diff options
Diffstat (limited to 'udevd.c')
| -rw-r--r-- | udevd.c | 299 |
1 files changed, 116 insertions, 183 deletions
@@ -2,6 +2,7 @@ * udevd.c - hotplug event serializer * * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org> + * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca> * * * This program is free software; you can redistribute it and/or modify it @@ -19,7 +20,6 @@ * */ -#include <pthread.h> #include <stddef.h> #include <sys/wait.h> #include <signal.h> @@ -32,6 +32,7 @@ #include <sys/types.h> #include <sys/socket.h> #include <sys/un.h> +#include <sys/time.h> #include "list.h" #include "udev.h" @@ -39,22 +40,17 @@ #include "udevd.h" #include "logging.h" - unsigned char logname[42]; -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; +volatile static int children_waiting; +volatile static int msg_q_timeout; LIST_HEAD(msg_list); LIST_HEAD(exec_list); LIST_HEAD(running_list); +static void exec_queue_manager(void); +static void msg_queue_manager(void); static void msg_dump_queue(void) { @@ -75,17 +71,16 @@ static struct hotplug_msg *msg_create(void) struct hotplug_msg *new_msg; new_msg = malloc(sizeof(struct hotplug_msg)); - if (new_msg == NULL) { + if (new_msg == NULL) dbg("error malloc"); - return NULL; - } return new_msg; } -static void msg_delete(struct hotplug_msg *msg) +static void run_queue_delete(struct hotplug_msg *msg) { - if (msg != NULL) - free(msg); + list_del(&msg->list); + free(msg); + exec_queue_manager(); } /* orders the message in the queue by sequence number */ @@ -103,21 +98,16 @@ static void msg_queue_insert(struct hotplug_msg *msg) /* 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); + /* run msg queue manager */ + msg_queue_manager(); return ; } /* forks event and removes event from run queue when finished */ -static void *run_threads(void * parm) +static void udev_run(struct hotplug_msg *msg) { pid_t pid; - struct hotplug_msg *msg; - - msg = parm; setenv("ACTION", msg->action, 1); setenv("DEVPATH", msg->devpath, 1); @@ -131,190 +121,124 @@ static void *run_threads(void * parm) break; case -1: dbg("fork of child failed"); - goto exit; + run_queue_delete(msg); + break; default: - /* 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); + /* get SIGCHLD in main loop */ + dbg("==> exec seq %d [%d] working at '%s'", msg->seqnum, pid, msg->devpath); + msg->pid = pid; } - -exit: - /* remove event from run list */ - pthread_mutex_lock(&running_lock); - list_del_init(&msg->list); - pthread_mutex_unlock(&running_lock); - - msg_delete(msg); - - /* 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); } /* returns already running task with devpath */ static struct hotplug_msg *running_with_devpath(struct hotplug_msg *msg) { struct hotplug_msg *loop_msg; - struct hotplug_msg *tmp_msg; - - list_for_each_entry_safe(loop_msg, tmp_msg, &running_list, list) + list_for_each_entry(loop_msg, &running_list, list) if (strncmp(loop_msg->devpath, msg->devpath, sizeof(loop_msg->devpath)) == 0) return loop_msg; return NULL; } -/* queue management executes the events and delays events for the same devpath */ -static void *exec_queue_manager(void * parm) +/* exec queue management routine executes the events and delays events for the same devpath */ +static void exec_queue_manager() { struct hotplug_msg *loop_msg; struct hotplug_msg *tmp_msg; struct hotplug_msg *msg; - pthread_t run_tid; - while (1) { - 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); - } + list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, list) { + msg = running_with_devpath(loop_msg); + if (!msg) { + /* move event to run list */ + list_move_tail(&loop_msg->list, &running_list); + udev_run(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); } - 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); } } -static void exec_queue_activate(void) -{ - pthread_mutex_lock(&exec_active_lock); - pthread_cond_signal(&exec_active); - pthread_mutex_unlock(&exec_active_lock); -} - -/* move message from incoming to exec queue */ -static void msg_move_exec(struct list_head *head) +static void msg_move_exec(struct hotplug_msg *msg) { - list_move_tail(head, &exec_list); - exec_queue_activate(); + list_move_tail(&msg->list, &exec_list); + exec_queue_manager(); + expected_seqnum = msg->seqnum+1; + dbg("moved seq %d to exec, next expected is %d", + msg->seqnum, expected_seqnum); } -/* queue management thread handles the timeouts and dispatches the events */ -static void *msg_queue_manager(void * parm) +/* msg queue management routine handles the timeouts and dispatches the events */ +static void msg_queue_manager() { 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); + dbg("msg queue manager, next expected is %d", expected_seqnum); 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; - } + 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); + continue; } - 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); + /* 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); + goto recheck; } else { - pthread_cond_wait(&msg_active, &msg_active_lock); + break; } - pthread_mutex_unlock(&msg_active_lock); + } + + msg_dump_queue(); + + if (list_empty(&msg_list) == 0) { + /* set timeout for remaining queued events */ + struct itimerval itv = {{0, 0}, {EVENT_TIMEOUT_SEC - msg_age, 0}}; + dbg("next event expires in %li seconds", + EVENT_TIMEOUT_SEC - msg_age); + setitimer(ITIMER_REAL, &itv, 0); } } -/* every connect creates a thread which gets the msg, queues it and exits */ -static void *client_threads(void * parm) +/* receive the msg, do some basic sanity checks, and queue it */ +static void handle_msg(int sock) { - int sock; struct hotplug_msg *msg; int retval; - sock = (int) parm; - msg = msg_create(); if (msg == NULL) { dbg("unable to store message"); - goto exit; + return; } retval = recv(sock, msg, sizeof(struct hotplug_msg), 0); if (retval < 0) { - dbg("unable to receive message"); - goto exit; + if (errno != EINTR) + dbg("unable to receive message"); + return; } - + if (strncmp(msg->magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) { dbg("message magic '%s' doesn't match, ignore it", msg->magic); - msg_delete(msg); - goto exit; + free(msg); + return; } /* if no seqnum is given, we move straight to exec queue */ - if (msg->seqnum == 0) { - pthread_mutex_lock(&exec_lock); + if (msg->seqnum == -1) { list_add(&msg->list, &exec_list); - exec_queue_activate(); - pthread_mutex_unlock(&exec_lock); + exec_queue_manager(); } else { - 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) @@ -324,28 +248,48 @@ static void sig_handler(int signum) case SIGTERM: exit(20 + signum); break; + case SIGALRM: + msg_q_timeout = 1; + break; + case SIGCHLD: + children_waiting = 1; + break; default: dbg("unhandled signal"); } } +static void udev_done(int pid) +{ + /* find msg associated with pid and delete it */ + struct hotplug_msg *msg; + + list_for_each_entry(msg, &running_list, list) { + if (msg->pid == pid) { + dbg("<== exec seq %d came back", msg->seqnum); + run_queue_delete(msg); + return; + } + } +} + int main(int argc, char *argv[]) { int ssock; - int csock; struct sockaddr_un saddr; - struct sockaddr_un caddr; socklen_t addrlen; - socklen_t clen; - pthread_t cli_tid; - pthread_t mgr_msg_tid; - pthread_t mgr_exec_tid; int retval; init_logging("udevd"); signal(SIGINT, sig_handler); signal(SIGTERM, sig_handler); + signal(SIGALRM, sig_handler); + signal(SIGCHLD, sig_handler); + + /* we want these two to interrupt system calls */ + siginterrupt(SIGALRM, 1); + siginterrupt(SIGCHLD, 1); memset(&saddr, 0x00, sizeof(saddr)); saddr.sun_family = AF_LOCAL; @@ -353,48 +297,37 @@ int main(int argc, char *argv[]) strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH); addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1; - ssock = socket(AF_LOCAL, SOCK_STREAM, 0); + ssock = socket(AF_LOCAL, SOCK_DGRAM, 0); if (ssock == -1) { dbg("error getting socket"); exit(1); } + /* the bind takes care of ensuring only one copy running */ retval = bind(ssock, &saddr, addrlen); 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); - pthread_attr_setstacksize(&thr_attr, 16 * 1024); + while (1) { + handle_msg(ssock); - /* 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); + while(msg_q_timeout) { + msg_q_timeout = 0; + msg_queue_manager(); + } - clen = sizeof(caddr); - /* main loop */ - while (1) { - csock = accept(ssock, &caddr, &clen); - if (csock < 0) { - dbg("client accept failed\n"); - continue; + while(children_waiting) { + children_waiting = 0; + /* reap all dead children */ + while(1) { + int pid = waitpid(-1, 0, WNOHANG); + if ((pid == -1) || (pid == 0)) + break; + udev_done(pid); + } } - pthread_create(&cli_tid, &thr_attr, client_threads, (void *) csock); } exit: close(ssock); 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