Implementace vyhradniho rezimu

[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 e11a0531e3d645496da4822a9a828c8a046f096f..63ccc6a05cb299bae0c8a099fc520be1f55bb2c3 100644 (file)
--- a/c/pthread_extra/pthread_pause.c
+++ b/c/pthread_extra/pthread_pause.c
@@ -6,12 +6,21 @@
 #include <errno.h>
 #include <unistd.h>
 #include <sys/resource.h>
+//#include <sys/siginfo.h>
 //#include <stdio.h>
 #include <stdlib.h>
 #include <assert.h>
 //#include <sys/time.h>
 
-void pthread_pause_handler() {
+///When this variable is nonzero, only referenced thread is allowed to run
+///Access has to be protected by pthread_user_data_lock()
+pthread_t pthread_pause_holder = PTHREAD_XNULL;
+
+void pthread_pause_handler(const int signal, siginfo_t *info, void *ptr) {
+       (void)signal; (void)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);
@@ -21,14 +30,18 @@ void pthread_pause_handler() {
        sigset_t sigset;
        sigfillset(&sigset);
        sigdelset(&sigset, PTHREAD_XSIG_STOP);
-       if(!pthread_user_data_internal(pthread_self())->running) {
+
+       //printf("RCV: %p = %p\n", (void *)pthread_user_data_internal(pthread_self()), (void *)td);
+
+       //if(!pthread_user_data_internal(pthread_self())->running) {
+       if(!run) {
                sigsuspend(&sigset);
        }
 }
 
 void pthread_pause_enable() {
        //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:
@@ -36,19 +49,28 @@ void pthread_pause_enable() {
        struct rlimit sigq = {.rlim_cur = 32, .rlim_max=32};
        setrlimit(RLIMIT_SIGPENDING, &sigq);
 
-       //Setup signal handler
-       signal(PTHREAD_XSIG_STOP, pthread_pause_handler);
-
-       //Unblock signal
+       //Prepare signal mask
        sigset_t sigset;
        sigemptyset(&sigset);
        sigaddset(&sigset, PTHREAD_XSIG_STOP);
+
+       //Setup signal handler
+       //signal(PTHREAD_XSIG_STOP, pthread_pause_handler);
+       const struct sigaction pause_sa = {
+               .sa_sigaction = pthread_pause_handler,
+               .sa_mask = sigset,
+               .sa_flags = SA_SIGINFO,
+               .sa_restorer = NULL
+       };
+       sigaction(PTHREAD_XSIG_STOP, &pause_sa, NULL);
+
+       //Unblock signal
        pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
 }
 
 void pthread_pause_disable() {
        //Add thread to internal registry
-       pthread_user_data_internal(pthread_self());
+       //pthread_user_data_internal(pthread_self());
 
        //Block signal
        sigset_t sigset;
@@ -57,10 +79,35 @@ void pthread_pause_disable() {
        pthread_sigmask(SIG_BLOCK, &sigset, NULL);
 }
 
+/*
 int pthread_pause_reschedule(pthread_t thread) {
        //Send signal to initiate pause handler
+       //printf("SND: %p\n", (void *)pthread_user_data_internal(thread));
        //while(pthread_kill(thread, PTHREAD_XSIG_STOP) == EAGAIN) usleep(1000);
-       while(pthread_sigqueue(thread, PTHREAD_XSIG_STOP, (const union sigval){.sival_ptr=NULL}) == EAGAIN) usleep(1000);
+       while(pthread_sigqueue(thread, PTHREAD_XSIG_STOP,
+               (const union sigval){.sival_ptr=pthread_user_data_internal(thread)}
+               ) == EAGAIN) usleep(1000);
+       return 0;
+}
+*/
+
+int pthread_pause_reschedule(pthread_t thread) {
+       //Decide if the thread should run
+
+       pthread_user_data_lock();
+       //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)) {
+               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);
+       while(pthread_sigqueue(thread, PTHREAD_XSIG_STOP,
+               (const union sigval){.sival_int=run}
+               ) == EAGAIN) usleep(1000);
        return 0;
 }
 
@@ -72,18 +119,39 @@ int pthread_extra_yield() {
 
 int pthread_pause(pthread_t thread) {
        //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);
        return 0;
 }
 
 int pthread_unpause(pthread_t thread) {
        //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);
        return 0;
 }
 
+int pthread_pause_all() {
+       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);
+       return 0;
+}
+
+int pthread_unpause_all() {
+       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);
+       return 0;
+}
 
 
 // Wrappers ///////////////////////////////////////////////////////////
@@ -105,8 +173,10 @@ void *pthread_extra_thread_wrapper(void *arg) {
        pthread_cleanup_push(pthread_user_data_cleanup, (void *)pthread_self());
 
        //Check if we should be running according to pthread_pause sub-scheduler
-       pthread_pause_reschedule(pthread_self());
+       //pthread_pause_reschedule(pthread_self());
+       pthread_extra_yield();
 
+       //Run actual task
        return task.start_routine(task.arg);
 
        pthread_cleanup_pop(1); //Needed by pthread_cleanup_push() macro