Use virtually dispatched specialized scavengers instead of single generic ScavengeObjectSlow implementation.
Rollback of r5041 with assertion checking callback alignment removed. Map space is iterated in a special fashion during scavenges so special callback alignment is not required.
Review URL: http://codereview.chromium.org/2950003
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5047 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Added support for more precise break points when debugging and stepping. To achieve that additional nop instructions are inserted where breaking would otherwise be impossible. The number of nop instructions inserted are sufficient to make place for patching with a call to a debug break code stub. On Intel that is 5 nop's for 32-bit and 13 for 64-bit. Om ARM 3 nop instructions (12 bytes) are required.
In order to avoid inserting nop's in to many places a simple ast checker have been added to check whether there are breakable code in a statement or expression. If it is possible to break in an expression no additional break enabeling code is inserted.
Added break locations to the true and false part of a conditional expression.
Added stepping tests to cover more constructs.
These changes are only in the full compiler.
Changed the default value for the option --debugger in teh d8 shell from true to false. The reason for this is that with --debugger turned on the full compiler will be used for all code in when running d8, which can be unexpeceted.
Review URL: http://codereview.chromium.org/2693002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4820 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- New сardmarking write barrier handles large objects and normal objects in a similar fashion (no more additional space for pointer tracking is required, no conditional branches in WB code).
- Changes to enable oldspaces iteration without maps decoding:
-- layout change for FixedArrays: length is stored as a smis (initial patch by
Kevin Millikin)
-- layout change for SharedFunctionInfo: integer fields are stored as smi on
arm, ia32 and rearranged on x64.
-- layout change for String: meaning of LSB bit is fliped (1 now means hash not
computed); on x64 padding is added.
-- layout of maps is _not_ changed. Map space is currently iterated in a special
way.
Review URL: http://codereview.chromium.org/2144006
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4715 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
-- layout change for FixedArrays: length is stored as a smis (initial patch by Kevin Millikin)
-- layout change for SharedFunctionInfo: integer fields are stored as smi on arm, ia32 and rearranged on x64.
-- layout change for String: meaning of LSB bit is fliped (1 now means hash not computed); on x64 padding is added.
-- layout of maps is _not_ changed. Map space is currently iterated in a special way.
- Cardmarking write barrier. New barrier handles large objects and normal objects in a similar fashion (no more additional space for pointer tracking is required, no conditional branches in WB code).
Review URL: http://codereview.chromium.org/2101002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4685 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- RelinkPageListInChunkOrder might relink unused pages into the middle of a sequence of used pages. Filler objects should be placed at the beginning of such unused pages otherwise generic iterators (e.g. HeapObjectIterator) would not handle them correctly.
- ObjectAreaEnd() should not be used as an allocation limit for pages from FixedSpace. Pages in such spaces do not use top page_extra_ bytes of object area.
TBR=ager@chromium.org
Review URL: http://codereview.chromium.org/1700005
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4476 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
As an afterthought, I realized that I put function objects moves
reporting into a method that deals with only code object moves. I've
looked up that function objects are allocated in old pointer space and
new space, so I moved logging to the corresponding VM methods.
BUG=553
Review URL: http://codereview.chromium.org/552089
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3679 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The problem appeared due to a fact that stubs doesn't create a stack
frame, reusing the stack frame of the caller function. When building
stack traces, the current function is retrieved from PC, and its
callees are retrieved by traversing the stack backwards. Thus, for
stubs, the stub itself was discovered via PC, and then stub's caller's
caller was retrieved from stack.
To fix this problem, a pointer to JSFunction object is now captured
from the topmost stack frame, and is saved into stack trace log
record. Then a simple heuristics is applied whether a referred
function should be added to decoded stack, or not, to avoid reporting
the same function twice (from PC and from the pointer.)
BUG=553
TEST=added to mjsunit/tools/tickprocessor
Review URL: http://codereview.chromium.org/546089
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3673 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Always invoke HeapObjectIterator::has_next() before invoking HeapObjectIterator::next().
This is necessary as ::has_next() has an important side-effect of going to the next
page when current page is exhausted.
And to find if pointers are encodable use more precise data---top of map space, not a number
of pages, as pages might stay in map space due to chunking.
Review URL: http://codereview.chromium.org/552066
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3672 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
On 32-bit the maps are now aligned on a 32-byte boundary in order to encode more maps during compacting GC. The actual size of a map on 32-bit is 28 bytes making this change waste 4 bytes per map.
On 64-bit the encoding for compacting GC is now using more than 32-bits and the maps here are still pointer size aligned. The actual size of a map on 64-bit is 48 bytes and this change does not intruduce any waste.
My choice of 16 bits for kMapPageIndexBits for 64-bit should give the same maximum number of pages (8K) for map space. As maps on 64-bit are larger than on 32-bit the total number of maps on 64-bit will be smaller than on 32-bit. We could consider raising this to 17 or 18.
I moved the kPageSizeBits to globals.h as the calculation of the encoding really depended on this.
There are still an #ifdef/#endif in objects.h and this constant could be moved to globaks.h as well, but I kept it together with the related constants.
All the tests run in debug mode with additional options --gc-global --always-compact as well (except for a few tests on which also fails before this change when run with --gc-global --always-compact).
BUG=http://code.google.com/p/v8/issues/detail?id=524
BUG=http://crbug.com/29428
TEST=test/mjsunit/regress/regress-524.js
Review URL: http://codereview.chromium.org/504026
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3481 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Instead of weak handles external strings use a separate table. This
table uses 5 times less memory than weak handles. Moreover, since we
don't have to follow the weak handle callback protocol we can collect
the strings faster and even on scavenge collections.
Review URL: http://codereview.chromium.org/467037
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3439 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
in old space. Before this change we would compute the fragmentation
limit before the GC, but that means that we take all the garbage
into account - and consequently we almost never hit the limit (because
we have a lot of garbage).
This change changes the policy to compact on the *next* GC if we
determine that we have too much fragmentation after doing a GC.
We'll do a GC if we've wasted more than 1MB and more than 15% of
the old space size.
This can be further improved by computing whether or not to compact
during the marking phase.
Review URL: http://codereview.chromium.org/202008
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2841 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Android system provides a unique feature that it sends a notification to the
browser in low memory condition, and the browser cleans up cache and frees
resources. Forcing a GC in low memory condition can free DOM objects and also
can shrink the old spaces.
This patch addresses the last comment in
http://codereview.chromium.org/173016/show
Mads Ager 2009/08/19 17:24:23
I would prefer to not use the flags to signal that a compacting collection is
requested.
TBR = ager
Review URL: http://codereview.chromium.org/173102
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2725 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
space is similar to map space in that it has fixed-size objects. A
common superclass for a space with fixed size objects is used for the
map space and cell space.
Allocate all cells in cell space. Handle it during all GCs. Modify
the free-list node representation (so that the size is not at a fixed
offset in all cells) to allow two-pointer free-list nodes. Clean up
some stuff in the MC collector.
Review URL: http://codereview.chromium.org/155211
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2411 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This issue was raised by Brett Wilson while reviewing my changelist for readability. Craig Silverstein (one of C++ SG maintainers) confirmed that we should declare one namespace per line. Our way of namespaces closing seems not violating style guides (there is no clear agreement on it), so I left it intact.
Review URL: http://codereview.chromium.org/115756
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2038 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Mark all objects reachable from the symbols except the symbols
themselves as live (and reachable from strong roots). This ensures
that if the symbol itself remains alive for any reason, and if it was
a sliced string or cons string backed by an external string, then the
external string will be strongly reachable and therefore not get a
weak reference callback.
Review URL: http://codereview.chromium.org/100344
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1846 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
resource to NULL when removing it from the symbol table. This makes
sure that the debugger can recognize the external string as being
"deleted". Now, whenever an external resource is deleted, the
resource pointer is set to NULL.
This is really a workaround of a debugger problem. We need to make
sure that the debugger only finds scripts in the heap that are
actually live.
Review URL: http://codereview.chromium.org/69029
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1734 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- Added special cutouts if a Vector has NULL data, which will now happen
if an external string's resource has been deleted.
- Added an verification phase before old gen GC to verify that all real
entries in the SymbolTable are valid symbols.
- Added test that verifies the correct behaviour of the workaround.
Review URL: http://codereview.chromium.org/66011
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1689 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
