Revert^2 "lshal: use std::async"
This reverts commit 2cfbc514764472becab46b41ebe0323a68369cad.
Reason for revert: reapply change
Bug: 323268003
Bug: 311143089
Test: See next CL
Change-Id: I392eca8f3368c1d74b4de37d5f49663d3ddbf7e0
diff --git a/cmds/lshal/Timeout.h b/cmds/lshal/Timeout.h
index 37f41be..d97ba89 100644
--- a/cmds/lshal/Timeout.h
+++ b/cmds/lshal/Timeout.h
@@ -16,83 +16,44 @@
#pragma once
-#include <condition_variable>
#include <chrono>
-#include <functional>
-#include <mutex>
-#include <thread>
+#include <future>
#include <hidl/Status.h>
+#include <utils/Errors.h>
namespace android {
namespace lshal {
-class BackgroundTaskState {
-public:
- explicit BackgroundTaskState(std::function<void(void)> &&func)
- : mFunc(std::forward<decltype(func)>(func)) {}
- void notify() {
- std::unique_lock<std::mutex> lock(mMutex);
- mFinished = true;
- lock.unlock();
- mCondVar.notify_all();
- }
- template<class C, class D>
- bool wait(std::chrono::time_point<C, D> end) {
- std::unique_lock<std::mutex> lock(mMutex);
- mCondVar.wait_until(lock, end, [this](){ return this->mFinished; });
- return mFinished;
- }
- void operator()() {
- mFunc();
- }
-private:
- std::mutex mMutex;
- std::condition_variable mCondVar;
- bool mFinished = false;
- std::function<void(void)> mFunc;
-};
-
-void *callAndNotify(void *data) {
- BackgroundTaskState &state = *static_cast<BackgroundTaskState *>(data);
- state();
- state.notify();
- return nullptr;
-}
-
-template<class R, class P>
-bool timeout(std::chrono::duration<R, P> delay, std::function<void(void)> &&func) {
- auto now = std::chrono::system_clock::now();
- BackgroundTaskState state{std::forward<decltype(func)>(func)};
- pthread_t thread;
- if (pthread_create(&thread, nullptr, callAndNotify, &state)) {
- std::cerr << "FATAL: could not create background thread." << std::endl;
- return false;
- }
- bool success = state.wait(now + delay);
- if (!success) {
- pthread_kill(thread, SIGINT);
- }
- pthread_join(thread, nullptr);
- return success;
-}
-
+// Call function on interfaceObject and wait for result until the given timeout has reached.
+// Callback functions pass to timeoutIPC() may be executed after the this function
+// has returned, especially if deadline has been reached. Hence, care must be taken when passing
+// data between the background thread and the main thread. See b/311143089.
template<class R, class P, class Function, class I, class... Args>
typename std::invoke_result<Function, I *, Args...>::type
timeoutIPC(std::chrono::duration<R, P> wait, const sp<I> &interfaceObject, Function &&func,
Args &&... args) {
using ::android::hardware::Status;
- typename std::result_of<Function(I *, Args...)>::type ret{Status::ok()};
- auto boundFunc = std::bind(std::forward<Function>(func),
- interfaceObject.get(), std::forward<Args>(args)...);
- bool success = timeout(wait, [&ret, &boundFunc] {
- ret = std::move(boundFunc());
- });
- if (!success) {
+
+ // Execute on a background thread but do not defer execution.
+ auto future =
+ std::async(std::launch::async, func, interfaceObject, std::forward<Args>(args)...);
+ auto status = future.wait_for(wait);
+ if (status == std::future_status::ready) {
+ return future.get();
+ }
+
+ // This future belongs to a background thread that we no longer care about.
+ // Putting this in the global list avoids std::future::~future() that may wait for the
+ // result to come back.
+ // This leaks memory, but lshal is a debugging tool, so this is fine.
+ static std::vector<decltype(future)> gDeadPool{};
+ gDeadPool.emplace_back(std::move(future));
+
+ if (status == std::future_status::timeout) {
return Status::fromStatusT(TIMED_OUT);
}
- return ret;
+ return Status::fromExceptionCode(Status::Exception::EX_ILLEGAL_STATE, "Illegal future_status");
}
-
-} // namespace lshal
-} // namespace android
+} // namespace lshal
+} // namespace android
diff --git a/cmds/lshal/main.cpp b/cmds/lshal/main.cpp
index 366c938..bd5fa32 100644
--- a/cmds/lshal/main.cpp
+++ b/cmds/lshal/main.cpp
@@ -18,5 +18,6 @@
int main(int argc, char **argv) {
using namespace ::android::lshal;
- return Lshal{}.main(Arg{argc, argv});
+ // Use _exit() to force terminate background threads in Timeout.h
+ _exit(Lshal{}.main(Arg{argc, argv}));
}
diff --git a/cmds/lshal/test.cpp b/cmds/lshal/test.cpp
index cba7c4b..c24f827 100644
--- a/cmds/lshal/test.cpp
+++ b/cmds/lshal/test.cpp
@@ -14,6 +14,10 @@
* limitations under the License.
*/
+#include <chrono>
+#include <future>
+#include <mutex>
+#include "android/hidl/base/1.0/IBase.h"
#define LOG_TAG "Lshal"
#include <android-base/logging.h>
@@ -36,6 +40,8 @@
using namespace testing;
+using std::chrono_literals::operator""ms;
+
using ::android::hidl::base::V1_0::DebugInfo;
using ::android::hidl::base::V1_0::IBase;
using ::android::hidl::manager::V1_0::IServiceManager;
@@ -934,12 +940,9 @@
return hardware::Void();
}));
EXPECT_CALL(*serviceManager, get(_, _))
- .WillRepeatedly(
- Invoke([&](const hidl_string&, const hidl_string& instance) -> sp<IBase> {
- int id = getIdFromInstanceName(instance);
- if (id > inheritanceLevel) return nullptr;
- return sp<IBase>(service);
- }));
+ .WillRepeatedly(Invoke([&](const hidl_string&, const hidl_string&) -> sp<IBase> {
+ return sp<IBase>(service);
+ }));
const std::string expected = "[fake description 0]\n"
"Interface\n"
@@ -957,6 +960,110 @@
EXPECT_EQ("", err.str());
}
+// In SlowService, everything goes slooooooow. Each IPC call will wait for
+// the specified time before calling the callback function or returning.
+class SlowService : public IBase {
+public:
+ explicit SlowService(std::chrono::milliseconds wait) : mWait(wait) {}
+ android::hardware::Return<void> interfaceDescriptor(interfaceDescriptor_cb cb) override {
+ std::this_thread::sleep_for(mWait);
+ cb(getInterfaceName(1));
+ storeHistory("interfaceDescriptor");
+ return hardware::Void();
+ }
+ android::hardware::Return<void> interfaceChain(interfaceChain_cb cb) override {
+ std::this_thread::sleep_for(mWait);
+ std::vector<hidl_string> ret;
+ ret.push_back(getInterfaceName(1));
+ ret.push_back(IBase::descriptor);
+ cb(ret);
+ storeHistory("interfaceChain");
+ return hardware::Void();
+ }
+ android::hardware::Return<void> getHashChain(getHashChain_cb cb) override {
+ std::this_thread::sleep_for(mWait);
+ std::vector<hidl_hash> ret;
+ ret.push_back(getHashFromId(0));
+ ret.push_back(getHashFromId(0xff));
+ cb(ret);
+ storeHistory("getHashChain");
+ return hardware::Void();
+ }
+ android::hardware::Return<void> debug(const hidl_handle&,
+ const hidl_vec<hidl_string>&) override {
+ std::this_thread::sleep_for(mWait);
+ storeHistory("debug");
+ return Void();
+ }
+
+ template <class R, class P, class Pred>
+ bool waitForHistory(std::chrono::duration<R, P> wait, Pred predicate) {
+ std::unique_lock<std::mutex> lock(mLock);
+ return mCv.wait_for(lock, wait, [&]() { return predicate(mCallHistory); });
+ }
+
+private:
+ void storeHistory(std::string hist) {
+ {
+ std::lock_guard<std::mutex> lock(mLock);
+ mCallHistory.emplace_back(std::move(hist));
+ }
+ mCv.notify_all();
+ }
+
+ const std::chrono::milliseconds mWait;
+ std::mutex mLock;
+ std::condition_variable mCv;
+ // List of functions that have finished being called on this interface.
+ std::vector<std::string> mCallHistory;
+};
+
+class TimeoutTest : public ListTest {
+public:
+ void setMockServiceManager(sp<IBase> service) {
+ EXPECT_CALL(*serviceManager, list(_))
+ .WillRepeatedly(Invoke([&](IServiceManager::list_cb cb) {
+ std::vector<hidl_string> ret;
+ ret.push_back(getInterfaceName(1) + "/default");
+ cb(ret);
+ return hardware::Void();
+ }));
+ EXPECT_CALL(*serviceManager, get(_, _))
+ .WillRepeatedly(Invoke([&](const hidl_string&, const hidl_string&) -> sp<IBase> {
+ return service;
+ }));
+ }
+};
+
+TEST_F(TimeoutTest, BackgroundThreadIsKept) {
+ auto lshalIpcTimeout = 100ms;
+ auto serviceIpcTimeout = 200ms;
+ lshal->setWaitTimeForTest(lshalIpcTimeout, lshalIpcTimeout);
+ sp<SlowService> service = new SlowService(serviceIpcTimeout);
+ setMockServiceManager(service);
+
+ optind = 1; // mimic Lshal::parseArg()
+ EXPECT_NE(0u, mockList->main(createArg({"lshal", "--types=b", "-i", "--neat"})));
+ EXPECT_THAT(err.str(), HasSubstr("Skipping \"a.h.foo1@1.0::IFoo/default\""));
+ EXPECT_TRUE(service->waitForHistory(serviceIpcTimeout * 5, [](const auto& hist) {
+ return hist.size() == 1 && hist[0] == "interfaceChain";
+ })) << "The background thread should continue after the main thread moves on, but it is killed";
+}
+
+TEST_F(TimeoutTest, BackgroundThreadDoesNotBlockMainThread) {
+ auto lshalIpcTimeout = 100ms;
+ auto serviceIpcTimeout = 2000ms;
+ auto start = std::chrono::system_clock::now();
+ lshal->setWaitTimeForTest(lshalIpcTimeout, lshalIpcTimeout);
+ sp<SlowService> service = new SlowService(serviceIpcTimeout);
+ setMockServiceManager(service);
+
+ optind = 1; // mimic Lshal::parseArg()
+ EXPECT_NE(0u, mockList->main(createArg({"lshal", "--types=b", "-i", "--neat"})));
+ EXPECT_LE(std::chrono::system_clock::now(), start + 5 * lshalIpcTimeout)
+ << "The main thread should not be blocked by the background task";
+}
+
class ListVintfTest : public ListTest {
public:
virtual void SetUp() override {
@@ -1079,5 +1186,6 @@
int main(int argc, char **argv) {
::testing::InitGoogleMock(&argc, argv);
- return RUN_ALL_TESTS();
+ // Use _exit() to force terminate background threads in Timeout.h
+ _exit(RUN_ALL_TESTS());
}