| 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 <stdio.h> |
| 10 | //#include <sys/time.h> |
| 11 | |
| 12 | void pthread_pause_handler() { |
| 13 | //Do nothing when there are more signals pending (to cleanup the queue) |
| 14 | sigset_t pending; |
| 15 | sigpending(&pending); |
| 16 | if(sigismember(&pending, PTHREAD_XSIG_STOP)) return; |
| 17 | |
| 18 | //Keep waiting for signals until we are supposed to be running |
| 19 | sigset_t sigset; |
| 20 | sigfillset(&sigset); |
| 21 | sigdelset(&sigset, PTHREAD_XSIG_STOP); |
| 22 | if(!pthread_user_data_internal(pthread_self())->running) { |
| 23 | sigsuspend(&sigset); |
| 24 | } |
| 25 | } |
| 26 | |
| 27 | void pthread_pause_enable() { |
| 28 | //Nesting signals too deep is not good for stack |
| 29 | //You can get runtime stats using following command: |
| 30 | //grep -i sig /proc/$(pgrep binary)/status |
| 31 | struct rlimit sigq = {.rlim_cur = 32, .rlim_max=32}; |
| 32 | setrlimit(RLIMIT_SIGPENDING, &sigq); |
| 33 | |
| 34 | //Setup signal handler |
| 35 | signal(PTHREAD_XSIG_STOP, pthread_pause_handler); |
| 36 | |
| 37 | //Unblock signal |
| 38 | sigset_t sigset; |
| 39 | sigemptyset(&sigset); |
| 40 | sigaddset(&sigset, PTHREAD_XSIG_STOP); |
| 41 | pthread_sigmask(SIG_UNBLOCK, &sigset, NULL); |
| 42 | } |
| 43 | |
| 44 | void pthread_pause_disable() { |
| 45 | //Block signal |
| 46 | sigset_t sigset; |
| 47 | sigemptyset(&sigset); |
| 48 | sigaddset(&sigset, PTHREAD_XSIG_STOP); |
| 49 | pthread_sigmask(SIG_BLOCK, &sigset, NULL); |
| 50 | } |
| 51 | |
| 52 | int pthread_pause(pthread_t thread) { |
| 53 | //Set thread as paused and notify it via signal (wait when queue full) |
| 54 | pthread_user_data_internal(thread)->running = 0; |
| 55 | while(pthread_kill(thread, PTHREAD_XSIG_STOP) == EAGAIN) usleep(1000); |
| 56 | return 0; |
| 57 | } |
| 58 | |
| 59 | int pthread_unpause(pthread_t thread) { |
| 60 | //Set thread as running and notify it via signal (wait when queue full) |
| 61 | pthread_user_data_internal(thread)->running = 1; |
| 62 | while(pthread_kill(thread, PTHREAD_XSIG_STOP) == EAGAIN) usleep(1000); |
| 63 | return 0; |
| 64 | } |