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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
/*
* Test various cases of behavior when a synchronous method call times out.
*/
#include "gtest/gtest.h"
#include "mozilla/_ipdltest/IPDLUnitTest.h"
#include "mozilla/_ipdltest/PTestHangsChild.h"
#include "mozilla/_ipdltest/PTestHangsParent.h"
#include "mozilla/ipc/CrossProcessSemaphore.h"
using namespace mozilla::ipc;
namespace mozilla::_ipdltest {
enum class HangMode : uint32_t {
/// No hang should occur.
None,
/// The synchronous call should time out.
Hang,
/// The synchronous call should time out but the response should still be
/// received (racing with the reply timeout logic).
HangButReceive,
/// The synchronous call should time out but the response should still be
/// received because the child indicates that processing should continue after
/// timeout.
HangPermitted
};
class TestHangsChild : public PTestHangsChild {
NS_INLINE_DECL_REFCOUNTING(TestHangsChild, override)
TestHangsChild() : timeout(CrossProcessSemaphore::Create("timeout", 0)) {}
private:
IPCResult RecvStart(const uint32_t& hangMode,
StartResolver&& resolve) final override {
// Minimum possible, 2 ms. We want to detect a hang to race with the reply
// coming in, as reliably as possible. After 1ms the wait for a response
// will be retried.
SetReplyTimeoutMs(2);
this->hangMode = (HangMode)hangMode;
auto result = SendHang(hangMode, timeout->CloneHandle());
// Only the `Hang` mode should actually fail.
if (this->hangMode == HangMode::Hang) {
// See description in parent.
timeout->Signal();
EXPECT_FALSE(result);
} else {
EXPECT_TRUE(result);
}
resolve(detectedHang);
return IPC_OK();
}
bool ShouldContinueFromReplyTimeout() final override {
timeout->Signal();
detectedHang = true;
if (hangMode == HangMode::HangButReceive) {
// Wait until the transaction is complete so that we can still receive the
// result after returning.
while (!GetIPCChannel()->TestOnlyIsTransactionComplete()) {
PR_Sleep(ticksPerSecond / 1000);
}
}
// Return true if `HangPermitted` mode (allowing the receive loop to
// continue).
return hangMode == HangMode::HangPermitted;
}
~TestHangsChild() = default;
HangMode hangMode = HangMode::None;
uint32_t ticksPerSecond = PR_TicksPerSecond();
UniquePtr<CrossProcessSemaphore> timeout;
public:
bool detectedHang = false;
};
class TestHangsParent : public PTestHangsParent {
NS_INLINE_DECL_REFCOUNTING(TestHangsParent, override)
private:
IPCResult RecvHang(
const uint32_t& hangMode,
CrossProcessSemaphoreHandle&& timeout_handle) final override {
UniquePtr<CrossProcessSemaphore> timeout(
CrossProcessSemaphore::Create(std::move(timeout_handle)));
if (hangMode != (uint32_t)HangMode::None) {
// Wait to ensure the child process has called
// ShouldContinueFromReplyTimeout().
timeout->Wait();
if (hangMode == (uint32_t)HangMode::Hang) {
// Wait to ensure the child process has returned from `SendHang()`,
// otherwise the reply message can race with the processing after
// ShouldContinueFromReplyTimeout().
timeout->Wait();
}
}
return IPC_OK();
}
~TestHangsParent() = default;
};
// We can verify that the Start message callbacks are run with the `Close()`
// calls; without a `Close()`, the test will hang.
#define TEST_HANGS(mode) \
IPDL_TEST(TestHangs, mode) { \
mActor->SendStart( \
(uint32_t)HangMode::mode, \
[=](bool detectedHang) { \
EXPECT_EQ(detectedHang, HangMode::mode != HangMode::None); \
mActor->Close(); \
}, \
[](auto&& reason) { FAIL() << "failed to send start"; }); \
}
TEST_HANGS(None)
TEST_HANGS(Hang)
TEST_HANGS(HangButReceive)
TEST_HANGS(HangPermitted)
#undef TEST_HANGS
} // namespace mozilla::_ipdltest