Debugger: CliContext: Introduce the notion of events

* The input loop can now wait on abstract events, which other threads
  (or even the input loop thread itself) can signal.
* Use the new mechanism in QuitSession().
* Also (with the exception of the SIGINT part) implement
  WaitForThreadOrUser().

src/apps/debugger/user_interface/cli/CliContext.cpp

@@ -28,16 +28,22 @@ CliContext::CliContext()
 	fHistory(NULL),
 	fPrompt(NULL),
 	fBlockingSemaphore(-1),
+	fInputLoopWaitingForEvents(0),
+	fEventsOccurred(0),
 	fInputLoopWaiting(false),
 	fTerminating(false)
 {
 	sCurrentContext = this;
 }
 
+
 CliContext::~CliContext()
 {
 	Cleanup();
 	sCurrentContext = NULL;
+
+	if (fBlockingSemaphore >= 0)
+		delete_sem(fBlockingSemaphore);
 }
 
 
@@ -47,6 +53,8 @@ CliContext::Init(Team* team, UserInterfaceListener* listener)
 	fTeam = team;
 	fListener = listener;
 
+	fTeam->AddListener(this);
+
 	status_t error = fLock.InitCheck();
 	if (error != B_OK)
 		return error;
@@ -88,6 +96,11 @@ CliContext::Cleanup()
 		history_end(fHistory);
 		fHistory = NULL;
 	}
+
+	if (fTeam != NULL) {
+		fTeam->RemoveListener(this);
+		fTeam = NULL;
+	}
 }
 
 
@@ -97,13 +110,7 @@ CliContext::Terminating()
 	AutoLocker<BLocker> locker(fLock);
 
 	fTerminating = true;
-
-	if (fBlockingSemaphore >= 0) {
-		delete_sem(fBlockingSemaphore);
-		fBlockingSemaphore = -1;
-	}
-
-	fInputLoopWaiting = false;
+	_SignalInputLoop(EVENT_QUIT);
 
 	// TODO: Signal the input loop, should it be in PromptUser()!
 }
@@ -134,27 +141,104 @@ CliContext::AddLineToInputHistory(const char* line)
 void
 CliContext::QuitSession(bool killTeam)
 {
-	AutoLocker<BLocker> locker(fLock);
-
-	sem_id blockingSemaphore = fBlockingSemaphore;
-	fInputLoopWaiting = true;
-
-	locker.Unlock();
+	_PrepareToWaitForEvents(EVENT_QUIT);
 
 	fListener->UserInterfaceQuitRequested(
 		killTeam
 			? UserInterfaceListener::QUIT_OPTION_ASK_KILL_TEAM
 			: UserInterfaceListener::QUIT_OPTION_ASK_RESUME_TEAM);
 
-	while (acquire_sem(blockingSemaphore) == B_INTERRUPTED) {
-	}
+	_WaitForEvents();
 }
 
 
 void
 CliContext::WaitForThreadOrUser()
 {
-	// TODO:...
+// TODO: Deal with SIGINT as well!
+	for (;;) {
+		_PrepareToWaitForEvents(
+			EVENT_USER_INTERRUPT | EVENT_THREAD_STATE_CHANGED);
+
+		// check whether there are any threads stopped already
+		thread_id stoppedThread = -1;
+		AutoLocker<Team> teamLocker(fTeam);
+
+		for (ThreadList::ConstIterator it = fTeam->Threads().GetIterator();
+				Thread* thread = it.Next();) {
+			if (thread->State() == THREAD_STATE_STOPPED) {
+				stoppedThread = thread->ID();
+				break;
+			}
+		}
+
+		teamLocker.Unlock();
+
+		if (stoppedThread >= 0)
+			_SignalInputLoop(EVENT_THREAD_STATE_CHANGED);
+
+		uint32 events = _WaitForEvents();
+		if ((events & EVENT_QUIT) != 0 || stoppedThread >= 0)
+			return;
+	}
+}
+
+
+void
+CliContext::ThreadStateChanged(const Team::ThreadEvent& event)
+{
+	_SignalInputLoop(EVENT_THREAD_STATE_CHANGED);
+}
+
+
+void
+CliContext::_PrepareToWaitForEvents(uint32 eventMask)
+{
+	// Set the events we're going to wait for -- always wait for "quit".
+	AutoLocker<BLocker> locker(fLock);
+	fInputLoopWaitingForEvents = eventMask | EVENT_QUIT;
+	fEventsOccurred = fTerminating ? EVENT_QUIT : 0;
+}
+
+
+uint32
+CliContext::_WaitForEvents()
+{
+	AutoLocker<BLocker> locker(fLock);
+
+	if (fEventsOccurred == 0) {
+		sem_id blockingSemaphore = fBlockingSemaphore;
+		fInputLoopWaiting = true;
+
+		locker.Unlock();
+
+		while (acquire_sem(blockingSemaphore) == B_INTERRUPTED) {
+		}
+
+		locker.Lock();
+	}
+
+	uint32 events = fEventsOccurred;
+	fEventsOccurred = 0;
+	return events;
+}
+
+
+void
+CliContext::_SignalInputLoop(uint32 events)
+{
+	AutoLocker<BLocker> locker(fLock);
+
+	if ((fInputLoopWaitingForEvents & events) == 0)
+		return;
+
+	fEventsOccurred = fInputLoopWaitingForEvents & events;
+	fInputLoopWaitingForEvents = 0;
+
+	if (fInputLoopWaiting) {
+		fInputLoopWaiting = false;
+		release_sem(fBlockingSemaphore);
+	}
 }
 
 

src/apps/debugger/user_interface/cli/CliContext.h

@@ -12,12 +12,21 @@
 
 #include <Locker.h>
 
+#include "Team.h"
+
 
 class Team;
 class UserInterfaceListener;
 
 
-class CliContext {
+class CliContext : private Team::Listener {
+public:
+			enum {
+				EVENT_QUIT					= 0x01,
+				EVENT_USER_INTERRUPT		= 0x02,
+				EVENT_THREAD_STATE_CHANGED	= 0x04,
+			};
+
 public:
 								CliContext();
 								~CliContext();
@@ -40,6 +49,15 @@ public:
 			void				WaitForThreadOrUser();
 
 private:
+	// Team::Listener
+	virtual	void				ThreadStateChanged(
+									const Team::ThreadEvent& event);
+
+private:
+			void				_PrepareToWaitForEvents(uint32 eventMask);
+			uint32				_WaitForEvents();
+			void				_SignalInputLoop(uint32 events);
+
 	static	const char*			_GetPrompt(EditLine* editLine);
 
 private:
@@ -50,6 +68,8 @@ private:
 			History*			fHistory;
 			const char*			fPrompt;
 			sem_id				fBlockingSemaphore;
+			uint32				fInputLoopWaitingForEvents;
+			uint32				fEventsOccurred;
 			bool				fInputLoopWaiting;
 	volatile bool				fTerminating;
 };