Author: labath Date: Wed Mar 30 03:43:54 2016 New Revision: 264846 URL: http://llvm.org/viewvc/llvm-project?rev=264846&view=rev Log: Fix flakyness in TestWatchpointMultipleThreads
Summary: the inferior in the test deliberately does not lock a mutex when accessing the watched variable. The reason for that is unclear as, based on the logs, the original intention of the test was to check whether watchpoints get propagated to newly created threads, which should work fine even with a mutex. Furthermore, in the unlikely event (which I have still observed happening from time to time) that two threads do manage the execute the "critical section" simultaneously, the test will fail, as it is expecting the watchpoint "hit count" to be 1, but in this case it will be 2. Given this, I have simply chose to lock the mutex always, so that we have more predictible behavior. Watchpoints being hit simultaneously is still (and correctly!) tested by TestConcurrentEvents. Reviewers: clayborg, jingham Subscribers: lldb-commits Differential Revision: http://reviews.llvm.org/D18558 Modified: lldb/trunk/packages/Python/lldbsuite/test/functionalities/watchpoint/multiple_threads/TestWatchpointMultipleThreads.py lldb/trunk/packages/Python/lldbsuite/test/functionalities/watchpoint/multiple_threads/main.cpp Modified: lldb/trunk/packages/Python/lldbsuite/test/functionalities/watchpoint/multiple_threads/TestWatchpointMultipleThreads.py URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/packages/Python/lldbsuite/test/functionalities/watchpoint/multiple_threads/TestWatchpointMultipleThreads.py?rev=264846&r1=264845&r2=264846&view=diff ============================================================================== --- lldb/trunk/packages/Python/lldbsuite/test/functionalities/watchpoint/multiple_threads/TestWatchpointMultipleThreads.py (original) +++ lldb/trunk/packages/Python/lldbsuite/test/functionalities/watchpoint/multiple_threads/TestWatchpointMultipleThreads.py Wed Mar 30 03:43:54 2016 @@ -58,9 +58,6 @@ class WatchpointForMultipleThreadsTestCa 'stop reason = breakpoint']) # Now let's set a write-type watchpoint for variable 'g_val'. - # The main.cpp, by design, misbehaves by not following the agreed upon - # protocol of using a mutex while accessing the global pool and by not - # writing to the variable. self.expect("watchpoint set variable -w write g_val", WATCHPOINT_CREATED, substrs = ['Watchpoint created', 'size = 4', 'type = w']) @@ -102,9 +99,6 @@ class WatchpointForMultipleThreadsTestCa 'stop reason = breakpoint']) # Now let's set a write-type watchpoint for variable 'g_val'. - # The main.cpp, by design, misbehaves by not following the agreed upon - # protocol of using a mutex while accessing the global pool and by not - # writing to the variable. self.expect("watchpoint set variable -w write g_val", WATCHPOINT_CREATED, substrs = ['Watchpoint created', 'size = 4', 'type = w']) Modified: lldb/trunk/packages/Python/lldbsuite/test/functionalities/watchpoint/multiple_threads/main.cpp URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/packages/Python/lldbsuite/test/functionalities/watchpoint/multiple_threads/main.cpp?rev=264846&r1=264845&r2=264846&view=diff ============================================================================== --- lldb/trunk/packages/Python/lldbsuite/test/functionalities/watchpoint/multiple_threads/main.cpp (original) +++ lldb/trunk/packages/Python/lldbsuite/test/functionalities/watchpoint/multiple_threads/main.cpp Wed Mar 30 03:43:54 2016 @@ -23,8 +23,7 @@ uint32_t access_pool (bool flag = false) { static std::mutex g_access_mutex; - if (!flag) - g_access_mutex.lock(); + g_access_mutex.lock(); uint32_t old_val = g_val; if (flag) @@ -33,17 +32,14 @@ access_pool (bool flag = false) g_val = old_val + 1; } - if (!flag) - g_access_mutex.unlock(); + g_access_mutex.unlock(); return g_val; } void thread_func (uint32_t thread_index) { - // Break here in order to allow the thread - // to inherit the global watchpoint state. - printf ("%s (thread index = %u) startng...\n", __FUNCTION__, thread_index); + printf ("%s (thread index = %u) starting...\n", __FUNCTION__, thread_index); uint32_t count = 0; uint32_t val; _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
