37 lines
1.1 KiB
C
37 lines
1.1 KiB
C
#include <sys/syscall.h>
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#include <sys/wait.h>
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#include <sys/time.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <spawn.h>
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#define NREPEATS 5000
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int main(int argc, const char *argv[]) {
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struct timeval tv_start, tv_end;
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gettimeofday(&tv_start, NULL);
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for (unsigned long i = 0; i < NREPEATS; i++) {
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int child_pid, status;
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if (posix_spawn(&child_pid, "/bin/empty", NULL, NULL, NULL, NULL) < 0) {
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printf("ERROR: failed to spawn (# of repeats = %lu)\n", i);
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return -1;
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}
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if (wait4(-1, &status, 0, NULL) < 0) {
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printf("ERROR: failed to wait4 (# of repeats = %lu)\n", i);
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return -1;
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}
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if (status != 0) {
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printf("ERROR: child process exits with error\n");
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return -1;
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}
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}
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gettimeofday(&tv_end, NULL);
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suseconds_t total_us = (tv_end.tv_sec - tv_start.tv_sec) * 1000000UL +
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+ (tv_end.tv_usec - tv_start.tv_usec);
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suseconds_t latency = total_us / NREPEATS;
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printf("Latency of spawn/exit = %lu us\n", latency);
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return 0;
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}
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