Setting a Read-Write Lock Attribute

pthread_rwlockattr_setpshared(3C) sets the process-shared read-write lock attribute.

pthread_rwlockattr_setpshared Syntax

#include <pthread.h>
int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr, int pshared);

The pshared lock attribute has one of the following values:

PTHREAD_PROCESS_SHARED

Description:

Permits a read-write lock to be operated on by any thread that has access to the memory where the read-write lock is allocated. Operation on the read-write lock is permitted even if the lock is allocated in memory that is shared by multiple processes.

PTHREAD_PROCESS_PRIVATE

Description:

The read-write lock is only operated upon by threads created within the same process as the thread that initialized the read-write lock. If threads of differing processes attempt to operate on such a read-write lock, the behavior is undefined. The default value of the process-shared attribute is PTHREAD_PROCESS_PRIVATE.

pthread_rwlockattr_setpshared Return Values

If successful, pthread_rwlockattr_setpshared() returns zero. Otherwise, an error number is returned to indicate the error.

EINVAL

Description:

The value specified by attr or pshared is invalid.