diff options
Diffstat (limited to 'linuxthreads/Examples/ex3.c')
| -rw-r--r-- | linuxthreads/Examples/ex3.c | 24 |
1 files changed, 11 insertions, 13 deletions
diff --git a/linuxthreads/Examples/ex3.c b/linuxthreads/Examples/ex3.c index 002bc90..7557cc7 100644 --- a/linuxthreads/Examples/ex3.c +++ b/linuxthreads/Examples/ex3.c @@ -1,6 +1,7 @@ /* Multi-thread searching. Illustrates: thread cancellation, cleanup handlers. */ +#include <errno.h> #include <stdio.h> #include <unistd.h> #include <stdlib.h> @@ -19,9 +20,7 @@ pthread_t threads[NUM_THREADS]; pthread_mutex_t lock; int tries; -int main(argc, argv) - int argc; - char ** argv; +int main(int argc, char ** argv) { int i; int pid; @@ -31,14 +30,14 @@ int main(argc, argv) printf("Searching for the number = %d...\n", pid); /* Initialize the mutex lock */ - pthread_mutex_init(&lock, NULL); + pthread_mutex_init(&lock, NULL); /* Create the searching threads */ for (i=0; i<NUM_THREADS; i++) pthread_create(&threads[i], NULL, search, (void *)pid); /* Wait for (join) all the searching threads */ - for (i=0; i<NUM_THREADS; i++) + for (i=0; i<NUM_THREADS; i++) pthread_join(threads[i], NULL); printf("It took %d tries to find the number.\n", tries); @@ -47,7 +46,7 @@ int main(argc, argv) return 0; } -/* This is the cleanup function that is called +/* This is the cleanup function that is called when the threads are cancelled */ void print_it(void *arg) @@ -59,7 +58,7 @@ void print_it(void *arg) tid = pthread_self(); /* Print where the thread was in its search when it was cancelled */ - printf("Thread %lx was canceled on its %d try.\n", tid, *try); + printf("Thread %lx was canceled on its %d try.\n", tid, *try); } /* This is the search routine that is executed in each thread */ @@ -82,20 +81,20 @@ void *search(void *arg) ntries = 0; /* Set the cancellation parameters -- - - Enable thread cancellation + - Enable thread cancellation - Defer the action of the cancellation */ pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL); pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL); /* Push the cleanup routine (print_it) onto the thread - cleanup stack. This routine will be called when the + cleanup stack. This routine will be called when the thread is cancelled. Also note that the pthread_cleanup_push call must have a matching pthread_cleanup_pop call. The - push and pop calls MUST be at the same lexical level + push and pop calls MUST be at the same lexical level within the code */ - /* Pass address of `ntries' since the current value of `ntries' is not + /* Pass address of `ntries' since the current value of `ntries' is not the one we want to use in the cleanup function */ pthread_cleanup_push(print_it, (void *)&ntries); @@ -118,7 +117,7 @@ void *search(void *arg) printf("Thread %lx found the number!\n", tid); /* Cancel all the other threads */ - for (j=0; j<NUM_THREADS; j++) + for (j=0; j<NUM_THREADS; j++) if (threads[j] != tid) pthread_cancel(threads[j]); /* Break out of the while loop */ @@ -141,4 +140,3 @@ void *search(void *arg) pthread_cleanup_pop(0); return((void *)0); } - |