| 1 | // RUN: %clang_tsan %s -lstdc++ -o %t && %run %t 2>&1 | FileCheck %s |
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| 2 | |
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| 3 | #include "test.h" |
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| 4 | #include <pthread.h> |
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| 5 | #include <signal.h> |
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| 6 | #include <stdio.h> |
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| 7 | |
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| 8 | #include <atomic> |
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| 9 | #include <cassert> |
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| 10 | #include <condition_variable> |
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| 11 | #include <mutex> |
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| 12 | |
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| 13 | std::mutex sampler_mutex; //dummy mutex to lock in the thread we spawn. |
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| 14 | std::mutex done_mutex; // guards the cv and done variables. |
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| 15 | std::condition_variable cv; |
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| 16 | bool done = false; |
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| 17 | std::atomic<bool> spin = true; |
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| 18 | |
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| 19 | void *ThreadFunc(void *x) { |
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| 20 | while (spin) { |
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| 21 | // Lock the mutex |
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| 22 | std::lock_guard<std::mutex> guard(sampler_mutex); |
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| 23 | // Mutex is released at the end |
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| 24 | } |
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| 25 | |
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| 26 | return nullptr; |
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| 27 | } |
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| 28 | |
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| 29 | static void SigprofHandler(int signal, siginfo_t *info, void *context) { |
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| 30 | // Assuming we did some work, change the variable to let the main thread |
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| 31 | // know that we are done. |
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| 32 | { |
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| 33 | std::unique_lock<std::mutex> lck(done_mutex); |
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| 34 | done = true; |
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| 35 | cv.notify_one(); |
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| 36 | } |
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| 37 | } |
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| 38 | |
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| 39 | int main() { |
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| 40 | alarm(seconds: 60); // Kill the test if it hangs. |
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| 41 | |
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| 42 | // Install the signal handler |
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| 43 | struct sigaction sa; |
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| 44 | sa.sa_sigaction = SigprofHandler; |
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| 45 | sigemptyset(set: &sa.sa_mask); |
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| 46 | sa.sa_flags = SA_RESTART | SA_SIGINFO; |
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| 47 | if (sigaction(SIGPROF, act: &sa, oact: 0) != 0) { |
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| 48 | fprintf(stderr, format: "failed to install signal handler\n" ); |
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| 49 | abort(); |
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| 50 | } |
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| 51 | |
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| 52 | // Spawn a thread that will just loop and get the mutex lock: |
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| 53 | pthread_t thread; |
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| 54 | pthread_create(newthread: &thread, NULL, start_routine: ThreadFunc, NULL); |
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| 55 | |
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| 56 | { |
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| 57 | // Lock the mutex before sending the signal |
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| 58 | std::lock_guard<std::mutex> guard(sampler_mutex); |
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| 59 | // From now on thread 1 will be waiting for the lock |
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| 60 | |
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| 61 | // Send the SIGPROF signal to thread. |
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| 62 | int r = pthread_kill(threadid: thread, SIGPROF); |
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| 63 | assert(r == 0); |
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| 64 | |
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| 65 | // Wait until signal handler sends the data. |
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| 66 | std::unique_lock lk(done_mutex); |
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| 67 | cv.wait(lk, [] { return done; }); |
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| 68 | |
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| 69 | // We got the done variable from the signal handler. Exiting successfully. |
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| 70 | fprintf(stderr, format: "PASS\n" ); |
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| 71 | } |
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| 72 | |
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| 73 | // Wait for thread to prevent it from spinning on a released mutex. |
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| 74 | spin = false; |
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| 75 | pthread_join(th: thread, thread_return: nullptr); |
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| 76 | } |
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| 77 | |
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| 78 | // CHECK-NOT: WARNING: ThreadSanitizer: |
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| 79 | // CHECK: PASS |
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| 80 | |
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