X-Git-Url: https://git.harvie.cz/?a=blobdiff_plain;f=c%2Fpthread_extra%2Fpthread_pause.c;h=4107b38004fac9c2cb1686b91ff546d157ca7518;hb=70bd1c94dee46dac0885831ccce3d1840388656e;hp=67a502331632de2ebf2acea1d6b322e06ce4824d;hpb=ae4849d11f804c0ea6c7ad4aea8a37702f3dd296;p=mirrors%2FPrograms.git diff --git a/c/pthread_extra/pthread_pause.c b/c/pthread_extra/pthread_pause.c index 67a5023..4107b38 100644 --- a/c/pthread_extra/pthread_pause.c +++ b/c/pthread_extra/pthread_pause.c @@ -1,20 +1,195 @@ +#define __PTHREAD_EXTRA_INTERNAL + #include #include #include +#include +#include +#include +//#include +//#include +#include +#include +//#include -void pthread_unpause_handler() { - //NOP -} +///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 = 0; + +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; -void pthread_pause_handler() { + //Do nothing when there are more signals pending (to cleanup the queue) + sigset_t pending; + sigpending(&pending); + if(sigismember(&pending, PTHREAD_XSIG_STOP)) return; + + //Keep waiting for signals until we are supposed to be running sigset_t sigset; sigfillset(&sigset); - sigdelset(&sigset, PTHREAD_XSIG_CONT); - sigsuspend(&sigset); - //int sig; sigwait(&sigset, &sig); + 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) { + sigsuspend(&sigset); + } } void pthread_pause_enable() { - signal(PTHREAD_XSIG_STOP, pthread_pause_handler); - signal(PTHREAD_XSIG_CONT, pthread_unpause_handler); + //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 + struct rlimit sigq = {.rlim_cur = 32, .rlim_max=32}; + setrlimit(RLIMIT_SIGPENDING, &sigq); + + //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()); + + //Block signal + sigset_t sigset; + sigemptyset(&sigset); + sigaddset(&sigset, PTHREAD_XSIG_STOP); + 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=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 != 0) && !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; +} + +int pthread_extra_yield() { + //Yield to both schedulers + pthread_pause_reschedule(pthread_self()); + return pthread_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!=0) assert(pthread_equal(pthread_pause_holder, pthread_self())); + pthread_pause_holder = pthread_self(); + pthread_user_data_unlock(); + //todo reschedule all + return 0; +} + +int pthread_unpause_all() { + pthread_user_data_lock(); + if(pthread_pause_holder!=0) assert(pthread_equal(pthread_pause_holder, pthread_self())); + pthread_pause_holder = 0; + pthread_user_data_unlock(); + //todo reschedule + return 0; +} + + +// Wrappers /////////////////////////////////////////////////////////// + + +typedef struct pthread_extra_wrapper_t { + void *(*start_routine)(void *); + void *restrict arg; +} pthread_extra_wrapper_t; + +void *pthread_extra_thread_wrapper(void *arg) { + pthread_extra_wrapper_t task = *((pthread_extra_wrapper_t*)arg); + free(arg); + + //Register new thread to user data structure + pthread_user_data_internal(pthread_self()); + + //TODO: user_data should do this automaticaly? + 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_extra_yield(); + + //Run actual task + return task.start_routine(task.arg); + + pthread_cleanup_pop(1); //Needed by pthread_cleanup_push() macro +} + +int pthread_extra_create(pthread_t *restrict thread, + const pthread_attr_t *restrict attr, + void *(*start_routine)(void *), + void *restrict arg) { + + pthread_extra_wrapper_t *task = malloc(sizeof(pthread_extra_wrapper_t)); + assert(task != NULL); + task->start_routine=start_routine; + task->arg=arg; + return pthread_create(thread, attr, pthread_extra_thread_wrapper, task); }