If a map has descendents in the map transition tree that are alive,
it is kept. Only maps such that they and all their descendants
have no live objects are collected. This happens in mark-sweep and
mark-compact garbage collections.
Review URL: http://codereview.chromium.org/8099
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@601 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
- Changed WeakReferenceCallback to take a Persistent<Value> instead of
a Persistent<Object>.
- Removed Message::GetUnderline and Message::GetScriptData.
- Added Value::IsDate, Date::Cast and Date::Value.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@564 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
underlying string representation of the two strings involved.
- Renamed ascii and two byte string classes to sequential ascii and
sequential two byte, and renamed IsAscii and friends to
IsAsciiRepresentation. This is to make a clear distinction between
strings with an ascii/two-byte representation, of which there is
four, and flat sequential ascii/two-byte string.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@474 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
are always odd if the bit-field bits are included.
Modified a couple of debugger tests that relied on the ordering of
elements in descriptor arrays. Descriptor arrays are sorted by
hash-code values, so the order changes if we change the hash code.
Review URL: http://codereview.chromium.org/6489
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@440 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
Update the lookup and update code for code caches to deal with deleted
elements.
Do not clear the code cache for the builtins object. If there was a
matching element in the code cache, we would have hit the monomorphic
prototype failure case and removed it.
Review URL: http://codereview.chromium.org/3140
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@340 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
occured. After a monomorphic prototype failure has been detected,
other monomorphic inline caches for the same type will have a code
object in the map's code cache which is not the current target. We
recognize this case and use the code object that is in the cache
instead of going megamorphic.
Review URL: http://codereview.chromium.org/2928
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@331 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
it for scripts too. In the context of Chromium, this should
have a very positive impact on memory consumption for web apps
that run multiple tabs from the same domain with a lot of the
same JavaScript code.
For now, the cache retirement policy is really simple:
Whenever a mark-sweep collection is started we clear the
cache. This guarantees that this change will not have a
huge negative impact on memory consumption, but it may
not be ideal. We should consider a more sophisticated LRU
scheme.
Review URL: http://codereview.chromium.org/1933
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@270 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The cache is a hashtable that takes String as key and JSFunction as the value.
Caches are cleared before mark-compact GC's.
Currently I don't put caps on cache size, string size, etc.
This cuts date-parse-totfe.js runtime by half.
Review URL: http://codereview.chromium.org/457
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@173 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
KeyedLoadIC::GenerateGeneric (on IA32), and the same on ARM.
Re-assignmed FIRST_JS_OBJECT_TYPE to JS_VALUE_TYPE.
Also changed JS_OBJECT_TYPE to FIRST_JS_OBJECT_TYPE in several places where
FIRST_JS_OBJECT_TYPE is intended.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@113 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
Added a few samples and support for building them. The samples include a simple shell that can be used to benchmark and test V8.
Changed V8::GetVersion to return the version as a string.
Added source for lazily loaded scripts to snapshots and made serialization non-destructive.
Improved ARM support by fixing the write barrier code to use aligned loads and stores and by removing premature locals optimization that relied on broken support for callee-saved registers (removed).
Refactored the code for marking live objects during garbage collection and the code for allocating objects in paged spaces. Introduced an abstraction for the map word of a heap-allocated object and changed the memory allocator to allocate executable memory only for spaces that may contain code objects.
Moved StringBuilder to utils.h and ScopedLock to platform.h, where they can be used by debugging and logging modules. Added thread-safe message queues for dealing with debugger events.
Fixed the source code reported by toString for certain builtin empty functions and made sure that the prototype property of a function is enumerable.
Improved performance of converting values to condition flags in generated code.
Merged disassembler-{arch} files.
git-svn-id: http://v8.googlecode.com/svn/trunk@8 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Added propagation of stack overflow exceptions that occur while compiling nested functions.
Improved debugger with support for recursive break points and handling of exceptions that occur in the debugger JavaScript code.
Renamed GetInternal to GetInternalField and SetInternal to SetInternalField in the API and moved InternalFieldCount and SetInternalFieldCount from FunctionTemplate to ObjectTemplate.
git-svn-id: http://v8.googlecode.com/svn/trunk@5 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
