/* *  Test case for assertion #2 of the sigaction system call that shows * sigaction (when used with a non-null oact pointer) changes the action * for a signal. * * Steps: * 1. Call sigaction to set handler for SIGUSR1 to use handler1 * 2. Call sigaction again to set handler for SIGUSR1 to use handler2, *    but this time use a non-null oarg and verify the sa_handler for  *    oarg is set for handler1.*/#include <signal.h>#include "compat.h"#define NTASKS 1static pthread_t thread[NTASKS];int handler_called = 0;void handler1(int signo){}void handler2(int signo){}void *th_code(void *arg){	struct sigaction act;	struct sigaction oact;		act.sa_handler = handler1;	act.sa_flags = 0;	sigemptyset(&act.sa_mask);	if (sigaction(SIGUSR1,  &act, 0) == -1) {		perror("Unexpected error while attempting to setup test "		       "pre-conditions");		return -1;	}		act.sa_handler = handler2;	sigemptyset(&act.sa_mask);	if (sigaction(SIGUSR1,  &act, &oact) == -1) {		perror("Unexpected error while attempting to setup test "		       "pre-conditions");		return -1;	}	if (oact.sa_handler == handler1) {	  printf("Test PASSED\n");	  return 0;	}	printf("Test Failed\n");	return -1;}int init_module(void){  int i;  for(i=0;i<NTASKS;i++)    pthread_create(&thread[i], NULL,th_code,(void *) i);  return 0;  }void cleanup_module(void){ int i;  for(i=0;i<NTASKS;i++)    pthread_delete_np(thread[i]);}