Thread Status

[Scott Turchin]

Got my home PC back up and going so I can reply now!

I like the idea, and while I probably won't go with a dialog box for each connection this is what I do have, individual threads, and I like the global UDT flag idea, as I usually used g_Finished for a specific thread...

So I am going to try to incorporate that - which can be set at the beginning of this function and reset after it's complete...

'==========================================================================================
'THREAD FOR Sending Data
Function SendDataThread(ByVal hTcp As Long) As Long
Local hThread   As Long
Local lResult   As Long
Thread Create SendDataThreadProc(ByVal hTcp) To hThread
Function = hThread
End Function
'==========================================================================================
Function SendDataThreadProc(ByVal hTcp As Long) As Long
Local lResult   As Long
Local lLoop     As Long
Local lCount    As Long
Local ErrType   As Long
Local Header    As String
Local sBuffer   As String
Local sPacket   As String
Local sTmp      As String
Local lHost     As String

Incr BBSDown.tcpCount

lHost = RemoteIp(ByVal hTcp)
sTmp = TimeStamp() & " Connection established from: " & lHost

lResult = SendMessage(BBSDown.txtHandle, %LB_ADDSTRING, 0, StrPtr(sTmp))
lResult = SendMessage(BBSDown.lblHandle, %WM_SETTEXT, 0, BBSDown.tcpCount)
'lResult = ListView_SetSelection (BYVAL BBSDown.lblHandle, BYVAL BBSDown.tcpCount)
ListView_SetItemState BBSDown.lblHandle, BBSDown.tcpCount, &hFFFFFFFF, %LVIS_SELECTED Or %LVIS_FOCUSED




'Perform a receive-loop until there is no data left (ie, the end of stream)
sBuffer = ""
sPacket = ""
Do
    Tcp Recv hTcp, 1024, sBuffer
    sPacket = sPacket & sBuffer
    If Len(sPacket) > 4096 Then Exit Do 'Buffer overflow prevention
'    ErrType = GetLastError()
Loop Until sBuffer = "" Or IsTrue Eof(hTcp) Or IsTrue Err
sPacket = Left$(sPacket,Len(sPacket)-2)
lResult = ParseAndUpdateLogfile(ByVal sPacket,ByVal hTcp) 'Updates window
' <-------------Send data and disconnect------------->
Header = "HTTP/1.1 200" & $CrLf
Header = Header & "Server: " & BBSDown.szMine & $CrLf
Header = Header & "Date: " & GetPCTimeandDate() & $CrLf
Header = Header & "Cache-Control: no-cache" & $CrLf
Header = Header & "Connection: close" & $CrLf

If IsFalse lResult Then 'html
    Header = Header & "Content-Type: text/html" & $CrLf
    Header = Header & "Content-Length: " & Format$(Len(g_BBSDown)) & $CrLf
    Tcp Send hTcp, Header & $CrLf
    Tcp Send hTcp, g_BBSDown
Else 'jpg
    Header = Header & "Content-Type: image/jpeg" & $CrLf
    Header = Header & "Content-Length: " & Format$(Len(g_BBSDownImage)) & $CrLf
    Header = Header & "Accept-range: bytes"  & $CrLf 'or something like that.
    Tcp Send hTcp, Header & $CrLf
    Tcp Send hTcp, g_BBSDownImage
End If
Tcp Close hTcp
' <-------------Send data and disconnect------------->
'End connection here
ErrType = GetLastError()
If ErrType <> %ERROR_SUCCESS Then
    sTmp = TimeStamp() & " Error: " & Format$(ErrType) & " - " & GetLastErrorDescription(ErrType) & " - Remote IP: " & lHost
    lResult = SendMessage(BBSDown.txtHandle, %LB_ADDSTRING, 0, StrPtr(sTmp))
End If
End Function
'==========================================================================================

[John Petty]

Scott
You are confusing me

I think the Dialog DoEvents is broken in my version

Not really, you just need to put a 1 msec sleep time in it, didn’t you find that on the search I suggested.

Modeless closed too soon, Modal is still onlyi one TCP connection at a time

Why?
Lets say you want to limit to 10 concurrent connections.
Create a Global UDT array with 10 members and one of the fields in that array should be an “in use” flag and the address of that UDT array member is then the single and only variable allowed to be passed to a thread
Each thread then just creates a modal dialog which of course has a unique handle which should then be stored in the UDT member as well and in it you create a new socket ie hTCP. All the threads will of course share the same Callback code so the first thing that should happen in the callback is to compare CBHNDL to all the stored handles in the Global UDT so you know which one you are working on. PB is threadsafe so it should be creating new locals for each thread that uses the callback, if you don’t feel safe then don’t use any locals in the callback just make provision for them in the UDT. The last thing the callback should do before DIALOG END CBHNDL (which will also ends the thread) is clear the “in use” flag in the UDT.
So when you get a new connection you merely scan the UDT array to see if you have a vacant slot, if not sleep, ignore or whatever you think is best.
What if a thread hangs? Just store the start time in the UDT member and on each new connection check no thread has been running longer than an allowed period say 2 or 3 minutes, if so close its Dialog and its TCP handle (which you should have also stored in the UDT) and mark the UDT member as not in use. All this small amount of work means you can still do an immediate THREAD CLOSE as you don’t need the handle anymore and no wait for any objects as all the code is non-blocking.

Postmessage api that I haven't used in 15 years....

POST and SEND are standard PB instructions, no need for API’s. Obviously one of the things you store in each UDT is the handle of the main (and only visible) dialog which gives feedback to the user.
Michael
You are correct that the simple ending of a sub or function does not end a modeless dialog though I suspect without any proof that ending a thread does or it would create a memory leak. Forgot that only recently (in my terms) had written a TCP server which relied on that feature and did not need a DIALOG DOEVENTS, I know I am getting old. Outside the scope of Scott’s app so wont confuse it with details.
I am always happy to admit the limits of my knowledge.
John

[Cliff Nichols]

I may have missed it, but if a hang, then wouldn't MCM's "Abort that Worker Thread" (or something like that), come into play here?

[Michael Mattias]

> think the Dialog DoEvents is broken in my version.

So create your notification window with CreateWindowEx, not DIALOG NEW and use a "real" message loop in the thread function... as demo'd here:
Progress Bar Dialog for PB/CC programs October 24, 2002
(Ignore the "PB/CC" in the thread title. This will work in a GUI program exactly the same way).

Note that each thread which creates a GUI window needs its own message queue.

That is, you will have one notification window for each current TCP session. If all that Window does is handle TCP notifications, no reason it has to be visible.

For that matter, there is such a thing as a "message only" window but my SDK is too old to tell me how to do that, I'd have to go to MS online. (At least I think you could use that).

MCM

[Scott Turchin]

I tried that notification window thing remember?
I think the Dialog DoEvents is broken in my version.

Modeless closed too soon, Modal is still onlyi one TCP connection at a time...I think.......except for that Postmessage api that I haven't used in 15 years....

OK I would *THINK*, although I'm not sure, but I would imagine hTCP is being passed here as a lo or hiwrd or something somewhere???
I could recover hTcp as a prameter of FD_READ or FDCLOSE? Or is it not set?
I Tried the Lo(Word, CBL, CBW, Hi of each, none came out to match....

    Case %TCP_ACCEPT
        Select Case Lo(Word, CbLParam)
            Case %FD_ACCEPT 'Create the new thread here  
                        Tcp Notify hTcp(lLoop), Recv Close To CbHndl As %TCP_HTML  
        End Select

    Case %TCP_HTML
        Select Case Lo(Word, CbLParam)
            Case %FD_READ 
            Case %FD_CLOSE 
        End Select

[Michael Mattias]

WinMain
LOCAL hThread()  AS LONG
REDIM hThread (some) 
DO Whenever needed 
  INCR iThread 
  THREAD CREATE TcpFunction (param) to hthread (iThread)
LOOP
Wait or something

END Winmain

FUNCTION TcpFunction (param) 
   hTCP = Freefile 
   CreateNotitification window for this thread. 
   wait until no more to do on this handle
   Close hTCP 
   Destroy Notification window
END FUNCTION

[Scott Turchin]

OK WaitForSingleObject works great.

Now, got any idea how I can synchronized hTCP here?

FD_READ is NOT going to work simpliy because hTcp(lLoop) is too dynamic, it'll be changed....

Would be nice to have 100 tcp handles available....

    Case %TCP_ACCEPT
        Select Case Lo(Word, CbLParam)
            Case %FD_ACCEPT 'Create the new thread here
                Incr tcpCount
                Control Set Text CbHndl,%IDCONNLABELTL, Format$(tcpCount,"")
                Control Set Focus CbHndl, %IDLABEL1
                For lLoop = 1 To %MAXTHREADS
                    'Make sure we have an available hthread, hTCP will be based on this
                    If IsFalse hThread(lLoop) Then
                        hTcp(lLoop) = FreeFile
                        Tcp Accept nServer As hTcp(lLoop)
                        Tcp Notify hTcp(lLoop), Recv Close To CbHndl As %TCP_HTML
                    End If
                Next
                Function = %TRUE
           End Select

    Case %TCP_HTML
        Select Case Lo(Word, CbLParam)
            Case %FD_READ
                If hTcp(lLoop) <> %INVALID_SOCKET Then
                    'Grab client IP and insert here
                    lHost = RemoteIp(ByVal hTcp(lLoop))
                    hThread(lLoop) = SendDataThread(ByVal hTcp(lLoop))
                End If

            Case %FD_CLOSE
                Tcp Close hTcp(lLoop)
                hTcp(lLoop) = %INVALID_SOCKET
        End Select

[Scott Turchin]

OK I want to use that WAitForSingleObject - I've got it in there but remarked out.
BUT - if I use that with %INFINITE and that thread hangs or locks up - it'll keep waiting, no?
I would think using my g_Timeout value or 10000 or 20000 should be sufficient for even the most bogged down computer....


Now all of that is good- on top of that but another problem exists -

If I do an array of thread handles to limit the threads- I've noticed I only have ONE hTCP

Therefore I'm going to need %MAXTHREADS hTcp Handles, ie 100


Otherwise hTCP = Freefile and it's passed around in the DialogpRoc pump but it's only going to handle ONE connection at a time..

So the big problem is how to pass on hTcp(value) to FD_READ, FD_CLOSE and keep them synchronized...

Let me see if I can get the code back in here....brb..

[Michael Mattias]

Am I to understand the PB Documentation in 8.04 that THREAD STATUS will return if the thread is still running regardless that the thread was closed?

I'm thinking it's NOT in my best interest to close the thread until I've done a thread status and ensured it's complete. We had that conversation in the internet forum.....

THREAD STATUS will always return. If it returns a value of &h103 WITH NO ERROR then the thread function is 'still executing'

However, you should get an 'invalid handle' error if the thread handle used in the THREAD STATUS statement has been closed. (You don't "close a thread" although you may "close a handle to the thread." We had that conversation in the other forum, too.)

I don't know what PB error is thrown for this particular error condition.

However....

 DO
    THREAD STATUS hThread TO iREt 
 LOOP UNTIL iRet <> &h103
 THREAD CLOSE hThread TO X     ' the "TO " requirement here is IMNSHO silly

..is the wimp way to wait for a thread to complete.

Real Men would use

  WaitForSingleObject  hThread, %INIFINTE
  THREAD STATUS  hThread To iRet 
  THREAD CLOSE hThread to X    ' TO X still silly

MCM
PS: using the Real Man approach also allows your thread function to return &h103 as a valid return value!

[Dale Yarker]

No, once you do THREAD CLOSE the handle is released, even if the thread is still running. You need the handle to do THREAD STATUS, no handle, no status.

So yes, don't close till you're done with the handle. From what you describe, that would be after the thread has exited.

Cheers,

[Scott Turchin]

Am I to understand the PB Documentation in 8.04 that THREAD STATUS will return if the thread is still running regardless that the thread was closed?

I'm thinking it's NOT in my best interest to close the thread until I've done a thread status and ensured it's complete. We had that conversation in the internet forum.....

Found my solution to handling the connection in a separate thread though, and it's far faster...

Reason I believe this is that my lil mini webserver may get bogged down and take more time in the event say, 200 people connected....There's also preventing a DOS attack on it...

I open a thread, receive a header, send a header and a page and close....

But I want to put a bandwidth limitation in of say 250 connections....so if Thread Status returns that a thread still has &H103 status (STill running) then I want to subtract the available threads, going to make that a user definable option starting at say 100....

Unless anyone has input on limiting connections?

%MAXTHREADS = 100 'Concurrent connections
%THREADALIVE =  &H103




    Case %TCP_ACCEPT
        Select Case Lo(Word, CbLParam)
            Case %FD_ACCEPT 'Create the new thread here
                Incr tcpCount
                Control Set Text CbHndl,%IDCONNLABELTL, Format$(tcpCount,"")
                Control Set Focus CbHndl, %IDLABEL1
                hTcp = FreeFile
                Tcp Accept nServer As hTcp
                Tcp Notify hTcp, Recv Close To CbHndl As %TCP_HTML
                Function = %TRUE
           End Select

    Case %TCP_HTML
        Select Case Lo(Word, CbLParam)
            Case %FD_READ
                If hTcp <> %INVALID_SOCKET Then
                    'Grab client IP and insert here
                    lHost = RemoteIp(ByVal hTcp)
                End If
                hThread(tcpCount) = SendDataThread(ByVal hTcp,lHost)
                hTcp = %INVALID_SOCKET 'This may be too soon on a slow connection...maybe poll it at 60 seconds?

            Case %FD_CLOSE
                Tcp Close hTcp
                hTcp = %INVALID_SOCKET
        End Select



    Case %WM_TIMER
        Select Case CbWParam
          Case %IDT_TIMER1
              g_BBSDown = LoadHtmlPage()
              g_BBSDownImage = LoadImageFile()
              sTmp = BBSDown.szMine & " " & BBSDown.szVer & " - " & BBSDown.szCopyrite
              SendMessage BBSDown.hStatus, %WM_SETTEXT, 0, StrPtr(sTmp)
              For lLoop = 1 To %MAXTHREADS
                  Thread Status hThread(lLoop) To lResult
                  If lResult = %THREADALIVE Then
                      Decr ThreadsAvailable
                  End If
              Next
                      




--------------------------------------------------------------------------------------------
'==========================================================================================
'THREAD FOR Sending Data
Function SendDataThread(ByVal hTcp As Long,lHost As String) As Long
Local hThread   As Long
Local lResult   As Long
Thread Create SendDataThreadProc(ByVal hTcp) To hThread
Thread Close hThread To lResult
hThread = %FALSE
End Function
'==========================================================================================
Function SendDataThreadProc(ByVal hTcp As Long) As Long
Local lResult   As Long
Local lLoop     As Long
Local lCount    As Long
Local ErrType   As Long
Local Header    As String
Local sBuffer   As String
Local sPacket   As String
Local sTmp      As String
Local lHost     As String


lHost = RemoteIp(ByVal hTcp)
sTmp = TimeStamp() & " Connection established from: " & lHost
lResult = SendMessage(BBSDown.txtHandle, %LB_ADDSTRING, 0, StrPtr(sTmp))
lResult = SendMessage(BBSDown.txtHandle, %LVM_GETITEMCOUNT, 0, 0)
lResult = SendMessage(BBSDown.txtHandle, %LVM_SETITEM, 0, lResult)


' Perform a receive-loop until there is no data left (ie, the end of stream)
sBuffer = ""
sPacket = ""
Do
    Tcp Recv hTcp, 1024, sBuffer
    sPacket = sPacket & sBuffer
    If Len(sPacket) > 4096 Then Exit Do 'Buffer overflow prevention
'    ErrType = GetLastError()
Loop Until sBuffer = "" Or IsTrue Eof(hTcp) Or IsTrue Err
sPacket = Left$(sPacket,Len(sPacket)-2)
lResult = ParseAndUpdateLogfile(ByVal sPacket,ByVal hTcp) 'Updates window
' <-------------Send data and disconnect------------->
Header = "HTTP/1.1 200" & $CrLf
Header = Header & "Server: " & BBSDown.szMine & $CrLf
Header = Header & "Date: " & GetPCTimeandDate() & $CrLf
Header = Header & "Cache-Control: no-cache" & $CrLf
Header = Header & "Connection: close" & $CrLf

If IsFalse lResult Then 'html
    Header = Header & "Content-Type: text/html" & $CrLf
    Header = Header & "Content-Length: " & Format$(Len(g_BBSDown)) & $CrLf
    Tcp Send hTcp, Header & $CrLf
    Tcp Send hTcp, g_BBSDown
Else 'jpg
    Header = Header & "Content-Type: image/jpeg" & $CrLf
    Header = Header & "Content-Length: " & Format$(Len(g_BBSDownImage)) & $CrLf
    Header = Header & "Accept-range: bytes"  & $CrLf 'or something like that.
    Tcp Send hTcp, Header & $CrLf
    Tcp Send hTcp, g_BBSDownImage
End If
Tcp Close hTcp
' <-------------Send data and disconnect------------->
'End connection here
ErrType = GetLastError()
If ErrType <> %ERROR_SUCCESS Then
'    Control Get Text CbHndl,%IDTEXT1 To sTmp
    If Not IsFalse Len(sTmp) Then
        sTmp = sTmp & $CrLf & TimeStamp() & " Error: " & Format$(ErrType) & " - " & GetLastErrorDescription(ErrType)' & $CrLf & "Remote IP: " & lHost
    Else
        sTmp = TimeStamp() & " Error: " & Format$(ErrType) & " - " & GetLastErrorDescription(ErrType)' & $CrLf & "Remote IP: " & lHost
    End If
    'Write sTmp
    SendMessage(BBSDown.txtHandle, %LB_ADDSTRING, 0, StrPtr(sTmp))
End If
End Function
'==========================================================================================