diff options
Diffstat (limited to 'src/jobs.c')
-rw-r--r-- | src/jobs.c | 596 |
1 files changed, 440 insertions, 156 deletions
@@ -30,20 +30,31 @@ #include "sig-monitor.h" #include "verbose.h" -/* describes pending job */ +#if 0 +#define _alert_ "do you really want to remove monitoring?" +#define sig_monitor_init_timeouts() ((void)0) +#define sig_monitor_clean_timeouts() ((void)0) +#define sig_monitor(to,cb,arg) (cb(0,arg)) +#endif + +/** Internal shortcut for callback */ +typedef void (*job_cb_t)(int, void*, void *, void*); + +/** Description of a pending job */ struct job { - struct job *next; /* link to the next job enqueued */ - void *group; /* group of the request */ - void (*callback)(int,void*,void*,void*); /* processing callback */ - void *arg1; /* first arg */ - void *arg2; /* second arg */ - void *arg3; /* second arg */ - int timeout; /* timeout in second for processing the request */ - int blocked; /* is an other request blocking this one ? */ + struct job *next; /**< link to the next job enqueued */ + void *group; /**< group of the request */ + job_cb_t callback; /**< processing callback */ + void *arg1; /**< first arg */ + void *arg2; /**< second arg */ + void *arg3; /**< third arg */ + int timeout; /**< timeout in second for processing the request */ + unsigned blocked: 1; /**< is an other request blocking this one ? */ + unsigned dropped: 1; /**< is removed ? */ }; -/** control of threads */ +/** Description of threads */ struct thread { struct thread *next; /**< next thread of the list */ @@ -52,17 +63,18 @@ struct thread pthread_t tid; /**< the thread id */ unsigned stop: 1; /**< stop requested */ unsigned lowered: 1; /**< has a lower same thread */ + unsigned waits: 1; /**< is waiting? */ }; /* synchronisation of threads */ static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; static pthread_cond_t cond = PTHREAD_COND_INITIALIZER; -/* count allowed, started and running threads */ +/* count allowed, started and waiting threads */ static int allowed = 0; /** allowed count of threads */ static int started = 0; /** started count of threads */ -static int running = 0; /** running count of threads */ -static int remains = 0; /** remaining count of jobs that can be created */ +static int waiting = 0; /** waiting count of threads */ +static int remains = 0; /** allowed count of waiting jobs */ /* list of threads */ static struct thread *threads; @@ -70,23 +82,23 @@ static _Thread_local struct thread *current; /* queue of pending jobs */ static struct job *first_job; -static struct job *first_evloop; +static struct job *first_events; static struct job *free_jobs; /** * Create a new job with the given parameters - * @param group the group of the job - * @param timeout the timeout of the job (0 if none) + * @param group the group of the job + * @param timeout the timeout of the job (0 if none) * @param callback the function that achieves the job - * @param arg1 the first argument of the callback - * @param arg2 the second argument of the callback - * @param arg3 the third argument of the callback + * @param arg1 the first argument of the callback + * @param arg2 the second argument of the callback + * @param arg3 the third argument of the callback * @return the created job unblock or NULL when no more memory */ static struct job *job_create( void *group, int timeout, - void (*callback)(int, void*, void *, void*), + job_cb_t callback, void *arg1, void *arg2, void *arg3) @@ -115,6 +127,7 @@ static struct job *job_create( job->arg2 = arg2; job->arg3 = arg3; job->blocked = 0; + job->dropped = 0; end: return job; } @@ -142,7 +155,7 @@ static void job_add2(struct job *job1, struct job *job2) job2->blocked = 1; } - /* search end and blackers */ + /* search end and blockers */ pjob = &first_job; ijob = first_job; while (ijob) { @@ -163,22 +176,20 @@ static void job_add2(struct job *job1, struct job *job2) /** * Get the next job to process or NULL if none. - * The returned job if any isn't removed from - * the list of jobs. - * @return the job to process + * @param job the head of the list to search. + * @return the first job that isn't blocked or NULL */ -static inline struct job *job_get() +static inline struct job *job_get(struct job *job) { - struct job *job; - - job = first_job; while (job && job->blocked) job = job->next; return job; } /** - * Releases the processed 'job' + * Releases the processed 'job': removes it + * from the list of jobs and unblock the first + * pending job of the same group if any. * @param job the job to release */ static inline void job_release(struct job *job) @@ -210,29 +221,96 @@ static inline void job_release(struct job *job) free_jobs = job; } -/** monitored call to the job */ +/** + * Releases the events 'job': removes it + * from the list of events. + * @param job the event to release + */ +static inline void events_release(struct job *job) +{ + struct job *ijob, **pjob; + + /* first unqueue the job */ + pjob = &first_events; + ijob = first_events; + while (ijob != job) { + pjob = &ijob->next; + ijob = ijob->next; + } + *pjob = job->next; + + /* recycle the job */ + job->next = free_jobs; + free_jobs = job; +} + +/** + * Get the events of 'key' if existing. + * @param key the key to search + * @return the found events or NULL if none existing has key + */ +static inline struct job *events_of_key(void *key) +{ + struct job *job; + + if (!key) + job = NULL; + else { + job = first_events; + while (job && (job->dropped || job->group != key)) + job = job->next; + } + return job; +} + +/** + * Monitored normal callback for a job. + * This function is called by the monitor + * to run the job when the safe environment + * is set. + * @param signum 0 on normal flow or the number + * of the signal that interrupted the normal + * flow + * @param arg the job to run + */ static void job_call(int signum, void *arg) { struct job *job = arg; job->callback(signum, job->arg1, job->arg2, job->arg3); } -/** monitored cancel of the job */ +/** + * Monitored cancel callback for a job. + * This function is called by the monitor + * to cancel the job when the safe environment + * is set. + * @param signum 0 on normal flow or the number + * of the signal that interrupted the normal + * flow, isn't used + * @param arg the job to run + */ static void job_cancel(int signum, void *arg) { job_call(SIGABRT, arg); } -/* main loop of processing threads */ +/** + * Main processing loop of threads processing jobs. + * The loop must be called with the mutex locked + * and it returns with the mutex locked. + * @param me the description of the thread to use + * TODO: how are timeout handled when reentering? + */ static void thread_run(struct thread *me) { struct thread **prv; struct job *job; - /* init */ + /* initialize description of itself and link it in the list */ me->tid = pthread_self(); me->stop = 0; me->lowered = 0; + me->waits = 0; me->upper = current; if (current) current->lowered = 1; @@ -241,49 +319,50 @@ static void thread_run(struct thread *me) current = me; me->next = threads; threads = me; + started++; /* loop until stopped */ - running++; while (!me->stop) { /* get a job */ - job = job_get(); - if (!job && first_job && running == 0) { - /* sad situation!! should not happen */ - ERROR("threads are blocked!"); - job = first_job; - first_job = job->next; - } + job = job_get(first_job); if (job) { + /* prepare running the job */ + remains++; /* increases count of job that can wait */ + job->blocked = 1; /* mark job as blocked */ + me->job = job; /* record the job (only for terminate) */ + /* run the job */ - remains++; - job->blocked = 1; - me->job = job; pthread_mutex_unlock(&mutex); sig_monitor(job->timeout, job_call, job); pthread_mutex_lock(&mutex); + + /* release the run job */ job_release(job); } else { - /* no job, check evloop */ - job = first_evloop; + /* no job, check events */ + job = job_get(first_events); if (job) { - /* evloop */ - first_evloop = job->next; + /* run the events */ + job->blocked = 1; pthread_mutex_unlock(&mutex); sig_monitor(job->timeout, job_call, job); pthread_mutex_lock(&mutex); - job->next = first_evloop; - first_evloop = job; + job->blocked = 0; + if (job->dropped) + events_release(job); } else { - /* no job and not evloop */ - running--; + /* no job and not events */ + waiting++; + me->waits = 1; pthread_cond_wait(&cond, &mutex); - running++; + me->waits = 0; + waiting--; } } } - running--; - /* uninit */ + /* unlink the current thread and cleanup */ + started--; prv = &threads; while (*prv != me) prv = &(*prv)->next; @@ -293,11 +372,14 @@ static void thread_run(struct thread *me) current->lowered = 0; else sig_monitor_clean_timeouts(); - pthread_mutex_unlock(&mutex); } -/* main loop of processing threads */ -static void *thread_create(void *data) +/** + * Entry point for created threads. + * @param data not used + * @return NULL + */ +static void *thread_main(void *data) { struct thread me; @@ -307,55 +389,90 @@ static void *thread_create(void *data) return NULL; } -/* start a new thread */ +/** + * Starts a new thread + * @return 0 in case of success or -1 in case of error + */ static int start_one_thread() { pthread_t tid; int rc; - assert(started < allowed); - - started++; - rc = pthread_create(&tid, NULL, thread_create, NULL); + rc = pthread_create(&tid, NULL, thread_main, NULL); if (rc != 0) { - started--; - errno = rc; + /* errno = rc; */ WARNING("not able to start thread: %m"); rc = -1; } return rc; } -static int start_one_thread_if_needed() -{ - int rc; - - if (started == running && started < allowed) { - /* all threads are busy and a new can be started */ - rc = start_one_thread(); - if (rc < 0 && started == 0) - return rc; /* no thread available */ - } - return 0; -} - +/** + * Queues a new asynchronous job represented by 'callback' + * for the 'group' and the 'timeout'. + * Jobs are queued FIFO and are possibly executed in parallel + * concurrently except for job of the same group that are + * executed sequentially in FIFO order. + * @param group The group of the job or NULL when no group. + * @param timeout The maximum execution time in seconds of the job + * or 0 for unlimited time. + * @param callback The function to execute for achieving the job. + * Its first parameter is either 0 on normal flow + * or the signal number that broke the normal flow. + * @return 0 in case of success or -1 in case of error + */ int jobs_queue0( void *group, int timeout, void (*callback)(int signum)) { - return jobs_queue3(group, timeout, (void(*)(int,void*,void*,void*))callback, NULL, NULL, NULL); + return jobs_queue3(group, timeout, (job_cb_t)callback, NULL, NULL, NULL); } +/** + * Queues a new asynchronous job represented by 'callback' and 'arg1' + * for the 'group' and the 'timeout'. + * Jobs are queued FIFO and are possibly executed in parallel + * concurrently except for job of the same group that are + * executed sequentially in FIFO order. + * @param group The group of the job or NULL when no group. + * @param timeout The maximum execution time in seconds of the job + * or 0 for unlimited time. + * @param callback The function to execute for achieving the job. + * Its first parameter is either 0 on normal flow + * or the signal number that broke the normal flow. + * The remaining parameter is the parameter 'arg1' + * given here. + * @param arg1 The second argument for 'callback' + * @return 0 in case of success or -1 in case of error + */ int jobs_queue( void *group, int timeout, void (*callback)(int, void*), void *arg) { - return jobs_queue3(group, timeout, (void(*)(int,void*,void*,void*))callback, arg, NULL, NULL); + return jobs_queue3(group, timeout, (job_cb_t)callback, arg, NULL, NULL); } +/** + * Queues a new asynchronous job represented by 'callback' and 'arg[12]' + * for the 'group' and the 'timeout'. + * Jobs are queued FIFO and are possibly executed in parallel + * concurrently except for job of the same group that are + * executed sequentially in FIFO order. + * @param group The group of the job or NULL when no group. + * @param timeout The maximum execution time in seconds of the job + * or 0 for unlimited time. + * @param callback The function to execute for achieving the job. + * Its first parameter is either 0 on normal flow + * or the signal number that broke the normal flow. + * The remaining parameters are the parameters 'arg[12]' + * given here. + * @param arg1 The second argument for 'callback' + * @param arg2 The third argument for 'callback' + * @return 0 in case of success or -1 in case of error + */ int jobs_queue2( void *group, int timeout, @@ -363,10 +480,28 @@ int jobs_queue2( void *arg1, void *arg2) { - return jobs_queue3(group, timeout, (void(*)(int,void*,void*,void*))callback, arg1, arg2, NULL); + return jobs_queue3(group, timeout, (job_cb_t)callback, arg1, arg2, NULL); } -/* queue the job to the 'callback' using a separate thread if available */ +/** + * Queues a new asynchronous job represented by 'callback' and 'arg[123]' + * for the 'group' and the 'timeout'. + * Jobs are queued FIFO and are possibly executed in parallel + * concurrently except for job of the same group that are + * executed sequentially in FIFO order. + * @param group The group of the job or NULL when no group. + * @param timeout The maximum execution time in seconds of the job + * or 0 for unlimited time. + * @param callback The function to execute for achieving the job. + * Its first parameter is either 0 on normal flow + * or the signal number that broke the normal flow. + * The remaining parameters are the parameters 'arg[123]' + * given here. + * @param arg1 The second argument for 'callback' + * @param arg2 The third argument for 'callback' + * @param arg3 The forth argument for 'callback' + * @return 0 in case of success or -1 in case of error + */ int jobs_queue3( void *group, int timeout, @@ -397,20 +532,22 @@ int jobs_queue3( } /* start a thread if needed */ - rc = start_one_thread_if_needed(); - if (rc < 0) { - /* failed to start threading */ - info = "can't start first thread"; - goto error2; + if (waiting == 0 && started < allowed) { + /* all threads are busy and a new can be started */ + rc = start_one_thread(); + if (rc < 0 && started == 0) { + info = "can't start first thread"; + goto error2; + } } /* queues the job */ remains--; job_add2(job, NULL); - pthread_mutex_unlock(&mutex); /* signal an existing job */ pthread_cond_signal(&cond); + pthread_mutex_unlock(&mutex); return 0; error2: @@ -422,57 +559,100 @@ error: return -1; } -/* initialise the threads */ -int jobs_init(int allowed_count, int start_count, int waiter_count) -{ - /* records the allowed count */ - allowed = allowed_count; - started = 0; - running = 0; - remains = waiter_count; - - /* start at least one thread */ - pthread_mutex_lock(&mutex); - while (started < start_count && start_one_thread() == 0); - pthread_mutex_unlock(&mutex); - - /* end */ - return -(started != start_count); -} - +/** + * Run a asynchronous job represented by 'callback' + * with the 'timeout' but only returns after job completion. + * @param timeout The maximum execution time in seconds of the job + * or 0 for unlimited time. + * @param callback The function to execute for achieving the job. + * Its first parameter is either 0 on normal flow + * or the signal number that broke the normal flow. + * @return 0 in case of success or -1 in case of error + */ int jobs_invoke0( int timeout, void (*callback)(int signum)) { - return jobs_invoke3(timeout, (void(*)(int,void*,void*,void*))callback, NULL, NULL, NULL); + return jobs_invoke3(timeout, (job_cb_t)callback, NULL, NULL, NULL); } +/** + * Run a asynchronous job represented by 'callback' and 'arg1' + * with the 'timeout' but only returns after job completion. + * @param timeout The maximum execution time in seconds of the job + * or 0 for unlimited time. + * @param callback The function to execute for achieving the job. + * Its first parameter is either 0 on normal flow + * or the signal number that broke the normal flow. + * The remaining parameter is the parameter 'arg1' + * given here. + * @param arg1 The second argument for 'callback' + * @return 0 in case of success or -1 in case of error + */ int jobs_invoke( int timeout, void (*callback)(int, void*), void *arg) { - return jobs_invoke3(timeout, (void(*)(int,void*,void*,void*))callback, arg, NULL, NULL); + return jobs_invoke3(timeout, (job_cb_t)callback, arg, NULL, NULL); } +/** + * Run a asynchronous job represented by 'callback' and 'arg[12]' + * with the 'timeout' but only returns after job completion. + * @param timeout The maximum execution time in seconds of the job + * or 0 for unlimited time. + * @param callback The function to execute for achieving the job. + * Its first parameter is either 0 on normal flow + * or the signal number that broke the normal flow. + * The remaining parameters are the parameters 'arg[12]' + * given here. + * @param arg1 The second argument for 'callback' + * @param arg2 The third argument for 'callback' + * @return 0 in case of success or -1 in case of error + */ int jobs_invoke2( int timeout, void (*callback)(int, void*, void*), void *arg1, void *arg2) { - return jobs_invoke3(timeout, (void(*)(int,void*,void*,void*))callback, arg1, arg2, NULL); + return jobs_invoke3(timeout, (job_cb_t)callback, arg1, arg2, NULL); } +/** + * Stops the thread pointed by 'arg1'. Used with + * invoke familly to return to the caller after completion. + * @param signum Unused + * @param arg1 The thread to stop + * @param arg2 Unused + * @param arg3 Unused + */ static void unlock_invoker(int signum, void *arg1, void *arg2, void *arg3) { struct thread *t = arg1; pthread_mutex_lock(&mutex); t->stop = 1; + if (t->waits) + pthread_cond_broadcast(&cond); pthread_mutex_unlock(&mutex); } -/* invoke the job to the 'callback' using a separate thread if available */ +/** + * Run a asynchronous job represented by 'callback' and 'arg[123]' + * with the 'timeout' but only returns after job completion. + * @param timeout The maximum execution time in seconds of the job + * or 0 for unlimited time. + * @param callback The function to execute for achieving the job. + * Its first parameter is either 0 on normal flow + * or the signal number that broke the normal flow. + * The remaining parameters are the parameters 'arg[123]' + * given here. + * @param arg1 The second argument for 'callback' + * @param arg2 The third argument for 'callback' + * @param arg3 The forth argument for 'callback' + * @return 0 in case of success or -1 in case of error + */ int jobs_invoke3( int timeout, void (*callback)(int, void*, void *, void*), @@ -480,9 +660,7 @@ int jobs_invoke3( void *arg2, void *arg3) { - const char *info; struct job *job1, *job2; - int rc; struct thread me; pthread_mutex_lock(&mutex); @@ -491,47 +669,75 @@ int jobs_invoke3( job1 = job_create(&me, timeout, callback, arg1, arg2, arg3); job2 = job_create(&me, 0, unlock_invoker, &me, NULL, NULL); if (!job1 || !job2) { + ERROR("out of memory"); errno = ENOMEM; - info = "out of memory"; - goto error; - } - - /* start a thread if needed */ - rc = start_one_thread_if_needed(); - if (rc < 0) { - /* failed to start threading */ - info = "can't start first thread"; - goto error; + if (job1) { + job1->next = free_jobs; + free_jobs = job1; + } + if (job2) { + job2->next = free_jobs; + free_jobs = job2; + } + pthread_mutex_unlock(&mutex); + return -1; } /* queues the job */ job_add2(job1, job2); - /* run untill stopped */ + /* run until stopped */ thread_run(&me); pthread_mutex_unlock(&mutex); return 0; +} -error: - if (job1) { - job1->next = free_jobs; - free_jobs = job1; - } - if (job2) { - job2->next = free_jobs; - free_jobs = job2; - } - ERROR("can't process job with threads: %s, %m", info); +/** + * Initialise the job stuff. + * @param allowed_count Maximum count of thread for jobs (can be 0, + * see 'jobs_add_me' for merging new threads) + * @param start_count Count of thread to start now, must be lower. + * @param waiter_count Maximum count of jobs that can be waiting. + * @return 0 in case of success or -1 in case of error. + */ +int jobs_init(int allowed_count, int start_count, int waiter_count) +{ + int rc, launched; + + assert(allowed_count >= 0); + assert(start_count >= 0); + assert(waiter_count > 0); + assert(start_count <= allowed_count); + + /* records the allowed count */ + allowed = allowed_count; + started = 0; + waiting = 0; + remains = waiter_count; + + /* start at least one thread */ + pthread_mutex_lock(&mutex); + launched = 0; + while (launched < start_count && start_one_thread() == 0) + launched++; + rc = -(launched != start_count); pthread_mutex_unlock(&mutex); - return -1; + + /* end */ + if (rc) + ERROR("Not all threads can be started"); + return rc; } -/* terminate all the threads and all pending requests */ +/** + * Terminate all the threads and cancel all pending jobs. + */ void jobs_terminate() { struct job *job, *head, *tail; - pthread_t me, other; + pthread_t me, *others; struct thread *t; + int count; /* how am i? */ me = pthread_self(); @@ -539,23 +745,42 @@ void jobs_terminate() /* request all threads to stop */ pthread_mutex_lock(&mutex); allowed = 0; - for(;;) { - /* search the next thread to stop */ - t = threads; - while (t && pthread_equal(t->tid, me)) - t = t->next; - if (!t) - break; - /* stop it */ - other = t->tid; + + /* count the number of threads */ + count = 0; + t = threads; + while (t) { + if (!t->upper && !pthread_equal(t->tid, me)) + count++; + t = t->next; + } + + /* fill the array of threads */ + others = alloca(count * sizeof *others); + count = 0; + t = threads; + while (t) { + if (!t->upper && !pthread_equal(t->tid, me)) + others[count++] = t->tid; + t = t->next; + } + + /* stops the threads */ + t = threads; + while (t) { t->stop = 1; - pthread_mutex_unlock(&mutex); - pthread_cond_broadcast(&cond); - pthread_join(other, NULL); - pthread_mutex_lock(&mutex); + t = t->next; } + /* wait the threads */ + pthread_cond_broadcast(&cond); + pthread_mutex_unlock(&mutex); + while (count) + pthread_join(others[--count], NULL); + pthread_mutex_lock(&mutex); + /* cancel pending jobs of other threads */ + remains = 0; head = first_job; first_job = NULL; tail = NULL; @@ -587,24 +812,83 @@ void jobs_terminate() pthread_mutex_unlock(&mutex); } -int jobs_add_event_loop(void *key, int timeout, void (*evloop)(int signum, void*), void *closure) +/** + * Adds the events waiter/dispatcher to the list of events waiters/dispatchers + * to monitor. + * @param key A key to register the events waiter/dispatcher (see + * 'jobs_del_events') + * @param timeout Timeout in second of the function or 0 if none + * @param events The callback, the first argument is 0 for normal + * flow or the signal number when normal flow failed + * @param closure The closure to give to the callback as secondd argument + * @return 0 in case of success or -1 in case of error + */ +int jobs_add_events(void *key, int timeout, void (*events)(int signum, void*), void *closure) { struct job *job; pthread_mutex_lock(&mutex); - job = job_create(key, timeout, (void (*)(int, void *, void *, void *))evloop, closure, NULL, NULL); + + /* look at an already existsing events for same key */ + job = events_of_key(key); if (job) { - /* adds the loop */ - job->next = first_evloop; - first_evloop = job; + pthread_mutex_unlock(&mutex); + ERROR("events of key %p already exist", key); + errno = EEXIST; + return -1; + } - /* signal the loop */ - pthread_cond_signal(&cond); + /* creates the job */ + job = job_create(key, timeout, (job_cb_t)events, closure, NULL, NULL); + if (!job) { + pthread_mutex_unlock(&mutex); + ERROR("Can't create events, out of memory"); + errno = ENOMEM; + return -1; } + + /* adds the loop */ + job->next = first_events; + first_events = job; + + /* signal the loop */ + if (waiting) + pthread_cond_signal(&cond); pthread_mutex_unlock(&mutex); + return 0; +} + +/** + * Removes the events of 'key' + * @param key The key of the events to remove + * @return 0 in case of success or -1 in case of error + */ +int jobs_del_events(void *key) +{ + struct job *job; + + pthread_mutex_lock(&mutex); + job = events_of_key(key); + if (job) + if (job->blocked) + job->dropped = 1; + else + events_release(job); + pthread_mutex_unlock(&mutex); + if (!job) { + ERROR("events of key %p not found", key); + errno = ENOENT; + } return -!job; } +/** + * Adds the current thread to the pool of threads + * processing the jobs. Returns normally when the threads are + * terminated or immediately with an error if the thread is + * already in the pool. + * @return 0 in case of success or -1 in case of error + */ int jobs_add_me() { struct thread me; |