Enum forwarding requires evaluating and canonicalizing the new enum instances. If these in turn refer to other instances of classes with shape changes, canonicalization may try to compare instances of the old and new shapes and dereference past the end of an object. By waiting for instance morphing to complete, canonicalization can only see instances with the new shape.
Also, don't attempt to forward Enum.values. When an enum member is added or removed, this has the same merging problem as 40442.
Cf. bad074cc49.
TEST=ci
Bug: https://github.com/flutter/flutter/issues/129177
Bug: https://github.com/dart-lang/sdk/issues/53039
Change-Id: Ib7a54db30c4d16a6ae6e1acd595dc7482134165b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/316527
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Ben Konyi <bkonyi@google.com>
Enum forwarding requires evaluating and canonicalizing the new enum instances. If these in turn refer to other instances of classes with shape changes, canonicalization may try to compare instances of the old and new shapes and dereference past the end of an object. By waiting for instance morphing to complete, canonicalization can only see instances with the new shape.
Also, don't attempt to forward Enum.values. When an enum member is added or removed, this has the same merging problem as 40442.
Cf. bad074cc49.
TEST=ci
Bug: https://github.com/flutter/flutter/issues/129177
Change-Id: I19d0508059bade8496000eeea257bb0730f11d17
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/316041
Reviewed-by: Ben Konyi <bkonyi@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
a) Remove 2 fields in our object representation:
* PatchClass::library_data_
* Library::kernel_data_
=> This saves O(#libraries + #patch-classes) which can amount up to
10+ MB for big apps, as we save not just the slots but the
[ExternalTypedData] objects they used to reference.
Instead we'll compute the KernelLibraryData when we need it by making a
[TypedDataView] of sub parts of the component.
b) We make a kernel binary be represented by a single [ExternalTypedData].
Whenever we need a sub-part of a kernel binary (e.g. one for each
component for concatinated kernels, or one for a library inside a
component) we use proper [TypedDataView]s for that.
c) As we sometimes need to create a view of only a particular library
within a component we need to find start/end of a library based on
index.
=> We store the library index instead of the library offset on
Library/PatchClass.
=> We can easily derive the start/end of a library from it's index by
looking at the kernel component encoding.
d) We make the [Reader] object work purely based on a pointer - instead
of making it have if/else when reading bytes (either from pointer or
from a view).
e) We make the [KernelProgramInfo] store the kernel_component and
various TD views into it.
TEST=ci
Change-Id: Ibe160881ff48635e834c3d647a977a144b5d0565
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/313561
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Previously, inliner was able to inline closure calls only when closure
was allocated in the current function (or in a function which was
inlined so far). This is not true for local functions declared in outer
functions (they are allocated at declaration site).
Now, when calling local functions, target of closure call is always
known regardless of where the function is declared, so calls to local
functions can be inlined.
TEST=runtime/tests/vm/dart/inline_local_functions_il_test.dart
Fixes https://github.com/dart-lang/sdk/issues/52695
Fixes https://github.com/dart-lang/sdk/issues/15558
Change-Id: I0e51dbaf63a6d4427bff366b40414ca5fac3d418
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/311465
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
This field is now only used when reloading to check assignability
during `ProgramReloadContext::ReloadPhase4CommitFinish()` (via
`PostCommit()` -> `InvalidateWorld()` -> `InvalidateFields`).
However, the method `DeoptimizeDependentCode()` is called near the
start of the actual reloading process in `Reload` prior to the
commit/rollback phases. This calls `DeoptimizeTypeTestingStubs()`, which
walks the heap and resets the contents of all `SubtypeTestCaches`
(`STC`s).
That means that the `STC` information isn't actually kept between
different reloads, so all this does is cause a number of `STC` objects
to be allocated during reload whose backing arrays are not used
post-reload for anything and so are unnecessary garbage.
That, and the creation of the `STC`s during `InvalidateFields` creates
all-input `STC`s, as they don't just check assignability to a given field type but also for checking elements of `RecordTypes`. That means
the per-field `STC`s contain way more information needed to check for
valid assignments to the corresponding field type, even if the `STC`
was used between reloads.
This CL removes the unnecessary field and changes `InvalidateFields`
so that the `STC`s used during reload are instead lazily allocated once
per `FieldInvalidator` object and now both the `STC` and its backing
array are now garbage post-field invalidation.
TEST=reload ci
Change-Id: I3ffa199551ba69f0afd4eba6303c6ff73d7473a3
Cq-Include-Trybots: luci.dart.try:vm-reload-linux-debug-x64-try,vm-reload-linux-release-x64-try,vm-reload-rollback-linux-debug-x64-try,vm-reload-rollback-linux-release-x64-try,vm-aot-linux-debug-x64-try,vm-aot-linux-product-x64-try,vm-aot-linux-release-x64-try,vm-linux-release-x64-try,vm-linux-debug-x64-try,vm-aot-dwarf-linux-product-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/311220
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Previously, SlowTypeTestStub would use the incoming instance and
destination type to determine which `SubtypeNTestCacheStub` to call,
where `N` is the number of inputs checked for each entry. The code
for generating `InstanceOf` instructions performs similar work,
inlining some checks and then falling back to checking and updating
an appropriate `SubtypeNTestCacheStub` if the inlined checks fail.
Meanwhile, the runtime would use all available information to
create a new entry when needed, depending on the `SubtypeNTestCacheStub`
called at runtime to ignore the parts of the entry it didn't need.
To illustrate a situation where the runtime might use more
information to create an entry than needed by the stub, consider
the following class header:
```
class C<T> extends D
```
If no subtype of `D` requires knowing the specific type arguments for
an instance to determine whether that instance is an instance of `D`,
then the compiler can generate a `Subtype1TestCacheStub` call, where
only the class id of the instance is checked.
However, in the runtime, when updating the cache, the runtime will
create an entry that includes the specific type arguments used to
instantiate `C` when the initial cache miss occurred, as the runtime
does not know how many inputs the code that checks that SubtypeTestCache
uses. If the cache has grown to the point that it is hash-based, that
means the runtime uses the instance type arguments of the first cache
miss to determine the correct place to create a new entry.
When the stub only performs a linear search over the cache contents,
this works, as every entry is checked until a matching entry is found,
and thus the stub can ignore unneeded information. However, if a cache
is hash-based, this doesn't work: if the first miss was an instance
of `C<int>`, then the runtime includes all that information in a new
entry. This means the stub has to calculate the instance type
arguments, which it did not have to do before, and if a subsequent
check uses different instance type arguments (e.g., an instance of
`C<String>`), the result may still be a cache miss, and the runtime
adds another entry which has the same information as the previous
entry as far as the stub was originally concerned.
Thus, to limit itself to considering only the inputs used by the
appropriate `SubtypeNTestCacheStub`, the runtime needs to be told how
many inputs are used. This CL adds an additional field to
`SubtypeTestCache`s which contains the number of used inputs, and
changes the places where `SubtypeTestCache`s are allocated in the
flow graph compiler and the `DRT_TypeCheck` runtime entry to pass the
appropriate number of inputs. To ensure that the runtime and stubs
agree on how many inputs should be used, the `SlowTypeTestStub` now
uses the value of this field to determine which `SubtypeNTestCacheStub`
to call.
TEST=vm/cc/STC_{Linear,Hash}Lookup
Bug: https://github.com/dart-lang/sdk/issues/48345
Change-Id: Ie16f2d12c4c5eae856b668f28178818203662d1c
Cq-Include-Trybots: luci.dart.try:vm-aot-linux-debug-simriscv64-try,vm-aot-linux-debug-x64-try,vm-aot-linux-release-x64-try,vm-aot-linux-product-x64-try,vm-aot-linux-release-simarm64-try,vm-aot-linux-release-simarm_x64-try,vm-aot-linux-debug-x64c-try,vm-aot-mac-release-arm64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-aot-dwarf-linux-product-x64-try,vm-linux-release-ia32-try,vm-linux-debug-x64c-try,vm-linux-debug-x64-try,vm-linux-debug-simriscv64-try,vm-linux-release-simarm64-try,vm-linux-release-simarm-try,vm-mac-release-arm64-try,vm-mac-release-x64-try,vm-tsan-linux-release-x64-try,vm-reload-rollback-linux-release-x64-try,vm-reload-linux-release-x64-try,vm-ffi-qemu-linux-release-arm-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/310180
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
We use specialized type testing stubs in `as` checks to quickly answer
whether the type of an object is assignable to a given type. However,
perfect specialization of the type testing stub is not possible in all
cases. Thus, we use SubtypeTestCaches (STCs) to cache the result of
checking assignability in the runtime to avoid repeated runtime calls
for the same check.
Previously, the STC was linear and capped at 100 entries. This cap was
for two reasons:
* STC are created per `as` check, not per checked type, so there could
be many STCs created for a given type if assignability to that type
is checked many times throughout the code.
* STC were strictly linear, and thus eventually the cost of
traversing the cache outweighs the cost of returning a false
negative that requires going to the runtime and doing the check there.
This CL provides a partial solution to the second reason by performing
similar work to that done for instantiation caches in TypeArguments
(4f925105), where the STC is linear up to a certain threshold, and then
converted to a hash-based STC. Like that CL, only the runtime currently
handles the lookup of cached results in hash-based STCs, with the
changes needed for the `SubtypeNTestCacheStub`s coming in a followup CL.
Since the stubs have not yet been adjusted, we keep the maximum size of
linear caches the same at 100, and allow hash-based STCs to grow to a
maximum size of 1000 since the STCs are still created per `as` check.
This means once the STC has grown over 100 entries, all STC checks
require a runtime call, but for checks cached in the STC, the answer is
found and provided without either doing the slower full runtime check
for assignability and without an attempt to respecialize the type
testing stub when applicable.
Our benchmarks generally see at most a ~2-5% performance regression for
cases where the STC remains linear (except for on the Raspberry Pi 4, where the hit ranges from ~25%-40%), but a performance improvement of
~500-1300% for cases where the STC is converted to a hash table.
TEST=vm/cc/TTS_STC_{Some,Many}Asserts
Change-Id: Ie8629708b5c12fa8464359a2f77c6da56ba46c0c
Cq-Include-Trybots: luci.dart.try:vm-aot-linux-debug-simriscv64-try,vm-aot-linux-debug-x64-try,vm-aot-linux-release-x64-try,vm-aot-linux-product-x64-try,vm-aot-linux-release-simarm64-try,vm-aot-linux-release-simarm_x64-try,vm-aot-linux-debug-x64c-try,vm-aot-mac-release-arm64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-aot-dwarf-linux-product-x64-try,vm-linux-release-ia32-try,vm-linux-debug-x64c-try,vm-linux-debug-x64-try,vm-linux-debug-simriscv64-try,vm-linux-release-simarm64-try,vm-linux-release-simarm-try,vm-mac-release-arm64-try,vm-mac-release-x64-try,vm-tsan-linux-release-x64-try,vm-reload-rollback-linux-release-x64-try,vm-reload-linux-release-x64-try,vm-ffi-qemu-linux-release-arm-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/284682
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
The [ReloadOperationScope] has [StackResource]s as fields and is itself
a [StackResource] which is problemantic if unwinding happens manually.
So we'll make it a macro that expands to the 3 fields instead.
TEST=ci
Change-Id: I3fb7bec7ca87193c83ec34908f9a43c5db005900
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/302201
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
The current hot-reload implementation [0] will perform a reload by
first sending OOB messages to all isolates and waiting until those OOB
messages are being handled. The handler of the OOB message will block
the thread (and unschedule isolate) and notify the thread performing
reload it's ready.
This requires that all isolates within a group can actually run & block.
This is the case for the VM implementation of isolates (as they are
run an unlimited size thread pool).
Though flutter seems to multiplex several engine isolates on the same OS
thread. Reloading can then result in one engine isolate performing
reload waiting for another to act on the OOB message (which it will not
do as it's multiplexed on the same thread as the former).
Now that we have a more flexible safepointing mechanism (introduced in
[1]) we can utilize for hot reloading by introducing a new "reloading"
safepoint level.
Reload safepoints
-----------------------
We introduce a new safepoint level (SafepointLevel::kGCAndDeoptAndReload).
Being at a "reload safepoint" implies being at a "deopt safepoint"
which implies being at a "gc safepoint".
Code has to explicitly opt-into making safepoint checks participate /
check into "reload safepoints" using [ReloadParticipationScope]. We do
that at certain well-defined places where reload is possible (e.g. event
loop boundaries, descheduling of isolates, OOM message processing, ...).
While running under [NoReloadScope] we disable checking into "reload
safepoints".
Initiator of hot-reload
-----------------------
When a mutator initiates a reload operation (e.g. as part of a
`ReloadSources` `vm-service` API call) it will use a
[ReloadSafepointOperationScope] to get all other mutators to a
safepoint.
For mutators that aren't already at a "reload safepoint", we'll
notify them via an OOB message (instead of scheduling kVMInterrupt).
While waiting for all mutators to check into a "reload safepoint", the
thread is itself at a safepoint (as other mutators may perform lower
level safepoint operations - e.g. GC, Deopt, ...)
Once all mutators are at a "reload safepoint" the thread will take
ownership of all safepoint levels.
Other mutators
-----------------------
Mutators can be at a "reload safepoint" already (e.g. isolate is not
scheduled). If they try to exit safepoint they will block until the
reload operation is finished.
Mutators that are not at a "reload safepoint" (e.g. executing Dart or VM
code) will be sent an OOB message indicating it should check into a
"reload safepoint". We assume mutators make progress until they can
process OOB message.
Mutators may run under a [NoReloadScope] when handling the OOM message.
In that case they will not check into the "reload safepoint" and simply
ignore the message. To ensure the thread will eventually check-in,
we'll make the destructor of [~NoReloadScope] check & send itself a new OOB
message indicating reload should happen. Eventually getting the mutator
to process the OOM message (which is a well-defined place where we can
check into the reload safepoint).
Non-isolate mutators such as the background compiler do not react to OOB
messages. This means that either those mutators have to be stopped (e.g.
bg compiler) before initiating a reload safepoint operation, the
threads have to explicitly opt-into participating in reload safepoints
or the threads have to deschedule themselves eventually.
Misc
----
Owning a reload safepoint operation implies also owning the deopt &
gc safepoint operation. Yet some code would like to ensure it actually
runs under a [DeoptSafepointOperatoinScope]/[GCSafepointOperationScope].
=> The `Thread::OwnsGCSafepoint()` handles that.
While performing hot-reload we may exercise common code (e.g. kernel
loader, ...) that acquires safepoint locks. Normally it's disallows to
acquire safepoint locks while holding a safepoint operation (since
mutators may be stopped at places where they hold locks, creating
deadlock scenarios).
=> We explicitly opt code into participating in reload safepointing
requests. Those well-defined places aren't holding safepoint locks.
=> The `Thread::CanAcquireSafepointLocks()` will return `true` despite
owning a reload operation. (But if one also holds deopt/gc safepoint
operation it will return false)
Example where this matters: As part of hot-reload, we load kernel which
may create new symbols. The symbol creation code may acquire the symbol
lock and `InsertNewOrGet()` a symbol. This is safe as other mutators
don't hold the symbol lock at reload safepoints. The same cannot be said
for Deopt/GC safepoint operations - as they can interrupt code at many
more places where there's no guarantee that no locks are held.
[0] https://dart-review.googlesource.com/c/sdk/+/187461
[1] https://dart-review.googlesource.com/c/sdk/+/196927
Issue https://github.com/flutter/flutter/issues/124546
TEST=Newly added Reload_* tests.
Change-Id: I6842d7d2b284d043cc047fd702b7c5c7dd1fa3c5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/296183
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
An embedder (or the VM) can exit an isolate via `Thread::ExitIsolate()`
at a point where there's still active state (e.g. dart frames).
Because of this the VM has so far conservatively retained the [Thread]
object of dart mutators throughout the isolate's lifetime. After which
is was manually `delete`ed. We'd never re-use those [Thread] objects (we
do re-use [Thread] objects of non-dart-mutator threads).
When exiting via `Thread::ExitIsolate()` with active state, the mutator
was assumed to be at-safepoint at all levels. It was removed from the
thread registry's active threads. This also means that when e.g. GC runs
it can't use the thread registry to find all active threads it may
need to scan, instead it uses [Isolate::mutator_thread_] of all isolates.
This causes a variety of subtle issues, but the main one that motivated
this change is the following:
If a thread obtains a safepoint operation it means all other mutators
are parked. The thread owning the safepoint can do whatever it likes.
When introducing reload operation safepoints, a thread may want to
ReloadSafepointOperation reload(thread);
...
// Compile sources.
{
TransitionVMToNative transition(thread);
// Will temporarily exit & re-enter current isolate.
response_port = Dart_NewNativePort();
Dart_PostCObject(kernel_isolate_port, ...);
// Wait on [response_port] for response.
}
This will cause the reloading thread to own the reload safepoint
operation but still transition states and even exit/re-enter the
isolate. Though this is currently not possible in the way enter/exit is
implemented.
So we'll refactor this fragile code in the following way:
* Move thread enter/exit logic entirely to the [Thread] object.
* Keep used threads in the thread registry's active list.
=> This allows us to keep various state on the [Thread] and thereby
avoids clearing it when suspending & re-initialing it when resuming
=> It makes nested `Thread::ExitIsolate()` faster as we mainly have
to enter safepoint (avoid acquiring threads lock, avoid releasing
storebuffers, ...)
=> It makes nested `Thread::EnterIsolate()` faster as we mainly have
to leave the safepoint (avoid acquiring threads lock, avoid acquiring
storebuffers, ...).
=> A mutator can now own a safepoint operation (e.g. reload safepoint
operation) and still `ExitSafepoint()` / `EnterSafepoint()` safely -
as those are based on the normal `EnterSafepoint()` and
`LeaveSafepoint()` APIs.
* We separate
- Suspend & Resume of a dart mutator (possibly with active stack)
- Setup & Reset of state only relevant for dart mutators
- Setup & Reset of state relevant for any mutator
* We unify how the [Thread] objects are freed between dart mutator and
non-dart mutators: [Thread] objects without state can be given back to
the [ThreadRegistry] and re-used (instead of being deleted in
`Isolate::~Isolate`)
* We have capability to free [Thread] objects if a dart mutator has an
empty stack & re-use for another isolate of the same group.
(In future we may have N Thread objects for N cores and the threads
would even maintain their TLABs when switching between isolates)
* Since we allow reusing of [Thread] objects also for dart mutators now,
we have extensive asserts to ensure they are "clean" when they get
into the free list and come out "clean" again.
TEST=ci
Change-Id: Id85e8e484efd98d28e323b33795716420e619986
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/296585
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
This is a reland of commit 87810072db
Original change's description:
> [vm] Account for changes in the implicit getters due to load guards
>
> Hot reload may mark certain fields as 'needs_load_guard', meaning
> types of their values should be checked on access, in the implicit
> getters.
>
> Unoptimized code for implicit getters of such fields should be
> forcefully recompiled during hot reload in order to update their
> code. This ensures that optimized code in future can deoptimize
> into the updated unoptimized code of implicit getters.
TEST=vm/cc/IsolateReload_ImplicitGetterWithLoadGuard
TEST=corelib/string_fromcharcodes_test, lib/convert/json_utf8_chunk_test
and vm/dart/string_equals_test on vm-reload-linux-{debug,release}-x64
configurations.
Fixes https://github.com/dart-lang/sdk/issues/51215
Fixes https://github.com/flutter/flutter/issues/103268
Change-Id: I22eb0f7addce387e7773e45c170c3f9050003083
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/282807
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
This reverts commit 87810072db.
Reason for revert: breaks hot reload test case in Flutter,
reverting as temporary workaround to https://github.com/flutter/flutter/issues/120091.
Original change's description:
> [vm] Account for changes in the implicit getters due to load guards
>
> Hot reload may mark certain fields as 'needs_load_guard', meaning
> types of their values should be checked on access, in the implicit
> getters.
>
> Unoptimized code for implicit getters of such fields should be
> forcefully recompiled during hot reload in order to update their
> code. This ensures that optimized code in future can deoptimize
> into the updated unoptimized code of implicit getters.
>
> TEST=vm/cc/IsolateReload_ImplicitGetterWithLoadGuard
> TEST=corelib/string_fromcharcodes_test, lib/convert/json_utf8_chunk_test
> and vm/dart/string_equals_test on vm-reload-linux-{debug,release}-x64
> configurations.
>
> Fixes https://github.com/dart-lang/sdk/issues/51215
> Fixes https://github.com/flutter/flutter/issues/103268
>
> Change-Id: I1afbeabb4a60b7a5f69ed055f40beeb6d3dcf359
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/280401
> Reviewed-by: Martin Kustermann <kustermann@google.com>
> Commit-Queue: Alexander Markov <alexmarkov@google.com>
> Reviewed-by: Ryan Macnak <rmacnak@google.com>
# Not skipping CQ checks because original CL landed > 1 day ago.
Change-Id: Ia7dba382547cceb38524707f9ecef892016108de
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/281220
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Zach Anderson <zra@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Hot reload may mark certain fields as 'needs_load_guard', meaning
types of their values should be checked on access, in the implicit
getters.
Unoptimized code for implicit getters of such fields should be
forcefully recompiled during hot reload in order to update their
code. This ensures that optimized code in future can deoptimize
into the updated unoptimized code of implicit getters.
TEST=vm/cc/IsolateReload_ImplicitGetterWithLoadGuard
TEST=corelib/string_fromcharcodes_test, lib/convert/json_utf8_chunk_test
and vm/dart/string_equals_test on vm-reload-linux-{debug,release}-x64
configurations.
Fixes https://github.com/dart-lang/sdk/issues/51215
Fixes https://github.com/flutter/flutter/issues/103268
Change-Id: I1afbeabb4a60b7a5f69ed055f40beeb6d3dcf359
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/280401
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
The representation of record shape in record instances and record
types is changed from a pair
int num_fields
Array field_names
to a single integer - packed bitfield
int num_fields(16)
int field_names_index(kSmiBits-16)
where field names index is an index in the array available from
ObjectStore.
With the new representation of record shapes:
1) Size of record instances is reduced.
2) Number of comparisons for a shape test reduced from 2 to 1
(shape test is used during type checks).
3) A few operations removed from Record.hashCode.
4) Type testing stubs (TTS) are now supported for record types with
named fields. Previously it was not possible to check shape of records
with named fields in TTS as TTS cannot access object pool and cannot
load field names array).
TEST=existing
Issue: https://github.com/dart-lang/sdk/issues/49719
Change-Id: I7cdcbb53938aba5d561cd24dc99530395dbbea7e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/276201
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
- Flip flag to make strong null safety the default
- Remove code that auto detects null safety mode from source files,
it is necessary to specify --no-strong-null-safety to opt out.
- Retains sniffing of AOT/JIT snapshots and kernel files to determine
null safety mode, the opt out has to be done when generating these
file.
TEST=ci
Change-Id: If2c9608eedb7c46d9c3cd85e261ee9640e0d28eb
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/261140
Reviewed-by: Alexander Thomas <athom@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Siva Annamalai <asiva@google.com>
Reviewed-by: Sigmund Cherem <sigmund@google.com>
'is' tests against record types are split into series of 'is' tests of
record fields. This is more efficient as record instances cannot be
added to subtype test caches (because type of a record instance
depends on types of its fields).
This change also adds canonicalization and constant evaluation of
LoadFieldInstr for record fields.
Performance on a trivial micro-benchmark (on x64):
JIT (RunTime): 4519104.5 -> 20031.5
AOT (RunTime): 4352583.0 -> 26281.6
TEST=ci
Issue: https://github.com/dart-lang/sdk/issues/49719
Change-Id: I2ed464cd3b31f365b17805f4e7debe1d6d1051fa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/268080
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Instead apply the same approach as we do in AOT: unbox based on the
static type information. There are no TFA results available in JIT,
but we could still unbox fields when running in sound null-safety.
TEST=ci
Cq-Include-Trybots: luci.dart.try:vm-kernel-reload-linux-release-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-reload-rollback-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-nnbd-linux-release-simarm64-try,vm-kernel-linux-debug-simriscv64-try,vm-kernel-precomp-linux-debug-simriscv64-try,vm-kernel-nnbd-linux-release-ia32-try,vm-kernel-nnbd-linux-debug-x64-try,vm-kernel-nnbd-linux-debug-ia32-try,vm-kernel-nnbd-linux-release-simarm-try,vm-kernel-nnbd-linux-release-simarm64-try
Change-Id: Ide2e78c6659261ef8d245a4586cf699ea0fbb459
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/256211
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
* Merge ClassTable and SharedClassTable back together;
* Simplify handling of multiple arrays growing in sync;
* Refactor how reload deals with ClassTable.
The last change is the most important because it makes it
much easier to reason about the code. We move away from
copying bits and pieces of the class table and shared
class table into reload contexts.
Having two class table fields in the isolate group makes
it easier to reason about. One field contains program
class table (one modified by kernel loader and accessed
by various program structure cid lookups) and heap
walk class table (used by GC visitors). Normally these
two fields point to the same class table, but during
hot reload we temporary split them apart: original
class table is kept as a heap walk class table, while
program class table is replaced by a clone and updated
by reload.
If reload succeeds we drop original class table and
set program class table as heap walk one.
If reload fails we drop the program class table and
restore original one from heap walk table.
TEST=ci
Cq-Include-Trybots: luci.dart.try:vm-kernel-reload-linux-release-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-reload-rollback-linux-release-x64-try,vm-kernel-linux-debug-x64-try,vm-kernel-precomp-tsan-linux-release-x64-try,vm-kernel-tsan-linux-release-x64-try,vm-kernel-precomp-asan-linux-release-x64-try,vm-kernel-asan-linux-release-x64-try
Change-Id: I8b66259fcc474dea7dd2af063e4772df99be06c4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/258361
Commit-Queue: Slava Egorov <vegorov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
The new implementation is based on suspend/resume stubs and doesn't
use desugaring of async functions on kernel AST.
Previously, new implementation of async/async* was only supported in
AOT mode. This change adds all necessary bits for the JIT mode:
* Suspending variable-length frames (for unoptimized code).
* Handling of Code and pool pointers in Dart stack frames.
* OSR.
* Deoptimization.
* Hot reload.
* Debugger.
The new implementation is not enabled in JIT mode yet.
Design doc: go/compact-async-await.
TEST=ci
Issue: https://github.com/dart-lang/sdk/issues/48378
Change-Id: I477d6684bdce7cbc1edb179ae2271ff598b7dcc5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/246081
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
4 instances of the following issue: redundant get() call on smart pointer
Tested: Only through CI. There are no changes in behavior, all possible problems would be found through a compilation failure.
Change-Id: Ib11432baef83d3daebd800b365183e1ea6621136
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/240540
Reviewed-by: Aske Simon Christensen <askesc@google.com>
Commit-Queue: Oleh Prypin <oprypin@google.com>
These GCs usually did not free very much memory but did consume a lot of CPU. They would on low-powered, low-memory devices often take ~1s, during which time the OS might decide the OOM signal wasn't working and kill us before the compaction can complete and free pages. Instead, only release pooled memory.
Also use more appropriate GCReasons in calls of CollectMost/AllGarbage.
TEST=ci
Bug: b/216333343
Change-Id: Ia56b9ca409410f17d40508c69fb1bc9df0ce4028
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/235300
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Alexander Markov