xref: /aosp_15_r20/external/cronet/base/test/multiprocess_test.h (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1 // Copyright 2012 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef BASE_TEST_MULTIPROCESS_TEST_H_
6 #define BASE_TEST_MULTIPROCESS_TEST_H_
7 
8 #include <string>
9 
10 #include "base/process/launch.h"
11 #include "base/process/process.h"
12 #include "build/build_config.h"
13 #include "testing/platform_test.h"
14 
15 namespace base {
16 
17 class CommandLine;
18 
19 // Helpers to spawn a child for a multiprocess test and execute a designated
20 // function. Use these when you already have another base class for your test
21 // fixture, but you want (some) of your tests to be multiprocess (otherwise you
22 // may just want to derive your fixture from |MultiProcessTest|, below).
23 //
24 // Use these helpers as follows:
25 //
26 //   TEST_F(MyTest, ATest) {
27 //     CommandLine command_line(
28 //         base::GetMultiProcessTestChildBaseCommandLine());
29 //     // Maybe add our own switches to |command_line|....
30 //
31 //     LaunchOptions options;
32 //     // Maybe set some options (e.g., |start_hidden| on Windows)....
33 //
34 //     // Start a child process and run |a_test_func|.
35 //     base::Process test_child_process =
36 //         base::SpawnMultiProcessTestChild("a_test_func", command_line,
37 //                                          options);
38 //
39 //     // Do stuff involving |test_child_process| and the child process....
40 //
41 //     int rv = -1;
42 //     ASSERT_TRUE(base::WaitForMultiprocessTestChildExit(test_child_process,
43 //         TestTimeouts::action_timeout(), &rv));
44 //     EXPECT_EQ(0, rv);
45 //   }
46 //
47 //   // Note: |MULTIPROCESS_TEST_MAIN()| is defined in
48 //   // testing/multiprocess_func_list.h.
49 //   MULTIPROCESS_TEST_MAIN(a_test_func) {
50 //     // Code here runs in a child process....
51 //     return 0;
52 //   }
53 //
54 // If you need to terminate the child process, use the
55 // TerminateMultiProcessTestChild method to ensure that test will work on
56 // Android.
57 
58 // Spawns a child process and executes the function |procname| declared using
59 // |MULTIPROCESS_TEST_MAIN()| or |MULTIPROCESS_TEST_MAIN_WITH_SETUP()|.
60 // |command_line| should be as provided by
61 // |GetMultiProcessTestChildBaseCommandLine()| (below), possibly with arguments
62 // added. Note: On Windows, you probably want to set |options.start_hidden|.
63 Process SpawnMultiProcessTestChild(const std::string& procname,
64                                    const CommandLine& command_line,
65                                    const LaunchOptions& options);
66 
67 // Gets the base command line for |SpawnMultiProcessTestChild()|. To this, you
68 // may add any flags needed for your child process.
69 CommandLine GetMultiProcessTestChildBaseCommandLine();
70 
71 // Waits for the child process to exit. Returns true if the process exited
72 // within |timeout| and sets |exit_code| if non null.
73 bool WaitForMultiprocessTestChildExit(const Process& process,
74                                       TimeDelta timeout,
75                                       int* exit_code);
76 
77 // Terminates |process| with |exit_code|. If |wait| is true, this call blocks
78 // until the process actually terminates.
79 bool TerminateMultiProcessTestChild(const Process& process,
80                                     int exit_code,
81                                     bool wait);
82 
83 #if BUILDFLAG(IS_ANDROID)
84 // Returns whether the child process exited cleanly from the main runloop.
85 bool MultiProcessTestChildHasCleanExit(const Process& process);
86 #endif
87 
88 // MultiProcessTest ------------------------------------------------------------
89 
90 // A MultiProcessTest is a test class which makes it easier to
91 // write a test which requires code running out of process.
92 //
93 // To create a multiprocess test simply follow these steps:
94 //
95 // 1) Derive your test from MultiProcessTest. Example:
96 //
97 //    class MyTest : public MultiProcessTest {
98 //    };
99 //
100 //    TEST_F(MyTest, TestCaseName) {
101 //      ...
102 //    }
103 //
104 // 2) Create a mainline function for the child processes and include
105 //    testing/multiprocess_func_list.h.
106 //    See the declaration of the MULTIPROCESS_TEST_MAIN macro
107 //    in that file for an example.
108 // 3) Call SpawnChild("foo"), where "foo" is the name of
109 //    the function you wish to run in the child processes.
110 // That's it!
111 class MultiProcessTest : public PlatformTest {
112  public:
113   MultiProcessTest();
114 
115   MultiProcessTest(const MultiProcessTest&) = delete;
116   MultiProcessTest& operator=(const MultiProcessTest&) = delete;
117 
118  protected:
119   // Run a child process.
120   // 'procname' is the name of a function which the child will
121   // execute.  It must be exported from this library in order to
122   // run.
123   //
124   // Example signature:
125   //    extern "C" int __declspec(dllexport) FooBar() {
126   //         // do client work here
127   //    }
128   //
129   // Returns the child process.
130   Process SpawnChild(const std::string& procname);
131 
132   // Run a child process using the given launch options.
133   //
134   // Note: On Windows, you probably want to set |options.start_hidden|.
135   Process SpawnChildWithOptions(const std::string& procname,
136                                 const LaunchOptions& options);
137 
138   // Set up the command line used to spawn the child process.
139   // Override this to add things to the command line (calling this first in the
140   // override).
141   // Note that currently some tests rely on this providing a full command line,
142   // which they then use directly with |LaunchProcess()|.
143   // TODO(viettrungluu): Remove this and add a virtual
144   // |ModifyChildCommandLine()|; make the two divergent uses more sane.
145   virtual CommandLine MakeCmdLine(const std::string& procname);
146 };
147 
148 }  // namespace base
149 
150 #endif  // BASE_TEST_MULTIPROCESS_TEST_H_
151