#include <pthread.h>
int pthread_mutexattr_init(pthread_mutexattr_t *attr);
Threadsafe: Yes
Signal Safe: Yes

The pthread_mutexattr_init() function initializes the mutex attributes object referenced by attr to the default attributes. The mutex attributes object can be used in a call to pthread_mutex_init() to create a mutex.

Attribute	Default value	supported values
pshared	PTHREAD_PROCESS_PRIVATE	PTHREAD_PROCESS_PRIVATE or PTHREAD_PROCESS_SHARED
kind (non portable)	PTHREAD_MUTEX_NONRECURSIVE_NP	PTHREAD_MUTEX_NONRECURSIVE_NP or PTHREAD_MUTEX_RECURSIVE_NP
name (non portable)	PTHREAD_DEFAULT_MUTEX_NAME_NP "QP0WMTX UNNAMED"	Any name 15 characters or less. If not terminated by a null character, name is truncated to 15 characters.
type	PTHREAD_MUTEX_DEFAULT (PTHREAD_MUTEX_NORMAL)	PTHREAD_MUTEX_DEFAULT or PTHREAD_MUTEX_NORMAL or PTHREAD_MUTEX_RECURSIVE or PTHREAD_MUTEX_ERRORCHECK or PTHREAD_MUTEX_OWNERTERM_NP The PTHREAD_MUTEX_OWNERTERM_NP attribute value is non portable

Parameters

attr

(Input/Output) Address of the variable to contain the mutex attributes object

None.

Return Value

0

pthread_mutexattr_init() was successful.

value

pthread_mutexattr_init() was not successful. value is set to indicate the error condition.

If pthread_mutexattr_init() was not successful, the error condition returned usually indicates one of the following errors. Under some conditions, the value returned could indicate an error other than those listed here.

[EINVAL]

The value specified for the argument is not correct.

• The <pthread.h> header file. See Header files for Pthread functions
• pthread_mutexattr_destroy()--Destroy Mutex Attributes Object
• pthread_mutex_destroy()--Destroy Mutex
• pthread_mutex_init()--Initialize Mutex

#include <pthread.h>
#include <stdio.h>
#include "check.h"

pthread_mutex_t    mutex;

int main(int argc, char **argv)
{
  int                   rc=0;
  pthread_mutexattr_t   mta;

  printf("Entering testcase\n");

  printf("Create a default mutex attribute\n");
  rc = pthread_mutexattr_init(&mta);
  checkResults("pthread_mutexattr_init\n", rc);

  printf("Create the mutex using a mutex attributes object\n");
  rc = pthread_mutex_init(&mutex, &mta);
  checkResults("pthread_mutex_init(mta)\n", rc);

  printf("- At this point, the mutex with its default attributes\n");
  printf("- Can be used from any threads that want to use it\n");

  printf("Destroy mutex attribute\n");
  rc = pthread_mutexattr_destroy(&mta);
  checkResults("pthread_mutexattr_destroy()\n", rc);

  
  printf("Destroy mutex\n");
  rc = pthread_mutex_destroy(&mutex);
  checkResults("pthread_mutex_destroy()\n", rc);
  
  printf("Main completed\n");
  return 0;
}

Entering testcase
Create a default mutex attribute
Create the mutex using a mutex attributes object
- At this point, the mutex with its default attributes
- Can be used from any threads that want to use it
Destroy mutex attribute
Destroy mutex
Main completed