pthread_attr_setinheritsched()--Set Thread Attribute Inherit Scheduling Attributes

 #include <pthread.h>
 #include <sched.h>
 int pthread_attr_setinheritsched(pthread_attr_t *attr,
 				  int *inheritsched);

The pthread_attr_setinheritsched() function sets the inheritsched attribute in the thread attributes object specified. The inheritsched attribute should be one of PTHREAD_EXPLICIT_SCHED or PTHREAD_INHERIT_SCHED. The default inheritsched attribute is PTHREAD_EXPLICIT_SCHED, with a default priority of zero.

Use the inheritsched attribute to inherit or explicitly specify the scheduling attributes when creating new threads.

Authorities and Locks

None.

Parameters

attr

(Input) Address of thread creation attributes

inheritsched

(Output) Address of the variable to receive the inheritsched attribute

Return Value

0

pthread_attr_setinheritsched() was successful

value

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

Error Conditions

If pthread_attr_setinheritsched() 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_attr_getinheritsched()--Get Thread Attribute Object Inherit Scheduling Attributes
  
  
• pthread_attr_getschedparam()--Get Thread Attributes Object Scheduling Parameters

Example

See Code disclaimer information for information pertaining to code examples.

#define _MULTI_THREADED
#include <pthread.h>
#include <stdio.h>
#include <except.h>
#include "check.h"

void showInheritSched(pthread_attr_t *attr) {
  int rc;
  int inheritsched;
  rc = pthread_attr_getinheritsched(attr, &inheritsched);
  checkResults("pthread_attr_getinheritsched()\n", rc);
 
  switch(inheritsched) {
  case PTHREAD_EXPLICIT_SCHED:
    printf("Inherit Sched - PTHREAD_EXPLICIT_SCHED\n");
    break;
  case PTHREAD_INHERIT_SCHED:
    printf("Inherit Sched - PTHREAD_INHERIT_SCHED\n");
    break;
  default:
    printf("Invalid inheritsched attribute!\n");
    exit(1);
  }
  return; 
}

int main(int argc, char **argv)
{
  pthread_t             thread;
  int                   rc=0;
  pthread_attr_t        attr;
  char                  c;
  void                  *status;

  printf("Enter Testcase - %s\n", argv[0]);

  rc = pthread_attr_init(&attr);
  checkResults("pthread_attr_init()\n", rc);

  showInheritSched(&attr);
 
  rc = pthread_attr_setinheritsched(&attr, PTHREAD_INHERIT_SCHED);
  checkResults("pthread_attr_setinheritsched()\n", rc);
 
  showInheritSched(&attr);

  rc = pthread_attr_destroy(&attr);
  checkResults("pthread_attr_destroy()\n", rc);

  printf("Main completed\n");
  return 0;
}

Output:

Enter Testcase - QP0WTEST/TPSIS0
Inherit Sched - PTHREAD_EXPLICIT_SCHED
Inherit Sched - PTHREAD_INHERIT_SCHED
Main completed