/*
- * Copyright (C) 2016-2019 "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 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*);
+/** starting mode for jobs */
+enum start_mode
+{
+ Start_Default, /**< Start a thread if more than one jobs is pending */
+ Start_Urgent, /**< Always start a thread */
+ Start_Lazy /**< Never start a thread */
+};
+
/** Description of a pending job */
struct job
{
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; /** allowed count of waiting jobs */
+/* 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 *free_jobs;
+static struct job *first_pending_job;
+static struct job *first_free_job;
/* event loop */
static struct evmgr *evmgr;
struct job *job;
/* try recyle existing job */
- job = free_jobs;
+ job = first_free_job;
if (job)
- free_jobs = job->next;
+ first_free_job = job->next;
else {
/* allocation without blocking */
pthread_mutex_unlock(&mutex);
job->next = NULL;
/* search end and blockers */
- pjob = &first_job;
- ijob = first_job;
+ pjob = &first_pending_job;
+ ijob = first_pending_job;
while (ijob) {
if (group && ijob->group == group)
job->blocked = 1;
/* queue the jobs */
*pjob = job;
- remains--;
+ remaining_job_count--;
}
/**
*/
static inline struct job *job_get()
{
- struct job *job = first_job;
+ struct job *job = first_pending_job;
while (job && job->blocked)
job = job->next;
if (job)
- remains++;
+ remaining_job_count++;
return job;
}
const void *group;
/* first unqueue the job */
- pjob = &first_job;
- ijob = first_job;
+ pjob = &first_pending_job;
+ ijob = first_pending_job;
while (ijob != job) {
pjob = &ijob->next;
ijob = ijob->next;
}
/* recycle the job */
- job->next = free_jobs;
- free_jobs = job;
+ job->next = first_free_job;
+ first_free_job = job;
}
/**
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)
+ 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;
- running++;
+ busy_thread_count++;
}
}
/* cleanup */
{
struct thread me;
- running++;
- started++;
+ busy_thread_count++;
+ started_thread_count++;
sig_monitor_init_timeouts();
thread_run_internal(&me);
sig_monitor_clean_timeouts();
- started--;
- running--;
+ started_thread_count--;
+ busy_thread_count--;
}
/**
* 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
+ * @param start The start mode for threads
* @return 0 in case of success or -1 in case of error
*/
-static int queue_job(
+static int queue_job_internal(
const void *group,
int timeout,
void (*callback)(int, void*),
void *arg,
- int start)
+ enum start_mode start_mode)
{
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, arg);
if (!job)
goto error;
- /* check availability */
- if (remains <= 0) {
- ERROR("can't process job with threads: too many jobs");
- errno = EBUSY;
- goto error2;
- }
-
/* start a thread if needed */
- if (start && running == started && 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) {
+ if (rc < 0 && started_thread_count == 0) {
ERROR("can't start initial thread: %m");
goto error2;
}
+ busy = 0;
}
/* queues the job */
job_add(job);
- /* signal an existing job */
+ /* wakeup an evloop if needed */
+ if (busy)
+ evloop_wakeup();
+
pthread_cond_signal(&cond);
- pthread_mutex_unlock(&mutex);
return 0;
error2:
- job->next = free_jobs;
- free_jobs = job;
+ job->next = first_free_job;
+ first_free_job = job;
error:
- pthread_mutex_unlock(&mutex);
return -1;
}
+/**
+ * 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)
+{
+ int rc;
+
+ pthread_mutex_lock(&mutex);
+ rc = queue_job_internal(group, timeout, callback, arg, start_mode);
+ pthread_mutex_unlock(&mutex);
+ return rc;
+
+}
+
/**
* Queues a new asynchronous job represented by 'callback' and 'arg'
* for the 'group' and the 'timeout'.
void (*callback)(int, void*),
void *arg)
{
- return queue_job(group, timeout, callback, arg, 1);
+ return queue_job(group, timeout, callback, arg, Start_Default);
+}
+
+/**
+ * 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);
}
/**
struct sync *sync
)
{
- struct job *job;
+ int rc;
pthread_mutex_lock(&mutex);
- /* allocates the job */
- job = job_create(group, timeout, sync_cb, sync);
- if (!job) {
- pthread_mutex_unlock(&mutex);
- return -1;
+ 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;
+ }
}
-
- /* 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;
+ return rc;
}
/**
* @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 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;
pthread_mutex_lock(&mutex);
/* check whether already running */
- if (current_thread || allowed) {
+ if (current_thread || allowed_thread_count) {
ERROR("thread already started");
errno = EINVAL;
goto error;
}
/* records the allowed count */
- allowed = allowed_count;
- started = 0;
- running = 0;
- remains = waiter_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;
t = t->next;
}
- /* wait the threads */
+ /* wake up the threads */
+ evloop_wakeup();
pthread_cond_broadcast(&cond);
/* leave */