<rdar://problem/12446222>
Implement the ability for Python commands to be interrupted by pressing CTRL+C
Also add a new Mutex subclass that attempts to be helpful for debugging by logging actions performed on it
FYI of all interested - there is a separate deadlocking issue related to how LLDB dispatches CTRL+C that might cause LLDB to deadlock upon pressing CTRL+C while in a Python command.
This is not a regression, and was just previously masked by us not even trying to bail out of Python commands, so that it would not be clear from a user perspective whether we were
deadlocked or stuck in an inconsistent state within the Python interpreter.
git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@170612 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/lldb/Host/Mutex.h b/include/lldb/Host/Mutex.h
index 38f4f31..63f759e 100644
--- a/include/lldb/Host/Mutex.h
+++ b/include/lldb/Host/Mutex.h
@@ -193,6 +193,9 @@
/// @return
/// The error code from \c pthread_mutex_lock().
//------------------------------------------------------------------
+#ifdef LLDB_CONFIGURATION_DEBUG
+ virtual
+#endif
int
Lock();
@@ -280,6 +283,27 @@
pthread_t m_thread_that_tried;
std::string m_failure_message;
};
+
+class LoggingMutex : public Mutex
+{
+public:
+ LoggingMutex() : Mutex(),m_locked(false) {}
+ LoggingMutex(Mutex::Type type) : Mutex (type),m_locked(false) {}
+
+ virtual
+ ~LoggingMutex() {}
+
+ virtual int
+ Lock ();
+
+ virtual int
+ Unlock ();
+
+ virtual int
+ TryLock (const char *failure_message = NULL);
+protected:
+ bool m_locked;
+};
#endif
} // namespace lldb_private
diff --git a/include/lldb/Interpreter/ScriptInterpreterPython.h b/include/lldb/Interpreter/ScriptInterpreterPython.h
index de87443..fba3c6a 100644
--- a/include/lldb/Interpreter/ScriptInterpreterPython.h
+++ b/include/lldb/Interpreter/ScriptInterpreterPython.h
@@ -366,6 +366,7 @@
bool m_session_is_active;
bool m_pty_slave_is_open;
bool m_valid_session;
+ PyThreadState *m_command_thread_state;
};
} // namespace lldb_private
diff --git a/source/Host/common/Mutex.cpp b/source/Host/common/Mutex.cpp
index 4b0f2f9..fb666c5 100644
--- a/source/Host/common/Mutex.cpp
+++ b/source/Host/common/Mutex.cpp
@@ -27,6 +27,7 @@
// Enable extra mutex error checking
#ifdef LLDB_CONFIGURATION_DEBUG
#define ENABLE_MUTEX_ERROR_CHECKING 1
+#include <inttypes.h>
#endif
#if ENABLE_MUTEX_ERROR_CHECKING
@@ -352,6 +353,38 @@
assert (m_failure_message.empty());
return Mutex::Unlock();
}
+
+int
+LoggingMutex::Lock ()
+{
+ printf("locking mutex %p by [%4.4" PRIx64 "/%4.4" PRIx64 "]...", this, Host::GetCurrentProcessID(), Host::GetCurrentThreadID());
+ int x = Mutex::Lock();
+ m_locked = true;
+ printf("%d\n",x);
+ return x;
+}
+
+int
+LoggingMutex::Unlock ()
+{
+ printf("unlocking mutex %p by [%4.4" PRIx64 "/%4.4" PRIx64 "]...", this, Host::GetCurrentProcessID(), Host::GetCurrentThreadID());
+ int x = Mutex::Unlock();
+ m_locked = false;
+ printf("%d\n",x);
+ return x;
+}
+
+int
+LoggingMutex::TryLock (const char *failure_message)
+{
+ printf("trylocking mutex %p by [%4.4" PRIx64 "/%4.4" PRIx64 "]...", this, Host::GetCurrentProcessID(), Host::GetCurrentThreadID());
+ int x = Mutex::TryLock(failure_message);
+ if (x == 0)
+ m_locked = true;
+ printf("%d\n",x);
+ return x;
+}
+
#endif
-
+
diff --git a/source/Interpreter/ScriptInterpreterPython.cpp b/source/Interpreter/ScriptInterpreterPython.cpp
index a94f870..78f8524 100644
--- a/source/Interpreter/ScriptInterpreterPython.cpp
+++ b/source/Interpreter/ScriptInterpreterPython.cpp
@@ -371,7 +371,22 @@
break;
case eInputReaderInterrupt:
- reader.SetIsDone(true);
+ {
+ PyThreadState* state = _PyThreadState_Current;
+ if (!state)
+ state = script_interpreter->m_command_thread_state;
+ if (state)
+ {
+ long tid = state->thread_id;
+ _PyThreadState_Current = state;
+ int num_threads = PyThreadState_SetAsyncExc(tid, PyExc_KeyboardInterrupt);
+ if (log)
+ log->Printf("ScriptInterpreterPython::NonInteractiveInputReaderCallback, eInputReaderInterrupt, tid = %ld, num_threads = %d, state = %p",
+ tid,num_threads,state);
+ }
+ else if (log)
+ log->Printf("ScriptInterpreterPython::NonInteractiveInputReaderCallback, eInputReaderInterrupt, state = NULL");
+ }
break;
case eInputReaderEndOfFile:
@@ -446,7 +461,8 @@
m_dictionary_name (interpreter.GetDebugger().GetInstanceName().AsCString()),
m_terminal_state (),
m_session_is_active (false),
- m_valid_session (true)
+ m_valid_session (true),
+ m_command_thread_state (NULL)
{
static int g_initialized = false;
@@ -2643,8 +2659,16 @@
Locker py_lock(this,
Locker::AcquireLock | Locker::InitSession | Locker::InitGlobals,
Locker::FreeLock | Locker::TearDownSession);
+
SynchronicityHandler synch_handler(debugger_sp,
synchronicity);
+
+ // we need to save the thread state when we first start the command
+ // because we might decide to interrupt it while some action is taking
+ // place outside of Python (e.g. printing to screen, waiting for the network, ...)
+ // in that case, _PyThreadState_Current will be NULL - and we would be unable
+ // to set the asynchronous exception - not a desirable situation
+ m_command_thread_state = _PyThreadState_Current;
PythonInputReaderManager py_input(this);