Manual Pages  — PTHREAD_RWLOCKATTR_SETPSHARED

pthread_rwlockattr_setpshared – set the process shared attribute

LIBRARY SYNOPSIS DESCRIPTION RETURN VALUES ERRORS SEE ALSO STANDARDS HISTORY

POSIX Threads Library (libpthread, -lpthread)

#include <pthread.h>

int
pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr, int pshared);

The pthread_rwlockattr_setpshared() function sets the process shared attribute of attr to the value referenced by pshared. The pshared argument may be one of two values:

PTHREAD_PROCESS_SHARED	Any thread of any process that has access to the memory where the read/write lock resides can manipulate the lock.
PTHREAD_PROCESS_PRIVATE
	Only threads created within the same process as the thread that initialized the read/write lock can manipulate the lock. This is the default value.

If successful, the pthread_rwlockattr_setpshared() function will return zero. Otherwise an error number will be returned to indicate the error.

The pthread_rwlockattr_setpshared() function will fail if:

[EINVAL]
	The value specified by attr or pshared is invalid.

The pthread_rwlockattr_setpshared() function is expected to conform to Version 2 of the Single UNIX Specification.

The pthread_rwlockattr_setpshared() function first appeared in FreeBSD 3.0 . Support for process-shared read/write locks appeared in FreeBSD 11.0 .