Pthread pause based on pthread user data

[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 67a502331632de2ebf2acea1d6b322e06ce4824d..662d78fdd99a949e041a15c093f862c01d1f5a5d 100644 (file)
--- a/c/pthread_extra/pthread_pause.c
+++ b/c/pthread_extra/pthread_pause.c
@@ -1,20 +1,64 @@
+#define __PTHREAD_EXTRA_INTERNAL
+
 #include <pthread.h>
 #include <pthread_extra.h>
 #include <signal.h>
-
-void pthread_unpause_handler() {
-       //NOP
-}
+#include <errno.h>
+#include <unistd.h>
+#include <sys/resource.h>
+//#include <stdio.h>
+//#include <sys/time.h>
 
 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);
+       while(!pthread_user_data_internal(pthread_self())->running) {
+               sigsuspend(&sigset);
+       }
 }
 
 void pthread_pause_enable() {
+       //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);
+
+       //Setup signal handler
        signal(PTHREAD_XSIG_STOP, pthread_pause_handler);
-       signal(PTHREAD_XSIG_CONT, pthread_unpause_handler);
+
+       //Unblock signal
+       sigset_t sigset;
+       sigemptyset(&sigset);
+       sigaddset(&sigset, PTHREAD_XSIG_STOP);
+       pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
+}
+
+void pthread_pause_disable() {
+       //Block signal
+       sigset_t sigset;
+       sigemptyset(&sigset);
+       sigaddset(&sigset, PTHREAD_XSIG_STOP);
+       pthread_sigmask(SIG_BLOCK, &sigset, NULL);
+}
+
+int pthread_pause(pthread_t thread) {
+       //Set thread as paused and notify it via signal (wait when queue full)
+       pthread_user_data_internal(thread)->running = 0;
+       while(pthread_kill(thread, PTHREAD_XSIG_STOP) == EAGAIN) usleep(1000);
+       return 0;
+}
+
+int pthread_unpause(pthread_t thread) {
+       //Set thread as running and notify it via signal (wait when queue full)
+       pthread_user_data_internal(thread)->running = 1;
+       while(pthread_kill(thread, PTHREAD_XSIG_STOP) == EAGAIN) usleep(1000);
+       return 0;
 }