pthread_condattr_init()--Initialize Condition Variable Attributes Object

 #include <pthread.h>
 int pthread_condattr_init(pthread_condattr_t *attr); 

The pthread_condattr_init() function initializes the condition variable attributes object specified by attr to the default attributes. The condition variable attributes object is used to create condition variables with the pthread_cond_init() function.

Authorities and Locks

None.

Parameters

attr

(Output) The address of the variable to contain the condition variable attributes object

Return Value

0

pthread_condattr_init() was successful.

value

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

Error Conditions

If pthread_condattr_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.

Related Information

• The <pthread.h> header file. See Header files for Pthread functions.
  
  
• pthread_condattr_destroy()--Destroy Condition Variable Attributes Object
  
  
• pthread_cond_init()--Initialize Condition Variable

Example

See Code disclaimer information for information pertaining to code examples.

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

pthread_cond_t      cond;

int main(int argc, char **argv)
{
  int                   rc=0;
  pthread_condattr_t    attr;

  printf("Entering testcase\n");

  printf("Create a default condition attribute\n");
  rc = pthread_condattr_init(&attr);
  checkResults("pthread_condattr_init\n", rc);

  printf("Create the condition using the condition attributes object\n");
  rc = pthread_cond_init(&cond, &attr);
  checkResults("pthread_cond_init()\n", rc);

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

  printf("Destroy cond attribute\n");
  rc = pthread_condattr_destroy(&attr);
  checkResults("pthread_condattr_destroy()\n", rc);
 
  printf("Destroy condition\n");
  rc = pthread_cond_destroy(&cond);
  checkResults("pthread_cond_destroy()\n", rc);
 
  printf("Main completed\n");
  return 0;
}

Output:

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