1 2 /* Do simple things with a recursive mutex. */ 3 4 /* Needed for older glibcs (2.3 and older, at least) who don't 5 otherwise "know" about pthread_rwlock_anything or about 6 PTHREAD_MUTEX_RECURSIVE (amongst things). */ 7 #define _GNU_SOURCE 1 8 9 #include <stdio.h> 10 #include <stdlib.h> 11 #include <assert.h> 12 #include <pthread.h> 13 14 void nearly_main ( void ) 15 { 16 pthread_mutex_t mx1; 17 pthread_mutexattr_t attr; 18 int r; 19 20 r = pthread_mutexattr_init( &attr ); 21 assert(r==0); 22 r = pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE ); 23 assert(r==0); 24 r = pthread_mutex_init( &mx1, &attr ); 25 assert(r==0); 26 27 fprintf(stderr, "before lock #1\n"); 28 r = pthread_mutex_lock( &mx1 ); assert(r == 0); 29 fprintf(stderr, "before lock #2\n"); 30 r = pthread_mutex_lock( &mx1 ); assert(r == 0); 31 fprintf(stderr, "before lock #3\n"); 32 r = pthread_mutex_lock( &mx1 ); assert(r == 0); 33 34 fprintf(stderr, "before unlock #1\n"); 35 r = pthread_mutex_unlock( &mx1 ); assert(r == 0); 36 fprintf(stderr, "before unlock #2\n"); 37 r = pthread_mutex_unlock( &mx1 ); assert(r == 0); 38 fprintf(stderr, "before unlock #3\n"); 39 r = pthread_mutex_unlock( &mx1 ); assert(r == 0); 40 41 fprintf(stderr, "before unlock #4\n"); 42 r = pthread_mutex_unlock( &mx1 ); /* FAILS: assert(r == 0); */ 43 } 44 45 int main ( void ) 46 { 47 nearly_main(); 48 return 0; 49 } 50
