xref: /llvm-project/lldb/test/API/functionalities/thread/num_threads/TestNumThreads.py (revision 2238dcc39358353cac21df75c3c3286ab20b8f53) 
1"""
2Test number of threads.
3"""
4
5
6import lldb
7from lldbsuite.test.decorators import *
8from lldbsuite.test.lldbtest import *
9import lldbsuite.test.lldbutil as lldbutil
10
11
12class NumberOfThreadsTestCase(TestBase):
13    NO_DEBUG_INFO_TESTCASE = True
14
15    def setUp(self):
16        # Call super's setUp().
17        TestBase.setUp(self)
18        # Find the line numbers for our break points.
19        self.thread3_notify_all_line = line_number(
20            "main.cpp", "// Set thread3 break point on notify_all at this line."
21        )
22        self.thread3_before_lock_line = line_number(
23            "main.cpp", "// thread3-before-lock"
24        )
25
26    def test_number_of_threads(self):
27        """Test number of threads."""
28        self.build()
29        exe = self.getBuildArtifact("a.out")
30        self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)
31
32        # This should create a breakpoint with 1 location.
33        lldbutil.run_break_set_by_file_and_line(
34            self, "main.cpp", self.thread3_notify_all_line, num_expected_locations=1
35        )
36
37        # The breakpoint list should show 1 location.
38        self.expect(
39            "breakpoint list -f",
40            "Breakpoint location shown correctly",
41            substrs=[
42                "1: file = 'main.cpp', line = %d, exact_match = 0, locations = 1"
43                % self.thread3_notify_all_line
44            ],
45        )
46
47        # Run the program.
48        self.runCmd("run", RUN_SUCCEEDED)
49
50        # Stopped once.
51        self.expect(
52            "thread list",
53            STOPPED_DUE_TO_BREAKPOINT,
54            substrs=["stop reason = breakpoint 1."],
55        )
56
57        # Get the target process
58        target = self.dbg.GetSelectedTarget()
59        process = target.GetProcess()
60
61        # Get the number of threads
62        num_threads = process.GetNumThreads()
63
64        # Using std::thread may involve extra threads, so we assert that there are
65        # at least 4 rather than exactly 4.
66        self.assertTrue(
67            num_threads >= 13,
68            "Number of expected threads and actual threads do not match.",
69        )
70
71    @skipIfDarwin  # rdar://33462362
72    @skipIfWindows  # This is flakey on Windows: llvm.org/pr37658, llvm.org/pr38373
73    def test_unique_stacks(self):
74        """Test backtrace unique with multiple threads executing the same stack."""
75        self.build()
76        exe = self.getBuildArtifact("a.out")
77        self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)
78
79        # Set a break point on the thread3 notify all (should get hit on threads 4-13).
80        lldbutil.run_break_set_by_file_and_line(
81            self, "main.cpp", self.thread3_before_lock_line, num_expected_locations=1
82        )
83
84        # Run the program.
85        self.runCmd("run", RUN_SUCCEEDED)
86
87        # Stopped once.
88        self.expect(
89            "thread list",
90            STOPPED_DUE_TO_BREAKPOINT,
91            substrs=["stop reason = breakpoint 1."],
92        )
93
94        process = self.process()
95
96        # Get the number of threads
97        num_threads = process.GetNumThreads()
98
99        # Using std::thread may involve extra threads, so we assert that there are
100        # at least 10 thread3's rather than exactly 10.
101        self.assertTrue(
102            num_threads >= 10,
103            "Number of expected threads and actual threads do not match.",
104        )
105
106        # Attempt to walk each of the thread's executing the thread3 function to
107        # the same breakpoint.
108        def is_thread3(thread):
109            for frame in thread:
110                if frame.GetFunctionName() is None:
111                    continue
112                if "thread3" in frame.GetFunctionName():
113                    return True
114            return False
115
116        expect_threads = ""
117        for i in range(num_threads):
118            thread = process.GetThreadAtIndex(i)
119            self.assertTrue(thread.IsValid())
120            if not is_thread3(thread):
121                continue
122
123            # If we aren't stopped out the thread breakpoint try to resume.
124            if thread.GetStopReason() != lldb.eStopReasonBreakpoint:
125                self.runCmd("thread continue %d" % (i + 1))
126            self.assertStopReason(thread.GetStopReason(), lldb.eStopReasonBreakpoint)
127
128            expect_threads += " #%d" % (i + 1)
129
130        # Construct our expected back trace string
131        expect_string = "10 thread(s)%s" % (expect_threads)
132
133        # Now that we are stopped, we should have 10 threads waiting in the
134        # thread3 function. All of these threads should show as one stack.
135        self.expect(
136            "thread backtrace unique",
137            "Backtrace with unique stack shown correctly",
138            substrs=[expect_string, "main.cpp:%d" % self.thread3_before_lock_line],
139        )
140