| 1 | #define __PTHREAD_EXTRA_INTERNAL |
| 2 | |
| 3 | #include <pthread.h> |
| 4 | #include <pthread_extra.h> |
| 5 | #include <signal.h> |
| 6 | #include <errno.h> |
| 7 | #include <unistd.h> |
| 8 | #include <sys/resource.h> |
| 9 | //#include <sys/siginfo.h> |
| 10 | //#include <stdio.h> |
| 11 | #include <stdlib.h> |
| 12 | #include <assert.h> |
| 13 | //#include <sys/time.h> |
| 14 | |
| 15 | void pthread_pause_handler(const int signal, siginfo_t *info, void *ptr) { |
| 16 | (void)signal; (void)info; (void)ptr; |
| 17 | pthread_user_data_internal_t *td = (pthread_user_data_internal_t *)(info->si_value.sival_ptr); |
| 18 | (void)td; |
| 19 | |
| 20 | //Do nothing when there are more signals pending (to cleanup the queue) |
| 21 | sigset_t pending; |
| 22 | sigpending(&pending); |
| 23 | if(sigismember(&pending, PTHREAD_XSIG_STOP)) return; |
| 24 | |
| 25 | //Keep waiting for signals until we are supposed to be running |
| 26 | sigset_t sigset; |
| 27 | sigfillset(&sigset); |
| 28 | sigdelset(&sigset, PTHREAD_XSIG_STOP); |
| 29 | |
| 30 | //printf("RCV: %p = %p\n", (void *)pthread_user_data_internal(pthread_self()), (void *)td); |
| 31 | |
| 32 | //if(!pthread_user_data_internal(pthread_self())->running) { |
| 33 | if(!td->running) { |
| 34 | sigsuspend(&sigset); |
| 35 | } |
| 36 | } |
| 37 | |
| 38 | void pthread_pause_enable() { |
| 39 | //Add thread to internal registry |
| 40 | //pthread_user_data_internal(pthread_self()); |
| 41 | |
| 42 | //Nesting signals too deep is not good for stack |
| 43 | //You can get runtime stats using following command: |
| 44 | //grep -i sig /proc/$(pgrep binary)/status |
| 45 | struct rlimit sigq = {.rlim_cur = 32, .rlim_max=32}; |
| 46 | setrlimit(RLIMIT_SIGPENDING, &sigq); |
| 47 | |
| 48 | //Prepare signal mask |
| 49 | sigset_t sigset; |
| 50 | sigemptyset(&sigset); |
| 51 | sigaddset(&sigset, PTHREAD_XSIG_STOP); |
| 52 | |
| 53 | //Setup signal handler |
| 54 | //signal(PTHREAD_XSIG_STOP, pthread_pause_handler); |
| 55 | const struct sigaction pause_sa = { |
| 56 | .sa_sigaction = pthread_pause_handler, |
| 57 | .sa_mask = sigset, |
| 58 | .sa_flags = SA_SIGINFO, |
| 59 | .sa_restorer = NULL |
| 60 | }; |
| 61 | sigaction(PTHREAD_XSIG_STOP, &pause_sa, NULL); |
| 62 | |
| 63 | //Unblock signal |
| 64 | pthread_sigmask(SIG_UNBLOCK, &sigset, NULL); |
| 65 | } |
| 66 | |
| 67 | void pthread_pause_disable() { |
| 68 | //Add thread to internal registry |
| 69 | //pthread_user_data_internal(pthread_self()); |
| 70 | |
| 71 | //Block signal |
| 72 | sigset_t sigset; |
| 73 | sigemptyset(&sigset); |
| 74 | sigaddset(&sigset, PTHREAD_XSIG_STOP); |
| 75 | pthread_sigmask(SIG_BLOCK, &sigset, NULL); |
| 76 | } |
| 77 | |
| 78 | int pthread_pause_reschedule(pthread_t thread) { |
| 79 | //Send signal to initiate pause handler |
| 80 | //printf("SND: %p\n", (void *)pthread_user_data_internal(thread)); |
| 81 | //while(pthread_kill(thread, PTHREAD_XSIG_STOP) == EAGAIN) usleep(1000); |
| 82 | while(pthread_sigqueue(thread, PTHREAD_XSIG_STOP, |
| 83 | (const union sigval){.sival_ptr=pthread_user_data_internal(thread)} |
| 84 | ) == EAGAIN) usleep(1000); |
| 85 | return 0; |
| 86 | } |
| 87 | |
| 88 | int pthread_extra_yield() { |
| 89 | //Yield to both schedulers |
| 90 | pthread_pause_reschedule(pthread_self()); |
| 91 | return pthread_yield(); |
| 92 | } |
| 93 | |
| 94 | int pthread_pause(pthread_t thread) { |
| 95 | //Set thread as paused and notify it via signal (wait when queue full) |
| 96 | pthread_user_data_internal(thread)->running = 0; |
| 97 | pthread_pause_reschedule(thread); |
| 98 | return 0; |
| 99 | } |
| 100 | |
| 101 | int pthread_unpause(pthread_t thread) { |
| 102 | //Set thread as running and notify it via signal (wait when queue full) |
| 103 | pthread_user_data_internal(thread)->running = 1; |
| 104 | pthread_pause_reschedule(thread); |
| 105 | return 0; |
| 106 | } |
| 107 | |
| 108 | |
| 109 | |
| 110 | // Wrappers /////////////////////////////////////////////////////////// |
| 111 | |
| 112 | |
| 113 | typedef struct pthread_extra_wrapper_t { |
| 114 | void *(*start_routine)(void *); |
| 115 | void *restrict arg; |
| 116 | } pthread_extra_wrapper_t; |
| 117 | |
| 118 | void *pthread_extra_thread_wrapper(void *arg) { |
| 119 | pthread_extra_wrapper_t task = *((pthread_extra_wrapper_t*)arg); |
| 120 | free(arg); |
| 121 | |
| 122 | //Register new thread to user data structure |
| 123 | pthread_user_data_internal(pthread_self()); |
| 124 | |
| 125 | //TODO: user_data should do this automaticaly? |
| 126 | pthread_cleanup_push(pthread_user_data_cleanup, (void *)pthread_self()); |
| 127 | |
| 128 | //Check if we should be running according to pthread_pause sub-scheduler |
| 129 | pthread_pause_reschedule(pthread_self()); |
| 130 | |
| 131 | return task.start_routine(task.arg); |
| 132 | |
| 133 | pthread_cleanup_pop(1); //Needed by pthread_cleanup_push() macro |
| 134 | } |
| 135 | |
| 136 | int pthread_extra_create(pthread_t *restrict thread, |
| 137 | const pthread_attr_t *restrict attr, |
| 138 | void *(*start_routine)(void *), |
| 139 | void *restrict arg) { |
| 140 | |
| 141 | pthread_extra_wrapper_t *task = malloc(sizeof(pthread_extra_wrapper_t)); |
| 142 | assert(task != NULL); |
| 143 | task->start_routine=start_routine; |
| 144 | task->arg=arg; |
| 145 | return pthread_create(thread, attr, pthread_extra_thread_wrapper, task); |
| 146 | } |