"Stack Reserve Size" should increase to 10M

[ChristineBao]

Report from Autodesk QA:

1. Load the attached treepoints.sdf and create Basic web layout.
   
2. View the map in browser, select all the features.

Result:
Repeat with a similar selection set after the first completes and the server memory grows by about 10 or 11MB a request.

[ChristineBao]

Tech assement:

The memory leak associated with large selections is caused by a stack overflow when the MgSelectCommand FDO filter is released and destroyed:

[stack overflow]
	FDO.dll!FdoBinaryLogicalOperator::~FdoBinaryLogicalOperator()  Line 55	C++
	FDO.dll!FdoBinaryLogicalOperator::`scalar deleting destructor'()  + 0x8 bytes	C++
	FDO.dll!FdoDistanceCondition::Dispose()  Line 77	C++
	FDOCommon.dll!FdoIDisposable::Release()  Line 98	C++
	FDO.dll!FdoBinaryLogicalOperator::~FdoBinaryLogicalOperator()  Line 55	C++
	FDO.dll!FdoBinaryLogicalOperator::`scalar deleting destructor'()  + 0x8 bytes	C++
	FDO.dll!FdoDistanceCondition::Dispose()  Line 77	C++
	FDOCommon.dll!FdoIDisposable::Release()  Line 98	C++
	FDO.dll!FdoBinaryLogicalOperator::~FdoBinaryLogicalOperator()  Line 55	C++
	FDO.dll!FdoBinaryLogicalOperator::`scalar deleting destructor'()  + 0x8 bytes	C++
	FDO.dll!FdoDistanceCondition::Dispose()  Line 77	C++
	FDOCommon.dll!FdoIDisposable::Release()  Line 98	C++
	FDO.dll!FdoBinaryLogicalOperator::~FdoBinaryLogicalOperator()  Line 55	C++
	...
	MgServerFeatureServiced.dll!MgSelectCommand::~MgSelectCommand()  Line 57	C++
	MgServerFeatureServiced.dll!MgSelectCommand::`scalar deleting destructor'()  + 0x16 bytes	C++

When you have a large selection the filters can get very large, e.g.:

(FeatId=17282) OR (FeatId=17283) OR (FeatId=17284) OR (FeatId=17285) OR (FeatId=17286) OR
(FeatId=17287) OR (FeatId=17288) OR (FeatId=17289) OR (FeatId=17290) OR (FeatId=17291) OR
(FeatId=17292) OR (FeatId=17293) OR (FeatId=17294) OR (FeatId=17295) OR (FeatId=17296) OR
(FeatId=17297) OR (FeatId=17298) OR (FeatId=17299) OR (FeatId=17300) OR (FeatId=17301) OR
...

and so the hierarchy of objects in the FDO filter is also large. For the default stack size (1Mb) this hierarchy can eventually get too large, and you'll get the stack overflow. And once that happens then the memory associated with the filter objects is not released (plus the stack for that thread becomes corrupted).

[ChristineBao]

Solution:

Increate the stack reserve size to 10M.

[ChristineBao]

Attach ​http://trac.osgeo.org/mapguide/attachment/ticket/1606/Fix%231606.patch for fixing this defect.

[ChristineBao]

Submit the patch to fix this defect.

[brucedechant]

This only fixes Windows. Linux needs to be fixed too.

[brucedechant]

To fix Linux you need to update the Makefile.am files and remove this line:

ulimit -s 1024

The above line sets the stack to 1MB. The default stack size on Linux is 10MB.

[ChristineBao]

Thanks Bruce for picking up Linux. Attach ​http://trac.osgeo.org/mapguide/attachment/ticket/1606/FixLinux.patch for review.

[ChristineBao]

Commit the patch to fix it.