Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[ABorka]

It should be working.

You have to make sure you delete the httpd13 and httpd20 directories 
from your fpc units folder (where httpd.o and .ppu is stored) so only 
the httpd22 folder remains there. Otherwise the wrong units might be 
linked with your module and then crash when called.


With the latest Lazarus SVN you can find some examples for web apache 
modules and cgi programs under the lazarus /components/fpweb/demo/ folder.


AB

Leonardo M. Ramé wrote:

Does this was fixed? I'm trying to deploy an apache 2.2.9 module, it compiles 
and loads ok (it doesn't crash apache) but its exported function isn't called, 
I'm using the same code ABorka used in this example.

This is my configuration:

Free Pascal Compiler version 2.2.4-3 [2009/06/03] for i386
Copyright (c) 1993-2008 by Florian Klaempfl

Linux debian 2.6.26-1-686 #1 SMP Fri Mar 13 18:08:45 UTC 2009 i686 GNU/Linux

Leonardo.





- Original Message 
From: ABorka fpc-de...@aborka.com
To: FPC developers' list fpc-devel@lists.freepascal.org
Sent: Tuesday, September 30, 2008 11:03:26 PM
Subject: Re: [fpc-devel] Lazarus Apache module crashes during concurrent 
requests

Nevermind, on Ubuntu the request_rec is only 384 bytes for FPC instead of 412.

But that still does not explain why the handler function is not even getting 
called by apache.


ABorka wrote:

OK, after 4 days of pulling my (remaining) hair out I was able to compile a 
basic C apache module on Ubuntu 8.04 (apache 2.2.8).

It seems both fpc/lazarus (not working apache module) and the C compiled 
(working apache module) one shows

sizeof(request_rec) =  412
sizeof(module_struct) = 56

So the length seems to be the same for for both. Still, the Lazarus compiled 
apache module doesn't even load in apache (mod_hello.pp or any of the other 
examples included in fpc).
If the exports is included then it loads but doesn't work at all:

modified mod_hello.pp from fpc/packages/httpd22/examples/
{***
*  Test library of the Apache Pascal Headers
***}
library mod_hello;

{***
*  The mode must be objfpc on this unit because the unix code uses
* some extensions introduced on Free Pascal
***}
{$ifdef fpc}
  {$mode objfpc}{$H+}
{$endif}

{$IFDEF WIN32}
  {$DEFINE WINDOWS}
{$ENDIF}

{$define Apache2_2}

uses SysUtils, httpd {$ifndef Apache1_3}, apr{$endif};

var
 test_module: module; public name 'test_module';
 default_module_ptr: Pmodule;

const
  MODULE_NAME = 'mod_hello.so';

{***
*  Free Pascal only supports exporting variables on Windows
***}
{ $ifdef WINDOWS}//commented out, exports work in Linux now
exports
 test_module name 'test_module';
{ $endif}//commented out, exports work in Linux now
.
.snip
.


Not sure why the Lazarus/fpc apache modules do not work on apache 2.2.8 or 
2.2.9 on Ubuntu.
The above module is loaded, the handler registering function is called, but the 
handler never gets triggered when the module is called from a browser.


Michael Van Canneyt wrote:

Any suggestions?

Yes: please print the size of the Request_rec (or TRequest_Rec) and the
same record in C. Compare if they are equal. Same for the module record.
If they are not equal, then we know it is a problem with the pascal definition 
of this record. I've had to do this exercise about 30 times myself on various 
platforms to get it right. Maybe they changed the size again.

Michael.
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel


___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel



___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel



  
___

fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel



___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[Leonardo M . Ramé]

Does this was fixed? I'm trying to deploy an apache 2.2.9 module, it compiles 
and loads ok (it doesn't crash apache) but its exported function isn't called, 
I'm using the same code ABorka used in this example.

This is my configuration:

Free Pascal Compiler version 2.2.4-3 [2009/06/03] for i386
Copyright (c) 1993-2008 by Florian Klaempfl

Linux debian 2.6.26-1-686 #1 SMP Fri Mar 13 18:08:45 UTC 2009 i686 GNU/Linux

Leonardo.





- Original Message 
From: ABorka fpc-de...@aborka.com
To: FPC developers' list fpc-devel@lists.freepascal.org
Sent: Tuesday, September 30, 2008 11:03:26 PM
Subject: Re: [fpc-devel] Lazarus Apache module crashes during concurrent 
requests

Nevermind, on Ubuntu the request_rec is only 384 bytes for FPC instead of 412.

But that still does not explain why the handler function is not even getting 
called by apache.


ABorka wrote:
 OK, after 4 days of pulling my (remaining) hair out I was able to compile a 
 basic C apache module on Ubuntu 8.04 (apache 2.2.8).
 
 It seems both fpc/lazarus (not working apache module) and the C compiled 
 (working apache module) one shows
 
 sizeof(request_rec) =  412
 sizeof(module_struct) = 56
 
 So the length seems to be the same for for both. Still, the Lazarus compiled 
 apache module doesn't even load in apache (mod_hello.pp or any of the other 
 examples included in fpc).
 If the exports is included then it loads but doesn't work at all:
 
 modified mod_hello.pp from fpc/packages/httpd22/examples/
 {***
 *  Test library of the Apache Pascal Headers
 ***}
 library mod_hello;
 
 {***
 *  The mode must be objfpc on this unit because the unix code uses
 * some extensions introduced on Free Pascal
 ***}
 {$ifdef fpc}
   {$mode objfpc}{$H+}
 {$endif}
 
 {$IFDEF WIN32}
   {$DEFINE WINDOWS}
 {$ENDIF}
 
 {$define Apache2_2}
 
 uses SysUtils, httpd {$ifndef Apache1_3}, apr{$endif};
 
 var
  test_module: module; public name 'test_module';
  default_module_ptr: Pmodule;
 
 const
   MODULE_NAME = 'mod_hello.so';
 
 {***
 *  Free Pascal only supports exporting variables on Windows
 ***}
 { $ifdef WINDOWS}//commented out, exports work in Linux now
 exports
  test_module name 'test_module';
 { $endif}//commented out, exports work in Linux now
 .
 .snip
 .
 
 
 Not sure why the Lazarus/fpc apache modules do not work on apache 2.2.8 or 
 2.2.9 on Ubuntu.
 The above module is loaded, the handler registering function is called, but 
 the handler never gets triggered when the module is called from a browser.
 
 
 Michael Van Canneyt wrote:
 
 Any suggestions?
 
 Yes: please print the size of the Request_rec (or TRequest_Rec) and the
 same record in C. Compare if they are equal. Same for the module record.
 If they are not equal, then we know it is a problem with the pascal 
 definition of this record. I've had to do this exercise about 30 times 
 myself on various platforms to get it right. Maybe they changed the size 
 again.
 
 Michael.
 ___
 fpc-devel maillist  -  fpc-devel@lists.freepascal.org
 http://lists.freepascal.org/mailman/listinfo/fpc-devel
 
 
 ___
 fpc-devel maillist  -  fpc-devel@lists.freepascal.org
 http://lists.freepascal.org/mailman/listinfo/fpc-devel
 

___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel




___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[ABorka]

Hi Jonas,

This seems to work on Windows (and solves the problem), but on Linux 
WaitForThreadTerminate waits forever.


WaitForThreadTerminate(BeginThread(@__dummythread), 300);

apache just waits and doesn't start until I stop the apache loading with 
ctrl+c, as if it is in an infinite loop and waiting.


Any thoughts?

AB

Jonas Maebe wrote:


On 24 Sep 2008, at 10:58, ABorka wrote:


I'm not sure that something is changed to make it incompatible.
The apache modules compiled on windows are only crashing if multiple 
requests are coming at the same time, and they are crushing at 
function/procedure returns (Yes, on Linux it is even worse, since no 
module gets even loaded by apache. That might be some C API 
translation problem).



Maybe you have to initialise the threading system so all the necessary 
locks in the system unit get activated. Something like


{$ifdef unix}
uses
  cthreads;
{$endif}

...

function dummythread(p: pointer): ptrint;
begin
end;

initialisation
 WaitForThreadTerminate(BeginThread(@dummythread));
end.


Jonas
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel



___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[ABorka]

OK, after 4 days of pulling my (remaining) hair out I was able to 
compile a basic C apache module on Ubuntu 8.04 (apache 2.2.8).


It seems both fpc/lazarus (not working apache module) and the C compiled 
(working apache module) one shows


sizeof(request_rec) =  412
sizeof(module_struct) = 56

So the length seems to be the same for for both. Still, the Lazarus 
compiled apache module doesn't even load in apache (mod_hello.pp or any 
of the other examples included in fpc).

If the exports is included then it loads but doesn't work at all:

modified mod_hello.pp from fpc/packages/httpd22/examples/
{***
*  Test library of the Apache Pascal Headers
***}
library mod_hello;

{***
*  The mode must be objfpc on this unit because the unix code uses
* some extensions introduced on Free Pascal
***}
{$ifdef fpc}
  {$mode objfpc}{$H+}
{$endif}

{$IFDEF WIN32}
  {$DEFINE WINDOWS}
{$ENDIF}

{$define Apache2_2}

uses SysUtils, httpd {$ifndef Apache1_3}, apr{$endif};

var
 test_module: module; public name 'test_module';
 default_module_ptr: Pmodule;

const
  MODULE_NAME = 'mod_hello.so';

{***
*  Free Pascal only supports exporting variables on Windows
***}
{ $ifdef WINDOWS}//commented out, exports work in Linux now
exports
 test_module name 'test_module';
{ $endif}//commented out, exports work in Linux now
.
.snip
.


Not sure why the Lazarus/fpc apache modules do not work on apache 2.2.8 
or 2.2.9 on Ubuntu.
The above module is loaded, the handler registering function is called, 
but the handler never gets triggered when the module is called from a 
browser.



Michael Van Canneyt wrote:


Any suggestions?


Yes: please print the size of the Request_rec (or TRequest_Rec) and the
same record in C. Compare if they are equal. Same for the module record.
If they are not equal, then we know it is a problem with the pascal 
definition of this record. I've had to do this exercise about 30 times 
myself on various platforms to get it right. Maybe they changed the 
size again.


Michael.
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel



___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[ABorka]

Nevermind, on Ubuntu the request_rec is only 384 bytes for FPC instead 
of 412.


But that still does not explain why the handler function is not even 
getting called by apache.



ABorka wrote:
OK, after 4 days of pulling my (remaining) hair out I was able to 
compile a basic C apache module on Ubuntu 8.04 (apache 2.2.8).


It seems both fpc/lazarus (not working apache module) and the C compiled 
(working apache module) one shows


sizeof(request_rec) =  412
sizeof(module_struct) = 56

So the length seems to be the same for for both. Still, the Lazarus 
compiled apache module doesn't even load in apache (mod_hello.pp or any 
of the other examples included in fpc).

If the exports is included then it loads but doesn't work at all:

modified mod_hello.pp from fpc/packages/httpd22/examples/
{***
*  Test library of the Apache Pascal Headers
***}
library mod_hello;

{***
*  The mode must be objfpc on this unit because the unix code uses
* some extensions introduced on Free Pascal
***}
{$ifdef fpc}
  {$mode objfpc}{$H+}
{$endif}

{$IFDEF WIN32}
  {$DEFINE WINDOWS}
{$ENDIF}

{$define Apache2_2}

uses SysUtils, httpd {$ifndef Apache1_3}, apr{$endif};

var
 test_module: module; public name 'test_module';
 default_module_ptr: Pmodule;

const
  MODULE_NAME = 'mod_hello.so';

{***
*  Free Pascal only supports exporting variables on Windows
***}
{ $ifdef WINDOWS}//commented out, exports work in Linux now
exports
 test_module name 'test_module';
{ $endif}//commented out, exports work in Linux now
.
.snip
.


Not sure why the Lazarus/fpc apache modules do not work on apache 2.2.8 
or 2.2.9 on Ubuntu.
The above module is loaded, the handler registering function is called, 
but the handler never gets triggered when the module is called from a 
browser.



Michael Van Canneyt wrote:


Any suggestions?


Yes: please print the size of the Request_rec (or TRequest_Rec) and the
same record in C. Compare if they are equal. Same for the module record.
If they are not equal, then we know it is a problem with the pascal 
definition of this record. I've had to do this exercise about 30 times 
myself on various platforms to get it right. Maybe they changed the 
size again.


Michael.
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel



___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel



___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[ABorka]

I'm not sure that something is changed to make it incompatible.
The apache modules compiled on windows are only crashing if multiple 
requests are coming at the same time, and they are crushing at 
function/procedure returns (Yes, on Linux it is even worse, since no 
module gets even loaded by apache. That might be some C API translation 
problem).


Even if reduced to this small code it crushes (but only if multiple 
calls are inside this code) on windows:

===
Function TCustomApacheApplication.ProcessRequest(P: PRequest_Rec) : Integer;

Var
  Req : TApacheRequest;
  Resp : TApacheResponse;
  i:integer;

begin
  Req:=TApacheRequest.CreateReq(Self,P);
  Try
Resp:=TApacheResponse.CreateApache(Req);
Try
for i := 0 to maxint do ;//Time wasting for multiple requests at the 
same time to run this code

//  HandleRequest(Req,Resp);
//  If Not Resp.ContentSent then
//Resp.SendContent;
Finally
  Result:=OK;
  Resp.Free;//= crashes after here randomly for 2nd simultaneous 
caller

end;
  Finally
Req.Free;
  end;
end;
==
Sometimes when removing all the try/finally pairs from the function it 
works.
But then adding more code, even as simple as DateTimeToStr(Now), makes 
it crash. Sometimes more code can be added but then it will crash inside 
that code somewhere at function/procedure returns.


AB

Felipe Monteiro de Carvalho wrote:

Try installing an older Apache.

I installed here with XAMMP, Apache 2.2.9 and it just quits without
any error message when loading my Pascal module.

But when using the standard Apache 2.2.6 in Mandriva 2008 it works.
Actually I can't get it to show the page (some config problem?), but
it loads without problems, apache keeps working.

I think something changed in an incompatible way. This is pretty
unexpected, as I hoped that they would keep compatibility between all
2.2.x series.



___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[Jonas Maebe]

On 24 Sep 2008, at 10:58, ABorka wrote:


I'm not sure that something is changed to make it incompatible.
The apache modules compiled on windows are only crashing if multiple  
requests are coming at the same time, and they are crushing at  
function/procedure returns (Yes, on Linux it is even worse, since no  
module gets even loaded by apache. That might be some C API  
translation problem).



Maybe you have to initialise the threading system so all the necessary  
locks in the system unit get activated. Something like


{$ifdef unix}
uses
  cthreads;
{$endif}

...

function dummythread(p: pointer): ptrint;
begin
end;

initialisation
 WaitForThreadTerminate(BeginThread(@dummythread));
end.


Jonas
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[Michael Van Canneyt]

On Wed, 24 Sep 2008, ABorka wrote:

 I'm not sure that something is changed to make it incompatible.
 The apache modules compiled on windows are only crashing if multiple requests
 are coming at the same time, and they are crushing at function/procedure
 returns (Yes, on Linux it is even worse, since no module gets even loaded by
 apache. That might be some C API translation problem).
 
 Even if reduced to this small code it crushes (but only if multiple calls are
 inside this code) on windows:
 ===
 Function TCustomApacheApplication.ProcessRequest(P: PRequest_Rec) : Integer;
 
 Var
   Req : TApacheRequest;
   Resp : TApacheResponse;
   i:integer;
 
 begin
   Req:=TApacheRequest.CreateReq(Self,P);
   Try
 Resp:=TApacheResponse.CreateApache(Req);
 Try
 for i := 0 to maxint do ;//Time wasting for multiple requests at the same time
 to run this code
 //  HandleRequest(Req,Resp);
 //  If Not Resp.ContentSent then
 //Resp.SendContent;
 Finally
   Result:=OK;
   Resp.Free;//= crashes after here randomly for 2nd simultaneous 
 caller
 end;
   Finally
 Req.Free;
   end;
 end;
 ==
 Sometimes when removing all the try/finally pairs from the function it works.
 But then adding more code, even as simple as DateTimeToStr(Now), makes it
 crash. Sometimes more code can be added but then it will crash inside that
 code somewhere at function/procedure returns.

This is a known problem; the heap manager does not function correctly in a
DLL when an external program (apache, in this case) creates new threads.

Changing the heap manager to the C heap manager (just add 'uses cmem' as the
first line in the project) may solve the problem, but it is not guaranteed; 
there was another bug in the memory manager which prevented that from working 
correctly. Maybe it has been fixed meanwhile.

Michael.
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[Jonas Maebe]

On 24 Sep 2008, at 12:35, Michael Van Canneyt wrote:

This is a known problem; the heap manager does not function  
correctly in a
DLL when an external program (apache, in this case) creates new  
threads.


The heap manager is simply not thread safe until the FPC threading  
system has been initialised (by starting a thread).



Jonas
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[Michael Van Canneyt]

On Wed, 24 Sep 2008, Jonas Maebe wrote:

 
 On 24 Sep 2008, at 12:35, Michael Van Canneyt wrote:
 
 This is a known problem; the heap manager does not function correctly in a
 DLL when an external program (apache, in this case) creates new threads.
 
 The heap manager is simply not thread safe until the FPC threading system has
 been initialised (by starting a thread).

It is not that simple. The heap manager cannot handle situations where
threads have been started by code that is not aware of the FPC threading
mechanisms - such as apache. I have done some changes for this, but they 
are not sufficient. PThreads has no mechanisms for dealing with this
situation. Windows does (using the DLL_THREAD_ATTACH message).

Michael.
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[Jonas Maebe]

On 24 Sep 2008, at 13:02, Michael Van Canneyt wrote:


On Wed, 24 Sep 2008, Jonas Maebe wrote:



On 24 Sep 2008, at 12:35, Michael Van Canneyt wrote:

This is a known problem; the heap manager does not function  
correctly in a
DLL when an external program (apache, in this case) creates new  
threads.


The heap manager is simply not thread safe until the FPC threading  
system has

been initialised (by starting a thread).


It is not that simple. The heap manager cannot handle situations where
threads have been started by code that is not aware of the FPC  
threading

mechanisms - such as apache.


Ah yes, that's indeed a problem with the new 2.3.x heap manager. I  
don't think the 2.2.x heap manager cares though, since it uses a  
regular critical section/mutex.



Jonas
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[Felipe Monteiro de Carvalho]

Could it be then related to the Apache method of working? Apache has a
non-threaded version and several threaded versions.

In my Mandriva where it didn't crash I installed the non-threaded
version. (not sure if it won't create threads anyway for something
else, even if it works in a non-threaded principle).

I cannot find in the XAMMP website if they use the threaded or
non-threaded version.

-- 
Felipe Monteiro de Carvalho
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[Michael Van Canneyt]

On Wed, 24 Sep 2008, Jonas Maebe wrote:

 
 On 24 Sep 2008, at 13:02, Michael Van Canneyt wrote:
 
 On Wed, 24 Sep 2008, Jonas Maebe wrote:
 
  
  On 24 Sep 2008, at 12:35, Michael Van Canneyt wrote:
  
   This is a known problem; the heap manager does not function correctly in
   a
   DLL when an external program (apache, in this case) creates new threads.
  
  The heap manager is simply not thread safe until the FPC threading system
  has
  been initialised (by starting a thread).
 
 It is not that simple. The heap manager cannot handle situations where
 threads have been started by code that is not aware of the FPC threading
 mechanisms - such as apache.
 
 Ah yes, that's indeed a problem with the new 2.3.x heap manager. I don't think
 the 2.2.x heap manager cares though, since it uses a regular critical
 section/mutex.

2.2.2 has/had other problems for Apache :-)

Michael.
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[ABorka]

Well, it seems we have some progress now.

The
WaitForThreadTerminate(BeginThread(@__dummythread), 300);
seems to fix it on Windows. At least for 2 concurrent requests. For some 
reason Apache cannot seem to want to run more than 2 requests at a time. 
If more comes in at a time, the first 2 starts running and the rest have 
to wait till at least 1 current request is handled. Even when 
MaxConnectionsPerServer is set to higher than 2 in the registry.


uses cmem;  did not fix the crash on Windows.

I will try to make apache modules load in Linux next so some tests can 
be done there too.


AB

Jonas Maebe wrote:


On 24 Sep 2008, at 13:02, Michael Van Canneyt wrote:


On Wed, 24 Sep 2008, Jonas Maebe wrote:



On 24 Sep 2008, at 12:35, Michael Van Canneyt wrote:

This is a known problem; the heap manager does not function 
correctly in a
DLL when an external program (apache, in this case) creates new 
threads.


The heap manager is simply not thread safe until the FPC threading 
system has

been initialised (by starting a thread).


It is not that simple. The heap manager cannot handle situations where
threads have been started by code that is not aware of the FPC threading
mechanisms - such as apache.


Ah yes, that's indeed a problem with the new 2.3.x heap manager. I don't 
think the 2.2.x heap manager cares though, since it uses a regular 
critical section/mutex.



Jonas
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel



___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[ABorka]

For me in Windows XP 32bit/ FPC (apache modules load properly):
sizeof(request_rec)=416
sizeof(module_struct)=56

For me in Ubuntu 8.04 32bit/ FPC (apache modules don't load):
sizeof(request_rec)=412
sizeof(module_struct)=56


Used exactly the same files to compile a project on Ubuntu but for some 
reason it is 4 bytes shorter there for request_rec.

This shouldn't effect the module loading at apache2 startup, right?
Only module_struct incompatibility should give the ...Can't
locate API module structure `mod_apache1' in file ... error.



Michael Van Canneyt wrote:


Yes: please print the size of the Request_rec (or TRequest_Rec) and the
same record in C. Compare if they are equal. Same for the module record.
If they are not equal, then we know it is a problem with the pascal 
definition of this record. I've had to do this exercise about 30 times 
myself on various platforms to get it right. Maybe they changed the 
size again.


Michael.
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel



___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[Michael Van Canneyt]

On Mon, 22 Sep 2008, ABorka wrote:

 After some more debugging the result is even stranger:
 
 If I reduce the code to the bare minimum there is still a crash most of the
 time.
 
 1. works always for 2 concurrent requests:
 procedure TCustomApacheApplication.HandleRequest(ARequest: TRequest;
 AResponse: TResponse);
 Var
   MC : TCustomHTTPModuleClass;
   M  : TCustomHTTPModule;
   MN : String;
   MI : TModuleItem;
 i:Integer;
 
 begin
   MI:=ModuleFactory[0];
   MC:=MI.ModuleClass;
   M:=MC.Create(Self);
   M.Name := '';
 aresponse.content := 'htmlHello/html';
   for i := 0 to Maxint do;//time wasting loop, about 5 secs
 end;
 
 2. crashes randomly:
 begin
   MI:=ModuleFactory[0];
   MC:=MI.ModuleClass;
   M:=MC.Create(Self);
   M.Name := '';
 M.HandleRequest(ARequest,AResponse);
   for i := 0 to Maxint do;//time wasting loop, about 5 secs
 end;//= sometimes crash after here but before returning to caller function
 
 3. always crashes:
 begin
   try
   MI:=ModuleFactory[0];
   MC:=MI.ModuleClass;
   M:=MC.Create(Self);
   M.Name := '';
 aresponse.content := 'htmlHello/html';
   for i := 0 to Maxint do;//time wasting loop, about 5 secs
   except
 On E : Exception do
   ShowRequestException(AResponse,E);
   end;
 end;//= guaranteed crash after here but before returning to caller function
 
 
 When M.HandleRequest(ARequest,AResponse); is used instead of aresponse.content
 := 'htmlHello/html'; the crash is random at procedure return for the 2nd
 simultaneous caller.
 
 When the procedure contains any try/except it is guaranteed not returning
 (crashing) after the work is finished for the 2nd caller (2nd simultaneaous
 request).
 
 The first simultaneous caller always works without a problem.
 
 Any suggestions?

Yes: please print the size of the Request_rec (or TRequest_Rec) and the
same record in C. Compare if they are equal. Same for the module record.
If they are not equal, then we know it is a problem with the pascal 
definition of this record. I've had to do this exercise about 30 times 
myself on various platforms to get it right. Maybe they changed the 
size again.

Michael.
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[ABorka]

Hi Michael,

Unfortunately, I do not have any C compilers - nor the knowledge to 
compile something with the apache header files in C.
I manually compared the .h/.inc and the translated pascal 
structures/records for the two you have mentioned (module_struct and 
request_rec) and they seem to have the same fields, nothing added to 
them so far till Apache 2.2.9 .

For me in Windows XP 32bit/ FPC:
sizeof(request_rec)=416
sizeof(module_struct)=56

Not sure if it is a full list but in the apr header files (ap_mmn.h) 
there's a change list:

.
.snip I believe the translation happened for 2.2.3 so those are included
.
+* 20051115.4 (2.2.4)  Added ap_get_server_banner() and
 * ap_get_server_description() (minor)
 * 20051115.5 (2.2.5)  Added ap_mpm_safe_kill() (minor)
 * 20051115.6 (2.2.7)  Added retry_set to proxy_worker (minor)
+* 20051115.7 (2.2.7)  Added conn_rec::clogging_input_filters (minor)
 * 20051115.8 (2.2.7)  Added flags to proxy_alias (minor)
+* 20051115.9 (2.2.7)  Add ap_send_interim_response API
 * 20051115.10(2.2.7)  Added ap_mod_status_reqtail (minor)
 * 20051115.11(2.2.7)  Add *ftp_directory_charset to proxy_dir_conf
 * 20051115.12(2.2.8)  Add optional function ap_logio_add_bytes_in() to 
mog_logio

 * 20051115.13(2.2.9)  Add disablereuse and disablereuse_set
 * to proxy_worker struct (minor)
 * 20051115.14(2.2.9)  Add ap_proxy_ssl_connection_cleanup and
 * add *scpool, *r and need_flush to proxy_conn_rec
 * structure
 * 20051115.15(2.2.9)  Add interpolate_env to proxy_dir_conf and
 * introduce proxy_req_conf.

The ones marked with '+' I added to my httpd.inc and httpd_protocol.inc 
files. The rest were for apache mods (mod_proxy, etc.) so ignored them.
The crash did not go away. At least on Windows, Apache loads the module 
and executes it sometimes. On Linux the apache modules compiled don't 
even load.


AB


Michael Van Canneyt wrote:


On Mon, 22 Sep 2008, ABorka wrote:


After some more debugging the result is even stranger:

If I reduce the code to the bare minimum there is still a crash most of the
time.

1. works always for 2 concurrent requests:
procedure TCustomApacheApplication.HandleRequest(ARequest: TRequest;
AResponse: TResponse);
Var
  MC : TCustomHTTPModuleClass;
  M  : TCustomHTTPModule;
  MN : String;
  MI : TModuleItem;
i:Integer;

begin
  MI:=ModuleFactory[0];
  MC:=MI.ModuleClass;
  M:=MC.Create(Self);
  M.Name := '';
aresponse.content := 'htmlHello/html';
  for i := 0 to Maxint do;//time wasting loop, about 5 secs
end;

2. crashes randomly:
begin
  MI:=ModuleFactory[0];
  MC:=MI.ModuleClass;
  M:=MC.Create(Self);
  M.Name := '';
M.HandleRequest(ARequest,AResponse);
  for i := 0 to Maxint do;//time wasting loop, about 5 secs
end;//= sometimes crash after here but before returning to caller function

3. always crashes:
begin
  try
  MI:=ModuleFactory[0];
  MC:=MI.ModuleClass;
  M:=MC.Create(Self);
  M.Name := '';
aresponse.content := 'htmlHello/html';
  for i := 0 to Maxint do;//time wasting loop, about 5 secs
  except
On E : Exception do
  ShowRequestException(AResponse,E);
  end;
end;//= guaranteed crash after here but before returning to caller function


When M.HandleRequest(ARequest,AResponse); is used instead of aresponse.content
:= 'htmlHello/html'; the crash is random at procedure return for the 2nd
simultaneous caller.

When the procedure contains any try/except it is guaranteed not returning
(crashing) after the work is finished for the 2nd caller (2nd simultaneaous
request).

The first simultaneous caller always works without a problem.

Any suggestions?


Yes: please print the size of the Request_rec (or TRequest_Rec) and the
same record in C. Compare if they are equal. Same for the module record.
If they are not equal, then we know it is a problem with the pascal 
definition of this record. I've had to do this exercise about 30 times 
myself on various platforms to get it right. Maybe they changed the 
size again.


Michael.
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel



___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[Felipe Monteiro de Carvalho]

Try installing an older Apache.

I installed here with XAMMP, Apache 2.2.9 and it just quits without
any error message when loading my Pascal module.

But when using the standard Apache 2.2.6 in Mandriva 2008 it works.
Actually I can't get it to show the page (some config problem?), but
it loads without problems, apache keeps working.

I think something changed in an incompatible way. This is pretty
unexpected, as I hoped that they would keep compatibility between all
2.2.x series.

-- 
Felipe Monteiro de Carvalho
___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Re: [fpc-devel] Lazarus Apache module crashes during concurrent requests

[ABorka]

After some more debugging the result is even stranger:

If I reduce the code to the bare minimum there is still a crash most of 
the time.


1. works always for 2 concurrent requests:
procedure TCustomApacheApplication.HandleRequest(ARequest: TRequest; 
AResponse: TResponse);

Var
  MC : TCustomHTTPModuleClass;
  M  : TCustomHTTPModule;
  MN : String;
  MI : TModuleItem;
i:Integer;

begin
  MI:=ModuleFactory[0];
  MC:=MI.ModuleClass;
  M:=MC.Create(Self);
  M.Name := '';
aresponse.content := 'htmlHello/html';
  for i := 0 to Maxint do;//time wasting loop, about 5 secs
end;

2. crashes randomly:
begin
  MI:=ModuleFactory[0];
  MC:=MI.ModuleClass;
  M:=MC.Create(Self);
  M.Name := '';
M.HandleRequest(ARequest,AResponse);
  for i := 0 to Maxint do;//time wasting loop, about 5 secs
end;//= sometimes crash after here but before returning to caller function

3. always crashes:
begin
  try
  MI:=ModuleFactory[0];
  MC:=MI.ModuleClass;
  M:=MC.Create(Self);
  M.Name := '';
aresponse.content := 'htmlHello/html';
  for i := 0 to Maxint do;//time wasting loop, about 5 secs
  except
On E : Exception do
  ShowRequestException(AResponse,E);
  end;
end;//= guaranteed crash after here but before returning to caller function


When M.HandleRequest(ARequest,AResponse); is used instead of 
aresponse.content := 'htmlHello/html'; the crash is random at 
procedure return for the 2nd simultaneous caller.


When the procedure contains any try/except it is guaranteed not 
returning (crashing) after the work is finished for the 2nd caller (2nd 
simultaneaous request).


The first simultaneous caller always works without a problem.

Any suggestions?


ABorka wrote:

win32, latest Lazarus and FPC
Any single web request call works OK, returning the content.
When 2 browsers are open and calling the web module at the same time 
there is a crash happening after the 2nd one finishes working (just made 
a loop in the web action which lasts a few seconds to have both requests 
inside the server at the same time).

Details:
in /fpc/packages/fcl-web/src/fpapache.pp

Function TCustomApacheApplication.ProcessRequest(P: PRequest_Rec) : 
Integer;


Var
  Req : TApacheRequest;
  Resp : TApacheResponse;

begin
  Req:=TApacheRequest.CreateReq(Self,P);
  Try
Resp:=TApacheResponse.CreateApache(Req);
Try
  HandleRequest(Req,Resp);   == call happens here OK but 2nd 
concurrent request does not return, gets lost in the ether

Finally
  Result:=OK;
  Resp.Free;
end;
  Finally
Req.Free;
  end;
end;


procedure TCustomApacheApplication.HandleRequest(ARequest: TRequest; 
AResponse: TResponse);


Var
  MC : TCustomHTTPModuleClass;
  M  : TCustomHTTPModule;
  MN : String;
  MI : TModuleItem;

begin
  try
MC:=Nil;
If (OnGetModuleNil) then
  OnGetModule(Self,ARequest,MC);
If (MC=Nil) then
  begin
  MN:=GetModuleName(ARequest);
  If (MN='') and Not AllowDefaultModule then
Raise EFPApacheError.Create(SErrNoModuleNameForRequest);
  MI:=ModuleFactory.FindModule(MN);
  If (MI=Nil) and (ModuleFactory.Count=1) then
MI:=ModuleFactory[0];
  if (MI=Nil) then
begin
Raise EFPApacheError.CreateFmt(SErrNoModuleForRequest,[MN]);
end;
  MC:=MI.ModuleClass;
  end;
M:=FindModule(MC); // Check if a module exists already
If (M=Nil) then
  begin
M:=MC.Create(Self);
M.Name := '';//without this there's a crash due to same name
  end;
M.HandleRequest(ARequest,AResponse);//calls the web action here, 
works OK for both concurrent requests

  except
On E : Exception do
  ShowRequestException(AResponse,E);
  end;
end;  == everything works, but the 2nd concurrent request crashes after 
here but before returning to the caller function



A little bit strange that this happens. The return content is prepared 
in both simultaneous calls properly. Any thoughts what could be the cause?


AB


___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel



___
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel