mirror of
https://github.com/pineappleEA/pineapple-src.git
synced 2024-12-05 03:28:24 -05:00
261 lines
8.5 KiB
C++
Executable File
261 lines
8.5 KiB
C++
Executable File
/*
|
|
* Copyright © 2017 Mozilla Foundation
|
|
*
|
|
* This program is made available under an ISC-style license. See the
|
|
* accompanying file LICENSE for details.
|
|
*
|
|
*
|
|
* Purpose
|
|
* =============================================================================
|
|
* In CoreAudio, the data callback will holds a mutex shared with AudioUnit
|
|
* (mutex_AU). Thus, if the callback request another mutex M held by the another
|
|
* function, without releasing mutex_AU, then it will cause a deadlock when the
|
|
* another function, which holds the mutex M, request to use AudioUnit.
|
|
*
|
|
* The following figure illustrates the deadlock in bug 1337805:
|
|
* https://bugzilla.mozilla.org/show_bug.cgi?id=1337805
|
|
* (The detail analysis can be found on bug 1350511:
|
|
* https://bugzilla.mozilla.org/show_bug.cgi?id=1350511)
|
|
*
|
|
* holds
|
|
* data_callback <---------- mutext_AudioUnit(mutex_AU)
|
|
* | ^
|
|
* | |
|
|
* | request | request
|
|
* | |
|
|
* v holds |
|
|
* mutex_cubeb ------------> get_channel_layout
|
|
*
|
|
* In this example, the "audiounit_get_channel_layout" in f4edfb8:
|
|
* https://github.com/kinetiknz/cubeb/blob/f4edfb8eea920887713325e44773f3a2d959860c/src/cubeb_audiounit.cpp#L2725
|
|
* requests the mutex_AU to create an AudioUnit, when it holds a mutex for cubeb
|
|
* context. Meanwhile, the data callback who holds the mutex_AU requests the
|
|
* mutex for cubeb context. As a result, it causes a deadlock.
|
|
*
|
|
* The problem is solve by pull 236: https://github.com/kinetiknz/cubeb/pull/236
|
|
* We store the latest channel layout and return it when there is an active
|
|
* AudioUnit, otherwise, we will create an AudioUnit to get it.
|
|
*
|
|
* Although the problem is solved, to prevent it happens again, we add the test
|
|
* here in case someone without such knowledge misuses the AudioUnit in
|
|
* get_channel_layout. Moreover, it's a good way to record the known issues
|
|
* to warn other developers.
|
|
*/
|
|
|
|
#include "gtest/gtest.h"
|
|
//#define ENABLE_NORMAL_LOG
|
|
//#define ENABLE_VERBOSE_LOG
|
|
#include "common.h" // for layout_infos
|
|
#include "cubeb/cubeb.h" // for cubeb utils
|
|
#include "cubeb_utils.h" // for owned_critical_section, auto_lock
|
|
#include <iostream> // for fprintf
|
|
#include <pthread.h> // for pthread
|
|
#include <signal.h> // for signal
|
|
#include <stdexcept> // for std::logic_error
|
|
#include <string> // for std::string
|
|
#include <unistd.h> // for sleep, usleep
|
|
#include <atomic> // for std::atomic
|
|
|
|
// The signal alias for calling our thread killer.
|
|
#define CALL_THREAD_KILLER SIGUSR1
|
|
|
|
// This indicator will become true when our pending task thread is killed by
|
|
// ourselves.
|
|
bool killed = false;
|
|
|
|
// This indicator will become true when the assigned task is done.
|
|
std::atomic<bool> task_done{ false };
|
|
|
|
// Indicating the data callback is fired or not.
|
|
bool called = false;
|
|
|
|
// Toggle to true when running data callback. Before data callback gets
|
|
// the mutex for cubeb context, it toggles back to false.
|
|
// The task to get channel layout should be executed when this is true.
|
|
std::atomic<bool> callbacking_before_getting_context{ false };
|
|
|
|
owned_critical_section context_mutex;
|
|
cubeb * context = nullptr;
|
|
|
|
cubeb * get_cubeb_context_unlocked()
|
|
{
|
|
if (context) {
|
|
return context;
|
|
}
|
|
|
|
int r = CUBEB_OK;
|
|
r = common_init(&context, "Cubeb deadlock test");
|
|
if (r != CUBEB_OK) {
|
|
context = nullptr;
|
|
}
|
|
|
|
return context;
|
|
}
|
|
|
|
cubeb * get_cubeb_context()
|
|
{
|
|
auto_lock lock(context_mutex);
|
|
return get_cubeb_context_unlocked();
|
|
}
|
|
|
|
void state_cb_audio(cubeb_stream * /*stream*/, void * /*user*/, cubeb_state /*state*/)
|
|
{
|
|
}
|
|
|
|
// Fired by coreaudio's rendering mechanism. It holds a mutex shared with the
|
|
// current used AudioUnit.
|
|
template<typename T>
|
|
long data_cb(cubeb_stream * /*stream*/, void * /*user*/,
|
|
const void * /*inputbuffer*/, void * outputbuffer, long nframes)
|
|
{
|
|
called = true;
|
|
|
|
uint64_t tid; // Current thread id.
|
|
pthread_threadid_np(NULL, &tid);
|
|
fprintf(stderr, "Audio output is on thread %llu\n", tid);
|
|
|
|
if (!task_done) {
|
|
callbacking_before_getting_context = true;
|
|
fprintf(stderr, "[%llu] time to switch thread\n", tid);
|
|
// Force to switch threads by sleeping 10 ms. Notice that anything over
|
|
// 10ms would create a glitch. It's intended here for test, so the delay
|
|
// is ok.
|
|
usleep(10000);
|
|
callbacking_before_getting_context = false;
|
|
}
|
|
|
|
fprintf(stderr, "[%llu] try getting backend id ...\n", tid);
|
|
|
|
// Try requesting mutex for context by get_cubeb_context()
|
|
// when holding a mutex for AudioUnit.
|
|
char const * backend_id = cubeb_get_backend_id(get_cubeb_context());
|
|
fprintf(stderr, "[%llu] callback on %s\n", tid, backend_id);
|
|
|
|
// Mute the output (or get deaf)
|
|
memset(outputbuffer, 0, nframes * 2 * sizeof(float));
|
|
return nframes;
|
|
}
|
|
|
|
// Called by wait_to_get_layout, which is run out of main thread.
|
|
void get_preferred_channel_layout()
|
|
{
|
|
auto_lock lock(context_mutex);
|
|
cubeb * context = get_cubeb_context_unlocked();
|
|
ASSERT_TRUE(!!context);
|
|
|
|
// We will cause a deadlock if cubeb_get_preferred_channel_layout requests
|
|
// mutex for AudioUnit when it holds mutex for context.
|
|
cubeb_channel_layout layout;
|
|
int r = cubeb_get_preferred_channel_layout(context, &layout);
|
|
ASSERT_EQ(r == CUBEB_OK, layout != CUBEB_LAYOUT_UNDEFINED);
|
|
fprintf(stderr, "layout is %s\n", layout_infos[layout].name);
|
|
}
|
|
|
|
void * wait_to_get_layout(void *)
|
|
{
|
|
uint64_t tid; // Current thread id.
|
|
pthread_threadid_np(NULL, &tid);
|
|
|
|
while(!callbacking_before_getting_context) {
|
|
fprintf(stderr, "[%llu] waiting for data callback ...\n", tid);
|
|
usleep(1000); // Force to switch threads by sleeping 1 ms.
|
|
}
|
|
|
|
fprintf(stderr, "[%llu] try getting channel layout ...\n", tid);
|
|
get_preferred_channel_layout(); // Deadlock checkpoint.
|
|
task_done = true;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void * watchdog(void * s)
|
|
{
|
|
uint64_t tid; // Current thread id.
|
|
pthread_threadid_np(NULL, &tid);
|
|
|
|
pthread_t subject = *((pthread_t *) s);
|
|
uint64_t stid; // task thread id.
|
|
pthread_threadid_np(subject, &stid);
|
|
|
|
unsigned int sec = 2;
|
|
fprintf(stderr, "[%llu] sleep %d seconds before checking task for thread %llu\n", tid, sec, stid);
|
|
sleep(sec); // Force to switch threads.
|
|
|
|
fprintf(stderr, "[%llu] check task for thread %llu now\n", tid, stid);
|
|
if (!task_done) {
|
|
fprintf(stderr, "[%llu] kill the task thread %llu\n", tid, stid);
|
|
pthread_kill(subject, CALL_THREAD_KILLER);
|
|
pthread_detach(subject);
|
|
// pthread_kill doesn't release the mutex held by the killed thread,
|
|
// so we need to unlock it manually.
|
|
context_mutex.unlock();
|
|
}
|
|
fprintf(stderr, "[%llu] the assigned task for thread %llu is %sdone\n", tid, stid, (task_done) ? "" : "not ");
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void thread_killer(int signal)
|
|
{
|
|
ASSERT_EQ(signal, CALL_THREAD_KILLER);
|
|
fprintf(stderr, "task thread is killed!\n");
|
|
killed = true;
|
|
}
|
|
|
|
TEST(cubeb, run_deadlock_test)
|
|
{
|
|
#if !defined(__APPLE__)
|
|
FAIL() << "Deadlock test is only for OSX now";
|
|
#endif
|
|
|
|
cubeb * ctx = get_cubeb_context();
|
|
ASSERT_TRUE(!!ctx);
|
|
|
|
std::unique_ptr<cubeb, decltype(&cubeb_destroy)>
|
|
cleanup_cubeb_at_exit(ctx, cubeb_destroy);
|
|
|
|
cubeb_stream_params params;
|
|
params.format = CUBEB_SAMPLE_FLOAT32NE;
|
|
params.rate = 44100;
|
|
params.channels = 2;
|
|
params.layout = CUBEB_LAYOUT_STEREO;
|
|
params.prefs = CUBEB_STREAM_PREF_NONE;
|
|
|
|
cubeb_stream * stream = NULL;
|
|
int r = cubeb_stream_init(ctx, &stream, "test deadlock", NULL, NULL, NULL,
|
|
¶ms, 512, &data_cb<float>, state_cb_audio, NULL);
|
|
ASSERT_EQ(r, CUBEB_OK);
|
|
|
|
std::unique_ptr<cubeb_stream, decltype(&cubeb_stream_destroy)>
|
|
cleanup_stream_at_exit(stream, cubeb_stream_destroy);
|
|
|
|
// Install signal handler.
|
|
signal(CALL_THREAD_KILLER, thread_killer);
|
|
|
|
pthread_t subject, detector;
|
|
pthread_create(&subject, NULL, wait_to_get_layout, NULL);
|
|
pthread_create(&detector, NULL, watchdog, (void *) &subject);
|
|
|
|
uint64_t stid, dtid;
|
|
pthread_threadid_np(subject, &stid);
|
|
pthread_threadid_np(detector, &dtid);
|
|
fprintf(stderr, "task thread %llu, monitor thread %llu are created\n", stid, dtid);
|
|
|
|
cubeb_stream_start(stream);
|
|
|
|
pthread_join(subject, NULL);
|
|
pthread_join(detector, NULL);
|
|
|
|
ASSERT_TRUE(called);
|
|
|
|
fprintf(stderr, "\n%sDeadlock detected!\n", (called && !task_done.load()) ? "" : "No ");
|
|
|
|
// Check the task is killed by ourselves if deadlock happends.
|
|
// Otherwise, thread_killer should not be triggered.
|
|
ASSERT_NE(task_done.load(), killed);
|
|
|
|
ASSERT_TRUE(task_done.load());
|
|
|
|
cubeb_stream_stop(stream);
|
|
}
|