mirror of
https://github.com/ioacademy-jikim/debugging
synced 2025-06-08 08:26:14 +00:00
63 lines
953 B
C
63 lines
953 B
C
#include <stdio.h>
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#include <unistd.h>
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#include <signal.h>
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#include <errno.h>
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#include <sys/wait.h>
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#include <string.h>
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/* Make sure that a blocking syscall restarts if hit by a signal,
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and SA_RESTART is set */
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static void handler(int s)
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{
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}
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int main()
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{
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int pid;
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int fds[2];
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if (pipe(fds) == -1) {
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perror("FAIL: pipe\n");
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return 1;
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}
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pid = fork();
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if (pid == -1) {
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perror("fork failed");
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return 1;
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}
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if (pid == 0) {
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char ch = '?';
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int ret;
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struct sigaction sa;
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sa.sa_handler = handler;
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sigfillset(&sa.sa_mask);
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sa.sa_flags = SA_RESTART;
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sigaction(SIGUSR1, &sa, NULL);
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close(fds[1]);
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ret = read(fds[0], &ch, 1);
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if (ret != 1 || ch != 'x')
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fprintf(stderr, "FAIL: expected 1 byte, not %d/%s/%c\n",
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ret, strerror(errno), ch);
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} else {
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signal(SIGPIPE, SIG_IGN);
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close(fds[0]);
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sleep(1);
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kill(pid, SIGUSR1);
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sleep(1);
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write(fds[1], "x", 1);
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waitpid(pid, NULL, 0);
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}
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return 0;
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}
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