Template:OS2API Example CritSec

This example shows how a thread enters and exits a critical section of code.

#define INCL_DOSPROCESS      /* Process values */
#define INCL_DOSERRORS       /* Error values */
#include <os2.h>
#include <stdio.h>

int main(VOID)
{
  APIRET  rc = NO_ERROR;    /* Return code */

  rc = DosEnterCritSec();

  if (rc != NO_ERROR) {
      printf("DosEnterCritSec error: return code = %u\n",rc);
      return 1;
  }
    /***********************************************/
    /* Add critical section code here.  While this */
    /* code is running, all other threads are      */
    /* stopped.  CALL NO LIBRARY OR OS/2 FUNCTIONS */
    /* HERE UNLESS YOU KNOW THEY DO NOT REQUIRE    */
    /* ACTION BY ANOTHER THREAD IN THE PROCESS.    */
    /***********************************************/

  rc =  DosExitCritSec();

  if (rc != NO_ERROR) {
      printf("DosExitCritSec error: return code = %u\n",rc);
      return 1;
  }

  return NO_ERROR;
}