cosmopolitan/examples/forkrand.c

46 lines
1.6 KiB
C

#if 0
/*─────────────────────────────────────────────────────────────────╗
│ To the extent possible under law, Justine Tunney has waived │
│ all copyright and related or neighboring rights to this file, │
│ as it is written in the following disclaimers: │
│ • http://unlicense.org/ │
│ • http://creativecommons.org/publicdomain/zero/1.0/ │
╚─────────────────────────────────────────────────────────────────*/
#endif
#include "libc/calls/calls.h"
#include "libc/log/check.h"
#include "libc/log/log.h"
#include "libc/nt/nt/process.h"
#include "libc/rand/rand.h"
#include "libc/runtime/runtime.h"
#include "libc/stdio/stdio.h"
#include "libc/time/time.h"
noinline void dostuff(const char *s) {
int i, us;
srand(rand64()); /* seeds rand() w/ intel rdrnd, auxv, etc. */
for (i = 0; i < 5; ++i) {
us = rand() % 500000;
usleep(us);
printf("hello no. %u from %s %u [us=%d]\n", i, s, getpid(), us);
fflush(stdout);
}
}
int main(int argc, char *argv[]) {
int rc, child, wstatus;
CHECK_NE(-1, (child = fork()));
if (!child) {
/* child process */
dostuff("child");
return 0;
} else {
/* parent process */
dostuff("parent");
/* note: abandoned children become zombies */
CHECK_NE(-1, (rc = wait(&wstatus)));
CHECK_EQ(0, WEXITSTATUS(wstatus));
return 0;
}
}