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samba-mirror/lib/tsocket/tsocket_writev.c
Stefan Metzmacher f6efec5dd4 lib/tsocket: add a fast path to tsocket_writev_send/recv()
This is similar to the tsocket_sendto_send/recv() fast path.

metze
2009-03-19 16:25:57 +01:00

317 lines
7.4 KiB
C

/*
Unix SMB/CIFS implementation.
Copyright (C) Stefan Metzmacher 2009
** 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/>.
*/
#include "replace.h"
#include "system/network.h"
#include "tsocket.h"
#include "tsocket_internal.h"
struct tsocket_writev_state {
/* this structs are owned by the caller */
struct {
struct tsocket_context *sock;
const struct iovec *vector;
size_t count;
} caller;
struct iovec *iov;
size_t count;
int total_written;
};
static int tsocket_writev_state_destructor(struct tsocket_writev_state *state)
{
if (state->caller.sock) {
tsocket_set_writeable_handler(state->caller.sock, NULL, NULL);
}
ZERO_STRUCT(state->caller);
return 0;
}
static void tsocket_writev_handler(struct tsocket_context *sock,
void *private_data);
struct tevent_req *tsocket_writev_send(struct tsocket_context *sock,
TALLOC_CTX *mem_ctx,
const struct iovec *vector,
size_t count)
{
struct tevent_req *req;
struct tsocket_writev_state *state;
int ret;
int err;
bool dummy;
int to_write = 0;
size_t i;
req = tevent_req_create(mem_ctx, &state,
struct tsocket_writev_state);
if (!req) {
return NULL;
}
state->caller.sock = sock;
state->caller.vector = vector;
state->caller.count = count;
state->iov = NULL;
state->count = count;
state->total_written = 0;
state->iov = talloc_array(state, struct iovec, count);
if (tevent_req_nomem(state->iov, req)) {
goto post;
}
memcpy(state->iov, vector, sizeof(struct iovec) * count);
for (i=0; i < count; i++) {
int tmp = to_write;
tmp += state->iov[i].iov_len;
if (tmp < to_write) {
tevent_req_error(req, EMSGSIZE);
goto post;
}
to_write = tmp;
}
if (to_write == 0) {
tevent_req_done(req);
goto post;
}
/*
* this is a fast path, not waiting for the
* socket to become explicit writeable gains
* about 10%-20% performance in benchmark tests.
*/
tsocket_writev_handler(sock, req);
if (!tevent_req_is_in_progress(req)) {
goto post;
}
talloc_set_destructor(state, tsocket_writev_state_destructor);
ret = tsocket_set_writeable_handler(sock,
tsocket_writev_handler,
req);
err = tsocket_error_from_errno(ret, errno, &dummy);
if (tevent_req_error(req, err)) {
goto post;
}
return req;
post:
return tevent_req_post(req, sock->event.ctx);
}
static void tsocket_writev_handler(struct tsocket_context *sock,
void *private_data)
{
struct tevent_req *req = talloc_get_type(private_data,
struct tevent_req);
struct tsocket_writev_state *state = tevent_req_data(req,
struct tsocket_writev_state);
int ret;
int err;
bool retry;
ret = tsocket_writev(state->caller.sock,
state->iov,
state->count);
err = tsocket_error_from_errno(ret, errno, &retry);
if (retry) {
/* retry later */
return;
}
if (tevent_req_error(req, err)) {
return;
}
state->total_written += ret;
/*
* we have not written everything yet, so we need to truncate
* the already written bytes from our iov copy
*/
while (ret > 0) {
if (ret < state->iov[0].iov_len) {
uint8_t *base;
base = (uint8_t *)state->iov[0].iov_base;
base += ret;
state->iov[0].iov_base = base;
state->iov[0].iov_len -= ret;
break;
}
ret -= state->iov[0].iov_len;
state->iov += 1;
state->count -= 1;
}
if (state->count > 0) {
/* more to write */
return;
}
tevent_req_done(req);
}
int tsocket_writev_recv(struct tevent_req *req, int *perrno)
{
struct tsocket_writev_state *state = tevent_req_data(req,
struct tsocket_writev_state);
int ret;
ret = tsocket_simple_int_recv(req, perrno);
if (ret == 0) {
ret = state->total_written;
}
tevent_req_received(req);
return ret;
}
struct tsocket_writev_queue_state {
/* this structs are owned by the caller */
struct {
struct tsocket_context *sock;
const struct iovec *vector;
size_t count;
} caller;
int ret;
};
static void tsocket_writev_queue_trigger(struct tevent_req *req,
void *private_data);
static void tsocket_writev_queue_done(struct tevent_req *subreq);
/**
* @brief Queue a dgram blob for sending through the socket
* @param[in] mem_ctx The memory context for the result
* @param[in] sock The socket to send data through
* @param[in] queue The existing send queue
* @param[in] vector The iovec vector so write
* @param[in] count The size of the vector
* @retval The async request handle
*
* This function queues a blob for sending to destination through an existing
* dgram socket. The async callback is triggered when the whole blob is
* delivered to the underlying system socket.
*
* The caller needs to make sure that all non-scalar input parameters hang
* arround for the whole lifetime of the request.
*/
struct tevent_req *tsocket_writev_queue_send(TALLOC_CTX *mem_ctx,
struct tsocket_context *sock,
struct tevent_queue *queue,
const struct iovec *vector,
size_t count)
{
struct tevent_req *req;
struct tsocket_writev_queue_state *state;
bool ok;
req = tevent_req_create(mem_ctx, &state,
struct tsocket_writev_queue_state);
if (!req) {
return NULL;
}
state->caller.sock = sock;
state->caller.vector = vector;
state->caller.count = count;
state->ret = -1;
ok = tevent_queue_add(queue,
sock->event.ctx,
req,
tsocket_writev_queue_trigger,
NULL);
if (!ok) {
tevent_req_nomem(NULL, req);
goto post;
}
return req;
post:
return tevent_req_post(req, sock->event.ctx);
}
static void tsocket_writev_queue_trigger(struct tevent_req *req,
void *private_data)
{
struct tsocket_writev_queue_state *state = tevent_req_data(req,
struct tsocket_writev_queue_state);
struct tevent_req *subreq;
subreq = tsocket_writev_send(state->caller.sock,
state,
state->caller.vector,
state->caller.count);
if (tevent_req_nomem(subreq, req)) {
return;
}
tevent_req_set_callback(subreq, tsocket_writev_queue_done ,req);
}
static void tsocket_writev_queue_done(struct tevent_req *subreq)
{
struct tevent_req *req = tevent_req_callback_data(subreq,
struct tevent_req);
struct tsocket_writev_queue_state *state = tevent_req_data(req,
struct tsocket_writev_queue_state);
int ret;
int sys_errno;
ret = tsocket_writev_recv(subreq, &sys_errno);
talloc_free(subreq);
if (ret == -1) {
tevent_req_error(req, sys_errno);
return;
}
state->ret = ret;
tevent_req_done(req);
}
int tsocket_writev_queue_recv(struct tevent_req *req, int *perrno)
{
struct tsocket_writev_queue_state *state = tevent_req_data(req,
struct tsocket_writev_queue_state);
int ret;
ret = tsocket_simple_int_recv(req, perrno);
if (ret == 0) {
ret = state->ret;
}
tevent_req_received(req);
return ret;
}