/*
- * Copyright (C) 2016, 2017 "IoT.bzh"
+ * Copyright (C) 2016, 2017, 2018 "IoT.bzh"
* Author José Bollo <jose.bollo@iot.bzh>
*
* Licensed under the Apache License, Version 2.0 (the "License");
#define _GNU_SOURCE
+#if defined(NO_JOBS_WATCHDOG)
+# define HAS_WATCHDOG 0
+#else
+# define HAS_WATCHDOG 1
+#endif
+
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <signal.h>
+#include <string.h>
#include <time.h>
#include <sys/syscall.h>
#include <pthread.h>
#include <errno.h>
#include <assert.h>
+#include <sys/eventfd.h>
#include <systemd/sd-event.h>
+#include "fdev.h"
+#if HAS_WATCHDOG
+#include <systemd/sd-daemon.h>
+#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))
-#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*, void *, void*);
+typedef void (*job_cb_t)(int, void*);
/** Description of a pending job */
struct job
{
struct job *next; /**< link to the next job enqueued */
- void *group; /**< group of the request */
+ const void *group; /**< group of the request */
job_cb_t callback; /**< processing callback */
- void *arg1; /**< first arg */
- void *arg2; /**< second arg */
- void *arg3; /**< third arg */
+ void *arg; /**< argument */
int timeout; /**< timeout in second for processing the request */
unsigned blocked: 1; /**< is an other request blocking this one ? */
unsigned dropped: 1; /**< is removed ? */
};
/** Description of handled event loops */
-struct events
+struct evloop
{
- struct events *next;
- struct sd_event *event;
- uint64_t timeout;
- unsigned runs: 1;
+ 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 */
- struct events *events; /**< currently processed job */
pthread_t tid; /**< the thread id */
- unsigned stop: 1; /**< stop requested */
- unsigned lowered: 1; /**< has a lower same thread */
- unsigned waits: 1; /**< is waiting? */
+ volatile unsigned stop: 1; /**< stop requested */
+ volatile unsigned waits: 1; /**< is waiting? */
+};
+
+/**
+ * Description of synchronous callback
+ */
+struct sync
+{
+ struct thread thread; /**< thread loop data */
+ union {
+ void (*callback)(int, void*); /**< the synchronous callback */
+ void (*enter)(int signum, void *closure, struct jobloop *jobloop);
+ /**< the entering synchronous routine */
+ };
+ void *arg; /**< the argument of the callback */
};
+
/* synchronisation of threads */
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;
+static _Thread_local struct thread *current_thread;
/* 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;
+
/**
* 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 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 arg the argument of the callback
* @return the created job unblock or NULL when no more memory
*/
static struct job *job_create(
- void *group,
+ const void *group,
int timeout,
job_cb_t callback,
- void *arg1,
- void *arg2,
- void *arg3)
+ void *arg)
{
struct job *job;
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;
}
}
job->group = group;
job->timeout = timeout;
job->callback = callback;
- job->arg1 = arg1;
- job->arg2 = arg2;
- job->arg3 = arg3;
+ job->arg = arg;
job->blocked = 0;
job->dropped = 0;
end:
*/
static void job_add(struct job *job)
{
- void *group;
+ const void *group;
struct job *ijob, **pjob;
/* prepare to add */
/* queue the jobs */
*pjob = job;
+ remains--;
}
/**
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->runs)
- events = events->next;
- return events;
-}
-
/**
* Releases the processed 'job': removes it
* from the list of jobs and unblock the first
static inline void job_release(struct job *job)
{
struct job *ijob, **pjob;
- void *group;
+ const void *group;
/* first unqueue the job */
pjob = &first_job;
free_jobs = 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 callback for a job.
* This function is called by the monitor
*/
static void job_cancel(int signum, void *arg)
{
- job_call(SIGABRT, arg);
+ struct job *job = arg;
+ job->callback(SIGABRT, job->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;
+
+ if (!signum) {
+ se = evloop.sdev;
+ rc = sd_event_prepare(se);
+ if (rc < 0) {
+ errno = -rc;
+ 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, (uint64_t)(int64_t)-1);
+ if (rc < 0) {
+ errno = -rc;
+ 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(se));
+ }
+ }
+ }
+ }
+}
+
+/**
+ * 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()
{
- struct events *events = arg;
- if (!signum)
- sd_event_run(events->event, events->timeout);
+ uint64_t x;
+ read(evloop.efd, &x, sizeof x);
}
/**
- * 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?
+ * wakeup the event loop if needed by sending
+ * an event.
*/
-static void thread_run(volatile struct thread *me)
+static void evloop_wakeup()
{
- struct thread **prv;
- struct job *job;
- struct events *events;
- uint64_t evto;
+ 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 (ct && 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;
+
+ if (!evloop.sdev)
+ return 0;
+
+ 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)
+{
+ evloop_release();
/* 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;
- evto = EVENT_TIMEOUT_CHILD;
- } else {
- started++;
- sig_monitor_init_timeouts();
- evto = EVENT_TIMEOUT_TOP;
- }
+ me->upper = current_thread;
me->next = threads;
threads = (struct thread*)me;
- current = (struct thread*)me;
+ current_thread = (struct thread*)me;
+}
- NOTICE("job thread starting %d(/%d) %s", started, allowed, me->upper ? "child" : "parent");
+/**
+ * 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 */
- me->events = NULL;
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) */
/* run the job */
pthread_mutex_unlock(&mutex);
- sig_monitor(job->timeout, job_call, job);
+ sig_monitor(job->timeout, job->callback, job->arg);
pthread_mutex_lock(&mutex);
/* release the run job */
job_release(job);
-
- /* release event if any */
- events = me->events;
- if (events) {
- events->runs = 0;
- me->events = NULL;
+ /* 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, check events */
- events = events_get();
- if (events) {
- /* run the events */
- events->runs = 1;
- events->timeout = evto;
- me->events = events;
- pthread_mutex_unlock(&mutex);
- sig_monitor(0, events_call, events);
- pthread_mutex_lock(&mutex);
- events->runs = 0;
- me->events = NULL;
- } else {
- /* no job and not events */
- waiting++;
- me->waits = 1;
- pthread_cond_wait(&cond, &mutex);
- me->waits = 0;
- waiting--;
- }
+ /* 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++;
}
}
- NOTICE("job thread stoping %d(/%d) %s", started, allowed, me->upper ? "child" : "parent");
+ /* cleanup */
+ evloop_release();
+ thread_leave();
+}
- /* unlink the current thread and cleanup */
- prv = &threads;
- while (*prv != me)
- prv = &(*prv)->next;
- *prv = me->next;
- current = me->upper;
- if (current) {
- current->lowered = 0;
- } else {
- 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--;
}
/**
* @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;
}
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");
}
/**
- * 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, (job_cb_t)callback, NULL, NULL, NULL);
-}
-
-/**
- * Queues a new asynchronous job represented by 'callback' and 'arg1'
+ * Queues a new asynchronous job represented by 'callback' and 'arg'
* 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
* 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'
+ * @param arg The second argument for 'callback'
* @return 0 in case of success or -1 in case of error
*/
int jobs_queue(
- void *group,
+ const void *group,
int timeout,
void (*callback)(int, void*),
void *arg)
{
- 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,
- void (*callback)(int, void*, void*),
- void *arg1,
- void *arg2)
-{
- return jobs_queue3(group, timeout, (job_cb_t)callback, arg1, arg2, NULL);
-}
-
-/**
- * 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,
- void (*callback)(int, void*, void *, void*),
- void *arg1,
- void *arg2,
- void *arg3)
-{
- const char *info;
struct job *job;
int rc;
pthread_mutex_lock(&mutex);
/* allocates the job */
- job = job_create(group, timeout, callback, arg1, arg2, arg3);
- if (!job) {
- errno = ENOMEM;
- info = "out of memory";
+ job = job_create(group, timeout, callback, arg);
+ 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 */
job->next = free_jobs;
free_jobs = job;
error:
- ERROR("can't process job with threads: %s, %m", info);
pthread_mutex_unlock(&mutex);
return -1;
}
/**
- * Enter a synchronisation point: activates the job given by 'callback'
- * @param group the gro
+ * Internal helper function for 'jobs_enter'.
+ * @see jobs_enter, jobs_leave
*/
-int jobs_enter(
- void *group,
+static void enter_cb(int signum, void *closure)
+{
+ struct sync *sync = closure;
+ sync->enter(signum, sync->arg, (void*)&sync->thread);
+}
+
+/**
+ * Internal helper function for 'jobs_call'.
+ * @see jobs_call
+ */
+static void call_cb(int signum, void *closure)
+{
+ struct sync *sync = closure;
+ sync->callback(signum, sync->arg);
+ jobs_leave((void*)&sync->thread);
+}
+
+/**
+ * Internal helper for synchronous jobs. It enters
+ * a new thread loop for evaluating the given job
+ * as recorded by the couple 'sync_cb' and 'sync'.
+ * @see jobs_call, jobs_enter, jobs_leave
+ */
+static int do_sync(
+ const void *group,
int timeout,
- void (*callback)(int signum, void *closure, struct jobloop *jobloop),
- void *closure)
+ void (*sync_cb)(int signum, void *closure),
+ struct sync *sync
+)
{
-
struct job *job;
- struct thread me;
pthread_mutex_lock(&mutex);
/* allocates the job */
- job = job_create(group, timeout, (job_cb_t)callback, closure, &me, NULL);
+ job = job_create(group, timeout, sync_cb, sync);
if (!job) {
- ERROR("out of memory");
- errno = ENOMEM;
pthread_mutex_unlock(&mutex);
return -1;
}
job_add(job);
/* run until stopped */
- thread_run(&me);
+ if (current_thread)
+ thread_run_internal(&sync->thread);
+ else
+ thread_run_external(&sync->thread);
pthread_mutex_unlock(&mutex);
return 0;
}
+/**
+ * Enter a synchronisation point: activates the job given by 'callback'
+ * and 'closure' using 'group' and 'timeout' to control sequencing and
+ * execution time.
+ * @param group the group for sequencing jobs
+ * @param timeout the time in seconds allocated to the job
+ * @param callback the callback that will handle the job.
+ * it receives 3 parameters: 'signum' that will be 0
+ * on normal flow or the catched signal number in case
+ * 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 closure the argument to the callback
+ * @return 0 on success or -1 in case of error
+ */
+int jobs_enter(
+ const void *group,
+ int timeout,
+ void (*callback)(int signum, void *closure, struct jobloop *jobloop),
+ void *closure
+)
+{
+ struct sync sync;
+
+ sync.enter = callback;
+ sync.arg = closure;
+ return do_sync(group, timeout, enter_cb, &sync);
+}
+
+/**
+ * Unlocks the execution flow designed by 'jobloop'.
+ * @param jobloop indication of the flow to unlock
+ * @return 0 in case of success of -1 on error
+ */
int jobs_leave(struct jobloop *jobloop)
{
struct thread *t;
- pthread_mutex_lock(&mutex);
+ pthread_mutex_lock(&mutex);
t = threads;
while (t && t != (struct thread*)jobloop)
t = t->next;
t->stop = 1;
if (t->waits)
pthread_cond_broadcast(&cond);
+ else
+ evloop_wakeup();
}
pthread_mutex_unlock(&mutex);
return -!t;
}
+/**
+ * Calls synchronously the job represented by 'callback' and 'arg1'
+ * for the 'group' and the 'timeout' and waits for its completion.
+ * @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 arg The second argument for 'callback'
+ * @return 0 in case of success or -1 in case of error
+ */
+int jobs_call(
+ const void *group,
+ int timeout,
+ void (*callback)(int, void*),
+ void *arg)
+{
+ struct sync sync;
+
+ sync.callback = callback;
+ sync.arg = arg;
+
+ 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;
+}
+
/**
* 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;
- struct thread *me;
int rc;
- pthread_mutex_lock(&mutex);
-
- /* search events on stack */
- me = current;
- while (me && !me->events)
- me = me->upper;
- if (me)
- /* return the stacked events */
- events = me->events;
- else {
- /* 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->runs = 0;
- 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) {
- /* */
- me = current;
- if (me) {
- events->runs = 1;
- me->events = events;
- } else {
- WARNING("event returned for unknown thread!");
- }
+ /* 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");
+ sd_event_unref(evloop.sdev);
+ evloop.sdev = NULL;
+error2:
+ close(evloop.efd);
+error1:
+ return NULL;
}
}
+
+ /* 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;
}
/**
* @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 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);
pthread_mutex_lock(&mutex);
/* check whether already running */
- if (current || allowed) {
+ if (current_thread || allowed) {
ERROR("thread already started");
errno = EINVAL;
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;
}
/* queue the start job */
- job = job_create(NULL, 0, (job_cb_t)start, NULL, NULL, 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);
head = job->next;
/* search if job is stacked for current */
- t = current;
+ t = current_thread;
while (t && t->job != job)
t = t->upper;
if (t) {
Code Review / src / app-framework-binder.git / blobdiff