Adding support for setting thread stop state when a process stops.
This re-submission of this patch fixes a problem where the code sometimes caused a deadlock. The Process::SetPrivateState method was locking the Process::m_private_state variable and then later calling ThreadList::DidStop, which locks the ThreadList mutex. Other methods in ThreadList which were being called from other threads lock the ThreadList mutex and then call Process::GetPrivateState which locks the Process::m_private_state mutex. To avoid deadlocks, Process::SetPrivateState now locks the ThreadList mutex before locking the Process::m_private_state mutex.
git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@181609 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/lldb/Target/Thread.h b/include/lldb/Target/Thread.h
index e2207a0..fc58a69 100644
--- a/include/lldb/Target/Thread.h
+++ b/include/lldb/Target/Thread.h
@@ -277,6 +277,10 @@
virtual void
DidResume ();
+ // This notifies the thread when a private stop occurs.
+ virtual void
+ DidStop ();
+
virtual void
RefreshStateAfterStop() = 0;
diff --git a/include/lldb/Target/ThreadList.h b/include/lldb/Target/ThreadList.h
index 959091c..ddf49b0 100644
--- a/include/lldb/Target/ThreadList.h
+++ b/include/lldb/Target/ThreadList.h
@@ -120,6 +120,9 @@
DidResume ();
void
+ DidStop ();
+
+ void
DiscardThreadPlans();
uint32_t
diff --git a/source/Target/Process.cpp b/source/Target/Process.cpp
index 93fd93a..01ee7e4 100644
--- a/source/Target/Process.cpp
+++ b/source/Target/Process.cpp
@@ -1699,6 +1699,7 @@
if (log)
log->Printf("Process::SetPrivateState (%s)", StateAsCString(new_state));
+ Mutex::Locker thread_locker(m_thread_list.GetMutex());
Mutex::Locker locker(m_private_state.GetMutex());
const StateType old_state = m_private_state.GetValueNoLock ();
@@ -1722,6 +1723,19 @@
m_private_state.SetValueNoLock (new_state);
if (StateIsStoppedState(new_state, false))
{
+ // Note, this currently assumes that all threads in the list
+ // stop when the process stops. In the future we will want to
+ // support a debugging model where some threads continue to run
+ // while others are stopped. When that happens we will either need
+ // a way for the thread list to identify which threads are stopping
+ // or create a special thread list containing only threads which
+ // actually stopped.
+ //
+ // The process plugin is responsible for managing the actual
+ // behavior of the threads and should have stopped any threads
+ // that are going to stop before we get here.
+ m_thread_list.DidStop();
+
m_mod_id.BumpStopID();
m_memory_cache.Clear();
if (log)
diff --git a/source/Target/Thread.cpp b/source/Target/Thread.cpp
index 646a635..c4aa254 100644
--- a/source/Target/Thread.cpp
+++ b/source/Target/Thread.cpp
@@ -658,6 +658,12 @@
SetResumeSignal (LLDB_INVALID_SIGNAL_NUMBER);
}
+void
+Thread::DidStop ()
+{
+ SetState (eStateStopped);
+}
+
bool
Thread::ShouldStop (Event* event_ptr)
{
diff --git a/source/Target/ThreadList.cpp b/source/Target/ThreadList.cpp
index d84a234..1f8b351 100644
--- a/source/Target/ThreadList.cpp
+++ b/source/Target/ThreadList.cpp
@@ -11,6 +11,7 @@
#include <algorithm>
#include "lldb/Core/Log.h"
+#include "lldb/Core/State.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/ThreadList.h"
#include "lldb/Target/Thread.h"
@@ -643,6 +644,27 @@
}
}
+void
+ThreadList::DidStop ()
+{
+ Mutex::Locker locker(GetMutex());
+ collection::iterator pos, end = m_threads.end();
+ for (pos = m_threads.begin(); pos != end; ++pos)
+ {
+ // Notify threads that the process just stopped.
+ // Note, this currently assumes that all threads in the list
+ // stop when the process stops. In the future we will want to support
+ // a debugging model where some threads continue to run while others
+ // are stopped. We either need to handle that somehow here or
+ // create a special thread list containing only threads which will
+ // stop in the code that calls this method (currently
+ // Process::SetPrivateState).
+ ThreadSP thread_sp(*pos);
+ if (StateIsRunningState(thread_sp->GetState()))
+ thread_sp->DidStop ();
+ }
+}
+
ThreadSP
ThreadList::GetSelectedThread ()
{
diff --git a/test/functionalities/thread/state/TestThreadStates.py b/test/functionalities/thread/state/TestThreadStates.py
index 7e59b22..185eb50 100644
--- a/test/functionalities/thread/state/TestThreadStates.py
+++ b/test/functionalities/thread/state/TestThreadStates.py
@@ -14,14 +14,12 @@
@unittest2.skipUnless(sys.platform.startswith("darwin"), "requires Darwin")
@dsym_test
- @unittest2.expectedFailure("PR-15824") # thread states not properly maintained
def test_state_after_breakpoint_with_dsym(self):
"""Test thread state after breakpoint."""
self.buildDsym()
self.thread_state_after_breakpoint_test()
@dwarf_test
- @unittest2.expectedFailure("PR-15824") # thread states not properly maintained
def test_state_after_breakpoint_with_dwarf(self):
"""Test thread state after breakpoint."""
self.buildDwarf()