Standards
| Standards / Extensions |
C or C++ |
Dependencies |
|---|
z/OS UNIX
Single UNIX Specification, Version 3
|
both |
POSIX(ON)
OS/390 V2R7
|
Format
#define _OPEN_THREADS
#include <pthread.h>
int pthread_mutexattr_getpshared(const pthread_mutexattr_t *attr, int *pshared);
SUSV3: #define _UNIX03_THREADS
#include <pthread.h>
int pthread_mutexattr_getpshared(const pthread_mutexattr_t *__restrict__attr,
int * __restrict__ pshared);
General description
The pthread_mutexattr_getpshared()
function gets the attribute pshared for
the mutex attribute object attr. By using attr with
the pthread_mutexattr_getpshared() function you can determine its process-shared value
for a mutex.
The valid values for the attribute
pshared are:
- PTHREAD_PROCESS_SHARED
- Permits a mutex to be operated upon by any thread that has access
to the memory where the mutex is allocated, even if the mutex is allocated
in memory that is shared by multiple processes.
- PTHREAD_PROCESS_PRIVATE
- A mutex can only be operated upon by threads created within the
same process as the thread that initialized the mutex. When a new
process is created by the parent process it will receive a different
copy of the private mutex and this new mutex can only be used to serialize
between threads in the child process. The default value of the attribute
is PTHREAD_PROCESS_PRIVATE.
Returned value
If successful, pthread_mutexattr_getpshared()
returns 0.
If unsuccessful, pthread_mutexattr_getpshared()
returns -1 and sets errno to one of the following values:
- Error Code
- Description
- EINVAL
- The value specified for attr is not
valid.
Special behavior for Single UNIX Specification, Version 3: If
unsuccessful, pthread_mutexattr_getpshared() returns an error number
to indicate the error.