This makes back pointers in the map transition tree explicit by having
accurate back pointers throughout the lifetime of maps instead of
establishing and destroying back pointers before and after each marking
phase. This is a prerequisite for being able to clear map transitions
during incremental marking.
R=vegorov@chromium.org
BUG=v8:1465
Review URL: https://chromiumcodereview.appspot.com/10381053
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11528 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This simple refactoring makes it very clear that clearing non-live transitions
actually consists of 2 quite separate things. Things would even be nicer if the
prototype transitions were represented by a separate data structure instead of
reusing FixedArray in an interesting way once again.
As an additional bonus, this CL makes it possible to read each of the methods in
question on a 30" screen without scrolling!
Review URL: https://chromiumcodereview.appspot.com/9169045
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10501 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This refactoring (almost) gets rid of the requirement to get the target
object address for an object pointer embedded in code objects. This is
not possible on MIPS as pointers are encoded using two instructions. All
usages of RelocInfo::target_object_address() are (almost) obsoleted by
this change. The serializer still uses it, so MIPS will not yet work
with snapshots turned on.
R=danno@chromium.org,vegorov@chromium.org
Review URL: http://codereview.chromium.org/8245007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9597 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
All slots that were recorded on these objects during incremental marking should be ignored as they are no longer valid.
To filter such invalidated slots out during slots buffers iteration we set all markbits under the invalidated code object to 1 after the code space was swept and before slots buffers are processed.
R=erik.corry@gmail.com
BUG=v8:1713
TEST=test/mjsunit/regress/regress-1713.js
Review URL: http://codereview.chromium.org/7983045
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9402 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The "live bytes" count is *really* a "marked black" count - i.e., the count of bytes *known* to be live.
Fix aggravating bug on X64 where assembler code used a value that was off
by a factor of 2^31.
Ensure that sweeping clears live-bytes. Added other missing increments.
Added print statements to trace live-byte modifications, under a flag.
Still a few cases of undercounting left.
(New issue to merge from GC branch to bleeding_edge)
Review URL: http://codereview.chromium.org/7970009
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9338 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
That could improve chances for commit success as currently,
if we moved free pages out of order, we cannot shrink spaces.
However, when we experience problems commiting from space back, we should
use most of resources at our disposal.
Also get rid of currently unused parameter to DeallocateFunction.
Review URL: http://codereview.chromium.org/3260001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5372 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
the code object's instructions.
This allows us to find a code object using just the pc. This approach
uses a cache (PcToCodeCache) to make sure we don't continuously have
to iterate heap pages.
This change eliminates the need for cooking and uncooking of stack frames.
Review URL: http://codereview.chromium.org/3226014
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5369 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
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
for partial snapshots. After reserving space we can be sure that allocations
will happen linearly (no GCs and no free-list allocation). This change also
contains the start of the partial snapshot support, which, however is not yet
completed or tested.
Review URL: http://codereview.chromium.org/545026
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3584 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
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
* Make old_data_space non-executable on OSs and hardware that support it.
* Rename old_space to old_pointer_space (can contain pointers, esp. to new space).
* Ensure that individual pages allocated for old_space are only executable when
they are for code objects.
* Ensure Space::Setup can cope with non-aligned memory.
* Make some methods on Spaces virtual. Make a way to iterate over all spaces.
* Replace executability flag with Executability enum in order to make intent at
call site clearer.
* Fix serialization/deserialization to allocate write barrier memory for large
arrays.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@165 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Extended the shell sample with a --runtime-flags option.
Added Visual Studio project files for the shell.cc and process.cc samples.
git-svn-id: http://v8.googlecode.com/svn/trunk@14 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Cleaned up ARM version by removing top of stack caching and by introducing push/pop elimination.
Cleaned up the way runtime functions are called to allow runtime calls with no arguments.
Changed Windows build options to make sure that exceptions are disabled and that optimization flags are enabled.
Added first version of Visual Studio project files.
git-svn-id: http://v8.googlecode.com/svn/trunk@13 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
