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This commit is contained in:
Simon Gardling
2024-09-10 13:03:02 -04:00
parent 53c617d779
commit d66450e427
381 changed files with 28864 additions and 34170 deletions
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231
userland/testbin/forktest/forktest.c
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@@ -51,16 +51,13 @@ static volatile int mypid;
/*
* Helper function for fork that prints a warning on error.
*/
static
int
dofork(void)
{
int pid;
pid = fork();
if (pid < 0) {
warn("fork");
}
return pid;
static int dofork(void) {
int pid;
pid = fork();
if (pid < 0) {
warn("fork");
}
return pid;
}
/*
@@ -68,24 +65,22 @@ dofork(void)
* the pid into the data segment and read it back repeatedly, making
* sure it's correct every time.
*/
static
void
check(void)
{
int i;
static void check(void) {
int i;
mypid = getpid();
mypid = getpid();
/* Make sure each fork has its own address space. */
for (i=0; i<800; i++) {
volatile int seenpid;
seenpid = mypid;
if (seenpid != getpid()) {
errx(1, "pid mismatch (%d, should be %d) "
"- your vm is broken!",
seenpid, getpid());
}
}
/* Make sure each fork has its own address space. */
for (i = 0; i < 800; i++) {
volatile int seenpid;
seenpid = mypid;
if (seenpid != getpid()) {
errx(1,
"pid mismatch (%d, should be %d) "
"- your vm is broken!",
seenpid, getpid());
}
}
}
/*
@@ -97,121 +92,109 @@ check(void)
* generated the current process; that means it's time to exit. Only
* the parent of all the processes returns from the chain of dowaits.
*/
static
void
dowait(int nowait, int pid)
{
int x;
static void dowait(int nowait, int pid) {
int x;
if (pid<0) {
/* fork in question failed; just return */
return;
}
if (pid==0) {
/* in the fork in question we were the child; exit */
exit(0);
}
if (pid < 0) {
/* fork in question failed; just return */
return;
}
if (pid == 0) {
/* in the fork in question we were the child; exit */
exit(0);
}
if (!nowait) {
if (waitpid(pid, &x, 0)<0) {
warn("waitpid");
}
else if (WIFSIGNALED(x)) {
warnx("pid %d: signal %d", pid, WTERMSIG(x));
}
else if (WEXITSTATUS(x) != 0) {
warnx("pid %d: exit %d", pid, WEXITSTATUS(x));
}
}
if (!nowait) {
if (waitpid(pid, &x, 0) < 0) {
warn("waitpid");
} else if (WIFSIGNALED(x)) {
warnx("pid %d: signal %d", pid, WTERMSIG(x));
} else if (WEXITSTATUS(x) != 0) {
warnx("pid %d: exit %d", pid, WEXITSTATUS(x));
}
}
}
/*
* Actually run the test.
*/
static
void
test(int nowait)
{
int pid0, pid1, pid2, pid3;
int depth = 0;
static void test(int nowait) {
int pid0, pid1, pid2, pid3;
int depth = 0;
/*
* Caution: This generates processes geometrically.
*
* It is unrolled to encourage gcc to registerize the pids,
* to prevent wait/exit problems if fork corrupts memory.
*
* Note: if the depth prints trigger and show that the depth
* is too small, the most likely explanation is that the fork
* child is returning from the write() inside putchar()
* instead of from fork() and thus skipping the depth++. This
* is a fairly common problem caused by races in the kernel
* fork code.
*/
/*
* Caution: This generates processes geometrically.
*
* It is unrolled to encourage gcc to registerize the pids,
* to prevent wait/exit problems if fork corrupts memory.
*
* Note: if the depth prints trigger and show that the depth
* is too small, the most likely explanation is that the fork
* child is returning from the write() inside putchar()
* instead of from fork() and thus skipping the depth++. This
* is a fairly common problem caused by races in the kernel
* fork code.
*/
pid0 = dofork();
depth++;
putchar('A');
if (depth != 1) {
warnx("depth %d, should be 1", depth);
}
check();
pid0 = dofork();
depth++;
putchar('A');
if (depth != 1) {
warnx("depth %d, should be 1", depth);
}
check();
pid1 = dofork();
depth++;
putchar('B');
if (depth != 2) {
warnx("depth %d, should be 2", depth);
}
check();
pid1 = dofork();
depth++;
putchar('B');
if (depth != 2) {
warnx("depth %d, should be 2", depth);
}
check();
pid2 = dofork();
depth++;
putchar('C');
if (depth != 3) {
warnx("depth %d, should be 3", depth);
}
check();
pid2 = dofork();
depth++;
putchar('C');
if (depth != 3) {
warnx("depth %d, should be 3", depth);
}
check();
pid3 = dofork();
depth++;
putchar('D');
if (depth != 4) {
warnx("depth %d, should be 4", depth);
}
check();
pid3 = dofork();
depth++;
putchar('D');
if (depth != 4) {
warnx("depth %d, should be 4", depth);
}
check();
/*
* These must be called in reverse order to avoid waiting
* improperly.
*/
dowait(nowait, pid3);
dowait(nowait, pid2);
dowait(nowait, pid1);
dowait(nowait, pid0);
/*
* These must be called in reverse order to avoid waiting
* improperly.
*/
dowait(nowait, pid3);
dowait(nowait, pid2);
dowait(nowait, pid1);
dowait(nowait, pid0);
putchar('\n');
putchar('\n');
}
int
main(int argc, char *argv[])
{
static const char expected[] =
"|----------------------------|\n";
int nowait=0;
int main(int argc, char *argv[]) {
static const char expected[] = "|----------------------------|\n";
int nowait = 0;
if (argc==2 && !strcmp(argv[1], "-w")) {
nowait=1;
}
else if (argc!=1 && argc!=0) {
warnx("usage: forktest [-w]");
return 1;
}
warnx("Starting. Expect this many:");
write(STDERR_FILENO, expected, strlen(expected));
if (argc == 2 && !strcmp(argv[1], "-w")) {
nowait = 1;
} else if (argc != 1 && argc != 0) {
warnx("usage: forktest [-w]");
return 1;
}
warnx("Starting. Expect this many:");
write(STDERR_FILENO, expected, strlen(expected));
test(nowait);
test(nowait);
warnx("Complete.");
return 0;
warnx("Complete.");
return 0;
}