/*
- * Copyright (C) 2016, 2017 "IoT.bzh"
+ * Copyright (C) 2016-2019 "IoT.bzh"
* Author José Bollo <jose.bollo@iot.bzh>
*
* Licensed under the Apache License, Version 2.0 (the "License");
#define _GNU_SOURCE
#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 "jobs.h"
+#include "evmgr.h"
#include "sig-monitor.h"
#include "verbose.h"
+#include "systemd.h"
+
+#define EVENT_TIMEOUT_TOP ((uint64_t)-1)
+#define EVENT_TIMEOUT_CHILD ((uint64_t)10000)
+
+struct thread;
-/* describes pending job */
+/** Internal shortcut for callback */
+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 */
- 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 */
+ const void *group; /**< group of the request */
+ job_cb_t callback; /**< processing callback */
+ 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 ? */
};
-/** control of threads */
+/** Description of threads */
struct thread
{
- struct thread *next; /**< next thread of the list */
- struct thread *upper; /**< upper same thread */
- struct job *job; /**< currently processed job */
- pthread_t tid; /**< the thread id */
- unsigned stop: 1; /**< stop requested */
- unsigned lowered: 1; /**< has a lower same 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 */
+ volatile unsigned waits: 1; /**< is waiting? */
+ volatile unsigned leaved: 1; /**< was leaved? */
+};
+
+/**
+ * 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 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 remains = 0; /** allowed count of waiting jobs */
/* 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 job *first_evloop;
static struct job *free_jobs;
+/* event loop */
+static struct evmgr *evmgr;
+
+static void (*exit_handler)();
+
/**
* 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 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,
- void (*callback)(int, void*, void *, void*),
- void *arg1,
- void *arg2,
- void *arg3)
+ job_cb_t callback,
+ 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:
return job;
}
/**
- * Adds 'job1' and 'job2' at the end of the list of jobs, marking it
+ * Adds 'job' at the end of the list of jobs, marking it
* as blocked if an other job with the same group is pending.
- * @param job1 the first job to add
- * @param job2 the second job to add or NULL
+ * @param job the job to add
*/
-static void job_add2(struct job *job1, struct job *job2)
+static void job_add(struct job *job)
{
- void *group1, *group2, *group;
+ const void *group;
struct job *ijob, **pjob;
/* prepare to add */
- group1 = job1->group;
- job1->next = job2;
- if (!job2)
- group2 = NULL;
- else {
- job2->next = NULL;
- group2 = job2->group;
- if (group2 && group2 == group1)
- job2->blocked = 1;
- }
+ group = job->group;
+ job->next = NULL;
- /* search end and blackers */
+ /* search end and blockers */
pjob = &first_job;
ijob = first_job;
while (ijob) {
- group = ijob->group;
- if (group) {
- if (group == group1)
- job1->blocked = 1;
- if (group == group2)
- job2->blocked = 1;
- }
+ if (group && ijob->group == group)
+ job->blocked = 1;
pjob = &ijob->next;
ijob = ijob->next;
}
/* queue the jobs */
- *pjob = job1;
+ *pjob = job;
+ remains--;
}
/**
* 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
+ * @return the first job that isn't blocked or NULL
*/
static inline struct job *job_get()
{
- struct job *job;
-
- job = first_job;
+ struct job *job = first_job;
while (job && job->blocked)
job = job->next;
+ if (job)
+ remains++;
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)
{
struct job *ijob, **pjob;
- void *group;
+ const void *group;
/* first unqueue the job */
pjob = &first_job;
free_jobs = job;
}
-/** monitored call to the job */
-static void job_call(int signum, void *arg)
+/**
+ * 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
+ */
+__attribute__((unused))
+static void job_cancel(int signum, void *arg)
{
struct job *job = arg;
- job->callback(signum, job->arg1, job->arg2, job->arg3);
+ job->callback(SIGABRT, job->arg);
}
-/** monitored cancel of the job */
-static void job_cancel(int signum, void *arg)
+/**
+ * wakeup the event loop if needed by sending
+ * an event.
+ */
+static void evloop_wakeup()
{
- job_call(SIGABRT, arg);
+ if (evmgr)
+ evmgr_wakeup(evmgr);
}
-/* main loop of processing threads */
-static void thread_run(struct thread *me)
+/**
+ * Release the currently held event loop
+ */
+static void evloop_release()
{
- struct thread **prv;
- struct job *job;
+ struct thread *nh, *ct = current_thread;
+
+ if (ct && evmgr && evmgr_release_if(evmgr, ct)) {
+ nh = ct->nholder;
+ ct->nholder = 0;
+ if (nh) {
+ evmgr_try_hold(evmgr, nh);
+ pthread_cond_signal(nh->cwhold);
+ }
+ }
+}
- /* init */
+/**
+ * get the eventloop for the current thread
+ */
+static int evloop_get()
+{
+ return evmgr && evmgr_try_hold(evmgr, current_thread);
+}
+
+/**
+ * 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 = evmgr_holder(evmgr);
+ while (pwait->nholder)
+ pwait = pwait->nholder;
+ pwait->nholder = 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->upper = current;
- if (current)
- current->lowered = 1;
- else
- sig_monitor_init_timeouts();
- current = me;
+ me->waits = 0;
+ me->leaved = 0;
+ me->nholder = 0;
+ me->upper = current_thread;
me->next = threads;
- threads = me;
+ 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 */
- running++;
while (!me->stop) {
+ /* release the current event loop */
+ evloop_release();
+
/* 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;
- }
if (job) {
+ /* prepare running the job */
+ 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);
+ sig_monitor(job->timeout, job->callback, job->arg);
pthread_mutex_lock(&mutex);
+
+ /* release the run job */
job_release(job);
- } else {
- /* no job, check evloop */
- job = first_evloop;
- if (job) {
- /* evloop */
- first_evloop = job->next;
- pthread_mutex_unlock(&mutex);
- sig_monitor(job->timeout, job_call, job);
- pthread_mutex_lock(&mutex);
- job->next = first_evloop;
- first_evloop = job;
- } else {
- /* no job and not evloop */
- running--;
- pthread_cond_wait(&cond, &mutex);
- running++;
+ /* no job, check event loop wait */
+ } else if (evloop_get()) {
+ if (!evmgr_can_run(evmgr)) {
+ /* busy ? */
+ CRITICAL("Can't enter dispatch while in dispatch!");
+ abort();
}
+ /* run the events */
+ evmgr_prepare_run(evmgr);
+ pthread_mutex_unlock(&mutex);
+ sig_monitor(0, (void(*)(int,void*))evmgr_job_run, evmgr);
+ pthread_mutex_lock(&mutex);
+ } 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++;
}
}
- running--;
+ /* cleanup */
+ evloop_release();
+ thread_leave();
+}
- /* uninit */
- prv = &threads;
- while (*prv != me)
- prv = &(*prv)->next;
- *prv = me->next;
- current = me->upper;
- if (current)
- current->lowered = 0;
- else
- sig_monitor_clean_timeouts();
- pthread_mutex_unlock(&mutex);
+/**
+ * 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();
}
-/* main loop of processing threads */
-static void *thread_create(void *data)
+/**
+ * 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--;
+}
+
+/**
+ * Entry point for created threads.
+ * @param data not used
+ * @return NULL
+ */
+static void *thread_starter(void *data)
+{
pthread_mutex_lock(&mutex);
- thread_run(&me);
+ thread_main();
pthread_mutex_unlock(&mutex);
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_starter, 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;
-}
-
-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);
-}
-
-int jobs_queue(
- void *group,
+/**
+ * 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
+ * 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 arg The second argument for 'callback'
+ * @param start Allow to start a thread if not zero
+ * @return 0 in case of success or -1 in case of error
+ */
+static int queue_job(
+ const void *group,
int timeout,
void (*callback)(int, void*),
- void *arg)
-{
- return jobs_queue3(group, timeout, (void(*)(int,void*,void*,void*))callback, arg, NULL, NULL);
-}
-
-int jobs_queue2(
- void *group,
- int timeout,
- void (*callback)(int, void*, void*),
- void *arg1,
- void *arg2)
-{
- return jobs_queue3(group, timeout, (void(*)(int,void*,void*,void*))callback, arg1, arg2, NULL);
-}
-
-/* queue the job to the 'callback' using a separate thread if available */
-int jobs_queue3(
- void *group,
- int timeout,
- void (*callback)(int, void*, void *, void*),
- void *arg1,
- void *arg2,
- void *arg3)
+ void *arg,
+ int start)
{
- 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 */
- rc = start_one_thread_if_needed();
- if (rc < 0) {
- /* failed to start threading */
- info = "can't start first thread";
- goto error2;
+ if (start && running == started && started < allowed) {
+ /* all threads are busy and a new can be started */
+ rc = start_one_thread();
+ if (rc < 0 && started == 0) {
+ ERROR("can't start initial thread: %m");
+ goto error2;
+ }
}
/* queues the job */
- remains--;
- job_add2(job, NULL);
- pthread_mutex_unlock(&mutex);
+ job_add(job);
/* signal an existing job */
pthread_cond_signal(&cond);
+ pthread_mutex_unlock(&mutex);
return 0;
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;
}
-/* initialise the threads */
-int jobs_init(int allowed_count, int start_count, int waiter_count)
+/**
+ * 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
+ * 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 arg The second argument for 'callback'
+ * @return 0 in case of success or -1 in case of error
+ */
+int jobs_queue(
+ const void *group,
+ int timeout,
+ void (*callback)(int, void*),
+ void *arg)
{
- /* 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);
+ return queue_job(group, timeout, callback, arg, 1);
+}
- /* end */
- return -(started != start_count);
+/**
+ * Internal helper function for 'jobs_enter'.
+ * @see jobs_enter, jobs_leave
+ */
+static void enter_cb(int signum, void *closure)
+{
+ struct sync *sync = closure;
+ sync->enter(signum, sync->arg, (void*)&sync->thread);
}
-int jobs_invoke0(
- int timeout,
- void (*callback)(int signum))
+/**
+ * Internal helper function for 'jobs_call'.
+ * @see jobs_call
+ */
+static void call_cb(int signum, void *closure)
{
- return jobs_invoke3(timeout, (void(*)(int,void*,void*,void*))callback, NULL, NULL, NULL);
+ struct sync *sync = closure;
+ sync->callback(signum, sync->arg);
+ jobs_leave((void*)&sync->thread);
}
-int jobs_invoke(
+/**
+ * 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, void*),
- void *arg)
+ void (*sync_cb)(int signum, void *closure),
+ struct sync *sync
+)
{
- return jobs_invoke3(timeout, (void(*)(int,void*,void*,void*))callback, arg, NULL, NULL);
+ struct job *job;
+
+ pthread_mutex_lock(&mutex);
+
+ /* allocates the job */
+ job = job_create(group, timeout, sync_cb, sync);
+ if (!job) {
+ pthread_mutex_unlock(&mutex);
+ return -1;
+ }
+
+ /* queues the job */
+ job_add(job);
+
+ /* run until stopped */
+ if (current_thread)
+ thread_run_internal(&sync->thread);
+ else
+ thread_run_external(&sync->thread);
+ pthread_mutex_unlock(&mutex);
+ if (sync->thread.leaved)
+ return 0;
+ errno = EINTR;
+ return -1;
}
-int jobs_invoke2(
+/**
+ * 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, void*, void*),
- void *arg1,
- void *arg2)
+ void (*callback)(int signum, void *closure, struct jobloop *jobloop),
+ void *closure
+)
{
- return jobs_invoke3(timeout, (void(*)(int,void*,void*,void*))callback, arg1, arg2, NULL);
+ struct sync sync;
+
+ sync.enter = callback;
+ sync.arg = closure;
+ return do_sync(group, timeout, enter_cb, &sync);
}
-static void unlock_invoker(int signum, void *arg1, void *arg2, void *arg3)
+/**
+ * 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 = arg1;
+ struct thread *t;
+
pthread_mutex_lock(&mutex);
- t->stop = 1;
+ t = threads;
+ while (t && t != (struct thread*)jobloop)
+ t = t->next;
+ if (!t) {
+ errno = EINVAL;
+ } else {
+ t->leaved = 1;
+ t->stop = 1;
+ if (t->waits)
+ pthread_cond_broadcast(&cond);
+ else
+ evloop_wakeup();
+ }
pthread_mutex_unlock(&mutex);
+ return -!t;
}
-/* invoke the job to the 'callback' using a separate thread if available */
-int jobs_invoke3(
+/**
+ * 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 *, void*),
- void *arg1,
- void *arg2,
- void *arg3)
+ void (*callback)(int, void*),
+ void *arg)
{
- const char *info;
- struct job *job1, *job2;
- int rc;
- struct thread me;
-
- pthread_mutex_lock(&mutex);
+ struct sync sync;
- /* allocates the job */
- job1 = job_create(&me, timeout, callback, arg1, arg2, arg3);
- job2 = job_create(&me, 0, unlock_invoker, &me, NULL, NULL);
- if (!job1 || !job2) {
- errno = ENOMEM;
- info = "out of memory";
- goto error;
- }
+ sync.callback = callback;
+ sync.arg = arg;
- /* 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;
+ return do_sync(group, timeout, call_cb, &sync);
+}
+
+/**
+ * Ensure that the current running thread can control the event loop.
+ */
+void jobs_acquire_event_manager()
+{
+ struct thread lt;
+
+ /* ensure an existing thread environment */
+ if (!current_thread) {
+ memset(<, 0, sizeof lt);
+ current_thread = <
}
- /* queues the job */
- job_add2(job1, job2);
+ /* lock */
+ pthread_mutex_lock(&mutex);
- /* run untill stopped */
- thread_run(&me);
+ /* creates the evloop on need */
+ if (!evmgr)
+ evmgr_create(&evmgr);
+
+ /* acquire the event loop under lock */
+ if (evmgr)
+ evloop_acquire();
+
+ /* unlock */
pthread_mutex_unlock(&mutex);
- return 0;
-error:
- if (job1) {
- job1->next = free_jobs;
- free_jobs = job1;
+ /* 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 event manager/loop from outside of binder's callback is hazardous!");
+ if (verbose_wants(Log_Level_Info))
+ sig_monitor_dumpstack();
+ evloop_release();
+ current_thread = NULL;
}
- if (job2) {
- job2->next = free_jobs;
- free_jobs = job2;
- }
- ERROR("can't process job with threads: %s, %m", info);
- pthread_mutex_unlock(&mutex);
- return -1;
}
-/* terminate all the threads and all pending requests */
-void jobs_terminate()
+/**
+ * Enter the jobs processing loop.
+ * @param allowed_count Maximum count of thread for jobs including this one
+ * @param start_count Count of thread to start now, must be lower.
+ * @param waiter_count Maximum count of jobs that can be waiting.
+ * @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, void* arg), void *arg)
{
- struct job *job, *head, *tail;
- pthread_t me, other;
- struct thread *t;
+ int rc, launched;
+ struct job *job;
- /* how am i? */
- me = pthread_self();
+ assert(allowed_count >= 1);
+ assert(start_count >= 0);
+ assert(waiter_count > 0);
+ assert(start_count <= allowed_count);
- /* request all threads to stop */
+ rc = -1;
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;
- t->stop = 1;
- pthread_mutex_unlock(&mutex);
- pthread_cond_broadcast(&cond);
- pthread_join(other, NULL);
- pthread_mutex_lock(&mutex);
+
+ /* check whether already running */
+ if (current_thread || allowed) {
+ ERROR("thread already started");
+ errno = EINVAL;
+ goto error;
}
- /* cancel pending jobs of other threads */
- head = first_job;
- first_job = NULL;
- tail = NULL;
- while (head) {
- /* unlink the job */
- job = head;
- head = job->next;
-
- /* search if job is stacked for current */
- t = current;
- while (t && t->job != job)
- t = t->upper;
- if (t) {
- /* yes, relink it at end */
- if (tail)
- tail->next = job;
- else
- first_job = job;
- tail = job;
- job->next = NULL;
- } else {
- /* no cancel the job */
- pthread_mutex_unlock(&mutex);
- sig_monitor(0, job_cancel, job);
- free(job);
- pthread_mutex_lock(&mutex);
+ /* records the allowed count */
+ allowed = allowed_count;
+ started = 0;
+ running = 0;
+ remains = waiter_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;
}
+ launched++;
}
+
+ /* queue the start job */
+ job = job_create(NULL, 0, start, arg);
+ if (!job)
+ goto error;
+ job_add(job);
+
+ /* run until end */
+ thread_main();
+ rc = 0;
+error:
pthread_mutex_unlock(&mutex);
+ if (exit_handler)
+ exit_handler();
+ return rc;
}
-int jobs_add_event_loop(void *key, int timeout, void (*evloop)(int signum, void*), void *closure)
+/**
+ * Exit jobs threads and call handler if not NULL.
+ */
+void jobs_exit(void (*handler)())
{
- struct job *job;
+ struct thread *t;
+ /* request all threads to stop */
pthread_mutex_lock(&mutex);
- job = job_create(key, timeout, (void (*)(int, void *, void *, void *))evloop, closure, NULL, NULL);
- if (job) {
- /* adds the loop */
- job->next = first_evloop;
- first_evloop = job;
-
- /* signal the loop */
- pthread_cond_signal(&cond);
- }
- pthread_mutex_unlock(&mutex);
- return -!job;
-}
-int jobs_add_me()
-{
- struct thread me;
+ /* set the handler */
+ exit_handler = handler;
- /* check whether already running */
- if (current) {
- ERROR("thread already running");
- errno = EINVAL;
- return -1;
+ /* stops the threads */
+ t = threads;
+ while (t) {
+ t->stop = 1;
+ t = t->next;
}
- /* allowed... */
- pthread_mutex_lock(&mutex);
- allowed++;
- thread_run(&me);
- allowed--;
+ /* wait the threads */
+ pthread_cond_broadcast(&cond);
+
+ /* leave */
pthread_mutex_unlock(&mutex);
- return 0;
}
-
-