84 lines
1.9 KiB
C++
84 lines
1.9 KiB
C++
// RUN: %clangxx_tsan %s -o %t && %run %t 2>&1 | FileCheck %s
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// UNSUPPORTED: darwin
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#include <errno.h>
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#include <limits.h>
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#include <pthread.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/select.h>
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#include <sys/time.h>
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#include <sys/types.h>
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#include <unistd.h>
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// This attempts to exercise a race condition where both a thread and its signal
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// handler allocate the SigCtx. If the race is allowed, it leads to a leak and
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// the first signal being dropped.
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// Spawn threads in a loop and send it SIGUSR1 concurrently with the thread
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// doing a bogus kill() call. The signal handler writes to a self-pipe which the
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// thread detects and then exits. A dropped signal results in a timeout.
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int pipes[2];
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static void handler(int sig) { write(pipes[1], "x", 1); }
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static int do_select() {
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struct timeval tvs {
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0, 1000
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};
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fd_set fds;
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FD_ZERO(&fds);
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FD_SET(pipes[0], &fds);
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return select(pipes[0] + 1, &fds, 0, 0, &tvs);
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}
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static void *thr(void *p) {
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// This kill() is expected to fail; it exists only to trigger a call to SigCtx
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// outside of the signal handler.
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kill(INT_MIN, 0);
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int success = 0;
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for (int i = 0; i < 1024; i++) {
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if (do_select() > 0) {
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success = 1;
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break;
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}
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}
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if (success) {
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char c;
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read(pipes[0], &c, 1);
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} else {
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fprintf(stderr, "Failed to receive signal\n");
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exit(1);
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}
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return p;
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}
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int main() {
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if (pipe(pipes)) {
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perror("pipe");
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exit(1);
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}
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struct sigaction act = {};
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act.sa_handler = &handler;
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if (sigaction(SIGUSR1, &act, 0)) {
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perror("sigaction");
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exit(1);
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}
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for (int i = 0; i < (1 << 10); i++) {
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pthread_t th{};
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if (pthread_create(&th, 0, thr, 0)) {
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perror("pthread_create");
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exit(1);
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}
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pthread_kill(th, SIGUSR1);
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pthread_join(th, 0);
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}
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fprintf(stderr, "DONE\n");
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return 0;
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}
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// CHECK-NOT: WARNING: ThreadSanitizer:
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// CHECK: DONE
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// CHECK-NOT: WARNING: ThreadSanitizer:
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