More strict ownership asserts

[mirrors/Programs.git] / c / pthread_extra / pthread_pause.c

diff --git a/c/pthread_extra/pthread_pause.c b/c/pthread_extra/pthread_pause.c
index 24521af71f38741c0e85ea04412f89724f173626..950d6fa26954ffdbf5d42ad9fcec3a27fd3e860b 100644 (file)
--- a/c/pthread_extra/pthread_pause.c
+++ b/c/pthread_extra/pthread_pause.c
@@ -49,9 +49,6 @@ void pthread_pause_handler(const int signal, siginfo_t *info, void *ptr) {
 void pthread_pause_enable() {
        pthread_pause_init(); //Make sure semaphore is init'd
 
-       //Add thread to internal registry
-       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
@@ -71,17 +68,22 @@ void pthread_pause_enable() {
                .sa_flags = SA_SIGINFO | SA_RESTART,
                .sa_restorer = NULL
        };
+
        sigaction(PTHREAD_XSIG_STOP, &pause_sa, NULL);
 
        //Unblock signal
        pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
+
+       //Add thread to internal registry
+       pthread_user_data_internal(pthread_self()); //Only now, when signals are unblocked!
 }
 
 void pthread_pause_disable() {
+       //pthread_user_data_lock();
        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()); //DEADLOCKS!
 
        //Block signal
        sigset_t sigset;
@@ -89,9 +91,12 @@ void pthread_pause_disable() {
        sigaddset(&sigset, PTHREAD_XSIG_STOP);
 
        //Make sure all signals are dispatched before we block them
-       sem_wait(&pthread_pause_sem);
+       //Maybe not a good idea, causes DEADLOCKS!
+       //sem_wait(&pthread_pause_sem);
        pthread_sigmask(SIG_BLOCK, &sigset, NULL);
-       sem_post(&pthread_pause_sem);
+       //sem_post(&pthread_pause_sem);
+
+       //pthread_user_data_unlock();
 }
 
 /*
@@ -108,7 +113,6 @@ int pthread_pause_reschedule(pthread_t thread) {
 
 int pthread_pause_reschedule(pthread_t thread) {
        //Decide if the thread should run and signal it
-
        pthread_user_data_lock();
 
        //Wait for semaphore which means signal queue is empty
@@ -146,18 +150,29 @@ int pthread_extra_yield() {
        return pthread_yield();
 }
 
+///Sanity check to be sure there are no race conditions
+inline void pthread_pause_assert_owner() {
+       if(!pthread_equal(pthread_pause_holder,PTHREAD_XNULL))
+               assert(pthread_equal(pthread_pause_holder, pthread_self()));
+}
+
+///Pause specified thread (block until it is paused)
 int pthread_pause(pthread_t thread) {
-       //Set thread as paused and notify it via signal (wait when queue full)
        pthread_user_data_lock();
+       pthread_pause_assert_owner();
+       //if(!pthread_equal(pthread_pause_holder,PTHREAD_XNULL)) assert(pthread_equal(pthread_pause_holder, pthread_self()));
+       //Set thread as paused and notify it via signal (wait when queue full)
        pthread_user_data_internal(thread)->running = 0;
        pthread_pause_reschedule(thread);
        pthread_user_data_unlock();
        return 0;
 }
 
+///UnPause specified thread (block until it is unpaused)
 int pthread_unpause(pthread_t thread) {
-       //Set thread as running and notify it via signal (wait when queue full)
        pthread_user_data_lock();
+       pthread_pause_assert_owner();
+       //Set thread as running and notify it via signal (wait when queue full)
        pthread_user_data_internal(thread)->running = 1;
        pthread_pause_reschedule(thread);
        pthread_user_data_unlock();
@@ -170,7 +185,7 @@ int pthread_pause_all() {
        pthread_user_data_lock();
        //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_assert_owner();
        pthread_pause_holder = pthread_self();
        pthread_user_data_internal_iterate(&pthread_pause_reschedule, NULL);
        //printf("Pause ALL!\n");
@@ -183,7 +198,7 @@ int pthread_unpause_all() {
        //printf("UnPause ALL\n");
        pthread_user_data_lock();
        //printf("UnPause ALL+\n");
-       if(!pthread_equal(pthread_pause_holder,PTHREAD_XNULL)) assert(pthread_equal(pthread_pause_holder, pthread_self()));
+       pthread_pause_assert_owner();
        pthread_pause_holder = PTHREAD_XNULL;
        pthread_user_data_internal_iterate(&pthread_pause_reschedule, NULL);
        //printf("UnPause ALL!\n");
@@ -204,8 +219,10 @@ void *pthread_extra_thread_wrapper(void *arg) {
        pthread_extra_wrapper_t task = *((pthread_extra_wrapper_t*)arg);
        free(arg);
 
+       pthread_pause_enable();
+
        //Register new thread to user data structure
-       pthread_user_data_internal(pthread_self()); //Perhaps already done in pthread_extra_yield()??
+       //pthread_user_data_internal(pthread_self()); //Perhaps already done in pthread_extra_yield() and pthread_pause_enable()??
 
        //TODO: user_data should do this automaticaly?
        pthread_cleanup_push(pthread_user_data_cleanup, (void *)pthread_self());