kaguya
94 lines
1.5 KiB
C
94 lines
1.5 KiB
C
#include <stdio.h>
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#include <assert.h>
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#include <signal.h>
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#include <unistd.h>
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#include <sys/wait.h>
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#include <errno.h>
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pid_t parent;
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pid_t child;
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int fds[2];
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void parent_fn() {
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int res;
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sigset_t set;
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sigemptyset(&set);
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sigaddset(&set, SIGUSR2);
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sigprocmask(SIG_BLOCK, &set, NULL);
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res = write(fds[1], "!", 1);
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assert(res == 1);
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siginfo_t info;
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res = sigwaitinfo(&set, &info);
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assert(res == SIGUSR2);
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assert(info.si_signo == SIGUSR2);
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res = write(fds[1], "!", 1);
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assert(res == 1);
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// XXX: This may not be long enough to get scheduled
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struct timespec tout = {1, 0};
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res = sigtimedwait(&set, &info, &tout);
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assert(res == SIGUSR2);
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assert(info.si_signo == SIGUSR2);
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res = write(fds[1], "!", 1);
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assert(res == 1);
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int sig;
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res = sigwait(&set, &sig);
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assert(res == 0);
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assert(sig == SIGUSR2);
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res = write(fds[1], "!", 1);
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assert(res == 1);
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res = sigtimedwait(&set, &info, &tout);
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assert(res < 0);
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assert(errno == EAGAIN);
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int wsts;
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res = waitpid(child, &wsts, 0);
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assert(res >= 0);
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}
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void child_fn() {
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int res;
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char c;
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res = read(fds[0], &c, 1);
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assert(res == 1);
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kill(parent, SIGUSR2);
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res = read(fds[0], &c, 1);
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assert(res == 1);
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kill(parent, SIGUSR2);
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res = read(fds[0], &c, 1);
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assert(res == 1);
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kill(parent, SIGUSR2);
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res = read(fds[0], &c, 1);
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assert(res == 1);
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}
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int main() {
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int res;
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parent = getpid();
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assert(parent > 0);
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res = pipe(fds);
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assert(res == 0);
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child = fork();
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assert(child >= 0);
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if (child)
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parent_fn();
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else
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child_fn();
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return 0;
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}
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