VxWorks_programs2.zip_inversion

1. Example: In the example below, the "sigGenerator" function generates the SIGINT or Ctrl-C signal, and directs the signal to the "sigCatcher" task. When "sigCatcher" receives the signal, it suspends its normal execution and branches to a signal hander that it has installed(catchSIGINT function). ------------------------------------------------------------------------------------ /* includes */ #include "vxWorks.h" #include "sigLib.h" #include "taskLib.h" #include "stdio.h" /* function prototypes */ void catchSIGINT(int); void sigCatcher(void); /* globals */ #define NO_OPTIONS 0 #define ITER1 100 #define LONG_TIME 1000000 #define HIGHPRIORITY 101 #define MIDPRIORITY 102 #define LOWPRIORITY 103 int ownId; void sigGenerator(void) /* task to generate the SIGINT signal */ { int i, j, taskId; STATUS taskAlive; if((taskId = taskSpawn("signal",MIDPRIORITY,0x100,20000,(FUNCPTR)sigCatcher,0,0,0,0,0,0,0, 0,0,0)) == ERROR) printf("taskSpawn sigCatcher failed\n"); ownId = taskIdSelf(); /* get sigGenerator's task id */ taskDelay(30); /* allow time to get sigCatcher to run */ for (i=0; i < ITER1; i++) { if ((taskAlive = taskIdVerify(taskId)) == OK) { printf("+++++++++++++++++++++++++++++++SIGINT sinal generated\n"); kill(taskId, SIGINT); /* generate signal */ /* lower sigGenerator priority to allow sigCatcher to run */ taskPrioritySet(ownId,LOWPRIORITY); } else /* sigCatcher is dead */ break; } printf("\n***************sigGenerator Exited***************\n"); } void sigCatcher(void) /* task to handle the SIGINT signal */ { struct sigaction newAction; int i, j; newAction.sa_handler = catchSIGINT; /* set the new handler */ sigemptyset(&newAction.sa_mask); /* no other signals blocked */ newAction.sa_flags = NO_OPTIONS; /* no special options */ if(sigaction(SIGINT, &newAction, NULL) == -1) printf("Could not install signal handler\n"); for (i=0; i < ITER1; i++) { for (j=0; j < LONG_TIME; j++); printf("Normal processing in sigCatcher\n"); } printf("\n+++++++++++++++sigCatcher Exited+++++++++++++++\n"); } void catchSIGINT(int signal) /* signal handler code */ { printf("-------------------------------SIGINT signal caught\n"); /* increase sigGenerator priority to allow sigGenerator to run */ taskPrioritySet(ownId,HIGHPRIORITY); }