#include <stdint.h>
#include <unistd.h>
#include <signal.h>
+#include <string.h>
#include <time.h>
#include <sys/syscall.h>
#include <pthread.h>
#include <sys/eventfd.h>
#include <systemd/sd-event.h>
+#include "fdev.h"
#if HAS_WATCHDOG
#include <systemd/sd-daemon.h>
#endif
#include "sig-monitor.h"
#include "verbose.h"
-#if 0
-#define _alert_ "do you really want to remove signal monitoring?"
-#define sig_monitor_init_timeouts() ((void)0)
-#define sig_monitor_clean_timeouts() ((void)0)
-#define sig_monitor(to,cb,arg) (cb(0,arg))
+#if defined(REMOVE_SYSTEMD_EVENT)
+#include "fdev-epoll.h"
#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*);
unsigned state; /**< encoded state */
int efd; /**< event notification */
struct sd_event *sdev; /**< the systemd event loop */
- pthread_cond_t cond; /**< condition */
+ struct fdev *fdev; /**< handling of events */
+ struct thread *holder; /**< holder of the evloop */
};
#define EVLOOP_STATE_WAIT 1U
#define EVLOOP_STATE_RUN 2U
-#define EVLOOP_STATE_LOCK 4U
/** 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 */
- unsigned stop: 1; /**< stop requested */
- unsigned waits: 1; /**< is waiting? */
+ volatile unsigned stop: 1; /**< stop requested */
+ volatile unsigned waits: 1; /**< is waiting? */
};
/**
- * Description of synchonous callback
+ * Description of synchronous callback
*/
struct sync
{
/* list of threads */
static struct thread *threads;
static _Thread_local struct thread *current_thread;
-static _Thread_local struct evloop *current_evloop;
/* queue of pending jobs */
static struct job *first_job;
static struct job *free_jobs;
/* event loop */
-static struct evloop evloop[1];
+static struct evloop evloop;
+
+#if defined(REMOVE_SYSTEMD_EVENT)
+static struct fdev_epoll *fdevepoll;
+static int waitevt;
+#endif
/**
* Create a new job with the given parameters
job = malloc(sizeof *job);
pthread_mutex_lock(&mutex);
if (!job) {
- errno = -ENOMEM;
+ errno = ENOMEM;
goto end;
}
}
job->callback(SIGABRT, job->arg);
}
+#if defined(REMOVE_SYSTEMD_EVENT)
+/**
+ * Gets a fdev_epoll item.
+ * @return a fdev_epoll or NULL in case of error
+ */
+static struct fdev_epoll *get_fdevepoll()
+{
+ struct fdev_epoll *result;
+
+ result = fdevepoll;
+ if (!result)
+ result = fdevepoll = fdev_epoll_create();
+
+ return result;
+}
+#endif
+
/**
* Monitored normal callback for events.
* This function is called by the monitor
{
int rc;
struct sd_event *se;
- struct evloop *el = arg;
if (!signum) {
- se = el->sdev;
+ se = evloop.sdev;
rc = sd_event_prepare(se);
if (rc < 0) {
errno = -rc;
- ERROR("sd_event_prepare returned an error (state: %d): %m", sd_event_get_state(se));
+ 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);
ERROR("sd_event_wait returned an error (state: %d): %m", sd_event_get_state(se));
}
}
- __atomic_and_fetch(&el->state, ~(EVLOOP_STATE_WAIT), __ATOMIC_RELAXED);
-
+ evloop.state = EVLOOP_STATE_RUN;
if (rc > 0) {
rc = sd_event_dispatch(se);
if (rc < 0) {
}
}
}
- __atomic_and_fetch(&el->state, ~(EVLOOP_STATE_WAIT|EVLOOP_STATE_RUN), __ATOMIC_RELAXED);
}
+/**
+ * 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);
+ }
+}
+
+/**
+ * Release the currently held event loop
+ */
+static void evloop_release()
+{
+ struct thread *nh, *ct = current_thread;
+
+ if (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;
+
+ 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);
+ }
+}
+
+#if defined(REMOVE_SYSTEMD_EVENT)
+/**
+ * Monitored normal loop for waiting events.
+ * @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 monitored_wait_and_dispatch(int signum, void *arg)
+{
+ struct fdev_epoll *fdev_epoll = arg;
+ if (!signum) {
+ fdev_epoll_wait_and_dispatch(fdev_epoll, -1);
+ }
+}
+#endif
/**
* Main processing loop of threads processing jobs.
{
struct thread **prv;
struct job *job;
- struct evloop *el;
/* initialize description of itself and link it in the list */
me->tid = pthread_self();
/* loop until stopped */
while (!me->stop) {
- /* release the event loop */
- if (current_evloop) {
- __atomic_sub_fetch(¤t_evloop->state, EVLOOP_STATE_LOCK, __ATOMIC_RELAXED);
- current_evloop = NULL;
- }
+ /* 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 */
/* release the run job */
job_release(job);
- } else {
- /* no job, check events */
- el = &evloop[0];
- if (el->sdev && !__atomic_load_n(&el->state, __ATOMIC_RELAXED)) {
- /* run the events */
- __atomic_store_n(&el->state, EVLOOP_STATE_LOCK|EVLOOP_STATE_RUN|EVLOOP_STATE_WAIT, __ATOMIC_RELAXED);
- current_evloop = el;
- pthread_mutex_unlock(&mutex);
- sig_monitor(0, evloop_run, el);
- pthread_mutex_lock(&mutex);
- } else {
- /* no job and not events */
- running--;
- if (!running)
- ERROR("Entering job deep sleep! Check your bindings.");
- me->waits = 1;
- pthread_cond_wait(&cond, &mutex);
- me->waits = 0;
- running++;
+#if !defined(REMOVE_SYSTEMD_EVENT)
+
+
+
+ /* 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 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++;
+#else
+ } else if (waitevt) {
+ /* no job and not events */
+ running--;
+ if (!running)
+ ERROR("Entering job deep sleep! Check your bindings.");
+ me->waits = 1;
+ pthread_cond_wait(&cond, &mutex);
+ me->waits = 0;
+ running++;
+ } else {
+ /* wait for events */
+ waitevt = 1;
+ pthread_mutex_unlock(&mutex);
+ sig_monitor(0, monitored_wait_and_dispatch, get_fdevepoll());
+ pthread_mutex_lock(&mutex);
+ waitevt = 0;
+#endif
}
}
/* release the event loop */
- if (current_evloop) {
- __atomic_sub_fetch(¤t_evloop->state, EVLOOP_STATE_LOCK, __ATOMIC_RELAXED);
- current_evloop = NULL;
- }
+ evloop_release();
/* unlink the current thread and cleanup */
prv = &threads;
* 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 arg the argument to the callback
+ * @param closure the argument to the callback
* @return 0 on success or -1 in case of error
*/
int jobs_enter(
t->stop = 1;
if (t->waits)
pthread_cond_broadcast(&cond);
+ else
+ evloop_wakeup();
}
pthread_mutex_unlock(&mutex);
return -!t;
*/
static int on_evloop_efd(sd_event_source *s, int fd, uint32_t revents, void *userdata)
{
- uint64_t x;
- struct evloop *evloop = userdata;
- read(evloop->efd, &x, sizeof x);
- pthread_mutex_lock(&mutex);
- pthread_cond_broadcast(&evloop->cond);
- pthread_mutex_unlock(&mutex);
+ evloop_on_efd_event();
return 1;
}
+/* temporary hack */
+#if !defined(REMOVE_SYSTEMD_EVENT)
+__attribute__((unused))
+#endif
+static void evloop_callback(void *arg, uint32_t event, struct fdev *fdev)
+{
+ sig_monitor(0, evloop_run, arg);
+}
+
/**
* 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()
{
- struct evloop *el;
- uint64_t x;
int rc;
/* creates the evloop on need */
- el = &evloop[0];
- if (!el->sdev) {
+ if (!evloop.sdev) {
/* start the creation */
- el->state = 0;
+ evloop.state = 0;
/* creates the eventfd for waking up polls */
- el->efd = eventfd(0, EFD_CLOEXEC);
- if (el->efd < 0) {
+ 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(&el->sdev);
+ 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(el->sdev, NULL, el->efd, EPOLLIN, on_evloop_efd, el);
+ 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(el->sdev);
- el->sdev = NULL;
+#if !defined(REMOVE_SYSTEMD_EVENT)
+ sd_event_unref(evloop.sdev);
+ evloop.sdev = NULL;
error2:
- close(el->efd);
+ close(evloop.efd);
error1:
return NULL;
}
+#else
+ goto error3;
+ }
+ /* handle the event loop */
+ evloop.fdev = fdev_epoll_add(get_fdevepoll(), sd_event_get_fd(evloop.sdev));
+ if (!evloop.fdev) {
+ ERROR("can't create fdev");
+error3:
+ sd_event_unref(evloop.sdev);
+error2:
+ close(evloop.efd);
+error1:
+ memset(&evloop, 0, sizeof evloop);
+ return NULL;
+ }
+ fdev_set_autoclose(evloop.fdev, 0);
+ fdev_set_events(evloop.fdev, EPOLLIN);
+ fdev_set_callback(evloop.fdev, evloop_callback, NULL);
+#endif
}
- /* attach the event loop to the current thread */
- if (current_evloop != el) {
- if (current_evloop)
- __atomic_sub_fetch(¤t_evloop->state, EVLOOP_STATE_LOCK, __ATOMIC_RELAXED);
- current_evloop = el;
- __atomic_add_fetch(&el->state, EVLOOP_STATE_LOCK, __ATOMIC_RELAXED);
- }
-
- /* wait for a modifiable event loop */
- while (__atomic_load_n(&el->state, __ATOMIC_RELAXED) & EVLOOP_STATE_WAIT) {
- x = 1;
- write(el->efd, &x, sizeof x);
- pthread_cond_wait(&el->cond, &mutex);
- }
+ /* acquire the event loop */
+ evloop_acquire();
- return el->sdev;
+ return evloop.sdev;
}
/**
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);
+ /* 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;
}
+#if defined(REMOVE_SYSTEMD_EVENT)
+/**
+ * Gets the fdev_epoll item.
+ * @return a fdev_epoll or NULL in case of error
+ */
+struct fdev_epoll *jobs_get_fdev_epoll()
+{
+ struct fdev_epoll *result;
+
+ pthread_mutex_lock(&mutex);
+ result = get_fdevepoll();
+ pthread_mutex_unlock(&mutex);
+
+ return result;
+}
+#endif
+
/**
* Enter the jobs processing loop.
* @param allowed_count Maximum count of thread for jobs including this one
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;
remains--;
/* run until end */
+ running++;
thread_run(&me);
+ running--;
rc = 0;
error:
pthread_mutex_unlock(&mutex);
Code Review / src / app-framework-binder.git / blobdiff