https://github.com/charles-zablit updated https://github.com/llvm/llvm-project/pull/221697
>From 347f84e86e0b63da16669cfcf7d9a49df367b55f Mon Sep 17 00:00:00 2001 From: Charles Zablit <[email protected]> Date: Mon, 7 Sep 2026 12:36:49 +0200 Subject: [PATCH 1/3] [lldb] Isolate g_watchme in memory to fix flaky TestConcurrentTwoWatchpointsOneSignal --- .../API/functionalities/thread/concurrent_events/main.cpp | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lldb/test/API/functionalities/thread/concurrent_events/main.cpp b/lldb/test/API/functionalities/thread/concurrent_events/main.cpp index 84d8c7015a796..ba4ab62d3fca9 100644 --- a/lldb/test/API/functionalities/thread/concurrent_events/main.cpp +++ b/lldb/test/API/functionalities/thread/concurrent_events/main.cpp @@ -19,7 +19,9 @@ typedef std::vector<pthread_t> thread_vector; pseudo_barrier_t g_barrier; int g_breakpoint = 0; int g_sigusr1_count = 0; -uint32_t g_watchme; + +alignas(16) uint32_t g_watchme; +uint32_t g_watchme_padding[4]; struct action_args { int delay; >From 6b462a57434428656f044640030abbc2b2291186 Mon Sep 17 00:00:00 2001 From: Charles Zablit <[email protected]> Date: Mon, 7 Sep 2026 15:12:52 +0200 Subject: [PATCH 2/3] fixup! [lldb] Isolate g_watchme in memory to fix flaky TestConcurrentTwoWatchpointsOneSignal --- .../Python/lldbsuite/test/concurrent_base.py | 2 +- .../thread/concurrent_events/main.cpp | 16 ++++++++++++---- 2 files changed, 13 insertions(+), 5 deletions(-) diff --git a/lldb/packages/Python/lldbsuite/test/concurrent_base.py b/lldb/packages/Python/lldbsuite/test/concurrent_base.py index a45b4207a834b..adb5c1d0dce88 100644 --- a/lldb/packages/Python/lldbsuite/test/concurrent_base.py +++ b/lldb/packages/Python/lldbsuite/test/concurrent_base.py @@ -171,7 +171,7 @@ def do_thread_actions( # only report this as 1 hit for all threads, because they all wrote # the same value. The testsuite needs "write" style watchpoints to # get the correct number of hits reported. - self.runCmd("watchpoint set variable -w write g_watchme") + self.runCmd("watchpoint set variable -w write g_watchme.data") for w in self.inferior_target.watchpoint_iter(): self.thread_watchpoint = w self.assertTrue( diff --git a/lldb/test/API/functionalities/thread/concurrent_events/main.cpp b/lldb/test/API/functionalities/thread/concurrent_events/main.cpp index ba4ab62d3fca9..9fcc6769bf2f1 100644 --- a/lldb/test/API/functionalities/thread/concurrent_events/main.cpp +++ b/lldb/test/API/functionalities/thread/concurrent_events/main.cpp @@ -20,8 +20,16 @@ pseudo_barrier_t g_barrier; int g_breakpoint = 0; int g_sigusr1_count = 0; -alignas(16) uint32_t g_watchme; -uint32_t g_watchme_padding[4]; +// Hardware watchpoints round the watched address/size to an alignment +// boundary, so a watchpoint on a plain global could end up covering a +// neighboring global too. Group the watched data with trailing padding in a +// single aligned struct so the compiler is guaranteed to lay them out +// together and nothing else can share the watchpoint's range. +#define WATCHPOINT_SIZE 16 +struct alignas(WATCHPOINT_SIZE) WatchMePadding { + uint32_t data; + char padding_after[WATCHPOINT_SIZE]; +} g_watchme; struct action_args { int delay; @@ -66,7 +74,7 @@ watchpoint_func (void *input) { pseudo_barrier_wait(g_barrier); do_action_args(input); - g_watchme = 1; // watchpoint triggers here + g_watchme.data = 1; // watchpoint triggers here return 0; } @@ -114,7 +122,7 @@ void start_threads(thread_vector& threads, int dotest() { - g_watchme = 0; + g_watchme.data = 0; // Actions are triggered immediately after the thread is spawned unsigned num_breakpoint_threads = 1; >From 6954df3e86f0aac57d60a5319199239b3985f52c Mon Sep 17 00:00:00 2001 From: Charles Zablit <[email protected]> Date: Mon, 7 Sep 2026 15:16:54 +0200 Subject: [PATCH 3/3] fix formatting --- .../thread/concurrent_events/main.cpp | 115 +++++++++--------- 1 file changed, 59 insertions(+), 56 deletions(-) diff --git a/lldb/test/API/functionalities/thread/concurrent_events/main.cpp b/lldb/test/API/functionalities/thread/concurrent_events/main.cpp index 9fcc6769bf2f1..445c0cd9af2ce 100644 --- a/lldb/test/API/functionalities/thread/concurrent_events/main.cpp +++ b/lldb/test/API/functionalities/thread/concurrent_events/main.cpp @@ -74,7 +74,7 @@ watchpoint_func (void *input) { pseudo_barrier_wait(g_barrier); do_action_args(input); - g_watchme.data = 1; // watchpoint triggers here + g_watchme.data = 1; // watchpoint triggers here return 0; } @@ -122,61 +122,64 @@ void start_threads(thread_vector& threads, int dotest() { - g_watchme.data = 0; - - // Actions are triggered immediately after the thread is spawned - unsigned num_breakpoint_threads = 1; - unsigned num_watchpoint_threads = 0; - unsigned num_signal_threads = 1; - unsigned num_crash_threads = 0; - - // Actions below are triggered after a 1-second delay - unsigned num_delay_breakpoint_threads = 0; - unsigned num_delay_watchpoint_threads = 0; - unsigned num_delay_signal_threads = 0; - unsigned num_delay_crash_threads = 0; - - register_signal_handler(SIGUSR1, sigusr1_handler); // Break here and adjust num_[breakpoint|watchpoint|signal|crash]_threads - - unsigned total_threads = num_breakpoint_threads \ - + num_watchpoint_threads \ - + num_signal_threads \ - + num_crash_threads \ - + num_delay_breakpoint_threads \ - + num_delay_watchpoint_threads \ - + num_delay_signal_threads \ - + num_delay_crash_threads; - - // Don't let either thread do anything until they're both ready. - pseudo_barrier_init(g_barrier, total_threads); - - action_counts actions; - actions.push_back(std::make_pair(num_breakpoint_threads, breakpoint_func)); - actions.push_back(std::make_pair(num_watchpoint_threads, watchpoint_func)); - actions.push_back(std::make_pair(num_signal_threads, signal_func)); - actions.push_back(std::make_pair(num_crash_threads, crash_func)); - - action_counts delay_actions; - delay_actions.push_back(std::make_pair(num_delay_breakpoint_threads, breakpoint_func)); - delay_actions.push_back(std::make_pair(num_delay_watchpoint_threads, watchpoint_func)); - delay_actions.push_back(std::make_pair(num_delay_signal_threads, signal_func)); - delay_actions.push_back(std::make_pair(num_delay_crash_threads, crash_func)); - - // Create threads that handle instant actions - thread_vector threads; - start_threads(threads, actions); - - // Create threads that handle delayed actions - action_args delay_arg; - delay_arg.delay = 1; - start_threads(threads, delay_actions, &delay_arg); - - // Join all threads - typedef std::vector<pthread_t>::iterator thread_iterator; - for(thread_iterator t = threads.begin(); t != threads.end(); ++t) - pthread_join(*t, 0); - - return 0; + g_watchme.data = 0; + + // Actions are triggered immediately after the thread is spawned + unsigned num_breakpoint_threads = 1; + unsigned num_watchpoint_threads = 0; + unsigned num_signal_threads = 1; + unsigned num_crash_threads = 0; + + // Actions below are triggered after a 1-second delay + unsigned num_delay_breakpoint_threads = 0; + unsigned num_delay_watchpoint_threads = 0; + unsigned num_delay_signal_threads = 0; + unsigned num_delay_crash_threads = 0; + + register_signal_handler( + SIGUSR1, + sigusr1_handler); // Break here and adjust + // num_[breakpoint|watchpoint|signal|crash]_threads + + unsigned total_threads = num_breakpoint_threads + num_watchpoint_threads + + num_signal_threads + num_crash_threads + + num_delay_breakpoint_threads + + num_delay_watchpoint_threads + + num_delay_signal_threads + num_delay_crash_threads; + + // Don't let either thread do anything until they're both ready. + pseudo_barrier_init(g_barrier, total_threads); + + action_counts actions; + actions.push_back(std::make_pair(num_breakpoint_threads, breakpoint_func)); + actions.push_back(std::make_pair(num_watchpoint_threads, watchpoint_func)); + actions.push_back(std::make_pair(num_signal_threads, signal_func)); + actions.push_back(std::make_pair(num_crash_threads, crash_func)); + + action_counts delay_actions; + delay_actions.push_back( + std::make_pair(num_delay_breakpoint_threads, breakpoint_func)); + delay_actions.push_back( + std::make_pair(num_delay_watchpoint_threads, watchpoint_func)); + delay_actions.push_back( + std::make_pair(num_delay_signal_threads, signal_func)); + delay_actions.push_back(std::make_pair(num_delay_crash_threads, crash_func)); + + // Create threads that handle instant actions + thread_vector threads; + start_threads(threads, actions); + + // Create threads that handle delayed actions + action_args delay_arg; + delay_arg.delay = 1; + start_threads(threads, delay_actions, &delay_arg); + + // Join all threads + typedef std::vector<pthread_t>::iterator thread_iterator; + for (thread_iterator t = threads.begin(); t != threads.end(); ++t) + pthread_join(*t, 0); + + return 0; } int main () _______________________________________________ lldb-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
