Bug 4399

Summary:	Continue/Stop in Source WIndow causes ptrace to backtrace
Product:	frysk	Reporter:	Rick Moseley <rmoseley>
Component:	general	Assignee:	Mike Cvet <mcvet>
Status:	RESOLVED FIXED
Severity:	normal
Priority:	P2
Version:	unspecified
Target Milestone:	---
Host:		Target:
Build:		Last reconfirmed:
Project(s) to access:		ssh public key:
Bug Depends on:
Bug Blocks:	1633, 4193

Description Rick Moseley 2007-04-20 14:44:58 UTC

After adding a new executable to the source window via the "Run Executable"
option off of the "File" menu, a backtrace is "occasionally" generated when I do
a "Continue" and then a "Stop".  The following backtrace occurs:

Call stack is broken - couldn't unwind!
ptrace: No such process (pt 0xc, pid 2232, addr 0x0, data 0x20bc1e8)
   at frysk.sys.Ptrace$RegisterSet.get(Ptrace.cxx:159)
   at frysk.sys.PtraceServer$RegisterSetRequest.execute(PtraceServer.java:199)
   at frysk.sys.Server.run(Server.java:142)
java.lang.NullPointerException
   at frysk.rt.StackFrame.getSymbol(StackFrame.java:244)
   at frysk.gui.srcwin.SourceWindow.populateStackBrowser(SourceWindow.java:609)
   at frysk.gui.srcwin.SourceWindow$LockObserver$37.run(SourceWindow.java:2867)
   at org.gnu.glib.CustomEvents.runEvents(libgtkjava-2.8.so)
   at org.gnu.gtk.Gtk.gtk_main(libgtkjava-2.8.so)
   at org.gnu.gtk.Gtk.main(libgtkjava-2.8.so)
   at frysk.gui.Gui.gui(Gui.java:244)
   at frysk.gui.FryskGui.main(FryskGui.java:59)

Comment 1 Rick Moseley 2007-04-20 14:46:51 UTC

Ooops.  Put wrong blocker on.

Comment 2 Mike Cvet 2007-04-23 17:01:11 UTC

2007-04-23  Mike Cvet  <mcvet@redhat.com>

	* SteppingEngine.java (contextMap): Changed to synchronized HashMap.
	(tasks, stateProc, taskStepCount, current): Removed.
	(threadsList): Added. List of Tasks to be blocked.
	(setProc): Heavily cleaned up, fixed to use threadsList.
	(setProcs): Ditto.
	(addProc): Dito.
	(stepInstruction): Ditto. Uses contextMap to keep track of number of
	stepping threads.
	(setUpLineStep): Removed reference to taskStepCount.
	(setUpStepNextInstruction): Ditto.
	(setUpStepOver): Ditto.
	(setUpStepOut): Ditto.
	(continueExecution): Removed reference to old Tasks array.
	(stop): Ditto. Ensure that Tasks don't get added to threadsList
	more than once. Synchronized on threadsList.
	(blockTask): Removed.
	(executeTasks): Made use of threadsList.
	(isProcRunning): Assume if Task no longer exists in SteppingEngine
	data structures, it has exited and thus not running. Fixes #4401.
	(isTaskRunning): Ditto.
	(updateExecuted): Check number of remaining Tasks to be blocked before
	notifying any Observers. Update the number of remaining Tasks in the
	contextMap. If there are Tasks to be blocked, block them and return.
	Fixes #4399.
	(requestAdd): Rewritten. Faster, empties Tasks out of threadsList and
	blocks each as individual Tasks rather than threads of a process.
	(ThreadLifeObservable): Initialize threadsList.
	(ThreadLifeObservable.updateClonedOffspring): Don't explicitly block
	new Tasks with the steppingObserver. Update contextMap with new Task
	and put new Task in threadsList. Fixes #4399.