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@croepha
Last active January 20, 2019 14:17
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#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <assert.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
void*thread1(void*) {
auto p1 = fork();
assert(p1!=-1);
if (!p1) {
sleep(4);
exit(0);
}
auto p2 = fork();
assert(p2!=-1);
if (!p2) {
sleep(4);
exit(0);
}
printf("p1 %d\n", p1);
printf("p2 %d\n", p2);
// wait for either p1 or p2
while (p1 != -1 || p2 != -1) {
#if 1
siginfo_t w1;
auto r1 = waitid(P_ALL, -1, &w1, WEXITED|WNOWAIT);
printf("W1 %d %d %d %s\n", r1, w1.si_pid, w1.si_status, strerror(errno));
if (r1 != -1 && w1.si_pid == p1) {
int w2;
auto r2 = waitpid(p1, &w2, 0);
printf("W2 %d %d %s\n", r2, w2, strerror(errno));
assert(r2 == p1);
p1 = -1;
};
if (r1 != -1 && w1.si_pid == p2) {
int w2;
auto r2 = waitpid(p2, &w2, 0);
printf("W2 %d %d %s\n", r2, w2, strerror(errno));
assert(r2 == p2);
p2 = -1;
};
#else
int w1;
auto r1 = wait(&w1);
printf("W %d %d %s\n", r1, w1, strerror(errno));
if (r1 != -1 && r1 == p1) p1 = -1;
if (r1 != -1 && r1 == p2) p2 = -1;
#endif
}
printf("W\n");
return 0;
}
void thread2() {
sleep(1);
auto r1 = system("sleep 1");
printf("S1 %d\n", r1);
auto r2 = system("sleep 1");
printf("S2 %d\n", r2);
}
int main () {
pthread_t thread1_h;
pthread_create(&thread1_h, 0, thread1, 0);
thread2();
pthread_join(thread1_h, 0);
}
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