platform_system_core/libutils/CallStack_test.cpp
Christopher Ferris 15fee82247 Fix thread unwind in CallStack.
The CallStack unwind of a different thread was broken since it
wasn't properly setting the tid value.

Fix this problem and add new unit tests to verify the behavior.

Bug: 246405269

Test: New unit tests pass.
Test: Ran unit tests for 1000 operations to verify not flaky.
Change-Id: I00342e6cdcdb4bcb68f29734dadee6c987c98040
2022-09-12 18:37:22 -07:00

62 lines
1.8 KiB
C++

/*
* Copyright (C) 2022 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <unistd.h>
#include <thread>
#include <android-base/threads.h>
#include <gtest/gtest.h>
#include <utils/CallStack.h>
[[clang::noinline]] extern "C" void CurrentCaller(android::String8& backtrace) {
android::CallStack cs;
cs.update();
backtrace = cs.toString();
}
TEST(CallStackTest, current_backtrace) {
android::String8 backtrace;
CurrentCaller(backtrace);
ASSERT_NE(-1, backtrace.find("(CurrentCaller")) << "Full backtrace:\n" << backtrace;
}
[[clang::noinline]] extern "C" void ThreadBusyWait(std::atomic<pid_t>* tid, volatile bool* done) {
*tid = android::base::GetThreadId();
while (!*done) {
}
}
TEST(CallStackTest, thread_backtrace) {
// Use a volatile to avoid any problems unwinding since sometimes
// accessing a std::atomic does not include unwind data at every
// instruction and leads to failed unwinds.
volatile bool done = false;
std::atomic<pid_t> tid = -1;
std::thread thread([&tid, &done]() { ThreadBusyWait(&tid, &done); });
while (tid == -1) {
}
android::CallStack cs;
cs.update(0, tid);
done = true;
thread.join();
ASSERT_NE(-1, cs.toString().find("(ThreadBusyWait")) << "Full backtrace:\n" << cs.toString();
}