Re: [Pharo-project] Socket problems

April 29, 2009

      Ok, let's see if we can get a grip on what is going on.

what I did was in
sqSocketCreateNetTypeSocketTypeRecvBytesSendBytesSemaIDReadSemaIDWriteSemaID

after the socket() call and at the check for socket value = -1, I  
always fail the primitive call.
This mimics what happens when you run out of socket handles.
In this case since we never recover then it should result in a hard  
failure because the socket table is full.

I put a break point in to understand where we are, and a breakpoint at  
the full GC.

What I see is the first call, where we fail.

current pharo, closure based, macintosh vm 4.1.1b2
Process
557974616 Socket>initialize:family:
557974524 >newTCP:
557974308 BlockClosure>repeatWithGCIf:
557974216 >newTCP:
557974124 >newTCP
557973968 >new
557652968 >sendTest
557652876 >?
557649476 Compiler>evaluate:in:to:notifying:ifFail:logged:
557649384 ParagraphEditor>evaluateSelection
557649228 BlockClosure>on:do:
557649136 ParagraphEditor>evaluateSelection
557649024 ParagraphEditor>doIt

The second call I note the full GC hasn't happened yet, so the code is  
invoking create new socket again before the GC call, which *IS* rather  
pointless.
I wonder why the second call happens before the GC?

Process
557976760  
Socket
...
primSocketCreateNetwork:type:receiveBufferSize:sendBufSize:semaIndex:readSemaIndex:writeSemaIndex 
:
557974616 Socket>initialize:family:
557974524 >newTCP:
557974308 BlockClosure>repeatWithGCIf:
557974216 >newTCP:
557974124 >newTCP
557973968 >new
557652968 >sendTest
557652876 >?
557649476 Compiler>evaluate:in:to:notifying:ifFail:logged:
557649384 ParagraphEditor>evaluateSelection
557649228 BlockClosure>on:do:
557649136 ParagraphEditor>evaluateSelection
557649024 ParagraphEditor>doIt

then we see the full GC which has the intent of cleaning out zombies  
so that those sockets can be returned to the operating system.

Process
557683240 SystemDictionary>garbageCollect
557683044 BlockClosure>repeatWithGCIf:
557682952 >newTCP:
557682860 >newTCP
557682768 >new
557652968 >sendTest
557652876 >?
557649476 Compiler>evaluate:in:to:notifying:ifFail:logged:
557649384 ParagraphEditor>evaluateSelection
557649228 BlockClosure>on:do:
557649136 ParagraphEditor>evaluateSelection
557649024 ParagraphEditor>doIt

then again

Process
556761248 Socket>initialize:family:
556719648 >newTCP:
556692112 BlockClosure>repeatWithGCIf:
556692020 >newTCP:
556691928 >newTCP
556691836 >new
556662076 >sendTest
556661984 >?
556658584 Compiler>evaluate:in:to:notifying:ifFail:logged:
556658492 ParagraphEditor>evaluateSelection
556658336 BlockClosure>on:do:
556658244 ParagraphEditor>evaluateSelection
556658132 ParagraphEditor>doIt

and again, which seems rather pointless.

Process
556763348  
Socket
...
primSocketCreateNetwork:type:receiveBufferSize:sendBufSize:semaIndex:readSemaIndex:writeSemaIndex 
:
556761248 Socket>initialize:family:
556719648 >newTCP:
556692112 BlockClosure>repeatWithGCIf:
556692020 >newTCP:
556691928 >newTCP
556691836 >new
556662076 >sendTest
556661984 >?
556658584 Compiler>evaluate:in:to:notifying:ifFail:logged:
5566584\92 ParagraphEditor>evaluateSelection
556658336 BlockClosure>on:do:
556658244 ParagraphEditor>evaluateSelection
556658132 ParagraphEditor>doIt

Then the walkback pops up.  Obviously should the code try to make the  
socket 4 times?   versus say twice?

Socket>>connectNonBlockingTo:
	Receiver: a Socket[destroyed]
	Arguments and temporary variables:
		aSocketAddress: 	128.111.221.123(pulse),9(discard)
		status: 	-1
	Receiver's instance variables:
		semaphore: 	nil
		socketHandle: 	nil
		readSemaphore: 	nil
		writeSemaphore: 	nil
		primitiveOnlySupportsOneSemaphore: 	true

Socket>>connectTo:waitForConnectionFor:
	Receiver: a Socket[destroyed]
	Arguments and temporary variables:
		aSocketAddress: 	128.111.221.123(pulse),9(discard)
		timeout: 	45
	Receiver's instance variables:
		semaphore: 	nil
		socketHandle: 	nil
		readSemaphore: 	nil
		writeSemaphore: 	nil
		primitiveOnlySupportsOneSemaphore: 	true

Socket>>connectTo:
	Receiver: a Socket[destroyed]
	Arguments and temporary variables:
		aSocketAddress: 	128.111.221.123(pulse),9(discard)
	Receiver's instance variables:
		semaphore: 	nil
		socketHandle: 	nil
		readSemaphore: 	nil
		writeSemaphore: 	nil
		primitiveOnlySupportsOneSemaphore: 	true

Socket>>connectTo:port:
	Receiver: a Socket[destroyed]
	Arguments and temporary variables:
		hostAddress: 	128.111.221.123(pulse),9(discard)
		port: 	9
	Receiver's instance variables:
		semaphore: 	nil
		socketHandle: 	nil
		readSemaphore: 	nil
		writeSemaphore: 	nil
		primitiveOnlySupportsOneSemaphore: 	true

Socket class>>sendTest
	Receiver: Socket
	Arguments and temporary variables:
		sock: 	a Socket[destroyed]
		bytesToSend: 	nil
		sendBuf: 	nil
		t: 	nil
		serverName: 	'create.ucsb.edu'
		serverAddr: 	128.111.221.123(pulse),9(discard)
		bytesSent: 	#(nil)
	Receiver's instance variables:
		superclass: 	Object
		methodDict: 	a MethodDictionary(size 137)
		format: 	140
		instanceVariables: 	#('semaphore' 'socketHandle' 'readSemaphore'  
'writeSemaphore...etc...
		organization: 	('accessing' address localAddress localPort peerName  
port primiti...etc...
		subclasses: 	{SocksSocket . HTTPSocket . RFBSocket}
		name: 	#Socket
		classPool: 	a Dictionary(#Connected->2 #DeadServer-
...
'update.squeakfoundation.org...etc...
       sharedPools: 	nil
       environment: 	Smalltalk
       category: 	#'Network-Kernel'
       traitComposition: 	{}
       localSelectors: 	nil
Socket class>>DoIt
	Receiver: Socket
	Arguments and temporary variables:

	Receiver's instance variables:
		superclass: 	Object
		methodDict: 	a MethodDictionary(size 137)
		format: 	140
		instanceVariables: 	#('semaphore' 'socketHandle' 'readSemaphore'  
'writeSemaphore...etc...
		organization: 	('accessing' address localAddress localPort peerName  
port primiti...etc...
		subclasses: 	{SocksSocket . HTTPSocket . RFBSocket}
		name: 	#Socket
		classPool: 	a Dictionary(#Connected->2 #DeadServer-
...
'update.squeakfoundation.org...etc...
       sharedPools: 	nil
       environment: 	Smalltalk
       category: 	#'Network-Kernel'
       traitComposition: 	{}
       localSelectors: 	nil
For cross check let's look at what happens before the closure code.

pre closure work
in a pharo0.1-10211dev09.01.3.image

(gdb) call (int) printAllStacks()
Process
545073376 Socket>initialize:
545073560 [] in >newTCP
545073284 BlockContext>repeatWithGCIf:
545072904 >newTCP
545072812 >new
544992420 >sendTest
544992328 >?
544989336 Compiler>evaluate:in:to:notifying:ifFail:logged:
544989004 [] in ParagraphEditor>evaluateSelection
544988912 BlockContext>on:do:
544988664 ParagraphEditor>evaluateSelection
544988572 ParagraphEditor>doIt

again

545075672  
Socket
...
primSocketCreateNetwork:type:receiveBufferSize:sendBufSize:semaIndex:readSemaIndex:writeSemaIndex 
:
545073376 Socket>initialize:
545073560 [] in >newTCP
545073284 BlockContext>repeatWithGCIf:
545072904 >newTCP
545072812 >new
544992420 >sendTest
544992328 >?
544989336 Compiler>evaluate:in:to:notifying:ifFail:logged:
544989004 [] in ParagraphEditor>evaluateSelection
544988912 BlockContext>on:do:
544988664 ParagraphEditor>evaluateSelection
544988572 ParagraphEditor>doIt

fullGC happens.

Process
545024744 SystemDictionary>garbageCollect
545024440 BlockContext>repeatWithGCIf:
545024336 >newTCP
545024244 >new
544992420 >sendTest
544992328 >?
544989336 Compiler>evaluate:in:to:notifying:ifFail:logged:
544989004 [] in ParagraphEditor>evaluateSelection
544988912 BlockContext>on:do:
544988664 ParagraphEditor>evaluateSelection
544988572 ParagraphEditor>doIt

off we go again to create socket.

Process
543469672 Socket>initialize:
543447120 [] in >newTCP
543447028 BlockContext>repeatWithGCIf:
543446924 >newTCP
543446832 >new
543438208 >sendTest
543438116 >?
543435124 Compiler>evaluate:in:to:notifying:ifFail:logged:
543434792 [] in ParagraphEditor>evaluateSelection
543434700 BlockContext>on:do:
543434452 ParagraphEditor>evaluateSelection
543434360 ParagraphEditor>doIt

off we go again to create socket.

Process
543471784  
Socket
...
primSocketCreateNetwork:type:receiveBufferSize:sendBufSize:semaIndex:readSemaIndex:writeSemaIndex 
:
543469672 Socket>initialize:
543447120 [] in >newTCP
543447028 BlockContext>repeatWithGCIf:
543446924 >newTCP
543446832 >new
543438208 >sendTest
543438116 >?
543435124 Compiler>evaluate:in:to:notifying:ifFail:logged:
543434792 [] in ParagraphEditor>evaluateSelection
543434700 BlockContext>on:do:
543434452 ParagraphEditor>evaluateSelection
543434360 ParagraphEditor>doIt

and end up with walkback at.

Socket status must Unconnected before opening a new connection

connectNonBlockingTo: hostAddress port: port
	"Initiate a connection to the given port at the given host address.  
This operation will return immediately; follow it with  
waitForConnectionUntil: to wait until the connection is established."

	| status |
	self initializeNetwork.
	status := self primSocketConnectionStatus: socketHandle.
	(status == Unconnected)
		ifFalse: [InvalidSocketStatusException signal: 'Socket status must  
Unconnected before opening a new connection'].

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========================================================================
John M. McIntosh <johnmci@smalltalkconsulting.com>   Twitter:   
squeaker68882
Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com
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========================================================================

Re: [Pharo-project] Socket problems

John M McIntosh