diff options
Diffstat (limited to 'packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock')
4 files changed, 144 insertions, 0 deletions
diff --git a/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/.categories b/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/.categories new file mode 100644 index 000000000000..897e40a99dda --- /dev/null +++ b/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/.categories @@ -0,0 +1 @@ +expression diff --git a/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/Makefile b/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/Makefile new file mode 100644 index 000000000000..a10791d58907 --- /dev/null +++ b/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/Makefile @@ -0,0 +1,6 @@ +LEVEL = ../../make + +C_SOURCES := locking.c +ENABLE_THREADS := YES + +include $(LEVEL)/Makefile.rules diff --git a/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/TestExprDoesntBlock.py b/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/TestExprDoesntBlock.py new file mode 100644 index 000000000000..a54b45822a6a --- /dev/null +++ b/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/TestExprDoesntBlock.py @@ -0,0 +1,57 @@ +""" +Test that expr will time out and allow other threads to run if it blocks. +""" + +from __future__ import print_function + + + +import os, time +import re +import lldb +import lldbsuite.test.lldbutil as lldbutil +from lldbsuite.test.lldbtest import * + +class ExprDoesntDeadlockTestCase(TestBase): + + def getCategories(self): + return ['basic_process'] + + mydir = TestBase.compute_mydir(__file__) + + @expectedFailureFreeBSD('llvm.org/pr17946') + @expectedFlakeyLinux # failed 1/365 test runs, line 61, thread.IsValid() + @expectedFailureWindows # Windows doesn't have pthreads, need to port this test. + def test_with_run_command(self): + """Test that expr will time out and allow other threads to run if it blocks.""" + self.build() + exe = os.path.join(os.getcwd(), "a.out") + + # Create a target by the debugger. + target = self.dbg.CreateTarget(exe) + self.assertTrue(target, VALID_TARGET) + + # Now create a breakpoint at source line before call_me_to_get_lock gets called. + + main_file_spec = lldb.SBFileSpec ("locking.c") + breakpoint = target.BreakpointCreateBySourceRegex('Break here', main_file_spec) + if self.TraceOn(): + print("breakpoint:", breakpoint) + self.assertTrue(breakpoint and + breakpoint.GetNumLocations() == 1, + VALID_BREAKPOINT) + + # Now launch the process, and do not stop at entry point. + process = target.LaunchSimple (None, None, self.get_process_working_directory()) + self.assertTrue(process, PROCESS_IS_VALID) + + # Frame #0 should be on self.line1 and the break condition should hold. + from lldbsuite.test.lldbutil import get_stopped_thread + thread = get_stopped_thread(process, lldb.eStopReasonBreakpoint) + self.assertTrue(thread.IsValid(), "There should be a thread stopped due to breakpoint condition") + + frame0 = thread.GetFrameAtIndex(0) + + var = frame0.EvaluateExpression ("call_me_to_get_lock()") + self.assertTrue (var.IsValid()) + self.assertTrue (var.GetValueAsSigned (0) == 567) diff --git a/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/locking.c b/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/locking.c new file mode 100644 index 000000000000..fae9979611d5 --- /dev/null +++ b/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/locking.c @@ -0,0 +1,80 @@ +#include <pthread.h> +#include <stdlib.h> +#include <unistd.h> +#include <stdio.h> + +pthread_mutex_t contended_mutex = PTHREAD_MUTEX_INITIALIZER; + +pthread_mutex_t control_mutex = PTHREAD_MUTEX_INITIALIZER; +pthread_cond_t control_condition; + +pthread_mutex_t thread_started_mutex = PTHREAD_MUTEX_INITIALIZER; +pthread_cond_t thread_started_condition; + +// This function runs in a thread. The locking dance is to make sure that +// by the time the main thread reaches the pthread_join below, this thread +// has for sure acquired the contended_mutex. So then the call_me_to_get_lock +// function will block trying to get the mutex, and only succeed once it +// signals this thread, then lets it run to wake up from the cond_wait and +// release the mutex. + +void * +lock_acquirer_1 (void *input) +{ + pthread_mutex_lock (&contended_mutex); + + // Grab this mutex, that will ensure that the main thread + // is in its cond_wait for it (since that's when it drops the mutex. + + pthread_mutex_lock (&thread_started_mutex); + pthread_mutex_unlock(&thread_started_mutex); + + // Now signal the main thread that it can continue, we have the contended lock + // so the call to call_me_to_get_lock won't make any progress till this + // thread gets a chance to run. + + pthread_mutex_lock (&control_mutex); + + pthread_cond_signal (&thread_started_condition); + + pthread_cond_wait (&control_condition, &control_mutex); + + pthread_mutex_unlock (&contended_mutex); + return NULL; +} + +int +call_me_to_get_lock () +{ + pthread_cond_signal (&control_condition); + pthread_mutex_lock (&contended_mutex); + return 567; +} + +int main () +{ + pthread_t thread_1; + + pthread_cond_init (&control_condition, NULL); + pthread_cond_init (&thread_started_condition, NULL); + + pthread_mutex_lock (&thread_started_mutex); + + pthread_create (&thread_1, NULL, lock_acquirer_1, NULL); + + pthread_cond_wait (&thread_started_condition, &thread_started_mutex); + + pthread_mutex_lock (&control_mutex); + pthread_mutex_unlock (&control_mutex); + + // Break here. At this point the other thread will have the contended_mutex, + // and be sitting in its cond_wait for the control condition. So there is + // no way that our by-hand calling of call_me_to_get_lock will proceed + // without running the first thread at least somewhat. + + call_me_to_get_lock(); + pthread_join (thread_1, NULL); + + return 0; + +} |