/*
- * Copyright (C) 2016, 2017 "IoT.bzh"
+ * Copyright (C) 2015-2020 "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"
-/** control of threads */
-struct thread
+#define EVENT_TIMEOUT_TOP ((uint64_t)-1)
+#define EVENT_TIMEOUT_CHILD ((uint64_t)10000)
+
+/** Internal shortcut for callback */
+typedef void (*job_cb_t)(int, void*);
+
+/** starting mode for jobs */
+enum start_mode
{
- struct thread *next; /**< next thread of the list */
- pthread_t tid; /**< the thread id */
- unsigned stop: 1; /**< stop request */
+ Start_Default, /**< Start a thread if more than one jobs is pending */
+ Start_Urgent, /**< Always start a thread */
+ Start_Lazy /**< Never start a thread */
};
-/* describes pending job */
+/** 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 ? */
+};
+
+/** 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 */
+ 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 pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
-/* count allowed, started and running 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 */
+/* counts for threads */
+static int allowed_thread_count = 0; /** allowed count of threads */
+static int started_thread_count = 0; /** started count of threads */
+static int busy_thread_count = 0; /** count of busy threads */
/* list of threads */
static struct thread *threads;
+static _Thread_local struct thread *current_thread;
+
+/* counts for jobs */
+static int remaining_job_count = 0; /** count of job that can be created */
+static int allowed_job_count = 0; /** allowed count of pending jobs */
/* queue of pending jobs */
-static struct job *first_job;
-static struct job *first_evloop;
-static struct job *free_jobs;
+static struct job *first_pending_job;
+static struct job *first_free_job;
+
+/* event loop */
+static struct evmgr *evmgr;
+
+static void (*exit_handler)();
/**
- * Adds the 'job' at the end of the list of jobs, marking it
+ * 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 arg the argument of the callback
+ * @return the created job unblock or NULL when no more memory
+ */
+static struct job *job_create(
+ const void *group,
+ int timeout,
+ job_cb_t callback,
+ void *arg)
+{
+ struct job *job;
+
+ /* try recyle existing job */
+ job = first_free_job;
+ if (job)
+ first_free_job = job->next;
+ else {
+ /* allocation without blocking */
+ pthread_mutex_unlock(&mutex);
+ job = malloc(sizeof *job);
+ pthread_mutex_lock(&mutex);
+ if (!job) {
+ ERROR("out of memory");
+ errno = ENOMEM;
+ goto end;
+ }
+ }
+ /* initialises the job */
+ job->group = group;
+ job->timeout = timeout;
+ job->callback = callback;
+ job->arg = arg;
+ job->blocked = 0;
+ job->dropped = 0;
+end:
+ return job;
+}
+
+/**
+ * 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 job the job to add
*/
-static inline void job_add(struct job *job)
+static void job_add(struct job *job)
{
- void *group;
+ const void *group;
struct job *ijob, **pjob;
- pjob = &first_job;
- ijob = first_job;
- group = job->group ? : (void*)(intptr_t)1;
+ /* prepare to add */
+ group = job->group;
+ job->next = NULL;
+
+ /* search end and blockers */
+ pjob = &first_pending_job;
+ ijob = first_pending_job;
while (ijob) {
- if (ijob->group == group)
+ if (group && ijob->group == group)
job->blocked = 1;
pjob = &ijob->next;
ijob = ijob->next;
}
- job->next = NULL;
+
+ /* queue the jobs */
*pjob = job;
- remains--;
+ remaining_job_count--;
}
/**
* Get the next job to process or NULL if none.
- * The returned job if any is 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, **pjob;
-
- pjob = &first_job;
- job = first_job;
- while (job && job->blocked) {
- pjob = &job->next;
+ struct job *job = first_pending_job;
+ while (job && job->blocked)
job = job->next;
- }
- if (job) {
- *pjob = job->next;
- remains++;
- }
+ if (job)
+ remaining_job_count++;
return job;
}
/**
- * Unblock the first pending job of a group (if any)
- * @param group the group to unblock
+ * 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_unblock(void *group)
+static inline void job_release(struct job *job)
{
- struct job *job;
+ struct job *ijob, **pjob;
+ const void *group;
- job = first_job;
- while (job) {
- if (job->group == group) {
- job->blocked = 0;
- break;
- }
- job = job->next;
+ /* first unqueue the job */
+ pjob = &first_pending_job;
+ ijob = first_pending_job;
+ while (ijob != job) {
+ pjob = &ijob->next;
+ ijob = ijob->next;
+ }
+ *pjob = job->next;
+
+ /* then unblock jobs of the same group */
+ group = job->group;
+ if (group) {
+ ijob = job->next;
+ while (ijob && ijob->group != group)
+ ijob = ijob->next;
+ if (ijob)
+ ijob->blocked = 0;
}
+
+ /* recycle the job */
+ job->next = first_free_job;
+ first_free_job = job;
}
-static struct job *job_create(
- void *group,
- int timeout,
- void (*callback)(int, void*, void *, void*),
- void *arg1,
- void *arg2,
- void *arg3)
+/**
+ * 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;
+ struct job *job = arg;
+ job->callback(SIGABRT, job->arg);
+}
- /* allocates the job */
- job = free_jobs;
- if (job)
- free_jobs = job->next;
- else {
- pthread_mutex_unlock(&mutex);
- job = malloc(sizeof *job);
- pthread_mutex_lock(&mutex);
- if (!job) {
- errno = -ENOMEM;
- goto end;
+/**
+ * wakeup the event loop if needed by sending
+ * an event.
+ */
+static void evloop_wakeup()
+{
+ if (evmgr)
+ evmgr_wakeup(evmgr);
+}
+
+/**
+ * Release the currently held event loop
+ */
+static void evloop_release()
+{
+ 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);
}
}
- job->group = group;
- job->timeout = timeout;
- job->callback = callback;
- job->arg1 = arg1;
- job->arg2 = arg2;
- job->arg3 = arg3;
- job->blocked = 0;
-end:
- return job;
}
-static inline void job_destroy(struct job *job)
+/**
+ * get the eventloop for the current thread
+ */
+static int evloop_get()
{
- job->next = free_jobs;
- free_jobs = job;
+ return evmgr && evmgr_try_hold(evmgr, current_thread);
}
-static inline void job_release(struct job *job)
+/**
+ * acquire the eventloop for the current thread
+ */
+static void evloop_acquire()
{
- if (job->group)
- job_unblock(job->group);
- job_destroy(job);
+ 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);
+ }
}
-/** monitored call to the job */
-static void job_call(int signum, void *arg)
+/**
+ * Enter the thread
+ * @param me the description of the thread to enter
+ */
+static void thread_enter(volatile struct thread *me)
{
- struct job *job = arg;
- job->callback(signum, job->arg1, job->arg2, job->arg3);
+ evloop_release();
+ /* initialize description of itself and link it in the list */
+ me->tid = pthread_self();
+ me->stop = 0;
+ me->waits = 0;
+ me->leaved = 0;
+ me->nholder = 0;
+ me->upper = current_thread;
+ me->next = threads;
+ threads = (struct thread*)me;
+ current_thread = (struct thread*)me;
}
-/** monitored cancel of the job */
-static void job_cancel(int signum, void *arg)
+/**
+ * leave the thread
+ * @param me the description of the thread to leave
+ */
+static void thread_leave()
{
- job_call(SIGABRT, arg);
+ 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 loop of processing threads */
-static void *thread_main_loop(void *data)
+/**
+ * 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 thread me, **prv;
struct job *job;
- /* init */
- me.tid = pthread_self();
- me.stop = 0;
- sig_monitor_init_timeouts();
-
- /* chain in */
- pthread_mutex_lock(&mutex);
- me.next = threads;
- threads = &me;
+ /* enter thread */
+ thread_enter(me);
/* loop until stopped */
- running++;
- while (!me.stop) {
+ 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 */
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 */
+ busy_thread_count--;
+ if (!busy_thread_count)
+ ERROR("Entering job deep sleep! Check your bindings.");
+ me->waits = 1;
+ pthread_cond_wait(&cond, &mutex);
+ me->waits = 0;
+ busy_thread_count++;
}
}
- running--;
+ /* cleanup */
+ evloop_release();
+ thread_leave();
+}
- /* chain out */
- prv = &threads;
- while (*prv != &me)
- prv = &(*prv)->next;
- *prv = me.next;
- 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();
+}
- /* uninit and terminate */
+/**
+ * Root for created threads.
+ */
+static void thread_main()
+{
+ struct thread me;
+
+ busy_thread_count++;
+ started_thread_count++;
+ sig_monitor_init_timeouts();
+ thread_run_internal(&me);
sig_monitor_clean_timeouts();
+ started_thread_count--;
+ busy_thread_count--;
+}
+
+/**
+ * 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;
}
-/* 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_main_loop, 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;
}
-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 The start mode for threads
+ * @return 0 in case of success or -1 in case of error
+ */
+static int queue_job_internal(
+ 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)
+ void *arg,
+ enum start_mode start_mode)
{
- 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)
-{
- const char *info;
struct job *job;
- int rc;
+ int rc, busy;
- pthread_mutex_lock(&mutex);
+ /* check availability */
+ if (remaining_job_count <= 0) {
+ ERROR("can't process job with threads: too many jobs");
+ errno = EBUSY;
+ goto error;
+ }
/* 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;
- }
/* start a thread if needed */
- if (remains == 0) {
- errno = EBUSY;
- info = "too many jobs";
- goto error2;
- }
- if (started == running && started < allowed) {
+ busy = busy_thread_count == started_thread_count;
+ if (start_mode != Start_Lazy
+ && busy
+ && (start_mode == Start_Urgent || remaining_job_count + started_thread_count < allowed_job_count)
+ && started_thread_count < allowed_thread_count) {
+ /* all threads are busy and a new can be started */
rc = start_one_thread();
- if (rc < 0 && started == 0) {
- /* failed to start threading */
- info = "can't start first thread";
+ if (rc < 0 && started_thread_count == 0) {
+ ERROR("can't start initial thread: %m");
goto error2;
}
+ busy = 0;
}
/* queues the job */
job_add(job);
- pthread_mutex_unlock(&mutex);
- /* signal an existing job */
+ /* wakeup an evloop if needed */
+ if (busy)
+ evloop_wakeup();
+
pthread_cond_signal(&cond);
return 0;
error2:
- job_destroy(job);
+ job->next = first_free_job;
+ first_free_job = 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'
+ * @param start The start mode for threads
+ * @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,
+ enum start_mode start_mode)
{
- /* records the allowed count */
- allowed = allowed_count;
- started = 0;
- running = 0;
- remains = waiter_count;
+ int rc;
- /* start at least one thread */
pthread_mutex_lock(&mutex);
- while (started < start_count && start_one_thread() == 0);
+ rc = queue_job_internal(group, timeout, callback, arg, start_mode);
pthread_mutex_unlock(&mutex);
+ return rc;
- /* end */
- return -(started != start_count);
}
-/* terminate all the threads and all pending requests */
-void jobs_terminate(int wait)
+/**
+ * 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)
{
- struct job *job;
- pthread_t me, other;
- struct thread *t;
+ return queue_job(group, timeout, callback, arg, Start_Default);
+}
- /* how am i? */
- me = pthread_self();
+/**
+ * Queues lazyly 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_lazy(
+ const void *group,
+ int timeout,
+ void (*callback)(int, void*),
+ void *arg)
+{
+ return queue_job(group, timeout, callback, arg, Start_Lazy);
+}
+
+/**
+ * Queues urgently 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_urgent(
+ const void *group,
+ int timeout,
+ void (*callback)(int, void*),
+ void *arg)
+{
+ return queue_job(group, timeout, callback, arg, Start_Urgent);
+}
+
+/**
+ * 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);
+}
+
+/**
+ * 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 (*sync_cb)(int signum, void *closure),
+ struct sync *sync
+)
+{
+ int rc;
- /* request all threads to stop */
pthread_mutex_lock(&mutex);
- allowed = 0;
- for(;;) {
- /* search the next thread to stop */
- t = threads;
- while (t && pthread_equal(t->tid, me))
- t = t->next;
- if (!t)
- break;
- /* stop it */
- other = t->tid;
+
+ rc = queue_job_internal(group, timeout, sync_cb, sync, Start_Default);
+ if (rc == 0) {
+ /* run until stopped */
+ if (current_thread)
+ thread_run_internal(&sync->thread);
+ else
+ thread_run_external(&sync->thread);
+ if (!sync->thread.leaved) {
+ errno = EINTR;
+ rc = -1;
+ }
+ }
+ pthread_mutex_unlock(&mutex);
+ return rc;
+}
+
+/**
+ * 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);
+ t = threads;
+ while (t && t != (struct thread*)jobloop)
+ t = t->next;
+ if (!t) {
+ errno = EINVAL;
+ } else {
+ t->leaved = 1;
t->stop = 1;
- pthread_mutex_unlock(&mutex);
- pthread_cond_broadcast(&cond);
- pthread_join(other, NULL);
- pthread_mutex_lock(&mutex);
+ 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);
+}
+
+/**
+ * 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 = <
}
- /* cancel pending jobs */
- while (first_job) {
- job = first_job;
- first_job = job->next;
- sig_monitor(0, job_cancel, job);
- free(job);
+ /* lock */
+ pthread_mutex_lock(&mutex);
+
+ /* 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);
+
+ /* 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;
}
}
-int jobs_add_event_loop(void *key, int timeout, void (*evloop)(int signum, void*), void *closure)
+/**
+ * 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)
{
+ int rc, launched;
struct job *job;
+ assert(allowed_count >= 1);
+ assert(start_count >= 0);
+ assert(waiter_count > 0);
+ assert(start_count <= allowed_count);
+
+ rc = -1;
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);
+
+ /* check whether already running */
+ if (current_thread || allowed_thread_count) {
+ ERROR("thread already started");
+ errno = EINVAL;
+ goto error;
}
+
+ /* records the allowed count */
+ allowed_thread_count = allowed_count;
+ started_thread_count = 0;
+ busy_thread_count = 0;
+ remaining_job_count = waiter_count;
+ allowed_job_count = 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);
- return -!job;
+ if (exit_handler)
+ exit_handler();
+ return rc;
}
-int jobs_add_me()
+/**
+ * Exit jobs threads and call handler if not NULL.
+ */
+void jobs_exit(void (*handler)())
{
- pthread_t me;
struct thread *t;
- /* how am i? */
- me = pthread_self();
-
/* request all threads to stop */
pthread_mutex_lock(&mutex);
+
+ /* set the handler */
+ exit_handler = handler;
+
+ /* stops the threads */
t = threads;
while (t) {
- if (pthread_equal(t->tid, me)) {
- pthread_mutex_unlock(&mutex);
- ERROR("thread already running");
- errno = EINVAL;
- return -1;
- }
+ t->stop = 1;
t = t->next;
}
- /* allowed... */
- allowed++;
- pthread_mutex_unlock(&mutex);
-
- /* run */
- thread_main_loop(NULL);
+ /* wake up the threads */
+ evloop_wakeup();
+ pthread_cond_broadcast(&cond);
- /* returns */
- pthread_mutex_lock(&mutex);
- allowed--;
+ /* leave */
pthread_mutex_unlock(&mutex);
- return 0;
}
-
-
Code Review / src / app-framework-binder.git / blobdiff