pthread_mu...getpshared(3) Library Functions Manual pthread_mu...getpshared(3)
NAME
pthread_mutexattr_getpshared, pthread_mutexattr_setpshared - get/set
process-shared mutex attribute
LIBRARY
POSIX threads library (libpthread, -lpthread)
SYNOPSIS
#include <pthread.h>
int pthread_mutexattr_getpshared(
const pthread_mutexattr_t *restrict attr,
int *restrict pshared);
int pthread_mutexattr_setpshared(pthread_mutexattr_t *attr,
int pshared);
DESCRIPTION
These functions get and set the process-shared attribute in a mutex at-
tributes object. This attribute must be appropriately set to ensure
correct, efficient operation of a mutex created using this attributes
object.
The process-shared attribute can have one of the following values:
PTHREAD_PROCESS_PRIVATE
Mutexes created with this attributes object are to be shared
only among threads in the same process that initialized the mu-
tex. This is the default value for the process-shared mutex at-
tribute.
PTHREAD_PROCESS_SHARED
Mutexes created with this attributes object can be shared be-
tween any threads that have access to the memory containing the
object, including threads in different processes.
pthread_mutexattr_getpshared() places the value of the process-shared
attribute of the mutex attributes object referred to by attr in the lo-
cation pointed to by pshared.
pthread_mutexattr_setpshared() sets the value of the process-shared at-
tribute of the mutex attributes object referred to by attr to the value
specified in pshared.
If attr does not refer to an initialized mutex attributes object, the
behavior is undefined.
RETURN VALUE
On success, these functions return 0. On error, they return a positive
error number.
ERRORS
pthread_mutexattr_setpshared() can fail with the following errors:
EINVAL The value specified in pshared is invalid.
ENOTSUP
pshared is PTHREAD_PROCESS_SHARED but the implementation does
not support process-shared mutexes.
STANDARDS
POSIX.1-2008.
HISTORY
POSIX.1-2001.
SEE ALSO
pthread_mutexattr_init(3), pthreads(7)
Linux man-pages 6.7 2023-10-31 pthread_mu...getpshared(3)
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