foo=%d, bar=%d",
* data->foo, data->bar);
* }
* @endcode
*/
typedef char *(*tevent_req_print_fn)(struct tevent_req *req, TALLOC_CTX *ctx);
/**
* @brief This function sets a print function for the given request.
*
* This function can be used to setup a print function for the given request.
* This will be triggered if the tevent_req_print() function was
* called on the given request.
*
* @param[in] req The request to use.
*
* @param[in] fn A pointer to the print function
*
* @note This function should only be used for debugging.
*/
void tevent_req_set_print_fn(struct tevent_req *req, tevent_req_print_fn fn);
/**
* @brief The default print function for creating debug messages.
*
* The function should not be used by users of the async API,
* but custom print function can use it and append custom text
* to the string.
*
* @param[in] req The request to be printed.
*
* @param[in] mem_ctx The memory context for the result.
*
* @return Text representation of request.
*
*/
char *tevent_req_default_print(struct tevent_req *req, TALLOC_CTX *mem_ctx);
/**
* @brief Print an tevent_req structure in debug messages.
*
* This function should be used by callers of the async API.
*
* @param[in] mem_ctx The memory context for the result.
*
* @param[in] req The request to be printed.
*
* @return Text representation of request.
*/
char *tevent_req_print(TALLOC_CTX *mem_ctx, struct tevent_req *req);
/**
* @brief A typedef for a cancel function for a tevent request.
*
* @param[in] req The tevent request calling this function.
*
* @return True if the request could be canceled, false if not.
*/
typedef bool (*tevent_req_cancel_fn)(struct tevent_req *req);
/**
* @brief This function sets a cancel function for the given tevent request.
*
* This function can be used to setup a cancel function for the given request.
* This will be triggered if the tevent_req_cancel() function was
* called on the given request.
*
* @param[in] req The request to use.
*
* @param[in] fn A pointer to the cancel function.
*/
void tevent_req_set_cancel_fn(struct tevent_req *req, tevent_req_cancel_fn fn);
void _tevent_req_set_cancel_fn(struct tevent_req *req,
tevent_req_cancel_fn fn,
const char *fn_name);
#define tevent_req_set_cancel_fn(req, fn) \
_tevent_req_set_cancel_fn(req, fn, #fn)
#ifdef DOXYGEN
/**
* @brief Try to cancel the given tevent request.
*
* This function can be used to cancel the given request.
*
* It is only possible to cancel a request when the implementation
* has registered a cancel function via the tevent_req_set_cancel_fn().
*
* @param[in] req The request to use.
*
* @return This function returns true if the request is
* cancelable, otherwise false is returned.
*
* @note Even if the function returns true, the caller need to wait
* for the function to complete normally.
* Only the _recv() function of the given request indicates
* if the request was really canceled.
*/
bool tevent_req_cancel(struct tevent_req *req);
#else
bool _tevent_req_cancel(struct tevent_req *req, const char *location);
#define tevent_req_cancel(req) \
_tevent_req_cancel(req, __location__)
#endif
/**
* @brief A typedef for a cleanup function for a tevent request.
*
* @param[in] req The tevent request calling this function.
*
* @param[in] req_state The current tevent_req_state.
*
*/
typedef void (*tevent_req_cleanup_fn)(struct tevent_req *req,
enum tevent_req_state req_state);
/**
* @brief This function sets a cleanup function for the given tevent request.
*
* This function can be used to setup a cleanup function for the given request.
* This will be triggered when the tevent_req_done() or tevent_req_error()
* function was called, before notifying the callers callback function,
* and also before scheduling the deferred trigger.
*
* This might be useful if more than one tevent_req belong together
* and need to finish both requests at the same time.
*
* The cleanup function is able to call tevent_req_done() or tevent_req_error()
* recursively, the cleanup function is only triggered the first time.
*
* The cleanup function is also called by tevent_req_received()
* (possibly triggered from tevent_req_destructor()) before destroying
* the private data of the tevent_req.
*
* @param[in] req The request to use.
*
* @param[in] fn A pointer to the cancel function.
*/
void tevent_req_set_cleanup_fn(struct tevent_req *req, tevent_req_cleanup_fn fn);
void _tevent_req_set_cleanup_fn(struct tevent_req *req,
tevent_req_cleanup_fn fn,
const char *fn_name);
#define tevent_req_set_cleanup_fn(req, fn) \
_tevent_req_set_cleanup_fn(req, fn, #fn)
#ifdef DOXYGEN
/**
* @brief Create an async tevent request.
*
* The new async request will be initialized in state TEVENT_REQ_IN_PROGRESS.
*
* @code
* struct tevent_req *req;
* struct computation_state *state;
* req = tevent_req_create(mem_ctx, &state, struct computation_state);
* @endcode
*
* Tevent_req_create() allocates and zeros the state variable as a talloc
* child of its result. The state variable should be used as the talloc
* parent for all temporary variables that are allocated during the async
* computation. This way, when the user of the async computation frees
* the request, the state as a talloc child will be free'd along with
* all the temporary variables hanging off the state.
*
* @param[in] mem_ctx The memory context for the result.
* @param[in] pstate Pointer to the private request state.
* @param[in] type The name of the request.
*
* @return A new async request. NULL on error.
*/
struct tevent_req *tevent_req_create(TALLOC_CTX *mem_ctx,
void **pstate, #type);
#else
struct tevent_req *_tevent_req_create(TALLOC_CTX *mem_ctx,
void *pstate,
size_t state_size,
const char *type,
const char *location);
struct tevent_req *__tevent_req_create(TALLOC_CTX *mem_ctx,
void *pstate,
size_t state_size,
const char *type,
const char *func,
const char *location);
#define tevent_req_create(_mem_ctx, _pstate, _type) \
__tevent_req_create((_mem_ctx), \
(_pstate), \
sizeof(_type), \
#_type, \
__func__, \
__location__)
#endif
/**
* @brief Set a timeout for an async request. On failure, "req" is already
* set to state TEVENT_REQ_NO_MEMORY.
*
* @param[in] req The request to set the timeout for.
*
* @param[in] ev The event context to use for the timer.
*
* @param[in] endtime The endtime of the request.
*
* @return True if succeeded, false if not.
*/
bool tevent_req_set_endtime(struct tevent_req *req,
struct tevent_context *ev,
struct timeval endtime);
/**
* @brief Reset the timer set by tevent_req_set_endtime.
*
* @param[in] req The request to reset the timeout for
*/
void tevent_req_reset_endtime(struct tevent_req *req);
#ifdef DOXYGEN
/**
* @brief Call the notify callback of the given tevent request manually.
*
* @param[in] req The tevent request to call the notify function from.
*
* @see tevent_req_set_callback()
*/
void tevent_req_notify_callback(struct tevent_req *req);
#else
void _tevent_req_notify_callback(struct tevent_req *req, const char *location);
#define tevent_req_notify_callback(req) \
_tevent_req_notify_callback(req, __location__)
#endif
#ifdef DOXYGEN
/**
* @brief An async request has successfully finished.
*
* This function is to be used by implementors of async requests. When a
* request is successfully finished, this function calls the user's completion
* function.
*
* @param[in] req The finished request.
*/
void tevent_req_done(struct tevent_req *req);
#else
void _tevent_req_done(struct tevent_req *req,
const char *location);
#define tevent_req_done(req) \
_tevent_req_done(req, __location__)
#endif
#ifdef DOXYGEN
/**
* @brief An async request has seen an error.
*
* This function is to be used by implementors of async requests. When a
* request can not successfully completed, the implementation should call this
* function with the appropriate status code.
*
* If error is 0 the function returns false and does nothing more.
*
* @param[in] req The request with an error.
*
* @param[in] error The error code.
*
* @return On success true is returned, false if error is 0.
*
* @code
* int error = first_function();
* if (tevent_req_error(req, error)) {
* return;
* }
*
* error = second_function();
* if (tevent_req_error(req, error)) {
* return;
* }
*
* tevent_req_done(req);
* return;
* @endcode
*/
bool tevent_req_error(struct tevent_req *req,
uint64_t error);
#else
bool _tevent_req_error(struct tevent_req *req,
uint64_t error,
const char *location);
#define tevent_req_error(req, error) \
_tevent_req_error(req, error, __location__)
#endif
#ifdef DOXYGEN
/**
* @brief Helper function for nomem check.
*
* Convenience helper to easily check alloc failure within a callback
* implementing the next step of an async request.
*
* @param[in] p The pointer to be checked.
*
* @param[in] req The request being processed.
*
* @code
* p = talloc(mem_ctx, bla);
* if (tevent_req_nomem(p, req)) {
* return;
* }
* @endcode
*/
bool tevent_req_nomem(const void *p,
struct tevent_req *req);
#else
bool _tevent_req_nomem(const void *p,
struct tevent_req *req,
const char *location);
#define tevent_req_nomem(p, req) \
_tevent_req_nomem(p, req, __location__)
#endif
#ifdef DOXYGEN
/**
* @brief Indicate out of memory to a request
*
* @param[in] req The request being processed.
*/
void tevent_req_oom(struct tevent_req *req);
#else
void _tevent_req_oom(struct tevent_req *req,
const char *location);
#define tevent_req_oom(req) \
_tevent_req_oom(req, __location__)
#endif
/**
* @brief Finish a request before the caller had a chance to set the callback.
*
* An implementation of an async request might find that it can either finish
* the request without waiting for an external event, or it can not even start
* the engine. To present the illusion of a callback to the user of the API,
* the implementation can call this helper function which triggers an
* immediate event. This way the caller can use the same calling
* conventions, independent of whether the request was actually deferred.
*
* @code
* struct tevent_req *computation_send(TALLOC_CTX *mem_ctx,
* struct tevent_context *ev)
* {
* struct tevent_req *req, *subreq;
* struct computation_state *state;
* req = tevent_req_create(mem_ctx, &state, struct computation_state);
* if (req == NULL) {
* return NULL;
* }
* subreq = subcomputation_send(state, ev);
* if (tevent_req_nomem(subreq, req)) {
* return tevent_req_post(req, ev);
* }
* tevent_req_set_callback(subreq, computation_done, req);
* return req;
* }
* @endcode
*
* @param[in] req The finished request.
*
* @param[in] ev The tevent_context for the immediate event.
*
* @return The given request will be returned.
*/
struct tevent_req *tevent_req_post(struct tevent_req *req,
struct tevent_context *ev);
/**
* @brief Finish multiple requests within one function
*
* Normally tevent_req_notify_callback() and all wrappers
* (e.g. tevent_req_done() and tevent_req_error())
* need to be the last thing an event handler should call.
* This is because the callback is likely to destroy the
* context of the current function.
*
* If a function wants to notify more than one caller,
* it is dangerous if it just triggers multiple callbacks
* in a row. With tevent_req_defer_callback() it is possible
* to set an event context that will be used to defer the callback
* via an immediate event (similar to tevent_req_post()).
*
* @code
* struct complete_state {
* struct tevent_context *ev;
*
* struct tevent_req **reqs;
* };
*
* void complete(struct complete_state *state)
* {
* size_t i, c = talloc_array_length(state->reqs);
*
* for (i=0; i < c; i++) {
* tevent_req_defer_callback(state->reqs[i], state->ev);
* tevent_req_done(state->reqs[i]);
* }
* }
* @endcode
*
* @param[in] req The finished request.
*
* @param[in] ev The tevent_context for the immediate event.
*
* @return The given request will be returned.
*/
void tevent_req_defer_callback(struct tevent_req *req,
struct tevent_context *ev);
/**
* @brief Check if the given request is still in progress.
*
* It is typically used by sync wrapper functions.
*
* @param[in] req The request to poll.
*
* @return The boolean form of "is in progress".
*/
bool tevent_req_is_in_progress(struct tevent_req *req);
/**
* @brief Actively poll for the given request to finish.
*
* This function is typically used by sync wrapper functions.
*
* @param[in] req The request to poll.
*
* @param[in] ev The tevent_context to be used.
*
* @return On success true is returned. If a critical error has
* happened in the tevent loop layer false is returned.
* This is not the return value of the given request!
*
* @note This should only be used if the given tevent context was created by the
* caller, to avoid event loop nesting.
*
* @code
* req = tstream_writev_queue_send(mem_ctx,
* ev_ctx,
* tstream,
* send_queue,
* iov, 2);
* ok = tevent_req_poll(req, tctx->ev);
* rc = tstream_writev_queue_recv(req, &sys_errno);
* TALLOC_FREE(req);
* @endcode
*/
bool tevent_req_poll(struct tevent_req *req,
struct tevent_context *ev);
/**
* @brief Get the tevent request state and the actual error set by
* tevent_req_error.
*
* @code
* int computation_recv(struct tevent_req *req, uint64_t *perr)
* {
* enum tevent_req_state state;
* uint64_t err;
* if (tevent_req_is_error(req, &state, &err)) {
* *perr = err;
* return -1;
* }
* return 0;
* }
* @endcode
*
* @param[in] req The tevent request to get the error from.
*
* @param[out] state A pointer to store the tevent request error state.
*
* @param[out] error A pointer to store the error set by tevent_req_error().
*
* @return True if the function could set error and state, false
* otherwise.
*
* @see tevent_req_error()
*/
bool tevent_req_is_error(struct tevent_req *req,
enum tevent_req_state *state,
uint64_t *error);
/**
* @brief Use as the last action of a _recv() function.
*
* This function destroys the attached private data.
*
* @param[in] req The finished request.
*/
void tevent_req_received(struct tevent_req *req);
/**
* @brief Mark a tevent_req for profiling
*
* This will turn on profiling for this tevent_req an all subreqs that
* are directly started as helper requests off this
* tevent_req. subreqs are chained by walking up the talloc_parent
* hierarchy at a subreq's tevent_req_create. This means to get the
* profiling chain right the subreq that needs to be profiled as part
* of this tevent_req's profile must be a talloc child of the requests
* state variable.
*
* @param[in] req The request to do tracing for
*
* @return False if the profile could not be activated
*/
bool tevent_req_set_profile(struct tevent_req *req);
struct tevent_req_profile;
/**
* @brief Get a request's profile for inspection
*
* @param[in] req The request to get the profile from
*
* @return The request's profile
*/
const struct tevent_req_profile *tevent_req_get_profile(
struct tevent_req *req);
/**
* @brief Move the profile out of a request
*
* This function detaches the request's profile from the request, so
* that the profile can outlive the request in a _recv function.
*
* @param[in] req The request to move the profile out of
* @param[in] mem_ctx The new talloc context for the profile
*
* @return The moved profile
*/
struct tevent_req_profile *tevent_req_move_profile(struct tevent_req *req,
TALLOC_CTX *mem_ctx);
/**
* @brief Get a profile description
*
* @param[in] profile The profile to be queried
* @param[in] req_name The name of the request (state's name)
*
* "req_name" after this call is still in talloc-posession of "profile"
*/
void tevent_req_profile_get_name(const struct tevent_req_profile *profile,
const char **req_name);
/**
* @brief Get a profile's start event data
*
* @param[in] profile The profile to be queried
* @param[in] start_location The location where this event started
* @param[in] start_time The time this event started
*
* "start_location" after this call is still in talloc-posession of "profile"
*/
void tevent_req_profile_get_start(const struct tevent_req_profile *profile,
const char **start_location,
struct timeval *start_time);
/**
* @brief Get a profile's stop event data
*
* @param[in] profile The profile to be queried
* @param[in] stop_location The location where this event stopped
* @param[in] stop_time The time this event stopped
*
* "stop_location" after this call is still in talloc-posession of "profile"
*/
void tevent_req_profile_get_stop(const struct tevent_req_profile *profile,
const char **stop_location,
struct timeval *stop_time);
/**
* @brief Get a profile's result data
*
* @param[in] pid The process where this profile was taken
* @param[in] state The status the profile's tevent_req finished with
* @param[in] user_error The user error of the profile's tevent_req
*/
void tevent_req_profile_get_status(const struct tevent_req_profile *profile,
pid_t *pid,
enum tevent_req_state *state,
uint64_t *user_error);
/**
* @brief Retrieve the first subreq's profile from a profile
*
* @param[in] profile The profile to query
*
* @return The first tevent subreq's profile
*/
const struct tevent_req_profile *tevent_req_profile_get_subprofiles(
const struct tevent_req_profile *profile);
/**
* @brief Walk the chain of subreqs
*
* @param[in] profile The subreq's profile to walk
*
* @return The next subprofile in the list
*/
const struct tevent_req_profile *tevent_req_profile_next(
const struct tevent_req_profile *profile);
/**
* @brief Create a fresh tevent_req_profile
*
* @param[in] mem_ctx The talloc context to hang the fresh struct off
*
* @return The fresh struct
*/
struct tevent_req_profile *tevent_req_profile_create(TALLOC_CTX *mem_ctx);
/**
* @brief Set a profile's name
*
* @param[in] profile The profile to set the name for
* @param[in] name The new name for the profile
*
* @return True if the internal talloc_strdup succeeded
*/
bool tevent_req_profile_set_name(struct tevent_req_profile *profile,
const char *name);
/**
* @brief Set a profile's start event
*
* @param[in] profile The profile to set the start data for
* @param[in] start_location The new start location
* @param[in] start_time The new start time
*
* @return True if the internal talloc_strdup succeeded
*/
bool tevent_req_profile_set_start(struct tevent_req_profile *profile,
const char *start_location,
struct timeval start_time);
/**
* @brief Set a profile's stop event
*
* @param[in] profile The profile to set the stop data for
* @param[in] stop_location The new stop location
* @param[in] stop_time The new stop time
*
* @return True if the internal talloc_strdup succeeded
*/
bool tevent_req_profile_set_stop(struct tevent_req_profile *profile,
const char *stop_location,
struct timeval stop_time);
/**
* @brief Set a profile's exit status
*
* @param[in] profile The profile to set the exit status for
* @param[in] pid The process where this profile was taken
* @param[in] state The status the profile's tevent_req finished with
* @param[in] user_error The user error of the profile's tevent_req
*/
void tevent_req_profile_set_status(struct tevent_req_profile *profile,
pid_t pid,
enum tevent_req_state state,
uint64_t user_error);
/**
* @brief Add a subprofile to a profile
*
* @param[in] parent_profile The profile to be modified
* @param[in] sub_profile The subreqs profile profile to be added
*
* "subreq" is talloc_move'ed into "parent_profile", so the talloc
* ownership of "sub_profile" changes
*/
void tevent_req_profile_append_sub(struct tevent_req_profile *parent_profile,
struct tevent_req_profile **sub_profile);
/**
* @brief Create a tevent subrequest at a given time.
*
* The idea is that always the same syntax for tevent requests.
*
* @param[in] mem_ctx The talloc memory context to use.
*
* @param[in] ev The event handle to setup the request.
*
* @param[in] wakeup_time The time to wakeup and execute the request.
*
* @return The new subrequest, NULL on error.
*
* Example:
* @code
* static void my_callback_wakeup_done(tevent_req *subreq)
* {
* struct tevent_req *req = tevent_req_callback_data(subreq,
* struct tevent_req);
* bool ok;
*
* ok = tevent_wakeup_recv(subreq);
* TALLOC_FREE(subreq);
* if (!ok) {
* tevent_req_error(req, -1);
* return;
* }
* ...
* }
* @endcode
*
* @code
* subreq = tevent_wakeup_send(mem_ctx, ev, wakeup_time);
* if (tevent_req_nomem(subreq, req)) {
* return false;
* }
* tevent_set_callback(subreq, my_callback_wakeup_done, req);
* @endcode
*
* @see tevent_wakeup_recv()
*/
struct tevent_req *tevent_wakeup_send(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct timeval wakeup_time);
/**
* @brief Check if the wakeup has been correctly executed.
*
* This function needs to be called in the callback function set after calling
* tevent_wakeup_send().
*
* @param[in] req The tevent request to check.
*
* @return True on success, false otherwise.
*
* @see tevent_wakeup_recv()
*/
bool tevent_wakeup_recv(struct tevent_req *req);
/* @} */
/**
* @defgroup tevent_helpers The tevent helper functions
* @ingroup tevent
*
* @todo description
*
* @{
*/
/**
* @brief Compare two timeval values.
*
* @param[in] tv1 The first timeval value to compare.
*
* @param[in] tv2 The second timeval value to compare.
*
* @return 0 if they are equal.
* 1 if the first time is greater than the second.
* -1 if the first time is smaller than the second.
*/
int tevent_timeval_compare(const struct timeval *tv1,
const struct timeval *tv2);
/**
* @brief Get a zero timeval value.
*
* @return A zero timeval value.
*/
struct timeval tevent_timeval_zero(void);
/**
* @brief Get a timeval value for the current time.
*
* @return A timeval value with the current time.
*/
struct timeval tevent_timeval_current(void);
/**
* @brief Get a timeval structure with the given values.
*
* @param[in] secs The seconds to set.
*
* @param[in] usecs The microseconds to set.
*
* @return A timeval structure with the given values.
*/
struct timeval tevent_timeval_set(uint32_t secs, uint32_t usecs);
/**
* @brief Get the difference between two timeval values.
*
* @param[in] tv1 The first timeval.
*
* @param[in] tv2 The second timeval.
*
* @return A timeval structure with the difference between the
* first and the second value.
*/
struct timeval tevent_timeval_until(const struct timeval *tv1,
const struct timeval *tv2);
/**
* @brief Check if a given timeval structure is zero.
*
* @param[in] tv The timeval to check if it is zero.
*
* @return True if it is zero, false otherwise.
*/
bool tevent_timeval_is_zero(const struct timeval *tv);
/**
* @brief Add the given amount of time to a timeval structure.
*
* @param[in] tv The timeval structure to add the time.
*
* @param[in] secs The seconds to add to the timeval.
*
* @param[in] usecs The microseconds to add to the timeval.
*
* @return The timeval structure with the new time.
*/
struct timeval tevent_timeval_add(const struct timeval *tv, uint32_t secs,
uint32_t usecs);
/**
* @brief Get a timeval in the future with a specified offset from now.
*
* @param[in] secs The seconds of the offset from now.
*
* @param[in] usecs The microseconds of the offset from now.
*
* @return A timeval with the given offset in the future.
*/
struct timeval tevent_timeval_current_ofs(uint32_t secs, uint32_t usecs);
/**
*
* @brief A cached version of getpid()
*
* We use getpid() in a lot a performance critical situations
* in order to check if caches are still valid in the current process.
*
* Calling getpid() always add the cost of an additional syscall!
*
* When tevent is build with pthread support, we already make use
* of pthread_atfork(), so it's trivial to use it maintain a cache for getpid().
*
* @return The pid of the current process.
*/
pid_t tevent_cached_getpid(void);
/* @} */
/**
* @defgroup tevent_thread_call_depth The tevent call depth tracking functions
* @ingroup tevent
*
*
* The call depth tracking consists of two parts.
*
* Part 1 - storing the depth inside each tevent request.
*
* Each instance of 'struct tevent_req' internally stores the value of the
* current depth. If a new subrequest is created via tevent_req_create(), the
* newly created subrequest gets the value from the parent incremented by 1.
*
* Part 2 - updating external variable with the call depth of the currently
* processed tevent request.
*
* The intended use of call depth is for the trace indentation. This is done
* by registering the address of an external size_t variable via
* tevent_thread_call_depth_activate(). And the tracing code just reads it's
* value.
*
* The updates happen during:
*
* tevent_req_create()
* - external variable is set to the value of the newly created request (i.e.
* value of the parent incremented by 1)
*
* tevent_req_notify_callback()
* - external variable is set to the value of the parent tevent request, which
* is just about to be processed
*
* tevent_queue_immediate_trigger()
* - external variable is set to the value of the request coming from the queue
*
*
* While 'Part 1' maintains the call depth value inside each teven request
* precisely, the value of the external variable depends on the call flow and
* can be changed after return from a function call, so it no longer matches
* the value of the request being processed in the current function.
*
* @code
* struct tevent_req *foo_send(TALLOC_CTX *mem_ctx, struct tevent_context *ev)
* {
* struct tevent_req *req, *subreq;
* struct foo_state *state;
*
* // External variable has value 'X', which is the value in parent code
* // It is ok, since tracing starts often only after tevent_req_create()
* req = tevent_req_create(mem_ctx, &state, struct foo_state);
*
* // External variable has now value 'X + 1'
* D_DEBUG("foo_send(): the external variable has the expected value\n");
*
* subreq = bar_send(state, ev, ...);
* tevent_req_set_callback(subreq, foo_done, req);
*
* // External variable has value 'X + 1 + n', where n > 0 and n is the
* // depth reached in bar_send().
* // We want to reset it via tevent_thread_call_depth_reset_from_req(),
* // since we want the following D_DEBUG() to have the right trace
* //indentation.
*
* tevent_thread_call_depth_reset_from_req(req);
* // External variable has again value 'X + 1' taken from req.
* D_DEBUG("foo_send(): the external variable has the expected value\n");
* return req;
* }
*
* static void foo_done(struct tevent_req *subreq)
* {
* struct tevent_req *req =
* tevent_req_callback_data(subreq,
* struct tevent_req);
* struct foo_state *state =
* tevent_req_data(req,
* struct foo_state);
*
* // external variable has value 'X + 1'
*
* D_DEBUG("foo_done(): the external variable has the expected value\n");
* status = bar_recv(subreq, state, ...)
* tevent_req_done(req);
* }
*
* NTSTATUS foo_recv(struct tevent_req *req)
* {
* struct foo_state *state = tevent_req_data( req, struct foo_state);
*
* // external variable has value 'X' (not 'X + 1')
* // which is ok, if we consider _recv() to be an access function
* // called from the parent context
*
* D_DEBUG("foo_recv(): external variable has the value from parent\n");
* return NT_STATUS_OK;
* }
* @endcode
*
* Interface has 3 parts:
*
* Part 1: activation/deactivation
*
* void tevent_thread_call_depth_set_callback(f, private_data)
* Register a callback that can track 'call depth' and 'request flow'
* NULL as a function callback means deactivation.
*
* Part 2: Mark the request (and its subrequests) to be tracked
*
* tevent_thread_call_depth_start(struct tevent_req *req)
*
* By default, all newly created requests have call depth set to 0.
* tevent_thread_call_depth_start() should be called shortly after
* tevent_req_create(). It sets the call depth to 1.
* Subrequest will have call depth 2 and so on.
*
* Part 3: reset the external variable using value from tevent request
*
* tevent_thread_call_depth_reset_from_req(struct tevent_req *req)
*
* If the call depth is used for trace indentation, it might be useful to
* reset the external variable to the call depth of currently processed tevent
* request, since the ext. variable can be changed after return from a function
* call that has created subrequests.
*
* THREADING
*
* The state is thread specific, i.e. each thread can activate it and register
* its own external variable.
*
* @{
*/
enum tevent_thread_call_depth_cmd {
TEVENT_CALL_FLOW_REQ_RESET,
TEVENT_CALL_FLOW_REQ_CREATE,
TEVENT_CALL_FLOW_REQ_CANCEL,
TEVENT_CALL_FLOW_REQ_CLEANUP,
TEVENT_CALL_FLOW_REQ_NOTIFY_CB,
TEVENT_CALL_FLOW_REQ_QUEUE_ENTER,
TEVENT_CALL_FLOW_REQ_QUEUE_TRIGGER,
TEVENT_CALL_FLOW_REQ_QUEUE_LEAVE,
};
typedef void (*tevent_call_depth_callback_t)(
void *private_data,
enum tevent_thread_call_depth_cmd cmd,
struct tevent_req *req,
size_t depth,
const char *fname);
struct tevent_thread_call_depth_state {
tevent_call_depth_callback_t cb;
void *cb_private;
};
extern __thread struct tevent_thread_call_depth_state
tevent_thread_call_depth_state_g;
/**
* Register callback function for request/subrequest call depth / flow tracking.
*
* @param[in] f External call depth and flow handling function
*/
void tevent_thread_call_depth_set_callback(tevent_call_depth_callback_t f,
void *private_data);
#ifdef TEVENT_DEPRECATED
void tevent_thread_call_depth_activate(size_t *ptr) _DEPRECATED_;
void tevent_thread_call_depth_deactivate(void) _DEPRECATED_;
void tevent_thread_call_depth_start(struct tevent_req *req) _DEPRECATED_;
#endif
/**
* Reset the external call depth to the call depth of the request.
*
* @param[in] req Request from which the call depth is reset.
* variable.
*/
void tevent_thread_call_depth_reset_from_req(struct tevent_req *req);
void _tevent_thread_call_depth_reset_from_req(struct tevent_req *req,
const char *fname);
#define tevent_thread_call_depth_reset_from_req(req) \
_tevent_thread_call_depth_reset_from_req(req, __func__)
/* @} */
/**
* @defgroup tevent_queue The tevent queue functions
* @ingroup tevent
*
* A tevent_queue is used to queue up async requests that must be
* serialized. For example writing buffers into a socket must be
* serialized. Writing a large lump of data into a socket can require
* multiple write(2) or send(2) system calls. If more than one async
* request is outstanding to write large buffers into a socket, every
* request must individually be completed before the next one begins,
* even if multiple syscalls are required.
*
* Take a look at @ref tevent_queue_tutorial for more details.
* @{
*/
struct tevent_queue;
struct tevent_queue_entry;
/**
* @brief Associate a custom tag with the queue entry.
*
* This tag can be then retrieved with tevent_queue_entry_get_tag()
*
* @param[in] qe The queue entry.
*
* @param[in] tag Custom tag.
*/
void tevent_queue_entry_set_tag(struct tevent_queue_entry *qe, uint64_t tag);
/**
* @brief Get custom queue entry tag.
*/
uint64_t tevent_queue_entry_get_tag(const struct tevent_queue_entry *qe);
typedef void (*tevent_trace_queue_callback_t)(struct tevent_queue_entry *qe,
enum tevent_event_trace_point,
void *private_data);
/**
* Register a callback to be called at certain trace points of queue.
*
* @param[in] ev Event context
* @param[in] cb Trace callback
* @param[in] private_data Data to be passed to callback
*
* @note The callback will be called at trace points defined by
* tevent_event_trace_point. Call with NULL to reset.
*/
void tevent_set_trace_queue_callback(struct tevent_context *ev,
tevent_trace_queue_callback_t cb,
void *private_data);
/**
* Retrieve the current trace callback of queue.
*
* @param[in] ev Event context
* @param[out] cb Registered trace callback
* @param[out] p_private_data Registered data to be passed to callback
*
* @note This can be used to allow one component that wants to
* register a callback to respect the callback that another component
* has already registered.
*/
void tevent_get_trace_queue_callback(struct tevent_context *ev,
tevent_trace_queue_callback_t *cb,
void *p_private_data);
#ifdef DOXYGEN
/**
* @brief Create and start a tevent queue.
*
* @param[in] mem_ctx The talloc memory context to allocate the queue.
*
* @param[in] name The name to use to identify the queue.
*
* @return An allocated tevent queue on success, NULL on error.
*
* @see tevent_queue_start()
* @see tevent_queue_stop()
*/
struct tevent_queue *tevent_queue_create(TALLOC_CTX *mem_ctx,
const char *name);
#else
struct tevent_queue *_tevent_queue_create(TALLOC_CTX *mem_ctx,
const char *name,
const char *location);
#define tevent_queue_create(_mem_ctx, _name) \
_tevent_queue_create((_mem_ctx), (_name), __location__)
#endif
/**
* @brief A callback trigger function run by the queue.
*
* @param[in] req The tevent request the trigger function is executed on.
*
* @param[in] private_data The private data pointer specified by
* tevent_queue_add().
*
* @see tevent_queue_add()
* @see tevent_queue_add_entry()
* @see tevent_queue_add_optimize_empty()
*/
typedef void (*tevent_queue_trigger_fn_t)(struct tevent_req *req,
void *private_data);
/**
* @brief Add a tevent request to the queue.
*
* @param[in] queue The queue to add the request.
*
* @param[in] ev The event handle to use for the request.
*
* @param[in] req The tevent request to add to the queue.
*
* @param[in] trigger The function triggered by the queue when the request
* is called. Since tevent 0.9.14 it's possible to
* pass NULL, in order to just add a "blocker" to the
* queue.
*
* @param[in] private_data The private data passed to the trigger function.
*
* @return True if the request has been successfully added, false
* otherwise.
*/
bool tevent_queue_add(struct tevent_queue *queue,
struct tevent_context *ev,
struct tevent_req *req,
tevent_queue_trigger_fn_t trigger,
void *private_data);
bool _tevent_queue_add(struct tevent_queue *queue,
struct tevent_context *ev,
struct tevent_req *req,
tevent_queue_trigger_fn_t trigger,
const char* trigger_name,
void *private_data);
#define tevent_queue_add(queue, ev, req, trigger, private_data) \
_tevent_queue_add(queue, ev, req, trigger, #trigger, private_data)
/**
* @brief Add a tevent request to the queue.
*
* The request can be removed from the queue by calling talloc_free()
* (or a similar function) on the returned queue entry. This
* is the only difference to tevent_queue_add().
*
* @param[in] queue The queue to add the request.
*
* @param[in] ev The event handle to use for the request.
*
* @param[in] req The tevent request to add to the queue.
*
* @param[in] trigger The function triggered by the queue when the request
* is called. Since tevent 0.9.14 it's possible to
* pass NULL, in order to just add a "blocker" to the
* queue.
*
* @param[in] private_data The private data passed to the trigger function.
*
* @return a pointer to the tevent_queue_entry if the request
* has been successfully added, NULL otherwise.
*
* @see tevent_queue_add()
* @see tevent_queue_add_optimize_empty()
*/
struct tevent_queue_entry *tevent_queue_add_entry(
struct tevent_queue *queue,
struct tevent_context *ev,
struct tevent_req *req,
tevent_queue_trigger_fn_t trigger,
void *private_data);
struct tevent_queue_entry *_tevent_queue_add_entry(
struct tevent_queue *queue,
struct tevent_context *ev,
struct tevent_req *req,
tevent_queue_trigger_fn_t trigger,
const char* trigger_name,
void *private_data);
#define tevent_queue_add_entry(queue, ev, req, trigger, private_data) \
_tevent_queue_add_entry(queue, ev, req, trigger, #trigger, private_data);
/**
* @brief Add a tevent request to the queue using a possible optimization.
*
* This tries to optimize for the empty queue case and may calls
* the trigger function directly. This is the only difference compared
* to tevent_queue_add_entry().
*
* The caller needs to be prepared that the trigger function has
* already called tevent_req_notify_callback(), tevent_req_error(),
* tevent_req_done() or a similar function.
*
* The trigger function has no chance to see the returned
* queue_entry in the optimized case.
*
* The request can be removed from the queue by calling talloc_free()
* (or a similar function) on the returned queue entry.
*
* @param[in] queue The queue to add the request.
*
* @param[in] ev The event handle to use for the request.
*
* @param[in] req The tevent request to add to the queue.
*
* @param[in] trigger The function triggered by the queue when the request
* is called. Since tevent 0.9.14 it's possible to
* pass NULL, in order to just add a "blocker" to the
* queue.
*
* @param[in] private_data The private data passed to the trigger function.
*
* @return a pointer to the tevent_queue_entry if the request
* has been successfully added, NULL otherwise.
*
* @see tevent_queue_add()
* @see tevent_queue_add_entry()
*/
struct tevent_queue_entry *tevent_queue_add_optimize_empty(
struct tevent_queue *queue,
struct tevent_context *ev,
struct tevent_req *req,
tevent_queue_trigger_fn_t trigger,
void *private_data);
struct tevent_queue_entry *_tevent_queue_add_optimize_empty(
struct tevent_queue *queue,
struct tevent_context *ev,
struct tevent_req *req,
tevent_queue_trigger_fn_t trigger,
const char* trigger_name,
void *private_data);
#define tevent_queue_add_optimize_empty(queue, ev, req, trigger, private_data) \
_tevent_queue_add_optimize_empty(queue, ev, req, trigger, #trigger, private_data)
/**
* @brief Untrigger an already triggered queue entry.
*
* If a trigger function detects that it needs to remain
* in the queue, it needs to call tevent_queue_stop()
* followed by tevent_queue_entry_untrigger().
*
* @note In order to call tevent_queue_entry_untrigger()
* the queue must be already stopped and the given queue_entry
* must be the first one in the queue! Otherwise it calls abort().
*
* @note You can't use this together with tevent_queue_add_optimize_empty()
* because the trigger function don't have access to the quene entry
* in the case of an empty queue.
*
* @param[in] queue_entry The queue entry to rearm.
*
* @see tevent_queue_add_entry()
* @see tevent_queue_stop()
*/
void tevent_queue_entry_untrigger(struct tevent_queue_entry *entry);
/**
* @brief Start a tevent queue.
*
* The queue is started by default.
*
* @param[in] queue The queue to start.
*/
void tevent_queue_start(struct tevent_queue *queue);
/**
* @brief Stop a tevent queue.
*
* The queue is started by default.
*
* @param[in] queue The queue to stop.
*/
void tevent_queue_stop(struct tevent_queue *queue);
/**
* @brief Get the length of the queue.
*
* @param[in] queue The queue to get the length from.
*
* @return The number of elements.
*/
size_t tevent_queue_length(struct tevent_queue *queue);
/**
* @brief Is the tevent queue running.
*
* The queue is started by default.
*
* @param[in] queue The queue.
*
* @return Whether the queue is running or not..
*/
bool tevent_queue_running(struct tevent_queue *queue);
/**
* @brief Create a tevent subrequest that waits in a tevent_queue
*
* The idea is that always the same syntax for tevent requests.
*
* @param[in] mem_ctx The talloc memory context to use.
*
* @param[in] ev The event handle to setup the request.
*
* @param[in] queue The queue to wait in.
*
* @return The new subrequest, NULL on error.
*
* @see tevent_queue_wait_recv()
*/
struct tevent_req *tevent_queue_wait_send(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct tevent_queue *queue);
/**
* @brief Check if we no longer need to wait in the queue.
*
* This function needs to be called in the callback function set after calling
* tevent_queue_wait_send().
*
* @param[in] req The tevent request to check.
*
* @return True on success, false otherwise.
*
* @see tevent_queue_wait_send()
*/
bool tevent_queue_wait_recv(struct tevent_req *req);
typedef int (*tevent_nesting_hook)(struct tevent_context *ev,
void *private_data,
uint32_t level,
bool begin,
void *stack_ptr,
const char *location);
/**
* @brief Create a tevent_thread_proxy for message passing between threads.
*
* The tevent_context must have been allocated on the NULL
* talloc context, and talloc_disable_null_tracking() must
* have been called.
*
* @param[in] dest_ev_ctx The tevent_context to receive events.
*
* @return An allocated tevent_thread_proxy, NULL on error.
* If tevent was compiled without PTHREAD support
* NULL is always returned and errno set to ENOSYS.
*
* @see tevent_thread_proxy_schedule()
*/
struct tevent_thread_proxy *tevent_thread_proxy_create(
struct tevent_context *dest_ev_ctx);
/**
* @brief Schedule an immediate event on an event context from another thread.
*
* Causes dest_ev_ctx, being run by another thread, to receive an
* immediate event calling the handler with the *pp_private parameter.
*
* *pp_im must be a pointer to an immediate event talloced on a context owned
* by the calling thread, or the NULL context. Ownership will
* be transferred to the tevent_thread_proxy and *pp_im will be returned as NULL.
*
* *pp_private_data must be a talloced area of memory with no destructors.
* Ownership of this memory will be transferred to the tevent library and
* *pp_private_data will be set to NULL on successful completion of
* the call. Set pp_private to NULL if no parameter transfer
* needed (a pure callback). This is an asynchronous request, caller
* does not wait for callback to be completed before returning.
*
* @param[in] tp The tevent_thread_proxy to use.
*
* @param[in] pp_im Pointer to immediate event pointer.
*
* @param[in] handler The function that will be called.
*
* @param[in] pp_private_data The talloced memory to transfer.
*
* @see tevent_thread_proxy_create()
*/
void tevent_thread_proxy_schedule(struct tevent_thread_proxy *tp,
struct tevent_immediate **pp_im,
tevent_immediate_handler_t handler,
void *pp_private_data);
/*
* @brief Create a context for threaded activation of immediates
*
* A tevent_treaded_context provides a link into an event
* context. Using tevent_threaded_schedule_immediate, it is possible
* to activate an immediate event from within a thread.
*
* It is the duty of the caller of tevent_threaded_context_create() to
* keep the event context around longer than any
* tevent_threaded_context. tevent will abort if ev is talloc_free'ed
* with an active tevent_threaded_context.
*
* If tevent is build without pthread support, this always returns
* NULL with errno=ENOSYS.
*
* @param[in] mem_ctx The talloc memory context to use.
* @param[in] ev The event context to link this to.
* @return The threaded context, or NULL with errno set.
*
* @see tevent_threaded_schedule_immediate()
*
* @note Available as of tevent 0.9.30
*/
struct tevent_threaded_context *tevent_threaded_context_create(
TALLOC_CTX *mem_ctx, struct tevent_context *ev);
#ifdef DOXYGEN
/*
* @brief Activate an immediate from a thread
*
* Activate an immediate from within a thread.
*
* This routine does not watch out for talloc hierarchies. This means
* that it is highly recommended to create the tevent_immediate in the
* thread owning tctx, allocate a threaded job description for the
* thread, hand over both pointers to a helper thread and not touch it
* in the main thread at all anymore.
*
* tevent_threaded_schedule_immediate is intended as a job completion
* indicator for simple threaded helpers.
*
* Please be aware that tevent_threaded_schedule_immediate is very
* picky about its arguments: An immediate may not already be
* activated and the handler must exist. With
* tevent_threaded_schedule_immediate memory ownership is transferred
* to the main thread holding the tevent context behind tctx, the
* helper thread can't access it anymore.
*
* @param[in] tctx The threaded context to go through
* @param[in] im The immediate event to activate
* @param[in] handler The immediate handler to call in the main thread
* @param[in] private_data Pointer for the immediate handler
*
* @see tevent_threaded_context_create()
*
* @note Available as of tevent 0.9.30
*/
void tevent_threaded_schedule_immediate(struct tevent_threaded_context *tctx,
struct tevent_immediate *im,
tevent_immediate_handler_t handler,
void *private_data);
#else
void _tevent_threaded_schedule_immediate(struct tevent_threaded_context *tctx,
struct tevent_immediate *im,
tevent_immediate_handler_t handler,
void *private_data,
const char *handler_name,
const char *location);
#define tevent_threaded_schedule_immediate(tctx, im, handler, private_data) \
_tevent_threaded_schedule_immediate(tctx, im, handler, private_data, \
#handler, __location__);
#endif
#ifdef TEVENT_DEPRECATED
void tevent_loop_allow_nesting(struct tevent_context *ev) _DEPRECATED_;
void tevent_loop_set_nesting_hook(struct tevent_context *ev,
tevent_nesting_hook hook,
void *private_data) _DEPRECATED_;
int _tevent_loop_until(struct tevent_context *ev,
bool (*finished)(void *private_data),
void *private_data,
const char *location) _DEPRECATED_;
#define tevent_loop_until(ev, finished, private_data) \
_tevent_loop_until(ev, finished, private_data, __location__)
#endif
int tevent_re_initialise(struct tevent_context *ev);
/* @} */
/**
* @defgroup tevent_ops The tevent operation functions
* @ingroup tevent
*
* The following structure and registration functions are exclusively
* needed for people writing and pluggin a different event engine.
* There is nothing useful for normal tevent user in here.
* @{
*/
struct tevent_ops {
/* context init */
int (*context_init)(struct tevent_context *ev);
/* fd_event functions */
struct tevent_fd *(*add_fd)(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
int fd, uint16_t flags,
tevent_fd_handler_t handler,
void *private_data,
const char *handler_name,
const char *location);
void (*set_fd_close_fn)(struct tevent_fd *fde,
tevent_fd_close_fn_t close_fn);
uint16_t (*get_fd_flags)(struct tevent_fd *fde);
void (*set_fd_flags)(struct tevent_fd *fde, uint16_t flags);
/* timed_event functions */
struct tevent_timer *(*add_timer)(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
struct timeval next_event,
tevent_timer_handler_t handler,
void *private_data,
const char *handler_name,
const char *location);
/* immediate event functions */
void (*schedule_immediate)(struct tevent_immediate *im,
struct tevent_context *ev,
tevent_immediate_handler_t handler,
void *private_data,
const char *handler_name,
const char *location);
/* signal functions */
struct tevent_signal *(*add_signal)(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
int signum, int sa_flags,
tevent_signal_handler_t handler,
void *private_data,
const char *handler_name,
const char *location);
/* loop functions */
int (*loop_once)(struct tevent_context *ev, const char *location);
int (*loop_wait)(struct tevent_context *ev, const char *location);
};
bool tevent_register_backend(const char *name, const struct tevent_ops *ops);
const struct tevent_ops *tevent_find_ops_byname(const char *name);
/* @} */
#ifdef TEVENT_DEPRECATED
/**
* @defgroup tevent_wrapper_ops The tevent wrapper operation functions
* @ingroup tevent
*
* The following structure and registration functions are exclusively
* needed for people writing wrapper functions for event handlers
* e.g. wrappers can be used for debugging/profiling or impersonation.
*
* There is nothing useful for normal tevent user in here.
*
* @note That the close_fn() on tevent_fd is *NOT* wrapped!
*
* @see tevent_context_wrapper_create
* @see tevent_fd_set_auto_close
* @{
*/
struct tevent_wrapper_ops {
const char *name;
bool (*before_use)(struct tevent_context *wrap_ev,
void *private_state,
struct tevent_context *main_ev,
const char *location);
void (*after_use)(struct tevent_context *wrap_ev,
void *private_state,
struct tevent_context *main_ev,
const char *location);
void (*before_fd_handler)(struct tevent_context *wrap_ev,
void *private_state,
struct tevent_context *main_ev,
struct tevent_fd *fde,
uint16_t flags,
const char *handler_name,
const char *location);
void (*after_fd_handler)(struct tevent_context *wrap_ev,
void *private_state,
struct tevent_context *main_ev,
struct tevent_fd *fde,
uint16_t flags,
const char *handler_name,
const char *location);
void (*before_timer_handler)(struct tevent_context *wrap_ev,
void *private_state,
struct tevent_context *main_ev,
struct tevent_timer *te,
struct timeval requested_time,
struct timeval trigger_time,
const char *handler_name,
const char *location);
void (*after_timer_handler)(struct tevent_context *wrap_ev,
void *private_state,
struct tevent_context *main_ev,
struct tevent_timer *te,
struct timeval requested_time,
struct timeval trigger_time,
const char *handler_name,
const char *location);
void (*before_immediate_handler)(struct tevent_context *wrap_ev,
void *private_state,
struct tevent_context *main_ev,
struct tevent_immediate *im,
const char *handler_name,
const char *location);
void (*after_immediate_handler)(struct tevent_context *wrap_ev,
void *private_state,
struct tevent_context *main_ev,
struct tevent_immediate *im,
const char *handler_name,
const char *location);
void (*before_signal_handler)(struct tevent_context *wrap_ev,
void *private_state,
struct tevent_context *main_ev,
struct tevent_signal *se,
int signum,
int count,
void *siginfo,
const char *handler_name,
const char *location);
void (*after_signal_handler)(struct tevent_context *wrap_ev,
void *private_state,
struct tevent_context *main_ev,
struct tevent_signal *se,
int signum,
int count,
void *siginfo,
const char *handler_name,
const char *location);
};
#ifdef DOXYGEN
/**
* @brief Create a wrapper tevent_context.
*
* @param[in] main_ev The main event context to work on.
*
* @param[in] mem_ctx The talloc memory context to use.
*
* @param[in] ops The tevent_wrapper_ops function table.
*
* @param[out] private_state The private state use by the wrapper functions.
*
* @param[in] private_type The talloc type of the private_state.
*
* @return The wrapper event context, NULL on error.
*
* @note Available as of tevent 0.9.37
* @note Deprecated as of tevent 0.9.38
*/
struct tevent_context *tevent_context_wrapper_create(struct tevent_context *main_ev,
TALLOC_CTX *mem_ctx,
const struct tevent_wrapper_ops *ops,
void **private_state,
const char *private_type);
#else
struct tevent_context *_tevent_context_wrapper_create(struct tevent_context *main_ev,
TALLOC_CTX *mem_ctx,
const struct tevent_wrapper_ops *ops,
void *pstate,
size_t psize,
const char *type,
const char *location) _DEPRECATED_;
#define tevent_context_wrapper_create(main_ev, mem_ctx, ops, state, type) \
_tevent_context_wrapper_create(main_ev, mem_ctx, ops, \
state, sizeof(type), #type, __location__)
#endif
/**
* @brief Check if the event context is a wrapper event context.
*
* @param[in] ev The event context to work on.
*
* @return Is a wrapper (true), otherwise (false).
*
* @see tevent_context_wrapper_create()
*
* @note Available as of tevent 0.9.37
* @note Deprecated as of tevent 0.9.38
*/
bool tevent_context_is_wrapper(struct tevent_context *ev) _DEPRECATED_;
#ifdef DOXYGEN
/**
* @brief Prepare the environment of a (wrapper) event context.
*
* A caller might call this before passing a wrapper event context
* to a tevent_req based *_send() function.
*
* The wrapper event context might do something like impersonation.
*
* tevent_context_push_use() must always be used in combination
* with tevent_context_pop_use().
*
* There is a global stack of currently active/busy wrapper event contexts.
* Each wrapper can only appear once on that global stack!
* The stack size is limited to 32 elements, which should be enough
* for all useful scenarios.
*
* In addition to an explicit tevent_context_push_use() also
* the invocation of an immediate, timer or fd handler implicitly
* pushes the wrapper on the stack.
*
* Therefore there are some strict constraints for the usage of
* tevent_context_push_use():
* - It must not be called from within an event handler
* that already acts on the wrapper.
* - tevent_context_pop_use() must be called before
* leaving the code block that called tevent_context_push_use().
* - The caller is responsible ensure the correct stack ordering
* - Any violation of these constraints results in calling
* the abort handler of the given tevent context.
*
* Calling tevent_context_push_use() on a raw event context
* still consumes an element on the stack, but it's otherwise
* a no-op.
*
* If tevent_context_push_use() returns false, it means
* that the wrapper's before_use() hook returned this failure,
* in that case you must not call tevent_context_pop_use() as
* the wrapper is not pushed onto the stack.
*
* @param[in] ev The event context to work on.
*
* @return Success (true) or failure (false).
*
* @note This is only needed if wrapper event contexts are in use.
*
* @see tevent_context_pop_use
*
* @note Available as of tevent 0.9.37
* @note Deprecated as of tevent 0.9.38
*/
bool tevent_context_push_use(struct tevent_context *ev);
#else
bool _tevent_context_push_use(struct tevent_context *ev,
const char *location) _DEPRECATED_;
#define tevent_context_push_use(ev) \
_tevent_context_push_use(ev, __location__)
#endif
#ifdef DOXYGEN
/**
* @brief Release the environment of a (wrapper) event context.
*
* The wrapper event context might undo something like impersonation.
*
* This must be called after a successful tevent_context_push_use().
* Any ordering violation results in calling
* the abort handler of the given tevent context.
*
* This basically calls the wrapper's after_use() hook.
*
* @param[in] ev The event context to work on.
*
* @note This is only needed if wrapper event contexts are in use.
*
* @see tevent_context_push_use
*
* @note Available as of tevent 0.9.37
* @note Deprecated as of tevent 0.9.38
*/
void tevent_context_pop_use(struct tevent_context *ev);
#else
void _tevent_context_pop_use(struct tevent_context *ev,
const char *location) _DEPRECATED_;
#define tevent_context_pop_use(ev) \
_tevent_context_pop_use(ev, __location__)
#endif
/**
* @brief Check is the two context pointers belong to the same low level loop
*
* With the introduction of wrapper contexts it's not trivial
* to check if two context pointers belong to the same low level
* event loop. Some code may need to know this in order
* to make some caching decisions.
*
* @param[in] ev1 The first event context.
* @param[in] ev2 The second event context.
*
* @return true if both contexts belong to the same (still existing) context
* loop, false otherwise.
*
* @see tevent_context_wrapper_create
*
* @note Available as of tevent 0.9.37
* @note Deprecated as of tevent 0.9.38
*/
bool tevent_context_same_loop(struct tevent_context *ev1,
struct tevent_context *ev2) _DEPRECATED_;
/* @} */
#endif /* TEVENT_DEPRECATED */
/**
* @defgroup tevent_compat The tevent compatibility functions
* @ingroup tevent
*
* The following definitions are useful only for compatibility with the
* implementation originally developed within the samba4 code and will be
* soon removed. Please NEVER use in new code.
*
* @todo Ignore it?
*
* @{
*/
#ifdef TEVENT_COMPAT_DEFINES
#define event_context tevent_context
#define event_ops tevent_ops
#define fd_event tevent_fd
#define timed_event tevent_timer
#define signal_event tevent_signal
#define event_fd_handler_t tevent_fd_handler_t
#define event_timed_handler_t tevent_timer_handler_t
#define event_signal_handler_t tevent_signal_handler_t
#define event_context_init(mem_ctx) \
tevent_context_init(mem_ctx)
#define event_context_init_byname(mem_ctx, name) \
tevent_context_init_byname(mem_ctx, name)
#define event_backend_list(mem_ctx) \
tevent_backend_list(mem_ctx)
#define event_set_default_backend(backend) \
tevent_set_default_backend(backend)
#define event_add_fd(ev, mem_ctx, fd, flags, handler, private_data) \
tevent_add_fd(ev, mem_ctx, fd, flags, handler, private_data)
#define event_add_timed(ev, mem_ctx, next_event, handler, private_data) \
tevent_add_timer(ev, mem_ctx, next_event, handler, private_data)
#define event_add_signal(ev, mem_ctx, signum, sa_flags, handler, private_data) \
tevent_add_signal(ev, mem_ctx, signum, sa_flags, handler, private_data)
#define event_loop_once(ev) \
tevent_loop_once(ev)
#define event_loop_wait(ev) \
tevent_loop_wait(ev)
#define event_get_fd_flags(fde) \
tevent_fd_get_flags(fde)
#define event_set_fd_flags(fde, flags) \
tevent_fd_set_flags(fde, flags)
#define EVENT_FD_READ TEVENT_FD_READ
#define EVENT_FD_WRITE TEVENT_FD_WRITE
#define EVENT_FD_WRITEABLE(fde) \
TEVENT_FD_WRITEABLE(fde)
#define EVENT_FD_READABLE(fde) \
TEVENT_FD_READABLE(fde)
#define EVENT_FD_NOT_WRITEABLE(fde) \
TEVENT_FD_NOT_WRITEABLE(fde)
#define EVENT_FD_NOT_READABLE(fde) \
TEVENT_FD_NOT_READABLE(fde)
#define ev_debug_level tevent_debug_level
#define EV_DEBUG_FATAL TEVENT_DEBUG_FATAL
#define EV_DEBUG_ERROR TEVENT_DEBUG_ERROR
#define EV_DEBUG_WARNING TEVENT_DEBUG_WARNING
#define EV_DEBUG_TRACE TEVENT_DEBUG_TRACE
#define ev_set_debug(ev, debug, context) \
tevent_set_debug(ev, debug, context)
#define ev_set_debug_stderr(_ev) tevent_set_debug_stderr(ev)
#endif /* TEVENT_COMPAT_DEFINES */
/* @} */
#endif /* __TEVENT_H__ */
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