/*
- * Copyright (C) 2016, 2017, 2018 "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
-#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 <sys/eventfd.h>
#include <systemd/sd-event.h>
-#include "fdev.h"
-#if HAS_WATCHDOG
-#include <systemd/sd-daemon.h>
-#endif
#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;
-
/** 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
{
unsigned dropped: 1; /**< is removed ? */
};
-/** Description of handled event loops */
-struct evloop
-{
- unsigned state; /**< encoded state */
- int efd; /**< event notification */
- struct sd_event *sdev; /**< the systemd event loop */
- struct fdev *fdev; /**< handling of events */
- struct thread *holder; /**< holder of the evloop */
-};
-
-#define EVLOOP_STATE_WAIT 1U
-#define EVLOOP_STATE_RUN 2U
-
/** Description of threads */
struct thread
{
pthread_t tid; /**< the thread id */
volatile unsigned stop: 1; /**< stop requested */
volatile unsigned waits: 1; /**< is waiting? */
+ volatile unsigned leaved: 1; /**< was leaved? */
};
/**
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; /** 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 evloop evloop;
+static struct evmgr *evmgr;
+
+static void (*exit_handler)();
/**
* Create a new job with the given parameters
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;
}
/**
* 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(SIGABRT, job->arg);
}
-/**
- * Monitored normal callback for events.
- * This function is called by the monitor
- * to run the event loop 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 events to run
- */
-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()
-{
- uint64_t x;
- read(evloop.efd, &x, sizeof x);
-}
-
/**
* wakeup the event loop if needed by sending
* an event.
*/
static void evloop_wakeup()
{
- uint64_t x;
-
- if (evloop.state & EVLOOP_STATE_WAIT) {
- x = 1;
- write(evloop.efd, &x, sizeof x);
- }
+ if (evmgr)
+ evmgr_wakeup(evmgr);
}
/**
{
struct thread *nh, *ct = current_thread;
- if (evloop.holder == ct) {
+ if (ct && evmgr && evmgr_release_if(evmgr, ct)) {
nh = ct->nholder;
- evloop.holder = nh;
- if (nh)
+ ct->nholder = 0;
+ if (nh) {
+ evmgr_try_hold(evmgr, nh);
pthread_cond_signal(nh->cwhold);
+ }
}
}
*/
static int evloop_get()
{
- struct thread *ct = current_thread;
-
- if (evloop.holder)
- return evloop.holder == ct;
-
- ct->nholder = NULL;
- evloop.holder = ct;
- return 1;
+ return evmgr && evmgr_try_hold(evmgr, current_thread);
}
/**
*/
static void evloop_acquire()
{
- struct thread **pwait, *ct;
+ struct thread *pwait, *ct;
pthread_cond_t cond;
/* try to get the evloop */
pthread_cond_init(&cond, NULL);
/* queue current thread in holder list */
- pwait = &evloop.holder;
- while (*pwait)
- pwait = &(*pwait)->nholder;
- *pwait = ct;
+ pwait = evmgr_holder(evmgr);
+ while (pwait->nholder)
+ pwait = pwait->nholder;
+ pwait->nholder = ct;
/* wake up the evloop */
evloop_wakeup();
*/
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->waits = 0;
+ me->leaved = 0;
+ me->nholder = 0;
me->upper = current_thread;
me->next = threads;
threads = (struct thread*)me;
job_release(job);
/* no job, check event loop wait */
} else if (evloop_get()) {
- if (evloop.state != 0) {
+ if (!evmgr_can_run(evmgr)) {
/* busy ? */
CRITICAL("Can't enter dispatch while in dispatch!");
abort();
}
/* run the events */
- evloop.state = EVLOOP_STATE_RUN|EVLOOP_STATE_WAIT;
+ evmgr_prepare_run(evmgr);
pthread_mutex_unlock(&mutex);
- sig_monitor(0, evloop_run, NULL);
+ sig_monitor(0, (void(*)(int,void*))evmgr_job_run, evmgr);
pthread_mutex_lock(&mutex);
- evloop.state = 0;
} 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 The start mode for threads
* @return 0 in case of success or -1 in case of error
*/
-int jobs_queue(
+static int queue_job_internal(
const void *group,
int timeout,
void (*callback)(int, void*),
- void *arg)
+ void *arg,
+ 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 (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'.
+ * 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)
+{
+ 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);
+}
+
/**
* Internal helper function for 'jobs_enter'.
* @see jobs_enter, jobs_leave
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);
- return 0;
+ return rc;
}
/**
if (!t) {
errno = EINVAL;
} else {
+ t->leaved = 1;
t->stop = 1;
if (t->waits)
pthread_cond_broadcast(&cond);
}
/**
- * 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.
+ * Ensure that the current running thread can control the event loop.
*/
-static int on_evloop_efd(sd_event_source *s, int fd, uint32_t revents, void *userdata)
+void jobs_acquire_event_manager()
{
- 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
- */
-static struct sd_event *get_sd_event_locked()
-{
- int 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;
- }
- /* 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 */
current_thread = <
}
- /* process */
+ /* lock */
pthread_mutex_lock(&mutex);
- result = get_sd_event_locked();
+
+ /* 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 */
* 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!");
+ 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;
}
-
- 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 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;
-
-#if HAS_WATCHDOG
- /* set the watchdog */
- if (sd_watchdog_enabled(0, NULL))
- sd_event_set_watchdog(get_sd_event_locked(), 1);
-#endif
+ 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;
rc = 0;
error:
pthread_mutex_unlock(&mutex);
+ if (exit_handler)
+ exit_handler();
return rc;
}
/**
- * Terminate all the threads and cancel all pending jobs.
+ * Exit jobs threads and call handler if not NULL.
*/
-void jobs_terminate()
+void jobs_exit(void (*handler)())
{
- struct job *job, *head, *tail;
- pthread_t me, *others;
struct thread *t;
- int count;
-
- /* how am i? */
- me = pthread_self();
/* request all threads to stop */
pthread_mutex_lock(&mutex);
- allowed = 0;
-
- /* count the number of threads */
- count = 0;
- t = threads;
- while (t) {
- if (!t->upper && !pthread_equal(t->tid, me))
- count++;
- t = t->next;
- }
- /* fill the array of threads */
- others = alloca(count * sizeof *others);
- count = 0;
- t = threads;
- while (t) {
- if (!t->upper && !pthread_equal(t->tid, me))
- others[count++] = t->tid;
- t = t->next;
- }
+ /* set the handler */
+ exit_handler = handler;
/* stops the threads */
t = threads;
t = t->next;
}
- /* wait the threads */
+ /* wake up the threads */
+ evloop_wakeup();
pthread_cond_broadcast(&cond);
- pthread_mutex_unlock(&mutex);
- while (count)
- pthread_join(others[--count], NULL);
- pthread_mutex_lock(&mutex);
- /* cancel pending jobs of other threads */
- remains = 0;
- 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_thread;
- 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);
- }
- }
+ /* leave */
pthread_mutex_unlock(&mutex);
}
-
Code Review / src / app-framework-binder.git / blobdiff