This can lead to large objects which wastes a lot of space if we normalize properties. We therfore clear the inobject properties when normalizing properties. This is done by adjusting the instance size in the new map and overwriting the inobject properties with a filler.
Review URL: http://codereview.chromium.org/17308
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1051 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The performance of Array::concat is critical of jQuery benchmark from
http://www.dromaeo.com. Our current implementation in JavaScript is very
generic and is several times slower than JSC and SpiderMonkey.
Re-implement Array::concat in C++ to take advantage of underlying implementation
details. This cuts dom-travesal-jquery execution time by half.
We may want to move Array specific implementation into a separate source file,
say jsarray.cc.
Review URL: http://codereview.chromium.org/7990
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@625 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- Changed the structure of regexp objects from having two internal
fields to having a single field containing a fixed array, since it's
easier to store the whole fixed array in the cache.
- Move printing of the command to after printing std{err,out} in the
compact progress indicators in the test framework.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@579 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Here is a description of the background and design of split window in Chrome and V8:
https://docs.google.com/a/google.com/Doc?id=chhjkpg_47fwddxbfr
This change list splits the window object into two parts: 1) an inner window object used as the global object of contexts; 2) an outer window object exposed to JavaScript and accessible by the name 'window'. Firefox did it awhile ago, here are some discussions: https://wiki.mozilla.org/Gecko:SplitWindow. One additional benefit of splitting window in Chrome is that accessing global variables don't need security checks anymore, it can improve applications that use many global variables.
V8 support of split window:
There are a small number of changes on V8 api to support split window:
Security context is removed from V8, so does related API functions;
A global object can be detached from its context and reused by a new context;
Access checks on an object template can be turned on/off by default;
An object can turn on its access checks later;
V8 has a new object type, ApiGlobalObject, which is the outer window object type. The existing JSGlobalObject becomes the inner window object type. Security checks are moved from JSGlobalObject to ApiGlobalObject. ApiGlobalObject is the one exposed to JavaScript, it is accessible through Context::Global(). ApiGlobalObject's prototype is set to JSGlobalObject so that property lookups are forwarded to JSGlobalObject. ApiGlobalObject forwards all other property access requests to JSGlobalObject, such as SetProperty, DeleteProperty, etc.
Security token is moved to a global context, and ApiGlobalObject has a reference to its global context. JSGlobalObject has a reference to its global context as well. When accessing properties on a global object in JavaScript, the domain security check is performed by comparing the security token of the lexical context (Top::global_context()) to the token of global object's context. The check is only needed when the receiver is a window object, such as 'window.document'. Accessing global variables, such as 'var foo = 3; foo' does not need checks because the receiver is the inner window object.
When an outer window is detached from its global context (when a frame navigates away from a page), it is completely detached from the inner window. A new context is created for the new page, and the outer global object is reused. At this point, the access check on the DOMWindow wrapper of the old context is turned on. The code in old context is still able to access DOMWindow properties, but it has to go through domain security checks.
It is debatable on how to implement the outer window object. Currently each property access function has to check if the receiver is ApiGlobalObject type. This approach might be error-prone that one may forget to check the receiver when adding new functions. It is unlikely a performance issue because accessing global variables are more common than 'window.foo' style coding.
I am still working on the ARM port, and I'd like to hear comments and suggestions on the best way to support it in V8.
Review URL: http://codereview.chromium.org/7366
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
canonicalize maps for object literals. JSON objects
with the same set of properties names will then
share the same map.
This reduces the amount of generated code associated
with object literals.
- Added a flag canonicalize_object_literal_maps.
(default true)
- Changed the format of a function's literal array.
Only the global context is now stored in the literal prefix.
Review URL: http://codereview.chromium.org/4078
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@371 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
method ensures that there are no allocations during the setup.
This fixes test breakage on Linux in debug mode where allocation
happened while the debug info object was not fully set up making
verify heap unhappy.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@70 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- Fixed mozilla test breakage caused by python's obscure module
loading rules.
- Made sure test.py propagates test failures out as the exit code of
the script.
- Remove runtime calls to get number constants. Remove Heap roots for
some special numbers.
- Fix typo in accessors.h.
- Changes CopyMap to not copy descriptors. Adds
CopyMapRemoveTransitions that copies non-transition descriptors.
Changes interface of DescriptorArray::Copy operations to simplify
them.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@21 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Added better test support.
Added load, quit and version functions to the shell sample so it's easier to run benchmarks and tests.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
In the shell sample don't print the result of executing a script, only
evaluating expressions.
Fixed issue when building samples on Windows using a shared V8
library. Added visibility option on Linux build which makes the
generated library 18% smaller.
Changed build system to accept multiple build modes in one build and
generate seperate objects, libraries and executables for each mode.
Removed deferred negation optimization (a * -b => -(a * b)) since this
visibly changes operand conversion order.
Improved parsing performance by introducing stack guard in preparsing.
Without a stack guard preparsing always bails out with stack overflow.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
