216112 - add ability to disable object tracking in jsd

Status: RESOLVED FIXED

(Other Applications Graveyard :: Venkman JS Debugger, defect)

Description

[Robert Ginda]

The jsd library tracks the file name and line number of every object created and
every constructor called.  This is some expensive code, probably too expensive
to justify doing it all the time.  This patch disables object tracking on
mozilla startup, but turns it back on once venkman starts.  This shaved 25% off
of the following testcase:

    function f()
    {
        g();
        h();
    };

    function g() {};
    function h() {};
    
    for (var i = 0; i < 50000; ++i)
        f();


This means that in order to use "Find Constructor" or "Find Creator" on an
object, the object must be created *after* venkman is started.

Comment 1

[Robert Ginda]

Attachment: add ability to disable object tracking, and use it

Comment 2

[Brendan Eich [:brendan]]

Dumb question, but I couldn't see it grepping around: where does the
JSD_DISABLE_OBJECT_TRACE flag get cleared?  I see it tested and set only, and I
couldn't find a clear-all method.

BTW, do the JSD_DISABLE_OBJECT_TRACE and DISABLE_OBJECT_TRACE flags have to
match? Can't you consolidate on the .idl-defined ones?  Must be some history here.

/be

Comment 3

[Robert Ginda]

On startup, venkman explicitly sets the flags to JSD_ENABLE_NATIVE_FRAMES,
regardless of the previous value.  We can't consolidate to just the idl defines
because there are jsd clients that do not use XPCOM.

Comment 4

[Brendan Eich [:brendan]]

Comment on attachment 129771 [details] [diff] [review]
add ability to disable object tracking, and use it

Looks good to me, sr=brendan if caillon likes it.

/be

Comment 5

[Christopher Aillon (sabbatical, not receiving bugmail)]

Comment on attachment 129771 [details] [diff] [review]
add ability to disable object tracking, and use it

>Index: jsd_xpc.cpp

>@@ -3267,15 +3265,18 @@
>         return rv;
> 
>     rv = jsds->OnForRuntime(rt);
>+    if (NS_FAILED(rv))
>+        return rv;
>     
>+    rv = jsds->SetFlags(JSD_DISABLE_OBJECT_TRACE);
>     return rv;

How about a straight |return jsds->SetFlags(JSD_DISABLE_OBJECT_TRACE);| ?

Patch looks good.  r=caillon.

Comment 6

[Asa Dotzler [:asa]]

Comment on attachment 129771 [details] [diff] [review]
add ability to disable object tracking, and use it

a=asa (on behalf of drivers) for checkin to Mozilla 1.5beta.

Comment 7

[Robert Ginda]

checked in