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author | Roland McGrath <roland@gnu.org> | 2005-07-03 04:40:34 +0000 |
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committer | Roland McGrath <roland@gnu.org> | 2005-07-03 04:40:34 +0000 |
commit | 88e3fbcb5d6829f8980d6bb356b1c0cd7a38187b (patch) | |
tree | 41b73f55c91439f87d82e5d32b9d8e46e82ce3c1 /linuxthreads/Examples/ex3.c | |
parent | d19b1b4f2ff49e085b55e8564b52ca17b028e335 (diff) | |
download | glibc-88e3fbcb5d6829f8980d6bb356b1c0cd7a38187b.tar.gz glibc-88e3fbcb5d6829f8980d6bb356b1c0cd7a38187b.tar.xz glibc-88e3fbcb5d6829f8980d6bb356b1c0cd7a38187b.zip |
linuxthreads, linuxthreads_db: Directories removed (preserved in ports repository).
Diffstat (limited to 'linuxthreads/Examples/ex3.c')
-rw-r--r-- | linuxthreads/Examples/ex3.c | 152 |
1 files changed, 0 insertions, 152 deletions
diff --git a/linuxthreads/Examples/ex3.c b/linuxthreads/Examples/ex3.c deleted file mode 100644 index b80b323a33..0000000000 --- a/linuxthreads/Examples/ex3.c +++ /dev/null @@ -1,152 +0,0 @@ -/* Multi-thread searching. - Illustrates: thread cancellation, cleanup handlers. */ - -#include <errno.h> -#include <stdio.h> -#include <unistd.h> -#include <stdlib.h> -#include <sys/types.h> -#include <pthread.h> - -/* Defines the number of searching threads */ -#define NUM_THREADS 5 - -/* Function prototypes */ -void *search(void *); -void print_it(void *); - -/* Global variables */ -pthread_t threads[NUM_THREADS]; -pthread_mutex_t lock; -int tries; -volatile int started; - -int main(int argc, char ** argv) -{ - int i; - int pid; - - /* create a number to search for */ - pid = getpid(); - printf("Searching for the number = %d...\n", pid); - - /* Initialize the mutex lock */ - pthread_mutex_init(&lock, NULL); - - /* Create the searching threads */ - for (started=0; started<NUM_THREADS; started++) - pthread_create(&threads[started], NULL, search, (void *) (long int) pid); - - /* Wait for (join) all the searching threads */ - for (i=0; i<NUM_THREADS; i++) - pthread_join(threads[i], NULL); - - printf("It took %d tries to find the number.\n", tries); - - /* Exit the program */ - return 0; -} - -/* This is the cleanup function that is called - when the threads are cancelled */ - -void print_it(void *arg) -{ - int *try = (int *) arg; - pthread_t tid; - - /* Get the calling thread's ID */ - 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); -} - -/* This is the search routine that is executed in each thread */ - -void *search(void *arg) -{ - int num = (long int) arg; - int i, j, ntries; - pthread_t tid; - - /* get the calling thread ID */ - tid = pthread_self(); - - /* use the thread ID to set the seed for the random number generator */ - /* Since srand and rand are not thread-safe, serialize with lock */ - - /* Try to lock the mutex lock -- - if locked, check to see if the thread has been cancelled - if not locked then continue */ - while (pthread_mutex_trylock(&lock) == EBUSY) - pthread_testcancel(); - - srand((int)tid); - i = rand() & 0xFFFFFF; - pthread_mutex_unlock(&lock); - ntries = 0; - - /* Set the cancellation parameters -- - - Enable thread cancellation - - Defer the action of the cancellation */ - - pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL); - pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL); - - while (started < NUM_THREADS) - sched_yield (); - - /* Push the cleanup routine (print_it) onto the thread - 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 - within the code */ - - /* 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); - - /* Loop forever */ - while (1) { - i = (i + 1) & 0xFFFFFF; - ntries++; - - /* Does the random number match the target number? */ - if (num == i) { - /* Try to lock the mutex lock -- - if locked, check to see if the thread has been cancelled - if not locked then continue */ - while (pthread_mutex_trylock(&lock) == EBUSY) - pthread_testcancel(); - - /* Set the global variable for the number of tries */ - tries = ntries; - printf("Thread %lx found the number!\n", tid); - - /* Cancel all the other threads */ - for (j=0; j<NUM_THREADS; j++) - if (threads[j] != tid) pthread_cancel(threads[j]); - - /* Break out of the while loop */ - break; - } - - /* Every 100 tries check to see if the thread has been cancelled. */ - if (ntries % 100 == 0) { - pthread_testcancel(); - } - } - - /* The only way we can get here is when the thread breaks out - of the while loop. In this case the thread that makes it here - has found the number we are looking for and does not need to run - the thread cleanup function. This is why the pthread_cleanup_pop - function is called with a 0 argument; this will pop the cleanup - function off the stack without executing it */ - - pthread_cleanup_pop(0); - return((void *)0); -} |