X-Git-Url: https://gerrit.automotivelinux.org/gerrit/gitweb?p=src%2Fapp-framework-binder.git;a=blobdiff_plain;f=src%2Fjobs.c;fp=src%2Fjobs.c;h=4a88c3036bc05b86cc840880b6e82d71c7e4d0b0;hp=f2c9d52be375cf756ab904b4debce1e08db53f4b;hb=77bf8a30c07a4ab5690337ed362dae4414e590fb;hpb=a4bb03e57aa2f8b71840ec384356f6c283989d73 diff --git a/src/jobs.c b/src/jobs.c index f2c9d52b..4a88c303 100644 --- a/src/jobs.c +++ b/src/jobs.c @@ -45,10 +45,6 @@ #include "sig-monitor.h" #include "verbose.h" -#if defined(REMOVE_SYSTEMD_EVENT) -#include "fdev-epoll.h" -#endif - #define EVENT_TIMEOUT_TOP ((uint64_t)-1) #define EVENT_TIMEOUT_CHILD ((uint64_t)10000) @@ -75,20 +71,20 @@ struct evloop unsigned state; /**< encoded state */ int efd; /**< event notification */ struct sd_event *sdev; /**< the systemd event loop */ - pthread_cond_t cond; /**< condition */ struct fdev *fdev; /**< handling of events */ struct thread *holder; /**< holder of the evloop */ }; #define EVLOOP_STATE_WAIT 1U #define EVLOOP_STATE_RUN 2U -#define EVLOOP_STATE_LOCK 4U /** Description of threads */ struct thread { struct thread *next; /**< next thread of the list */ struct thread *upper; /**< upper same thread */ + struct thread *nholder;/**< next holder for evloop */ + pthread_cond_t *cwhold;/**< condition wait for holding */ struct job *job; /**< currently processed job */ pthread_t tid; /**< the thread id */ volatile unsigned stop: 1; /**< stop requested */ @@ -96,7 +92,7 @@ struct thread }; /** - * Description of synchonous callback + * Description of synchronous callback */ struct sync { @@ -123,19 +119,13 @@ static int remains = 0; /** allowed count of waiting jobs */ /* list of threads */ static struct thread *threads; static _Thread_local struct thread *current_thread; -static _Thread_local struct evloop *current_evloop; /* queue of pending jobs */ static struct job *first_job; static struct job *free_jobs; /* event loop */ -static struct evloop evloop[1]; - -#if defined(REMOVE_SYSTEMD_EVENT) -static struct fdev_epoll *fdevepoll; -static int waitevt; -#endif +static struct evloop evloop; /** * Create a new job with the given parameters @@ -163,6 +153,7 @@ static struct job *job_create( job = malloc(sizeof *job); pthread_mutex_lock(&mutex); if (!job) { + ERROR("out of memory"); errno = ENOMEM; goto end; } @@ -204,6 +195,7 @@ static void job_add(struct job *job) /* queue the jobs */ *pjob = job; + remains--; } /** @@ -215,6 +207,8 @@ static inline struct job *job_get() struct job *job = first_job; while (job && job->blocked) job = job->next; + if (job) + remains++; return job; } @@ -269,23 +263,6 @@ static void job_cancel(int signum, void *arg) job->callback(SIGABRT, job->arg); } -#if defined(REMOVE_SYSTEMD_EVENT) -/** - * Gets a fdev_epoll item. - * @return a fdev_epoll or NULL in case of error - */ -static struct fdev_epoll *get_fdevepoll() -{ - struct fdev_epoll *result; - - result = fdevepoll; - if (!result) - result = fdevepoll = fdev_epoll_create(); - - return result; -} -#endif - /** * Monitored normal callback for events. * This function is called by the monitor @@ -300,13 +277,9 @@ static void evloop_run(int signum, void *arg) { int rc; struct sd_event *se; - struct evloop *el = arg; if (!signum) { - current_evloop = el; - __atomic_store_n(&el->state, EVLOOP_STATE_LOCK|EVLOOP_STATE_RUN|EVLOOP_STATE_WAIT, __ATOMIC_RELAXED); - __atomic_store_n(&el->holder, current_thread, __ATOMIC_RELAXED); - se = el->sdev; + se = evloop.sdev; rc = sd_event_prepare(se); if (rc < 0) { errno = -rc; @@ -320,8 +293,7 @@ static void evloop_run(int signum, void *arg) ERROR("sd_event_wait returned an error (state: %d): %m", sd_event_get_state(se)); } } - __atomic_and_fetch(&el->state, ~(EVLOOP_STATE_WAIT), __ATOMIC_RELAXED); - + evloop.state = EVLOOP_STATE_RUN; if (rc > 0) { rc = sd_event_dispatch(se); if (rc < 0) { @@ -331,69 +303,151 @@ static void evloop_run(int signum, void *arg) } } } - __atomic_and_fetch(&el->state, ~(EVLOOP_STATE_WAIT|EVLOOP_STATE_RUN), __ATOMIC_RELAXED); } +/** + * Internal callback for evloop management. + * The effect of this function is hidden: it exits + * the waiting poll if any. + */ +static void evloop_on_efd_event() +{ + uint64_t x; + read(evloop.efd, &x, sizeof x); +} -#if defined(REMOVE_SYSTEMD_EVENT) /** - * Monitored normal loop for waiting events. - * @param signum 0 on normal flow or the number - * of the signal that interrupted the normal - * flow - * @param arg the events to run + * wakeup the event loop if needed by sending + * an event. */ -static void monitored_wait_and_dispatch(int signum, void *arg) +static void evloop_wakeup() { - struct fdev_epoll *fdev_epoll = arg; - if (!signum) { - fdev_epoll_wait_and_dispatch(fdev_epoll, -1); + uint64_t x; + + if (evloop.state & EVLOOP_STATE_WAIT) { + x = 1; + write(evloop.efd, &x, sizeof x); } } -#endif /** - * 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? + * Release the currently held event loop */ -static void thread_run(volatile struct thread *me) +static void evloop_release() { - struct thread **prv; - struct job *job; -#if !defined(REMOVE_SYSTEMD_EVENT) - struct evloop *el; -#endif + struct thread *nh, *ct = current_thread; + + if (evloop.holder == ct) { + nh = ct->nholder; + evloop.holder = nh; + if (nh) + pthread_cond_signal(nh->cwhold); + } +} + +/** + * get the eventloop for the current thread + */ +static int evloop_get() +{ + struct thread *ct = current_thread; + + if (evloop.holder) + return evloop.holder == ct; + + ct->nholder = NULL; + evloop.holder = ct; + return 1; +} + +/** + * acquire the eventloop for the current thread + */ +static void evloop_acquire() +{ + struct thread **pwait, *ct; + pthread_cond_t cond; + + /* try to get the evloop */ + if (!evloop_get()) { + /* failed, init waiting state */ + ct = current_thread; + ct->nholder = NULL; + ct->cwhold = &cond; + pthread_cond_init(&cond, NULL); + + /* queue current thread in holder list */ + pwait = &evloop.holder; + while (*pwait) + pwait = &(*pwait)->nholder; + *pwait = ct; + + /* wake up the evloop */ + evloop_wakeup(); + + /* wait to acquire the evloop */ + pthread_cond_wait(&cond, &mutex); + pthread_cond_destroy(&cond); + } +} +/** + * Enter the thread + * @param me the description of the thread to enter + */ +static void thread_enter(volatile struct thread *me) +{ /* initialize description of itself and link it in the list */ me->tid = pthread_self(); me->stop = 0; me->waits = 0; me->upper = current_thread; - if (!current_thread) { - started++; - sig_monitor_init_timeouts(); - } me->next = threads; threads = (struct thread*)me; current_thread = (struct thread*)me; +} + +/** + * leave the thread + * @param me the description of the thread to leave + */ +static void thread_leave() +{ + struct thread **prv, *me; + + /* unlink the current thread and cleanup */ + me = current_thread; + prv = &threads; + while (*prv != me) + prv = &(*prv)->next; + *prv = me->next; + + current_thread = me->upper; +} + +/** + * Main processing loop of internal threads with 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_internal(volatile struct thread *me) +{ + struct job *job; + + /* enter thread */ + thread_enter(me); /* loop until stopped */ while (!me->stop) { - /* release the event loop */ - if (current_evloop) { - __atomic_and_fetch(¤t_evloop->state, ~EVLOOP_STATE_LOCK, __ATOMIC_RELAXED); - __atomic_store_n(¤t_evloop->holder, NULL, __ATOMIC_RELAXED); - current_evloop = NULL; - } + /* release the current event loop */ + evloop_release(); /* get a job */ job = job_get(); 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) */ @@ -404,31 +458,21 @@ static void thread_run(volatile struct thread *me) /* release the run job */ job_release(job); -#if !defined(REMOVE_SYSTEMD_EVENT) - } else { - /* no job, check events */ - el = &evloop[0]; - if (el->sdev && !__atomic_load_n(&el->state, __ATOMIC_RELAXED)) { - /* run the events */ - __atomic_store_n(&el->state, EVLOOP_STATE_LOCK|EVLOOP_STATE_RUN|EVLOOP_STATE_WAIT, __ATOMIC_RELAXED); - __atomic_store_n(&el->holder, me, __ATOMIC_RELAXED); - current_evloop = el; - pthread_mutex_unlock(&mutex); - sig_monitor(0, evloop_run, el); - pthread_mutex_lock(&mutex); - } else { - /* no job and not events */ - running--; - if (!running) - ERROR("Entering job deep sleep! Check your bindings."); - me->waits = 1; - pthread_cond_wait(&cond, &mutex); - me->waits = 0; - running++; + /* no job, check event loop wait */ + } else if (evloop_get()) { + if (evloop.state != 0) { + /* busy ? */ + CRITICAL("Can't enter dispatch while in dispatch!"); + abort(); } -#else - } else if (waitevt) { - /* no job and not events */ + /* run the events */ + evloop.state = EVLOOP_STATE_RUN|EVLOOP_STATE_WAIT; + pthread_mutex_unlock(&mutex); + sig_monitor(0, evloop_run, NULL); + pthread_mutex_lock(&mutex); + evloop.state = 0; + } else { + /* no job and no event loop */ running--; if (!running) ERROR("Entering job deep sleep! Check your bindings."); @@ -436,49 +480,57 @@ static void thread_run(volatile struct thread *me) pthread_cond_wait(&cond, &mutex); me->waits = 0; running++; - } else { - /* wait for events */ - waitevt = 1; - pthread_mutex_unlock(&mutex); - sig_monitor(0, monitored_wait_and_dispatch, get_fdevepoll()); - pthread_mutex_lock(&mutex); - waitevt = 0; -#endif } } + /* cleanup */ + evloop_release(); + thread_leave(); +} - /* release the event loop */ - if (current_evloop) { - __atomic_and_fetch(¤t_evloop->state, ~EVLOOP_STATE_LOCK, __ATOMIC_RELAXED); - __atomic_store_n(&el->holder, NULL, __ATOMIC_RELAXED); - current_evloop = NULL; - } +/** + * Main processing loop of external threads. + * 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 + */ +static void thread_run_external(volatile struct thread *me) +{ + /* enter thread */ + thread_enter(me); - /* unlink the current thread and cleanup */ - prv = &threads; - while (*prv != me) - prv = &(*prv)->next; - *prv = me->next; - current_thread = me->upper; - if (!current_thread) { - sig_monitor_clean_timeouts(); - started--; - } + /* loop until stopped */ + me->waits = 1; + while (!me->stop) + pthread_cond_wait(&cond, &mutex); + me->waits = 0; + thread_leave(); } /** - * Entry point for created threads. - * @param data not used - * @return NULL + * Root for created threads. */ -static void *thread_main(void *data) +static void thread_main() { struct thread me; - pthread_mutex_lock(&mutex); running++; - thread_run(&me); + started++; + sig_monitor_init_timeouts(); + thread_run_internal(&me); + sig_monitor_clean_timeouts(); + started--; running--; +} + +/** + * Entry point for created threads. + * @param data not used + * @return NULL + */ +static void *thread_starter(void *data) +{ + pthread_mutex_lock(&mutex); + thread_main(); pthread_mutex_unlock(&mutex); return NULL; } @@ -492,7 +544,7 @@ static int start_one_thread() pthread_t tid; int rc; - rc = pthread_create(&tid, NULL, thread_main, NULL); + rc = pthread_create(&tid, NULL, thread_starter, NULL); if (rc != 0) { /* errno = rc; */ WARNING("not able to start thread: %m"); @@ -524,7 +576,6 @@ int jobs_queue( void (*callback)(int, void*), void *arg) { - const char *info; struct job *job; int rc; @@ -532,16 +583,13 @@ int jobs_queue( /* allocates the job */ job = job_create(group, timeout, callback, arg); - if (!job) { - errno = ENOMEM; - info = "out of memory"; + if (!job) goto error; - } /* check availability */ - if (remains == 0) { + if (remains <= 0) { + ERROR("can't process job with threads: too many jobs"); errno = EBUSY; - info = "too many jobs"; goto error2; } @@ -550,13 +598,12 @@ int jobs_queue( /* 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"; + ERROR("can't start initial thread: %m"); goto error2; } } /* queues the job */ - remains--; job_add(job); /* signal an existing job */ @@ -568,7 +615,6 @@ error2: job->next = free_jobs; free_jobs = job; error: - ERROR("can't process job with threads: %s, %m", info); pthread_mutex_unlock(&mutex); return -1; } @@ -614,8 +660,6 @@ static int do_sync( /* allocates the job */ job = job_create(group, timeout, sync_cb, sync); if (!job) { - ERROR("out of memory"); - errno = ENOMEM; pthread_mutex_unlock(&mutex); return -1; } @@ -624,7 +668,10 @@ static int do_sync( job_add(job); /* run until stopped */ - thread_run(&sync->thread); + if (current_thread) + thread_run_internal(&sync->thread); + else + thread_run_external(&sync->thread); pthread_mutex_unlock(&mutex); return 0; } @@ -658,41 +705,6 @@ int jobs_enter( return do_sync(group, timeout, enter_cb, &sync); } -/** - * Internal callback for evloop management. - * The effect of this function is hidden: it exits - * the waiting poll if any. Then it wakes up a thread - * awaiting the evloop using signal. - */ -static int on_evloop_efd(sd_event_source *s, int fd, uint32_t revents, void *userdata) -{ - uint64_t x; - struct evloop *evloop = userdata; - read(evloop->efd, &x, sizeof x); - pthread_mutex_lock(&mutex); - pthread_cond_broadcast(&evloop->cond); - pthread_mutex_unlock(&mutex); - return 1; -} - -/** - * unlock the event loop if needed by sending - * an event. - * @param el the event loop to unlock - * @param wait wait the unlocked state of the event loop - */ -static void unlock_evloop(struct evloop *el, int wait) -{ - /* wait for a modifiable event loop */ - while (__atomic_load_n(&el->state, __ATOMIC_RELAXED) & EVLOOP_STATE_WAIT) { - uint64_t x = 1; - write(el->efd, &x, sizeof x); - if (!wait) - break; - pthread_cond_wait(&el->cond, &mutex); - } -} - /** * Unlocks the execution flow designed by 'jobloop'. * @param jobloop indication of the flow to unlock @@ -701,7 +713,6 @@ static void unlock_evloop(struct evloop *el, int wait) int jobs_leave(struct jobloop *jobloop) { struct thread *t; - int i; pthread_mutex_lock(&mutex); t = threads; @@ -713,15 +724,8 @@ int jobs_leave(struct jobloop *jobloop) t->stop = 1; if (t->waits) pthread_cond_broadcast(&cond); - else { - i = (int)(sizeof evloop / sizeof *evloop); - while(i) { - if (evloop[--i].holder == t) { - unlock_evloop(&evloop[i], 0); - break; - } - } - } + else + evloop_wakeup(); } pthread_mutex_unlock(&mutex); return -!t; @@ -755,13 +759,16 @@ int jobs_call( return do_sync(group, timeout, call_cb, &sync); } -/* temporary hack */ -#if !defined(REMOVE_SYSTEMD_EVENT) -__attribute__((unused)) -#endif -static void evloop_callback(void *arg, uint32_t event, struct fdev *fdev) +/** + * Internal callback for evloop management. + * The effect of this function is hidden: it exits + * the waiting poll if any. Then it wakes up a thread + * awaiting the evloop using signal. + */ +static int on_evloop_efd(sd_event_source *s, int fd, uint32_t revents, void *userdata) { - sig_monitor(0, evloop_run, arg); + evloop_on_efd_event(); + return 1; } /** @@ -770,74 +777,41 @@ static void evloop_callback(void *arg, uint32_t event, struct fdev *fdev) */ static struct sd_event *get_sd_event_locked() { - struct evloop *el; int rc; /* creates the evloop on need */ - el = &evloop[0]; - if (!el->sdev) { + if (!evloop.sdev) { /* start the creation */ - el->state = 0; + evloop.state = 0; /* creates the eventfd for waking up polls */ - el->efd = eventfd(0, EFD_CLOEXEC); - if (el->efd < 0) { + evloop.efd = eventfd(0, EFD_CLOEXEC|EFD_SEMAPHORE); + if (evloop.efd < 0) { ERROR("can't make eventfd for events"); goto error1; } /* create the systemd event loop */ - rc = sd_event_new(&el->sdev); + rc = sd_event_new(&evloop.sdev); if (rc < 0) { ERROR("can't make new event loop"); goto error2; } /* put the eventfd in the event loop */ - rc = sd_event_add_io(el->sdev, NULL, el->efd, EPOLLIN, on_evloop_efd, el); + rc = sd_event_add_io(evloop.sdev, NULL, evloop.efd, EPOLLIN, on_evloop_efd, NULL); if (rc < 0) { ERROR("can't register eventfd"); -#if !defined(REMOVE_SYSTEMD_EVENT) - sd_event_unref(el->sdev); - el->sdev = NULL; -error2: - close(el->efd); -error1: - return NULL; - } -#else - goto error3; - } - /* handle the event loop */ - el->fdev = fdev_epoll_add(get_fdevepoll(), sd_event_get_fd(el->sdev)); - if (!el->fdev) { - ERROR("can't create fdev"); -error3: - sd_event_unref(el->sdev); + sd_event_unref(evloop.sdev); + evloop.sdev = NULL; error2: - close(el->efd); + close(evloop.efd); error1: - memset(el, 0, sizeof *el); return NULL; } - fdev_set_autoclose(el->fdev, 0); - fdev_set_events(el->fdev, EPOLLIN); - fdev_set_callback(el->fdev, evloop_callback, el); -#endif } - /* attach the event loop to the current thread */ - if (current_evloop != el) { - if (current_evloop) { - __atomic_and_fetch(¤t_evloop->state, ~EVLOOP_STATE_LOCK, __ATOMIC_RELAXED); - __atomic_store_n(¤t_evloop->holder, NULL, __ATOMIC_RELAXED); - } - current_evloop = el; - __atomic_or_fetch(&el->state, EVLOOP_STATE_LOCK, __ATOMIC_RELAXED); - __atomic_store_n(&el->holder, current_thread, __ATOMIC_RELAXED); - } - - /* wait for a modifiable event loop */ - unlock_evloop(el, 1); + /* acquire the event loop */ + evloop_acquire(); - return el->sdev; + return evloop.sdev; } /** @@ -847,30 +821,38 @@ error1: struct sd_event *jobs_get_sd_event() { struct sd_event *result; + struct thread lt; + + /* ensure an existing thread environment */ + if (!current_thread) { + memset(<, 0, sizeof lt); + current_thread = < + } + /* process */ pthread_mutex_lock(&mutex); result = get_sd_event_locked(); pthread_mutex_unlock(&mutex); - return result; -} - -#if defined(REMOVE_SYSTEMD_EVENT) -/** - * Gets the fdev_epoll item. - * @return a fdev_epoll or NULL in case of error - */ -struct fdev_epoll *jobs_get_fdev_epoll() -{ - struct fdev_epoll *result; - - pthread_mutex_lock(&mutex); - result = get_fdevepoll(); - pthread_mutex_unlock(&mutex); + /* release the faked thread environment if needed */ + if (current_thread == <) { + /* + * Releasing it is needed because there is no way to guess + * when it has to be released really. But here is where it is + * hazardous: if the caller modifies the eventloop when it + * is waiting, there is no way to make the change effective. + * A workaround to achieve that goal is for the caller to + * require the event loop a second time after having modified it. + */ + NOTICE("Requiring sd_event loop out of binder callbacks is hazardous!"); + if (verbose_wants(Log_Level_Info)) + sig_monitor_dumpstack(); + evloop_release(); + current_thread = NULL; + } return result; } -#endif /** * Enter the jobs processing loop. @@ -883,7 +865,6 @@ struct fdev_epoll *jobs_get_fdev_epoll() int jobs_start(int allowed_count, int start_count, int waiter_count, void (*start)(int signum, void* arg), void *arg) { int rc, launched; - struct thread me; struct job *job; assert(allowed_count >= 1); @@ -913,9 +894,9 @@ int jobs_start(int allowed_count, int start_count, int waiter_count, void (*star sd_event_set_watchdog(get_sd_event_locked(), 1); #endif - /* start at least one thread */ - launched = 0; - while ((launched + 1) < start_count) { + /* start at least one thread: the current one */ + launched = 1; + while (launched < start_count) { if (start_one_thread() != 0) { ERROR("Not all threads can be started"); goto error; @@ -925,18 +906,12 @@ int jobs_start(int allowed_count, int start_count, int waiter_count, void (*star /* queue the start job */ job = job_create(NULL, 0, start, arg); - if (!job) { - ERROR("out of memory"); - errno = ENOMEM; + if (!job) goto error; - } job_add(job); - remains--; /* run until end */ - running++; - thread_run(&me); - running--; + thread_main(); rc = 0; error: pthread_mutex_unlock(&mutex);