eatnumber1 · March 28, 2017 02:05 · Mar 28, 2017
diff --git a/wait-with-timeout.c b/wait-with-timeout.c
@@ -0,0 +1,72 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <time.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <stdbool.h>
+#include <limits.h>
+#include <sys/wait.h>
+#include <errno.h>
+
+void handler() {}
+
+int main() {
+  pid_t tid = (pid_t) syscall(SYS_gettid);
+
+  int signum = SIGRTMIN + 4;
+
+  timer_t timerid;
+  struct sigevent event = {
+    .sigev_notify = SIGEV_THREAD_ID,
+    .sigev_signo = signum,
+    ._sigev_un._tid = tid
+  };
+  if (timer_create(CLOCK_MONOTONIC, &event, &timerid) == -1) {
+    perror("timer_create");
+    exit(EXIT_FAILURE);
+  }
+
+  struct sigaction act = {
+    .sa_handler = handler
+  };
+  if (sigaction(signum, &act, NULL) == -1) {
+    perror("rt_sigaction");
+    exit(EXIT_FAILURE);
+  }
+
+  pid_t child_pid = fork();
+  if (child_pid == -1) {
+    perror("fork");
+    exit(EXIT_FAILURE);
+  } else if (child_pid == 0) {
+    // child
+    while (true) sleep(UINT_MAX);
+  }
+  // parent
+
+  struct itimerspec timerspec = {
+    .it_value = {
+      .tv_sec = 3
+    }
+  };
+  if (timer_settime(timerid, 0, &timerspec, NULL) == -1) {
+    perror("timer_settime");
+    exit(EXIT_FAILURE);
+  }
+
+  int wstatus;
+  pid_t dead_child = wait(&wstatus);
+  if (dead_child == -1) {
+    if (errno != EINTR) {
+      perror("wait");
+      exit(EXIT_FAILURE);
+    }
+  } else {
+    fprintf(stderr, "wait exited successfully, returning %d\n", dead_child);
+    return EXIT_FAILURE;
+  }
+  return EXIT_SUCCESS;
+}