If the length was set longer than the backing store, on a call to
`Set(index, false)`, and subsequently a call `Set(index-1, true)` was
done, it would try to write outside the backing store.
Closes: https://github.com/dart-lang/sdk/issues/44946
TEST=runtime/vm/bitmap_test.cc
TEST=tests/ffi_2/function_structs_by_value_generated_test.dart/0
Change-Id: Ib636e90b0f6acace9ec8b71557370c281e9e4a99
Cq-Include-Trybots: luci.dart.try:app-kernel-linux-debug-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/184423
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Aske Simon Christensen <askesc@google.com>
Unlike cfc8e6de, this does _not_ replace the default variable length
encoding for {Read,Write}Streams, but insteads adds separate
{Read,Write}{S,}LEB128 methods to the appropriate classes. If we later
find the cause of the issues that led to the revert of cfc8e6de, it'll
be easy to switch over then.
Note that WriteLEB128 asserts that the value is non-negative if used
with a signed type (since negative values suggests that SLEB128 should
be used instead for minimal encoding).
Also removes the various other encoding and decoding methods for
(S)LEB128 across the codebase and changes those clients to use
{Read,Write}Streams instead.
Other cleanups:
* Various constant-related cleanups in datastream.h.
* Adds DART_FORCE_INLINE to ReadStream::ReadByte and uses it in the
default variable length decoding methods for retrieving bytes
from the stream instead of managing current_ by hand.
* Creates a canonical empty CompressedStackMaps instance and uses
that instead of the null CompressedStackMaps instance in most cases.
The only remaining (expected) use of the null CompressedStackMaps
instance is for the global table in the object store when no global
table exists (e.g., in JIT mode before any snapshotting).
* Moves CompressedStackMapsIterator from code_descriptors.h to an
Iterator class within CompressedStackMaps in object.h (similar to
PcDescriptors::Iterator), to limit friend declarations and because it
conceptually makes more sense as part of CompressedStackMaps.
* Removed CompressedStackMaps::PayloadByte, since existing clients
(CompressedStackMaps::Iterator, StackMapEntry in program_visitor.cc)
are better served by just operating on the payload buffer directly
(with appropriate NoSafepointScopes).
* WriteStreams no longer allocate their initial space on construction,
but rather on the first write, so no allocation is performed by
constructing a never-used WriteStream.
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-mac-release-simarm64-try,vm-kernel-mac-debug-x64-try,vm-kernel-win-debug-x64-try,vm-kernel-win-debug-ia32-try,vm-kernel-precomp-win-release-x64-try,vm-kernel-ubsan-linux-release-x64-try,vm-kernel-tsan-linux-release-x64-try,vm-kernel-precomp-ubsan-linux-release-x64-try,vm-kernel-precomp-tsan-linux-release-x64-try,vm-kernel-precomp-msan-linux-release-x64-try,vm-kernel-precomp-asan-linux-release-x64-try,vm-kernel-msan-linux-release-x64-try,vm-kernel-asan-linux-release-x64-try
Change-Id: Ice63321abaa79157fbe9f230a864c8bba0e6dea9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/166421
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>
When we are writing a snapshot, canonicalize all entries within
CompressedStackMaps payloads. We do this by creating a global table
of stack map information (bit counts + bit payload) that we store
in the isolate object store, and then for each existing CSM, we
replace it with an alternate version that refers to the global table.
This gets back some of the canonicalization we lost when we moved from
individual StackMap objects to per-Code CompressedStackMaps objects.
Here, we also represent the global table as a CompressedStackMaps
object. This means that there are three types of CompressedStackMaps:
* The original version that directly contains all entry information.
* The version where each entry is just the PC offset delta and an
offset into the global table payload.
* A version representing the global table where the entries are like
the original version except they don't contain a PC offset delta.
-----
The impact on AOT snapshot size when compiling the Flutter Gallery
in release mode:
armv7: Total size -0.88% (Isolate RO: -5.05%, Isolate snapshot: +0.00%)
armv8: Total size -1.04% (Isolate RO: -5.28%, Isolate snapshot: +0.00%)
-----
Bug: https://github.com/dart-lang/sdk/issues/35274
Change-Id: I1ce0f8b3cc58e2f11584f3c218e0fdf8984b799b
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/120667
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Fixes an assumption that CompressedStackMapsIterator::Find() is never
passed a PC offset of 0. Adds back an ASSERT that was dropped which checks
for specific cases where a given PC offset does not have a stack map entry.
Original commit message:
Lifting the PC offset in a2bb730 was a small, lightweight change that
gave us big gains, at least on 32-bit architectures. Here, we make
much more invasive changes that will improve the amount of memory used
by the information previously stored in StackMap objects.
Instead of allocating separate objects for StackMaps, we instead compress
all StackMap information for a given Code object into a single object
(CompressedStackMaps, or CSM for short). This replaces the Array used to
store PC offsets (as Smis) and the individual StackMap objects.
While we lose all canonicalization for individual StackMap entries, the
drop in space required to store stack map information more than offsets that.
-----
The impact on AOT snapshot size when compiling the Flutter Gallery
in release mode:
armv7: Total size -2.58% (Isolate RO: +14.46%, Isolate snapshot: -22.93%)
armv8: Total size -1.85% (Isolate RO: +15.69%, Isolate snapshot: -22.97%)
The impact on in-memory, not on-disk, size for the Flutter Gallery as seen
in the Observatory while running a profile (not release) build:
armv7: Drops from 7.1 MB to 6.2MB (-0.9 MB)
armv8: Drops from 13.5MB to 11.7MB (-1.8 MB)
-----
Bug: https://github.com/dart-lang/sdk/issues/35274, https://github.com/dart-lang/sdk/issues/38873
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-mac-debug-simdbc64-try
Change-Id: I111b129b0ed64f03184370bceb7cda69d5d4b3c9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/121700
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
This reverts commit d77f4913a1.
Reason for revert: large number of flaky crashes on flakiness dashboard (https://github.com/dart-lang/sdk/issues/38873); crashes on vm-kernel-mac-debug-simdbc64 bot.
Original change's description:
> [vm/compiler] Further compress the information previously in StackMaps.
>
> Lifting the PC offset in a2bb730 was a small, lightweight change that
> gave us big gains, at least on 32-bit architectures. Here, we make
> much more invasive changes that will improve the amount of memory used
> by the information previously stored in StackMap objects.
>
> Instead of allocating separate objects for StackMaps, we instead compress
> all StackMap information for a given Code object into a single object
> (CompressedStackMaps, or CSM for short). This replaces the Array used to
> store PC offsets (as Smis) and the individual StackMap objects.
>
> While we lose all canonicalization for individual StackMap entries, the
> drop in space required to store stack map information more than offsets that.
>
> -----
>
> The impact on AOT snapshot size when compiling the Flutter Gallery
> in release mode:
>
> armv7: Total size -2.58% (Isolate RO: +14.46%, Isolate snapshot: -22.93%)
> armv8: Total size -1.85% (Isolate RO: +15.69%, Isolate snapshot: -22.97%)
>
> The impact on in-memory, not on-disk, size for the Flutter Gallery as seen
> in the Observatory while running a profile (not release) build:
>
> armv7: Drops from 7.1 MB to 6.2MB (-0.9 MB)
> armv8: Drops from 13.5MB to 11.7MB (-1.8 MB)
>
> -----
>
> Bug: https://github.com/dart-lang/sdk/issues/35274
> Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try
> Change-Id: Ie3bb898d557215146260a560423f5fa27bdff512
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/119640
> Commit-Queue: Teagan Strickland <sstrickl@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>
> Reviewed-by: Ryan Macnak <rmacnak@google.com>
TBR=kustermann@google.com,rmacnak@google.com,sstrickl@google.com
# Not skipping CQ checks because original CL landed > 1 day ago.
Bug: https://github.com/dart-lang/sdk/issues/35274
Change-Id: Ib844b4d52e3aa4aca62a896cfe349c680bda7461
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try, vm-kernel-precomp-linux-debug-simarm_x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/121642
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Lifting the PC offset in a2bb730 was a small, lightweight change that
gave us big gains, at least on 32-bit architectures. Here, we make
much more invasive changes that will improve the amount of memory used
by the information previously stored in StackMap objects.
Instead of allocating separate objects for StackMaps, we instead compress
all StackMap information for a given Code object into a single object
(CompressedStackMaps, or CSM for short). This replaces the Array used to
store PC offsets (as Smis) and the individual StackMap objects.
While we lose all canonicalization for individual StackMap entries, the
drop in space required to store stack map information more than offsets that.
-----
The impact on AOT snapshot size when compiling the Flutter Gallery
in release mode:
armv7: Total size -2.58% (Isolate RO: +14.46%, Isolate snapshot: -22.93%)
armv8: Total size -1.85% (Isolate RO: +15.69%, Isolate snapshot: -22.97%)
The impact on in-memory, not on-disk, size for the Flutter Gallery as seen
in the Observatory while running a profile (not release) build:
armv7: Drops from 7.1 MB to 6.2MB (-0.9 MB)
armv8: Drops from 13.5MB to 11.7MB (-1.8 MB)
-----
Bug: https://github.com/dart-lang/sdk/issues/35274
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try
Change-Id: Ie3bb898d557215146260a560423f5fa27bdff512
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/119640
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Instead of storing the PC offset inside the StackMap object, store it instead
in the `Array` containing `StackMap`s in `Code` objects. That is, the `Array`
provided by `Code::stackmaps()` no longer contains just `StackMap` objects, but
instead contains `Smi`s and `StackMap` objects in alternating fashion. Each
`Smi` is the PC offset for the `StackMap` object that follows.
This ends up changing very little code outside of `StackMap`,
`Code::GetStackMap`, and `StackMapTableBuilder`, as there are only two types of
`StackMap` users:
* Users that call `Code::GetStackMap` already have the PC offset.
* Users that call Code::stackmaps() can just fetch the PC offset from the
returned `Array` instead.
On 64-bit architectures, we will use more space to represent the PC offset
as a Smi in the Array than the old uint32_t field. However, the drop in total
number of StackMap objects due to an increased ability to canonicalize
them should offset this. On 32-bit architectures, we can only represent
30 bit PC offsets, not 32 bit PC offsets, but that shouldn't be a problem
in practice except for pathological cases.
_Numbers from building the Flutter gallery in android_release mode_
Since PC offsets are no longer in the `StackMap` objects, this enables
a lot more canonicalization than before. Previously, we generated
49379 `StackMap`s, but now we only generate 16139 `StackMap`s, just under
a third of the original number. This is because there were a lot of
`StackMap`s that differed only in their PC offset, and now they can
be canonicalized into the same `StackMap` object.
When building the Flutter gallery with android_release, the app.so size
drops from 11276896 bytes to 10908256 bytes, a difference of 368640
bytes, or 3.27%.
Using the AOT snapshot profiling support, we see the following drops:
Heap snapshot size drops from 10.7 MB to 10.4 MB.
`Code` | Before | After | Difference
---------------------------------------------------------
Shallow size | 352363 | 352363 | 0
Retained size | 9114801 | 8796064 | -318737
Percent of snapshot | 81.2% | 80.7% | -0.5%
`(RO)StackMap` | Before | After | Difference
---------------------------------------------------------
Shallow size | 49381 | 16141 | -33240
Retained size | 893965 | 286613 | -607352
Percent of snapshot | 7.97% | 2.63% | -5.34%
`StackMap` | Before | After | Difference
---------------------------------------------------------
Shallow size | 844584 | 270472 | -574112
Retained size | 844584 | 270472 | -574112
Percent of snapshot | 7.53% | 2.48% | -5.05%
As we'd expect from the `StackMap` numbers above, we end up using a little
under a third of the space for `StackMap`s. We actually use even less space
(32.0% of the original) than the drop in `StackMap` numbers (32.7%), because
each `RawStackMap` instance is 32 bits smaller due to dropping the `pc_offset_`
field. Note that even though these PC offsets now show up in the
`Code::stackmaps()` `Array`, we can see this is still a net drop in space used
by looking at the retained size of `Code` objects.
Bug: https://github.com/dart-lang/sdk/issues/35274
Change-Id: I0910a43e7a5a7e2e721676209196be1884c5a71c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/119147
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Mostly tests; 1 non-test bug in propagating an error through Dart_SetReturnValue.
This is progress towards asserting thread->excution_state() == kThreadInVM in Object::Allocate.
Change-Id: I6a59549868ab317b3c0d32aa42f3661289cbf456
Reviewed-on: https://dart-review.googlesource.com/71720
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Ben Konyi <bkonyi@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Only allocate space for the bits covered by the stackmap, instead of
for the backing store of the utility class that built it. Fix a bug
where the size in bytes was multiplied by the word size in bytes.
Also do some cleanup of the stackmap code and renaming in the tests.
BUG=
Review URL: https://chromiumcodereview.appspot.com//10832292
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@10870 260f80e4-7a28-3924-810f-c04153c831b5
Change 6302 description:
- Wire the stack frame iterator to use stack maps for traversing objects if
there are stack maps in the code object. If there are no stack maps it still
does the old style stack frame traversal between fp and sp looking for tagged
pointers.
- Added a mechanism to be able to iterate over the code space and look for a
particular object.
Review URL: https://chromiumcodereview.appspot.com//10030001
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@6331 260f80e4-7a28-3924-810f-c04153c831b5
Daco Harkes