1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
|
/* -*- 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,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* 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
|
