X-Git-Url: https://gerrit.automotivelinux.org/gerrit/gitweb?a=blobdiff_plain;f=src%2Fjobs.c;h=f5c9ddea2c66fc774925e8bd7b69e2ff3d904f07;hb=48df1b4c1e9d34ab8cafe0f496ddac299a00e00a;hp=b7d161120b250c7647fe481ac41c814ff253d821;hpb=674b01ab9887d7c16b674e32365c7ab1386ecc77;p=src%2Fapp-framework-binder.git diff --git a/src/jobs.c b/src/jobs.c index b7d16112..f5c9ddea 100644 --- a/src/jobs.c +++ b/src/jobs.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2016, 2017 "IoT.bzh" + * Copyright (C) 2016, 2017, 2018 "IoT.bzh" * Author José Bollo * * Licensed under the Apache License, Version 2.0 (the "License"); @@ -17,32 +17,43 @@ #define _GNU_SOURCE +#if defined(NO_JOBS_WATCHDOG) +# define HAS_WATCHDOG 0 +#else +# define HAS_WATCHDOG 1 +#endif + #include #include #include #include +#include #include #include #include #include #include +#include #include +#include "fdev.h" +#if HAS_WATCHDOG +#include +#endif #include "jobs.h" #include "sig-monitor.h" #include "verbose.h" -#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)) +#if defined(REMOVE_SYSTEMD_EVENT) +#include "fdev-epoll.h" #endif #define EVENT_TIMEOUT_TOP ((uint64_t)-1) #define EVENT_TIMEOUT_CHILD ((uint64_t)10000) +struct thread; + /** Internal shortcut for callback */ typedef void (*job_cb_t)(int, void*); @@ -59,31 +70,33 @@ struct job }; /** Description of handled event loops */ -struct events -{ - struct events *next; - struct sd_event *event; - uint64_t timeout; - enum { - Available, - Modifiable, - Locked - } state; +struct evloop +{ + unsigned state; /**< encoded state */ + int efd; /**< event notification */ + struct sd_event *sdev; /**< the systemd event loop */ + struct fdev *fdev; /**< handling of events */ + struct thread *holder; /**< holder of the evloop */ }; +#define EVLOOP_STATE_WAIT 1U +#define EVLOOP_STATE_RUN 2U + /** 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 */ - unsigned stop: 1; /**< stop requested */ - unsigned waits: 1; /**< is waiting? */ + volatile unsigned stop: 1; /**< stop requested */ + volatile unsigned waits: 1; /**< is waiting? */ }; /** - * Description of synchonous callback + * Description of synchronous callback */ struct sync { @@ -101,23 +114,28 @@ struct sync static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; static pthread_cond_t cond = PTHREAD_COND_INITIALIZER; -/* count allowed, started and waiting threads */ +/* count allowed, started and running threads */ static int allowed = 0; /** allowed count of threads */ static int started = 0; /** started count of threads */ -static int waiting = 0; /** waiting count of threads */ +static int running = 0; /** running count of threads */ static int remains = 0; /** allowed count of waiting jobs */ -static int nevents = 0; /** count of events */ /* list of threads */ static struct thread *threads; static _Thread_local struct thread *current_thread; -static _Thread_local struct events *current_events; /* queue of pending jobs */ static struct job *first_job; -static struct events *first_events; static struct job *free_jobs; +/* event loop */ +static struct evloop evloop; + +#if defined(REMOVE_SYSTEMD_EVENT) +static struct fdev_epoll *fdevepoll; +static int waitevt; +#endif + /** * Create a new job with the given parameters * @param group the group of the job @@ -139,12 +157,13 @@ static struct job *job_create( if (job) free_jobs = job->next; else { - /* allocation without blocking */ + /* allocation without blocking */ pthread_mutex_unlock(&mutex); job = malloc(sizeof *job); pthread_mutex_lock(&mutex); if (!job) { - errno = -ENOMEM; + ERROR("out of memory"); + errno = ENOMEM; goto end; } } @@ -185,6 +204,7 @@ static void job_add(struct job *job) /* queue the jobs */ *pjob = job; + remains--; } /** @@ -196,21 +216,11 @@ static inline struct job *job_get() struct job *job = first_job; while (job && job->blocked) job = job->next; + if (job) + remains++; return job; } -/** - * Get the next events to process or NULL if none. - * @return the first events that isn't running or NULL - */ -static inline struct events *events_get() -{ - struct events *events = first_events; - while (events && events->state != Available) - events = events->next; - return events; -} - /** * Releases the processed 'job': removes it * from the list of jobs and unblock the first @@ -262,6 +272,23 @@ 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 @@ -272,32 +299,32 @@ static void job_cancel(int signum, void *arg) * flow * @param arg the events to run */ -static void events_call(int signum, void *arg) +static void evloop_run(int signum, void *arg) { int rc; struct sd_event *se; - struct events *events = arg; if (!signum) { - se = events->event; + se = evloop.sdev; rc = sd_event_prepare(se); if (rc < 0) { errno = -rc; - ERROR("sd_event_prepare returned an error (state: %d): %m", sd_event_get_state(events->event)); + CRITICAL("sd_event_prepare returned an error (state: %d): %m", sd_event_get_state(se)); + abort(); } else { if (rc == 0) { - rc = sd_event_wait(se, events->timeout); + rc = sd_event_wait(se, (uint64_t)(int64_t)-1); if (rc < 0) { errno = -rc; - ERROR("sd_event_wait returned an error (state: %d): %m", sd_event_get_state(events->event)); + ERROR("sd_event_wait returned an error (state: %d): %m", sd_event_get_state(se)); } } - + evloop.state = EVLOOP_STATE_RUN; if (rc > 0) { rc = sd_event_dispatch(se); if (rc < 0) { errno = -rc; - ERROR("sd_event_dispatch returned an error (state: %d): %m", sd_event_get_state(events->event)); + ERROR("sd_event_dispatch returned an error (state: %d): %m", sd_event_get_state(se)); } } } @@ -305,42 +332,165 @@ static void events_call(int signum, void *arg) } /** - * 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? + * Internal callback for evloop management. + * The effect of this function is hidden: it exits + * the waiting poll if any. */ -static void thread_run(volatile struct thread *me) +static void evloop_on_efd_event() { - struct thread **prv; - struct job *job; - struct events *events; - uint64_t evto; + uint64_t x; + read(evloop.efd, &x, sizeof x); +} + +/** + * wakeup the event loop if needed by sending + * an event. + */ +static void evloop_wakeup() +{ + uint64_t x; + + if (evloop.state & EVLOOP_STATE_WAIT) { + x = 1; + write(evloop.efd, &x, sizeof x); + } +} + +/** + * Release the currently held event loop + */ +static void evloop_release() +{ + 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); + } +} + +#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 + */ +static void monitored_wait_and_dispatch(int signum, void *arg) +{ + struct fdev_epoll *fdev_epoll = arg; + if (!signum) { + fdev_epoll_wait_and_dispatch(fdev_epoll, -1); + } +} +#endif + +/** + * 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) { - evto = EVENT_TIMEOUT_CHILD; - } else { - started++; - sig_monitor_init_timeouts(); - evto = EVENT_TIMEOUT_TOP; - } 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 current event loop */ + evloop_release(); + /* get a job */ - job = job_get(first_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) */ @@ -349,53 +499,89 @@ static void thread_run(volatile struct thread *me) sig_monitor(job->timeout, job->callback, job->arg); pthread_mutex_lock(&mutex); - /* release event if any */ - events = current_events; - if (events && events->state == Modifiable) { - current_events = NULL; - events->state = Available; - } - /* release the run job */ job_release(job); - } else { - /* no job, check events */ - events = current_events; - if (!events) - events = events_get(); - else if (events->state == Locked) - events = 0; - if (events) { - /* run the events */ - events->state = Locked; - events->timeout = evto; - current_events = events; - pthread_mutex_unlock(&mutex); - sig_monitor(0, events_call, events); - pthread_mutex_lock(&mutex); - current_events = NULL; - events->state = Available; - } else { - /* no job and not events */ - waiting++; - me->waits = 1; - pthread_cond_wait(&cond, &mutex); - me->waits = 0; - waiting--; +#if !defined(REMOVE_SYSTEMD_EVENT) + /* no job, check event loop wait */ + } else if (evloop_get()) { + if (evloop.state != 0) { + /* busy ? */ + CRITICAL("Can't enter dispatch while in dispatch!"); + abort(); } + /* 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."); + me->waits = 1; + pthread_cond_wait(&cond, &mutex); + me->waits = 0; + running++; +#else + } else if (waitevt) { + /* 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++; + } 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(); +} - /* 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--; - } +/** + * 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); + + /* loop until stopped */ + me->waits = 1; + while (!me->stop) + pthread_cond_wait(&cond, &mutex); + me->waits = 0; + thread_leave(); +} + +/** + * Root for created threads. + */ +static void thread_main() +{ + struct thread me; + + running++; + started++; + sig_monitor_init_timeouts(); + thread_run_internal(&me); + sig_monitor_clean_timeouts(); + started--; + running--; } /** @@ -403,12 +589,10 @@ static void thread_run(volatile struct thread *me) * @param data not used * @return NULL */ -static void *thread_main(void *data) +static void *thread_starter(void *data) { - struct thread me; - pthread_mutex_lock(&mutex); - thread_run(&me); + thread_main(); pthread_mutex_unlock(&mutex); return NULL; } @@ -422,7 +606,7 @@ 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"); @@ -454,7 +638,6 @@ int jobs_queue( void (*callback)(int, void*), void *arg) { - const char *info; struct job *job; int rc; @@ -462,31 +645,27 @@ 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; } /* start a thread if needed */ - if (waiting == 0 && started < allowed) { + if (running == started && 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"; + ERROR("can't start initial thread: %m"); goto error2; } } /* queues the job */ - remains--; job_add(job); /* signal an existing job */ @@ -498,7 +677,6 @@ 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; } @@ -544,8 +722,6 @@ 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; } @@ -554,7 +730,10 @@ 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; } @@ -571,7 +750,7 @@ static int do_sync( * of interrupted flow, the context 'closure' as given and * a 'jobloop' reference that must be used when the job is * terminated to unlock the current execution flow. - * @param arg the argument to the callback + * @param closure the argument to the callback * @return 0 on success or -1 in case of error */ int jobs_enter( @@ -607,6 +786,8 @@ int jobs_leave(struct jobloop *jobloop) t->stop = 1; if (t->waits) pthread_cond_broadcast(&cond); + else + evloop_wakeup(); } pthread_mutex_unlock(&mutex); return -!t; @@ -640,64 +821,147 @@ int jobs_call( return do_sync(group, timeout, call_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) +{ + evloop_on_efd_event(); + return 1; +} + +/* temporary hack */ +#if !defined(REMOVE_SYSTEMD_EVENT) +__attribute__((unused)) +#endif +static void evloop_callback(void *arg, uint32_t event, struct fdev *fdev) +{ + sig_monitor(0, evloop_run, arg); +} + /** * Gets a sd_event item for the current thread. * @return a sd_event or NULL in case of error */ -struct sd_event *jobs_get_sd_event() +static struct sd_event *get_sd_event_locked() { - struct events *events; int rc; - pthread_mutex_lock(&mutex); - - /* search events on stack */ - events = current_events; - if (!events) { - /* search an available events */ - events = events_get(); - if (!events) { - /* not found, check if creation possible */ - if (nevents >= allowed) { - ERROR("not possible to add a new event"); - events = NULL; - } else { - events = malloc(sizeof *events); - if (events && (rc = sd_event_new(&events->event)) >= 0) { - if (nevents < started || start_one_thread() >= 0) { - events->state = Available; - events->next = first_events; - first_events = events; - } else { - ERROR("can't start thread for events"); - sd_event_unref(events->event); - free(events); - events = NULL; - } - } else { - if (!events) { - ERROR("out of memory"); - errno = ENOMEM; - } else { - free(events); - ERROR("creation of sd_event failed: %m"); - events = NULL; - errno = -rc; - } - } - } + /* creates the evloop on need */ + if (!evloop.sdev) { + /* start the creation */ + evloop.state = 0; + /* creates the eventfd for waking up polls */ + evloop.efd = eventfd(0, EFD_CLOEXEC|EFD_SEMAPHORE); + if (evloop.efd < 0) { + ERROR("can't make eventfd for events"); + goto error1; } - if (events) { - events->state = Modifiable; - if (!current_thread) - WARNING("event returned for unknown thread!"); - current_events = events; + /* create the systemd event loop */ + 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(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(evloop.sdev); + evloop.sdev = NULL; +error2: + close(evloop.efd); +error1: + return NULL; + } +#else + goto error3; + } + /* handle the event loop */ + evloop.fdev = fdev_epoll_add(get_fdevepoll(), sd_event_get_fd(evloop.sdev)); + if (!evloop.fdev) { + ERROR("can't create fdev"); +error3: + sd_event_unref(evloop.sdev); +error2: + close(evloop.efd); +error1: + memset(&evloop, 0, sizeof evloop); + return NULL; + } + fdev_set_autoclose(evloop.fdev, 0); + fdev_set_events(evloop.fdev, EPOLLIN); + fdev_set_callback(evloop.fdev, evloop_callback, NULL); +#endif + } + + /* acquire the event loop */ + evloop_acquire(); + + return evloop.sdev; +} + +/** + * Gets a sd_event item for the current thread. + * @return a sd_event or NULL in case of error + */ +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 events ? events->event : NULL; + + /* 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; } +#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); + + return result; +} +#endif + /** * Enter the jobs processing loop. * @param allowed_count Maximum count of thread for jobs including this one @@ -706,10 +970,9 @@ struct sd_event *jobs_get_sd_event() * @param start The start routine to activate (can't be NULL) * @return 0 in case of success or -1 in case of error. */ -int jobs_start(int allowed_count, int start_count, int waiter_count, void (*start)(int signum)) +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); @@ -727,21 +990,21 @@ int jobs_start(int allowed_count, int start_count, int waiter_count, void (*star goto error; } - /* start */ - if (sig_monitor_init() < 0) { - ERROR("failed to initialise signal handlers"); - goto error; - } - /* records the allowed count */ allowed = allowed_count; started = 0; - waiting = 0; + running = 0; remains = waiter_count; - /* start at least one thread */ - launched = 0; - while ((launched + 1) < start_count) { +#if HAS_WATCHDOG + /* set the watchdog */ + if (sd_watchdog_enabled(0, NULL)) + sd_event_set_watchdog(get_sd_event_locked(), 1); +#endif + + /* 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; @@ -750,17 +1013,13 @@ int jobs_start(int allowed_count, int start_count, int waiter_count, void (*star } /* queue the start job */ - job = job_create(NULL, 0, (job_cb_t)start, NULL); - if (!job) { - ERROR("out of memory"); - errno = ENOMEM; + job = job_create(NULL, 0, start, arg); + if (!job) goto error; - } job_add(job); - remains--; /* run until end */ - thread_run(&me); + thread_main(); rc = 0; error: pthread_mutex_unlock(&mutex);