Calling eval() in the WebBrowser control with a json object around 25k in size causes memory leak

Calling eval() in the WebBrowser control with a json object around 25k in size causes memory leak by SteveSteveSteveP

Closed

as External Help for as External

Type:	Bug
ID:	780067
Opened:	2/26/2013 4:53:25 PM
Access Restriction:	Public

Workaround(s)

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User(s) can reproduce this bug

Calling WebBrowser.Document.InvokeScript and then calling the eval() in the script causes a memory leak.

Calling the following line, where jsonMessages is a json object of 27k is size will result in a virtual memory allocation of 81,920 bytes that is never collected. The same line, with a small object of 1k in size does not causes the memory leak.

var message = eval('(' + jsonMessages + ')');

The stack trace of the allocation is below.

Note that is includes Debug method calls, despite being compiled in release mode.

ntdll!NtAllocateVirtualMemory( HANDLE, PVOID*, ULONG, PULONG, ULONG, ULONG )
KERNELBASE!_VirtualAllocEx@20() + 0x44 bytes
KERNELBASE!_VirtualAlloc@16() + 0x18 bytes
jscript9!PageAllocator::AddPageSegment( class DListBase<class PageSegment> & ) + 0x3b bytes
jscript9!PageAllocator::SnailAllocPages( unsigned int,class PageSegment * * ) + 0xdf7 bytes
jscript9!PageAllocator::AllocPages( unsigned int,class PageSegment * * ) + 0x46 bytes
jscript9!ArenaAllocatorNoFreeList::AddBigBlock( unsigned int ) + 0x4f bytes
jscript9!ArenaAllocatorNoFreeList::SnailAlloc( unsigned int ) + 0x92 bytes
jscript9!PoolAllocator::Alloc( unsigned int ) + 0x1f6 bytes
jscript9!Js::GlobalObject::DefaultEvalHelper( class Js::ScriptContext *,unsigned short const *,int,unsigned long,unsigned long,unsigned short const *,int ) + 0x13a bytes
jscript9!Js::GlobalObject::EntryEval( class Js::RecyclableObject *,struct Js::CallInfo,... ) + 0x1ae bytes
jscript9!Js::JavascriptFunction::CallFunction( class Js::RecyclableObject *,void * (cdecl*)(class Js::RecyclableObject *,struct Js::CallInfo,...),struct Js::Arguments ) + 0x87 bytes
jscript9!Js::InterpreterStackFrame::OP_CallFld( struct Js::OpLayoutCallFld *,unsigned int ) + 0x4d bytes
jscript9!Js::InterpreterStackFrame::ProcessWithDebugging( void ) + 0x94e bytes
jscript9!Js::InterpreterStackFrame::DebugProcess( void ) + 0x3e bytes
jscript9!Js::InterpreterStackFrame::DebugProcessThunk( void * & ) + 0x69 bytes
jscript9!Js::InterpreterStackFrame::InterpreterThunk( class Js::RecyclableObject *,struct Js::CallInfo,... ) + 0x846ad bytes
jscript9!Js::JavascriptFunction::CallFunction( class Js::RecyclableObject *,void * (cdecl*)(class Js::RecyclableObject *,struct Js::CallInfo,...),struct Js::Arguments ) + 0x87 bytes
jscript9!Js::JavascriptFunction::CallRootFunction( class Js::RecyclableObject *,struct Js::Arguments,class Js::ScriptContext * ) + 0xa9 bytes
jscript9!ScriptSite::CallRootFunction( class Js::JavascriptFunction *,struct Js::Arguments,struct IServiceProvider *,void * * ) + 0x4f bytes
jscript9!ScriptSite::Execute( class Js::RecyclableObject *,struct Js::Arguments *,struct IServiceProvider *,void * * ) + 0x5f bytes
jscript9!JavascriptDispatch::InvokeOnMember( long,unsigned long,unsigned short,struct tagDISPPARAMS *,struct tagVARIANT *,struct tagEXCEPINFO *,struct IServiceProvider * ) + 0xffffd5d2 bytes
jscript9!JavascriptDispatch::InvokeEx( long,unsigned long,unsigned short,struct tagDISPPARAMS *,struct tagVARIANT *,struct tagEXCEPINFO *,struct IServiceProvider * ) + 0x456cd bytes
mshtml!CScriptCollection::InvokeEx( class CScriptContext *,long,unsigned long,unsigned short,struct tagDISPPARAMS *,struct tagVARIANT *,struct tagEXCEPINFO *,struct IServiceProvider * ) + 0x95 bytes
mshtml!CWindow::InvokeEx( long,unsigned long,unsigned short,struct tagDISPPARAMS *,struct tagVARIANT *,struct tagEXCEPINFO *,struct IServiceProvider * ) + 0x1d88 bytes
[Truncated]

Details (expand)

Visual Studio 2012

Sample c# app to reproduce downloadable from here: http://db.tt/yu7hfUb1

Generally speaking:

From a windows app hosting the WebBrowser control:

this.webBrowser1.Document.InvokeScript("onExternalMessage", new object[] {"jsonObject", _json});

In the html in the webbrowser:

onExternalMessage = function (messageType, jsonMessages) {

                     //LEAKY VERSION for large objects

                    message = eval('(' + jsonMessages + ')');

        };

using the json_parse() function from https://raw.github.com/douglascrockford/JSON-js/master/json_parse.js instead of eval() will not leak memory

English

Any

English

81,920 bytes allocated for every call to eval() that is never reclaimed

New memory not allocated, or allocated and reclaimed.

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