#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);
}
}
void pthread_pause_enable() {
+ pthread_pause_init(); //Make sure semaphore is init'd
+
//Add thread to internal registry
- //pthread_user_data_internal(pthread_self());
+ pthread_user_data_internal(pthread_self());
//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);
//Prepare signal mask
sigset_t sigset;
const struct sigaction pause_sa = {
.sa_sigaction = pthread_pause_handler,
.sa_mask = sigset,
- .sa_flags = SA_SIGINFO,
+ .sa_flags = SA_SIGINFO | SA_RESTART,
.sa_restorer = NULL
};
sigaction(PTHREAD_XSIG_STOP, &pause_sa, NULL);
}
void pthread_pause_disable() {
+ pthread_pause_init(); //Make sure semaphore is init'd
+
//Add thread to internal registry
- //pthread_user_data_internal(pthread_self());
+ pthread_user_data_internal(pthread_self());
//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
pthread_user_data_lock();
+
+ //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()
+
//Check if thread has running flag
int run = (pthread_user_data_internal(thread)->running);
//Check if privileged (single thread) mode is active
- if((pthread_pause_holder != PTHREAD_XNULL) && !pthread_equal(pthread_pause_holder, thread)) {
+ if(!pthread_equal(pthread_pause_holder, PTHREAD_XNULL) && !pthread_equal(pthread_pause_holder, thread)) {
run = 0;
}
- pthread_user_data_unlock();
//Send signal to initiate pause handler (keep trying while SigQueue is full)
//while(pthread_kill(thread, PTHREAD_XSIG_STOP) == EAGAIN) usleep(1000);
+ //printf("Sched %lu = %d (self: %lu, lck: %lu)\n", thread, run, pthread_self(), pthread_pause_holder);
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);
+ pthread_user_data_unlock();
+
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;
}
+///Enter exclusive mode by pausing everyone else
int pthread_pause_all() {
+ //printf("Pause ALL\n");
pthread_user_data_lock();
- if(pthread_pause_holder!=PTHREAD_XNULL) assert(pthread_equal(pthread_pause_holder, pthread_self()));
+ //printf("Pause ALL+\n");
+ //printf("Pause %p == %p\n", (void *)pthread_pause_holder, (void *)pthread_self());
+ if(!pthread_equal(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);
+ //printf("Pause ALL!\n");
+ pthread_user_data_unlock();
return 0;
}
+///Leave exclusive mode by unpausing everyone else
int pthread_unpause_all() {
+ //printf("UnPause ALL\n");
pthread_user_data_lock();
- if(pthread_pause_holder!=PTHREAD_XNULL) assert(pthread_equal(pthread_pause_holder, pthread_self()));
+ //printf("UnPause ALL+\n");
+ if(!pthread_equal(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);
+ //printf("UnPause ALL!\n");
+ pthread_user_data_unlock();
return 0;
}
free(arg);
//Register new thread to user data structure
- pthread_user_data_internal(pthread_self());
+ pthread_user_data_internal(pthread_self()); //Perhaps already done in pthread_extra_yield()??
//TODO: user_data should do this automaticaly?
pthread_cleanup_push(pthread_user_data_cleanup, (void *)pthread_self());
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