{解决}读写锁，写锁呗读锁阻塞了 - Chinaunix

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#define size 10
int i = 0;
pthread_rwlock_t rwlock;
void *read_func( void *arg);
void *write_func( void *arg);
int main( void)
{
int j = 2*size;
pthread_t *tids = (pthread_t *)malloc( j*sizeof( pthread_t));
pthread_rwlockattr_t rwlockattr;
pthread_rwlockattr_init( &rwlockattr);
pthread_rwlockattr_setkind_np (&rwlockattr, PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP);
pthread_rwlock_init( &rwlock, NULL);
int m = 0;
for( m =0; m < j; m++)
{
if( m < size)
{
pthread_create( tids+m, NULL, write_func, (void*)m);
}
else
{
pthread_create( tids+m, NULL, read_func, (void *)m);
}
}
for( m = 0; m < j; m++)
{
pthread_join( *(tids+m), (void *)0);
}
pthread_rwlock_destroy( &rwlock);
return 0;
}
void * read_func( void *arg)
{
while( i < 10)
{
pthread_rwlock_rdlock( &rwlock);
printf("%d reading i:%d\n", (int)arg, i);
pthread_rwlock_unlock( &rwlock);
}
void *write_func( void *arg)
{
pthread_rwlock_wrlock( &rwlock);
printf("%d read i: %d\n", (int)arg, i++);
printf("%d writing i: %d\n", (int)arg, i);
pthread_rwlock_unlock( &rwlock);
}

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