int start3(char *arg)
{
int result;
int pid;
int status;
USLOSS_Console("start3(): started\n");
result = SemCreate(3, &sem1);
SemP(sem1);
USLOSS_Console("start3(): After P in the CS\n");
Spawn("Child1", Child1, "Child1", USLOSS_MIN_STACK, 2, &pid);
USLOSS_Console("\nstart3(): spawn %d\n", pid);
Spawn("Child2", Child2, "Child2", USLOSS_MIN_STACK, 3, &pid);
USLOSS_Console("start3(): spawn %d\n", pid);
SemV(sem1);
USLOSS_Console("\nstart3(): After V -- may appear before: Child1(): After P attempt #3\n");
Wait(&pid, &status);
USLOSS_Console("\nstart3(): status of quit child = %d\n",status);
Wait(&pid, &status);
USLOSS_Console("start3(): status of quit child = %d\n",status);
USLOSS_Console("start3(): Parent done\n");
Terminate(8);
return 0;
} /* start3 */
int Child2(char *arg)
{
int i;
USLOSS_Console("\n%s(): starting\n", arg);
for (i = 0; i < 5; i++) {
SemV(sem1);
USLOSS_Console("%s(): After V attempt #%d\n", arg, i);
}
USLOSS_Console("%s(): done\n", arg);
Terminate(10);
return 0;
} /* Child2 */
int
Child(char *arg)
{
int pid;
char str[64]= "This is the first page";
GetPID(&pid);
Tconsole("\nChild(%d): starting\n", pid);
Tconsole("Child(%d): str = %s\n", pid, str);
Tconsole("Child(%d): strlen(str) = %d\n", pid, strlen(str));
memcpy(vmRegion, str, strlen(str)+1); // +1 to copy nul character
Tconsole("Child(%d): after memcpy\n", pid);
if (strcmp(vmRegion, str) == 0)
Tconsole("Child(%d): strcmp first attempt worked!\n", pid);
else
Tconsole("Child(%d): Wrong string read, first attempt\n", pid);
assert(vmStats.faults == 1);
assert(vmStats.new == 1);
SemV(sem); // forces a context switch with start5
if (strcmp(vmRegion, str) == 0)
Tconsole("Child(%d): strcmp second attempt worked!\n", pid);
else
Tconsole("Child(%d): Wrong string read, second attempt\n", pid);
Tconsole("Child(%d): checking various vmStats\n", pid);
assert(vmStats.faults == 1);
assert(vmStats.new == 1);
assert(vmStats.pageOuts == 0);
assert(vmStats.pageIns == 0);
Tconsole("Child(%d): terminating\n\n", pid);
Terminate(117);
return 0;
} /* Child */
int
Child(char *arg)
{
int pid;
char *zeros;
GetPID(&pid);
Tconsole("Child(): starting (pid = %d)\n", pid);
zeros = calloc(USLOSS_MmuPageSize(), 1);
if (memcmp(vmRegion, zeros, USLOSS_MmuPageSize()) != 0) {
Tconsole("Child(): VmRegion is not zero-filled\n");
abort();
}
verify(vmStats.faults == 1);
SemV(sem);
Terminate(117);
return 0;
} /* Child */
