#include <pthread.h>
#include <pthread_extra.h>
#include <signal.h>
+#include <semaphore.h>
#include <errno.h>
#include <unistd.h>
#include <sys/resource.h>
#include <assert.h>
//#include <sys/time.h>
+//Mutex that ensures proper serialization of (un)pause calls
+//pthread_mutex_t pthread_pause_mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
+
+//Semaphore that ensures proper serialization of (un)pause signals
+sem_t pthread_pause_sem;
+//Once control to init the semaphore (and possibly other stuff)
+pthread_once_t pthread_pause_once_ctrl = PTHREAD_ONCE_INIT;
+void pthread_pause_once(void) {
+ sem_init(&pthread_pause_sem, 0, 1);
+}
+void pthread_pause_init() { pthread_once(&pthread_pause_once_ctrl, &pthread_pause_once); }
+
///When this variable is nonzero, only referenced thread is allowed to run
-///Access has to be protected by pthread_user_data_lock()
+///Access has to be protected by pthread_user_data_lock() and pthread_pause_sem;
pthread_t pthread_pause_holder = PTHREAD_XNULL;
void pthread_pause_handler(const int signal, siginfo_t *info, void *ptr) {
int run = info->si_value.sival_int;
//(void)td;
- //Do nothing when there are more signals pending (to cleanup the queue)
- sigset_t pending;
- sigpending(&pending);
- if(sigismember(&pending, PTHREAD_XSIG_STOP)) return;
+ //Post semaphore to confirm that signal is handled
+ sem_post(&pthread_pause_sem);
//Keep waiting for signals until we are supposed to be running
- sigset_t sigset;
- sigfillset(&sigset);
- sigdelset(&sigset, PTHREAD_XSIG_STOP);
-
- //printf("RCV: %p = %p\n", (void *)pthread_user_data_internal(pthread_self()), (void *)td);
-
- //if(!pthread_user_data_internal(pthread_self())->running) {
if(!run) {
+ sigset_t sigset;
+ sigfillset(&sigset);
+ sigdelset(&sigset, PTHREAD_XSIG_STOP);
sigsuspend(&sigset);
}
}
//Nesting signals too deep is not good for stack
//You can get runtime stats using following command:
//grep -i sig /proc/$(pgrep binary)/status
- struct rlimit sigq = {.rlim_cur = 32, .rlim_max=32};
- setrlimit(RLIMIT_SIGPENDING, &sigq);
+ //struct rlimit sigq = {.rlim_cur = 32, .rlim_max=32};
+ //setrlimit(RLIMIT_SIGPENDING, &sigq);
+
+ pthread_pause_init(); //Make sure semaphore is init'd
//Prepare signal mask
sigset_t sigset;
//Add thread to internal registry
//pthread_user_data_internal(pthread_self());
+ pthread_pause_init(); //Make sure semaphore is init'd
+
//Block signal
sigset_t sigset;
sigemptyset(&sigset);
sigaddset(&sigset, PTHREAD_XSIG_STOP);
+
+ //Make sure all signals are dispatched before we block them
+ sem_wait(&pthread_pause_sem);
pthread_sigmask(SIG_BLOCK, &sigset, NULL);
+ sem_post(&pthread_pause_sem);
}
/*
*/
int pthread_pause_reschedule(pthread_t thread) {
- //Decide if the thread should run
+ //Decide if the thread should run and signal it
+
+ //Wait for semaphore which means signal queue is empty
+ pthread_pause_init(); //Make sure semaphore is init'd
+ sem_wait(&pthread_pause_sem);
+
+ //Only call this if you already acquired pthread_pause_sem semaphore!!!!
+ //Otherwise call pthread_pause_reschedule()
pthread_user_data_lock();
//Check if thread has running flag
while(pthread_sigqueue(thread, PTHREAD_XSIG_STOP,
(const union sigval){.sival_int=run}
) == EAGAIN) usleep(1000);
+
+ //Wait for signal to be delivered
+ sem_wait(&pthread_pause_sem);
+ sem_post(&pthread_pause_sem);
+
return 0;
}
//Set thread as paused and notify it via signal (wait when queue full)
pthread_user_data_lock();
pthread_user_data_internal(thread)->running = 0;
- pthread_user_data_unlock();
pthread_pause_reschedule(thread);
+ pthread_user_data_unlock();
return 0;
}
//Set thread as running and notify it via signal (wait when queue full)
pthread_user_data_lock();
pthread_user_data_internal(thread)->running = 1;
- pthread_user_data_unlock();
pthread_pause_reschedule(thread);
+ pthread_user_data_unlock();
return 0;
}
pthread_user_data_lock();
if(pthread_pause_holder!=PTHREAD_XNULL) assert(pthread_equal(pthread_pause_holder, pthread_self()));
pthread_pause_holder = pthread_self();
- pthread_user_data_unlock();
pthread_user_data_internal_iterate(&pthread_pause_reschedule, NULL);
+ pthread_user_data_unlock();
return 0;
}
pthread_user_data_lock();
if(pthread_pause_holder!=PTHREAD_XNULL) assert(pthread_equal(pthread_pause_holder, pthread_self()));
pthread_pause_holder = PTHREAD_XNULL;
- pthread_user_data_unlock();
pthread_user_data_internal_iterate(&pthread_pause_reschedule, NULL);
+ pthread_user_data_unlock();
return 0;
}
#include <assert.h>
#include <unistd.h>
+pthread_t main_thread;
+
void *thread_test(void *arg) {
//Whole process dies if you kill thread immediately before it is pausable
//pthread_pause_enable();
while(1) {
- usleep(1000*300);
+ pthread_nsleep(0, 1000*1000*300);
+ //pthread_pause_all();
+ pthread_pause(main_thread);
printf("Running%s!\n", (char *)arg);
+ //pthread_unpause_all();
+ pthread_unpause(main_thread);
}
}
int main() {
+ main_thread = pthread_self();
+
pthread_t a, b;
pthread_pause_enable(); //Will get inherited by all threads from now on
//That way you can be sure it is pausable immediately
pthread_extra_create(&a, NULL, thread_test, " A");
pthread_extra_create(&b, NULL, thread_test, " B");
- //sleep(1);
+ //pthread_sleep(1);
//printf("OK\n");
/*
pthread_pause(b);
pthread_unpause(a);
printf("SWITCH A:\n");
- sleep(2);
+ pthread_sleep(2);
printf("SWITCH B:\n");
pthread_pause(a);
pthread_unpause(b);
- sleep(2);
+ pthread_sleep(2);
printf("SWITCH A+B:\n");
pthread_unpause(a);
pthread_unpause(b);
- sleep(1);
+ pthread_sleep(1);
printf("SWITCH MAIN ONLY:\n");
pthread_pause_all();
- sleep(1);
+ pthread_sleep(1);
printf("SWITCH MAIN A+B:\n");
pthread_unpause_all();
- sleep(1);
+ pthread_sleep(1);
}
pthread_join(a, NULL);
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