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[PATCH] udevd - cleanup and better timeout handling

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On Thu, Jan 29, 2004 at 04:55:11PM +0100, Kay Sievers wrote:
> On Thu, Jan 29, 2004 at 02:56:25AM +0100, Kay Sievers wrote:
> > On Wed, Jan 28, 2004 at 10:47:36PM +0100, Kay Sievers wrote:
> > > Oh, couldn't resist to try threads.
> > > It's a multithreaded udevd that communicates through a localhost socket.
> > > The message includes a magic with the udev version, so we don't accept
> > > older udevsend's.
> > >
> > > No need for locking, cause we can't bind two sockets on the same address.
> > > The daemon tries to connect and if it fails it starts the daemon.
> > >
> > > We create a thread for every incoming connection, handle over the socket,
> > > sort the messages in the global message queue and exit the thread.
> > > Huh, that was easy with threads :)
> > >
> > > With the addition of a message we wakeup the queue manager thread and
> > > handle timeouts or move the message to the global exec list. This wakes
> > > up the exec list manager who looks if a process is already running for this
> > > device path.
> > > If yes, the exec is delayed otherwise we create a thread that execs udev.
> > > n the background. With the return of udev we free the message and wakeup
> > > the exec list manager to look if something is pending.
> > >
> > > It is just a quick shot, cause I couldn't solve the problems with fork an
> > > scheduling and I wanted to see if I'm to stupid  :)
> > > But if anybody with a better idea or more experience with I/O scheduling
> > > we may go another way. The remaining problem is that klibc doesn't support
> > > threads.
> > >
> > > By now, we don't exec anything, it's just a sleep 3 for every exec,
> > > but you can see the queue management by watching syslog and do:
> > >
> > >   DEVPATH=/abc ACTION=add SEQNUM=0 ./udevsend /abc
>
> Next version, switched to unix domain sockets.

Next cleaned up version. Hey, nobody wants to try it :)

Works for me, It's funny if I connect/disconnect my 4in1-usb-flash-reader
every two seconds. The 2.6 usb rocks! I can connect/diconnect a hub with 3
devices plugged in every second and don't run into any problem but a _very_
big udevd queue.
This commit is contained in:
kay.sievers@vrfy.org 2004-02-01 09:12:36 -08:00 committed by Greg KH
parent 79080c2664
commit 53921bfa44
5 changed files with 361 additions and 271 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Makefile
View File

@ -255,7 +255,7 @@ $(HELPER): udevinfo.o $(OBJS) $(HEADERS)
$(STRIPCMD) $@
$(DAEMON): udevd.h udevd.o udevd.o logging.o
$(LD) $(LDFLAGS) -o $@ $(CRT0) udevd.o logging.o $(LIB_OBJS) $(ARCH_LIB_OBJS)
$(LD) $(LDFLAGS) -lpthread -o $@ $(CRT0) udevd.o logging.o $(LIB_OBJS) $(ARCH_LIB_OBJS)
$(STRIPCMD) $@
$(SENDER): udevd.h udevsend.o udevd.o logging.o

8
test/udevd_test.sh
View File

@ -1,9 +1,7 @@
#!/bin/bash
#!/bin/sh
# kill daemon, first event will start it again
killall udevd
# 3 x connect/disconnect sequence of sda/sdb/sdc
# add/rem/add/rem/add sequence of sda/sdb/sdc
# a few days longer and the socket of my usb-flash-reader is gone :)
export SEQNUM=3
export ACTION=add

520
udevd.c
View File

@ -1,9 +1,6 @@
/*
* udevd.c
* udevd.c - hotplug event serializer
*
* Userspace devfs
*
* Copyright (C) 2004 Ling, Xiaofeng <xiaofeng.ling@intel.com>
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
*
*
@ -24,9 +21,7 @@
#include <stddef.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/wait.h>
#include <sys/msg.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
@ -35,6 +30,10 @@
#include <string.h>
#include <time.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <pthread.h>
#include "list.h"
#include "udev.h"
@ -43,116 +42,27 @@
#include "logging.h"
#define BUFFER_SIZE 1024
static int running_remove_queue(pid_t pid);
static int msg_exec(struct hotplug_msg *msg);
static int expect_seqnum = 0;
static int lock_file = -1;
static char *lock_filename = ".udevd_lock";
static pthread_mutex_t msg_lock;
static pthread_mutex_t msg_active_lock;
static pthread_cond_t msg_active;
static pthread_mutex_t exec_lock;
static pthread_mutex_t exec_active_lock;
static pthread_cond_t exec_active;
static pthread_mutex_t running_lock;
static pthread_attr_t thr_attr;
static int expected_seqnum = 0;
LIST_HEAD(msg_list);
LIST_HEAD(exec_list);
LIST_HEAD(running_list);
LIST_HEAD(delayed_list);
static void sig_handler(int signum)
static void msg_dump_queue(void)
{
pid_t pid;
struct hotplug_msg *msg;
dbg("caught signal %d", signum);
switch (signum) {
case SIGALRM:
dbg("event timeout reached");
break;
case SIGCHLD:
/* catch signals from exiting childs */
while ( (pid = waitpid(-1, NULL, WNOHANG)) > 0) {
dbg("exec finished, pid %d", pid);
running_remove_queue(pid);
}
break;
case SIGINT:
case SIGTERM:
if (lock_file >= 0) {
close(lock_file);
unlink(lock_filename);
}
exit(20 + signum);
break;
default:
dbg("unhandled signal");
}
}
static void set_timeout(int seconds)
{
alarm(seconds);
dbg("set timeout in %d seconds", seconds);
}
static int running_moveto_queue(struct hotplug_msg *msg)
{
dbg("move sequence %d [%d] to running queue '%s'",
msg->seqnum, msg->pid, msg->devpath);
list_move_tail(&msg->list, &running_list);
return 0;
}
static int running_remove_queue(pid_t pid)
{
struct hotplug_msg *child;
struct hotplug_msg *tmp_child;
list_for_each_entry_safe(child, tmp_child, &running_list, list)
if (child->pid == pid) {
list_del_init(&child->list);
free(child);
return 0;
}
return -EINVAL;
}
static pid_t running_getpid_by_devpath(struct hotplug_msg *msg)
{
struct hotplug_msg *child;
struct hotplug_msg *tmp_child;
list_for_each_entry_safe(child, tmp_child, &running_list, list)
if (strncmp(child->devpath, msg->devpath, sizeof(child->devpath)) == 0)
return child->pid;
return 0;
}
static void delayed_dump_queue(void)
{
struct hotplug_msg *child;
list_for_each_entry(child, &delayed_list, list)
dbg("event for '%s' in queue", child->devpath);
}
static int delayed_moveto_queue(struct hotplug_msg *msg)
{
dbg("move event to delayed queue '%s'", msg->devpath);
list_move_tail(&msg->list, &delayed_list);
return 0;
}
static void delayed_check_queue(void)
{
struct hotplug_msg *delayed_child;
struct hotplug_msg *running_child;
struct hotplug_msg *tmp_child;
/* see if we have delayed exec's that can run now */
list_for_each_entry_safe(delayed_child, tmp_child, &delayed_list, list)
list_for_each_entry_safe(running_child, tmp_child, &running_list, list)
if (strncmp(delayed_child->devpath, running_child->devpath,
sizeof(running_child->devpath)) == 0) {
dbg("delayed exec for '%s' can run now", delayed_child->devpath);
msg_exec(delayed_child);
}
list_for_each_entry(msg, &msg_list, list)
dbg("sequence %d in queue", msg->seqnum);
}
static void msg_dump(struct hotplug_msg *msg)
@ -161,23 +71,53 @@ static void msg_dump(struct hotplug_msg *msg)
msg->seqnum, msg->action, msg->devpath, msg->subsystem);
}
static int msg_exec(struct hotplug_msg *msg)
/* allocates a new message */
static struct hotplug_msg *msg_create(void)
{
struct hotplug_msg *new_msg;
new_msg = malloc(sizeof(struct hotplug_msg));
if (new_msg == NULL) {
dbg("error malloc");
return NULL;
}
memset(new_msg, 0x00, sizeof(struct hotplug_msg));
return new_msg;
}
/* orders the message in the queue by sequence number */
static void msg_queue_insert(struct hotplug_msg *msg)
{
struct hotplug_msg *loop_msg;
/* sort message by sequence number into list*/
list_for_each_entry(loop_msg, &msg_list, list)
if (loop_msg->seqnum > msg->seqnum)
break;
list_add_tail(&msg->list, &loop_msg->list);
dbg("queued message seq %d", msg->seqnum);
/* store timestamp of queuing */
msg->queue_time = time(NULL);
/* signal queue activity to manager */
pthread_mutex_lock(&msg_active_lock);
pthread_cond_signal(&msg_active);
pthread_mutex_unlock(&msg_active_lock);
return ;
}
/* forks event and removes event from run queue when finished */
static void *run_threads(void * parm)
{
pid_t pid;
struct hotplug_msg *msg;
msg_dump(msg);
msg = parm;
setenv("ACTION", msg->action, 1);
setenv("DEVPATH", msg->devpath, 1);
/* delay exec, if we already have a udev working on the same devpath */
pid = running_getpid_by_devpath(msg);
if (pid != 0) {
dbg("delay exec of sequence %d, [%d] already working on '%s'",
msg->seqnum, pid, msg->devpath);
delayed_moveto_queue(msg);
}
pid = fork();
switch (pid) {
case 0:
@ -188,135 +128,206 @@ static int msg_exec(struct hotplug_msg *msg)
break;
case -1:
dbg("fork of child failed");
return -1;
goto exit;
default:
/* exec in background, get the SIGCHLD with the sig handler */
msg->pid = pid;
running_moveto_queue(msg);
break;
}
return 0;
}
static void msg_dump_queue(void)
{
struct hotplug_msg *msg;
list_for_each_entry(msg, &msg_list, list)
dbg("sequence %d in queue", msg->seqnum);
}
static void msg_check_queue(void)
{
struct hotplug_msg *msg;
struct hotplug_msg *tmp_msg;
time_t msg_age;
recheck:
/* dispatch events until one is missing */
list_for_each_entry_safe(msg, tmp_msg, &msg_list, list) {
if (msg->seqnum != expect_seqnum)
break;
msg_exec(msg);
expect_seqnum++;
/* wait for exit of child */
dbg("==> exec seq %d [%d] working at '%s'",
msg->seqnum, pid, msg->devpath);
wait(NULL);
dbg("<== exec seq %d came back", msg->seqnum);
}
/* recalculate next timeout */
if (list_empty(&msg_list) == 0) {
msg_age = time(NULL) - msg->queue_time;
if (msg_age > EVENT_TIMEOUT_SEC-1) {
info("event %d, age %li seconds, skip event %d-%d",
msg->seqnum, msg_age, expect_seqnum, msg->seqnum-1);
expect_seqnum = msg->seqnum;
goto recheck;
}
exit:
/* remove event from run list */
pthread_mutex_lock(&running_lock);
list_del_init(&msg->list);
pthread_mutex_unlock(&running_lock);
/* the first sequence gets its own timeout */
if (expect_seqnum == 0) {
msg_age = EVENT_TIMEOUT_SEC - FIRST_EVENT_TIMEOUT_SEC;
expect_seqnum = 1;
}
free(msg);
set_timeout(EVENT_TIMEOUT_SEC - msg_age);
return;
}
/* signal queue activity to exec manager */
pthread_mutex_lock(&exec_active_lock);
pthread_cond_signal(&exec_active);
pthread_mutex_unlock(&exec_active_lock);
pthread_exit(0);
}
static int msg_add_queue(struct hotplug_msg *msg)
/* returns already running task with devpath */
static struct hotplug_msg *running_with_devpath(struct hotplug_msg *msg)
{
struct hotplug_msg *new_msg;
struct hotplug_msg *loop_msg;
struct hotplug_msg *tmp_msg;
new_msg = malloc(sizeof(*new_msg));
if (new_msg == NULL) {
dbg("error malloc");
return -ENOMEM;
}
memcpy(new_msg, msg, sizeof(*new_msg));
/* store timestamp of queuing */
new_msg->queue_time = time(NULL);
/* sort message by sequence number into list*/
list_for_each_entry(tmp_msg, &msg_list, list)
if (tmp_msg->seqnum > new_msg->seqnum)
break;
list_add_tail(&new_msg->list, &tmp_msg->list);
return 0;
list_for_each_entry_safe(loop_msg, tmp_msg, &running_list, list)
if (strncmp(loop_msg->devpath, msg->devpath, sizeof(loop_msg->devpath)) == 0)
return loop_msg;
return NULL;
}
static void work(void)
/* queue management executes the events and delays events for the same devpath */
static void *exec_queue_manager(void * parm)
{
struct hotplug_msg *loop_msg;
struct hotplug_msg *tmp_msg;
struct hotplug_msg *msg;
int msgid;
key_t key;
char buf[BUFFER_SIZE];
int ret;
pthread_t run_tid;
key = ftok(UDEVD_BIN, IPC_KEY_ID);
msg = (struct hotplug_msg *) buf;
msgid = msgget(key, IPC_CREAT);
if (msgid == -1) {
dbg("open message queue error");
exit(1);
}
while (1) {
ret = msgrcv(msgid, (struct msgbuf *) buf, BUFFER_SIZE-4, HOTPLUGMSGTYPE, 0);
if (ret != -1) {
dbg("received sequence %d, expected sequence %d", msg->seqnum, expect_seqnum);
if (msg->seqnum >= expect_seqnum) {
msg_add_queue(msg);
msg_dump_queue();
msg_check_queue();
continue;
pthread_mutex_lock(&exec_lock);
list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, list) {
msg = running_with_devpath(loop_msg);
if (msg == NULL) {
/* move event to run list */
pthread_mutex_lock(&running_lock);
list_move_tail(&loop_msg->list, &running_list);
pthread_mutex_unlock(&running_lock);
pthread_create(&run_tid, &thr_attr, run_threads, (void *) loop_msg);
dbg("moved seq %d to running list", loop_msg->seqnum);
} else {
dbg("delay seq %d, cause seq %d already working on '%s'",
loop_msg->seqnum, msg->seqnum, msg->devpath);
}
dbg("too late for event with sequence %d, event skipped ", msg->seqnum);
} else {
if (errno == EINTR) {
msg_check_queue();
msg_dump_queue();
delayed_check_queue();
delayed_dump_queue();
continue;
}
dbg("ipc message receive error '%s'", strerror(errno));
}
pthread_mutex_unlock(&exec_lock);
/* wait for activation, new events or childs coming back */
pthread_mutex_lock(&exec_active_lock);
pthread_cond_wait(&exec_active, &exec_active_lock);
pthread_mutex_unlock(&exec_active_lock);
}
}
/* move message from incoming to exec queue */
static void msg_move_exec(struct list_head *head)
{
list_move_tail(head, &exec_list);
/* signal queue activity to manager */
pthread_mutex_lock(&exec_active_lock);
pthread_cond_signal(&exec_active);
pthread_mutex_unlock(&exec_active_lock);
}
/* queue management thread handles the timeouts and dispatches the events */
static void *msg_queue_manager(void * parm)
{
struct hotplug_msg *loop_msg;
struct hotplug_msg *tmp_msg;
time_t msg_age = 0;
struct timespec tv;
while (1) {
dbg("msg queue manager, next expected is %d", expected_seqnum);
pthread_mutex_lock(&msg_lock);
pthread_mutex_lock(&exec_lock);
recheck:
list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, list) {
/* move event with expected sequence to the exec list */
if (loop_msg->seqnum == expected_seqnum) {
msg_move_exec(&loop_msg->list);
expected_seqnum++;
dbg("moved seq %d to exec, next expected is %d",
loop_msg->seqnum, expected_seqnum);
continue;
}
/* move event with expired timeout to the exec list */
msg_age = time(NULL) - loop_msg->queue_time;
if (msg_age > EVENT_TIMEOUT_SEC-1) {
msg_move_exec(&loop_msg->list);
expected_seqnum = loop_msg->seqnum+1;
dbg("moved seq %d to exec, reset next expected to %d",
loop_msg->seqnum, expected_seqnum);
goto recheck;
} else {
break;
}
}
msg_dump_queue();
pthread_mutex_unlock(&exec_lock);
pthread_mutex_unlock(&msg_lock);
/* wait until queue gets active or next message timeout expires */
pthread_mutex_lock(&msg_active_lock);
if (list_empty(&msg_list) == 0) {
tv.tv_sec = time(NULL) + EVENT_TIMEOUT_SEC - msg_age;
tv.tv_nsec = 0;
dbg("next event expires in %li seconds",
EVENT_TIMEOUT_SEC - msg_age);
pthread_cond_timedwait(&msg_active, &msg_active_lock, &tv);
} else {
pthread_cond_wait(&msg_active, &msg_active_lock);
}
pthread_mutex_unlock(&msg_active_lock);
}
}
/* every connect creates a thread which gets the msg, queues it and exits */
static void *client_threads(void * parm)
{
int sock;
struct hotplug_msg *msg;
int retval;
sock = (int) parm;
msg = msg_create();
if (msg == NULL) {
dbg("unable to store message");
goto exit;
}
retval = recv(sock, msg, sizeof(struct hotplug_msg), 0);
if (retval < 0) {
dbg("unable to receive message");
goto exit;
}
if (strncmp(msg->magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
dbg("message magic '%s' doesn't match, ignore it", msg->magic);
goto exit;
}
pthread_mutex_lock(&msg_lock);
msg_queue_insert(msg);
pthread_mutex_unlock(&msg_lock);
exit:
close(sock);
pthread_exit(0);
}
static void sig_handler(int signum)
{
switch (signum) {
case SIGINT:
case SIGTERM:
unlink(UDEVD_LOCK);
unlink(UDEVD_SOCKET);
exit(20 + signum);
break;
default:
dbg("unhandled signal");
}
}
static int one_and_only(void)
{
char string[100];
lock_file = open(lock_filename, O_RDWR | O_CREAT, 0x640);
char string[50];
int lock_file;
/* see if we can open */
lock_file = open(UDEVD_LOCK, O_RDWR | O_CREAT, 0x640);
if (lock_file < 0)
return -1;
/* see if we can lock */
if (lockf(lock_file, F_TLOCK, 0) < 0) {
dbg("file is already locked, exit");
close(lock_file);
return -1;
}
@ -329,16 +340,73 @@ static int one_and_only(void)
int main(int argc, char *argv[])
{
int ssock;
int csock;
struct sockaddr_un saddr;
struct sockaddr_un caddr;
socklen_t clen;
pthread_t cli_tid;
pthread_t mgr_msg_tid;
pthread_t mgr_exec_tid;
int retval;
/* only let one version of the daemon run at any one time */
if (one_and_only() != 0)
exit(0);
/* set up signal handler */
signal(SIGINT, sig_handler);
signal(SIGTERM, sig_handler);
signal(SIGALRM, sig_handler);
signal(SIGCHLD, sig_handler);
work();
exit(0);
memset(&saddr, 0x00, sizeof(saddr));
saddr.sun_family = AF_LOCAL;
strcpy(saddr.sun_path, UDEVD_SOCKET);
unlink(UDEVD_SOCKET);
ssock = socket(AF_LOCAL, SOCK_STREAM, 0);
if (ssock == -1) {
dbg("error getting socket");
exit(1);
}
retval = bind(ssock, &saddr, sizeof(saddr));
if (retval < 0) {
dbg("bind failed\n");
goto exit;
}
retval = listen(ssock, SOMAXCONN);
if (retval < 0) {
dbg("listen failed\n");
goto exit;
}
pthread_mutex_init(&msg_lock, NULL);
pthread_mutex_init(&msg_active_lock, NULL);
pthread_mutex_init(&exec_lock, NULL);
pthread_mutex_init(&exec_active_lock, NULL);
pthread_mutex_init(&running_lock, NULL);
/* set default attributes for created threads */
pthread_attr_init(&thr_attr);
pthread_attr_setdetachstate(&thr_attr, PTHREAD_CREATE_DETACHED);
/* init queue management */
pthread_create(&mgr_msg_tid, &thr_attr, msg_queue_manager, NULL);
pthread_create(&mgr_exec_tid, &thr_attr, exec_queue_manager, NULL);
clen = sizeof(caddr);
/* main loop */
while (1) {
csock = accept(ssock, &caddr, &clen);
if (csock < 0) {
if (errno == EINTR)
continue;
dbg("client accept failed\n");
}
pthread_create(&cli_tid, &thr_attr, client_threads, (void *) csock);
}
exit:
close(ssock);
unlink(UDEVD_SOCKET);
exit(1);
}

20
udevd.h
View File

@ -4,6 +4,7 @@
* Userspace devfs
*
* Copyright (C) 2004 Ling, Xiaofeng <xiaofeng.ling@intel.com>
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
*
*
* This program is free software; you can redistribute it and/or modify it
@ -23,16 +24,21 @@
#include "list.h"
#define FIRST_EVENT_TIMEOUT_SEC 1
/*
* FIXME: udev_root is post compile configurable and may also be
* mounted over at any time and /var/run/ and /tmp/ is unusable,
* cause it's cleaned at system startup, long _after_ udevd is
* already running. Should we use udev_init_config()?
*/
#define UDEV_MAGIC "udev_" UDEV_VERSION
#define EVENT_TIMEOUT_SEC 5
#define UDEVSEND_RETRY_COUNT 50 /* x 10 millisec */
#define IPC_KEY_ID 1
#define HOTPLUGMSGTYPE 44
#define UDEVSEND_CONNECT_RETRY 20 /* x 100 millisec */
#define UDEVD_SOCKET UDEV_ROOT ".udevd.socket"
#define UDEVD_LOCK UDEV_ROOT ".udevd.pid"
struct hotplug_msg {
long mtype;
char magic[20];
struct list_head list;
pid_t pid;
int seqnum;

82
udevsend.c
View File

@ -32,12 +32,15 @@
#include <unistd.h>
#include <time.h>
#include <wait.h>
#include <sys/socket.h>
#include <sys/un.h>
#include "udev.h"
#include "udev_version.h"
#include "udevd.h"
#include "logging.h"
static inline char *get_action(void)
{
char *action;
@ -66,7 +69,7 @@ static int build_hotplugmsg(struct hotplug_msg *msg, char *action,
char *devpath, char *subsystem, int seqnum)
{
memset(msg, 0x00, sizeof(*msg));
msg->mtype = HOTPLUGMSGTYPE;
strfieldcpy(msg->magic, UDEV_MAGIC);
msg->seqnum = seqnum;
strncpy(msg->action, action, 8);
strncpy(msg->devpath, devpath, 128);
@ -108,12 +111,8 @@ static int start_daemon(void)
return 0;
}
int main(int argc, char* argv[])
{
int msgid;
key_t key;
struct msqid_ds msg_queue;
struct hotplug_msg message;
char *action;
char *devpath;
@ -124,6 +123,8 @@ int main(int argc, char* argv[])
int size;
int loop;
struct timespec tspec;
int sock;
struct sockaddr_un saddr;
subsystem = argv[1];
if (subsystem == NULL) {
@ -150,41 +151,58 @@ int main(int argc, char* argv[])
}
seq = atoi(seqnum);
/* create ipc message queue or get id of our existing one */
key = ftok(UDEVD_BIN, IPC_KEY_ID);
dbg("using ipc queue 0x%0x", key);
size = build_hotplugmsg(&message, action, devpath, subsystem, seq);
msgid = msgget(key, IPC_CREAT);
if (msgid == -1) {
dbg("error open ipc queue");
sock = socket(AF_LOCAL, SOCK_STREAM, 0);
if (sock == -1) {
dbg("error getting socket");
goto exit;
}
/* send ipc message to the daemon */
retval = msgsnd(msgid, &message, size, 0);
if (retval == -1) {
dbg("error sending ipc message");
goto exit;
}
memset(&saddr, 0x00, sizeof(saddr));
saddr.sun_family = AF_LOCAL;
strcpy(saddr.sun_path, UDEVD_SOCKET);
/* get state of ipc queue */
tspec.tv_sec = 0;
tspec.tv_nsec = 10000000; /* 10 millisec */
loop = UDEVSEND_RETRY_COUNT;
while (loop--) {
retval = msgctl(msgid, IPC_STAT, &msg_queue);
if (retval == -1) {
dbg("error getting info on ipc queue");
/* try to connect, if it fails start daemon */
retval = connect(sock, &saddr, sizeof(saddr));
if (retval != -1) {
goto send;
} else {
dbg("connect failed, try starting daemon...");
retval = start_daemon();
if (retval == 0) {
dbg("daemon started");
} else {
dbg("error starting daemon");
goto exit;
}
if (msg_queue.msg_qnum == 0)
goto exit;
nanosleep(&tspec, NULL);
}
info("message is still in the ipc queue, starting daemon...");
retval = start_daemon();
/* try to connect while daemon to starts */
tspec.tv_sec = 0;
tspec.tv_nsec = 100000000; /* 100 millisec */
loop = UDEVSEND_CONNECT_RETRY;
while (loop--) {
retval = connect(sock, &saddr, sizeof(saddr));
if (retval != -1)
goto send;
else
dbg("retry to connect %d",
UDEVSEND_CONNECT_RETRY - loop);
nanosleep(&tspec, NULL);
}
dbg("error connecting to daemon, start daemon failed");
goto exit;
send:
size = build_hotplugmsg(&message, action, devpath, subsystem, seq);
retval = send(sock, &message, size, 0);
if (retval == -1) {
dbg("error sending message");
close (sock);
goto exit;
}
close (sock);
return 0;
exit:
return retval;
return 1;
}