Synchronization functions are now thread pool specific

thpool.c

@@ -27,7 +27,6 @@
 #endif
 
 static volatile int threads_keepalive;
-static volatile int threads_on_hold;
 
 
 
@@ -76,6 +75,7 @@ typedef struct thpool_{
  pthread_mutex_t thcount_lock; /* used for thread count etc */
  pthread_cond_t threads_all_idle; /* signal to thpool_wait */
  jobqueue* jobqueue_p; /* pointer to the job queue */ 
+ int paused; /* thread pool is paused */
 } thpool_;
 
 
@@ -112,7 +112,6 @@ static void bsem_wait(struct bsem *bsem_p);
 /* Initialise thread pool */
 struct thpool_* thpool_init(int num_threads){
 
- threads_on_hold = 0;
  threads_keepalive = 1;
 
  if (num_threads < 0){
@@ -240,16 +239,24 @@ void thpool_destroy(thpool_* thpool_p){
 
 /* Pause all threads in threadpool */
 void thpool_pause(thpool_* thpool_p) {
- int n;
+ /* construct signal handler values for this thread pool */
+ union sigval value;
+ value.sival_ptr = (void *)thpool_p;
+
+ /* mark threadpool as paused */
+ thpool_p->paused = 1;
+
+ /* send sigqueue with specific thpool */
+ int n;
  for (n=0; n < thpool_p->num_threads_alive; n++){
- pthread_kill(thpool_p->threads[n]->pthread, SIGUSR1);
+ pthread_sigqueue(thpool_p->threads[n]->pthread, SIGUSR1, value);
  }
 }
 
 
 /* Resume all threads in threadpool */
 void thpool_resume(thpool_* thpool_p) {
- threads_on_hold = 0;
+ thpool_p->paused = 0;
 }
 
 
@@ -282,12 +289,11 @@ static int thread_init (thpool_* thpool_p, struct thread** thread_p, int id){
 }
 
 
-/* Sets the calling thread on hold */
-static void thread_hold () {
- threads_on_hold = 1;
- while (threads_on_hold){
- sleep(1);
- }
+/* Holds thread until parent threadpool resumes */
+static void thread_hold (int signo, siginfo_t *info, void *extra) {
+ while (((struct thpool_*)(info->si_ptr))->paused){
+ sleep(1);
+ }
 }
 
 
@@ -320,8 +326,8 @@ static void* thread_do(struct thread* thread_p){
  /* Register signal handler */
  struct sigaction act;
  sigemptyset(&act.sa_mask);
- act.sa_flags = 0;
- act.sa_handler = thread_hold;
+ act.sa_flags = SA_SIGINFO;
+ act.sa_sigaction = thread_hold;
  if (sigaction(SIGUSR1, &act, NULL) == -1) {
  fprintf(stderr, "thread_do(): cannot handle SIGUSR1");
  }