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>
The sweeper threads are bypassing safepoints and have no need for normal
mutator state (e.g. storebuffer, marking stacks, .,..) on the [Thread]
object.
This fixes a TSAN report where sweeper would clear reusable handles
(which it didn't actually modify) and scavenger is reading those
handles (which arguably it doesn't have to either).
Issue https://github.com/dart-lang/sdk/issues/52125
TEST=ci
Change-Id: I03a36e8518b6c00eb7f3b57f65fd469dddba23e0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/296860
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>
Some cleanups factored out of a larger CL (which refactors enter/exit of threads):
* remove unused `#include "vm/thread_registry.h"`
* remove unused/unnecessary fields from [Thread] object
* rename IsMutator() -> IsDartMutator()
* make tests using setjmp() drain the sticky error
=> to ensure there's no sticky error on isolate shutdown
TEST=ci
Change-Id: I53935e8bd0628ab3768627d6d5e01c3f0e3a57ad
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/296582
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
For every isolate there should be only one mutator with
a unique [Thread] object.
We change existing tests that use this functionality to instead use
`Thread::{Enter,Exit}IsolateGroupAsHelper`. It also results in a net
removal of code.
TEST=ci
Change-Id: Ic326e868a98ddedbab5b8c429252d38ea71bbf04
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/295940
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
During safepoint we can distinguish between
* owner of the safepoint operation (which is running code)
* everyone else (which are all blocked
Currently `Thread::IsAtSafepoint()` will return true for both. Since the
thread owning the safepoint operation is running, it's not actually
guaranteed that it's at "safe" point (e.g. to GC or to deopt) - it
really depends on what it's doing.
=> This CL will change it so that only actually parked threads will
have `Thread::IsAtSafepoint()`.
In order to do that we change varrious usages of `IsAtSafepoint()` to be
more precise:
* `Thread::OwnsSafepoint()`: True if this thread owns the
active safepoint. The thread is running.
* `Thread::OwnsGCSafepoint()`: True if the active safepoint is a GC
(or Deopt) safepoint and this thread owns it. The thread is running.
* `Thread::OwnsDeoptSafepoint()`: True if the active safepoint is a
Deopt safepoint and this thread owns it. The thread is running.
* `Thread::CanAcquireSafepointLocks()`: True if the thread is allowed
to acquire safepoint locks.
* `Thread::IsAtSafepoint()`: true if this thread is parked at a
safepoint
TEST=ci
Change-Id: I1a5a6727e84843ae79e0a344c438da19b7d6d916
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/295781
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Right each `Pointer.fromFunction()` invocation will lead to creation of
a new ffi trampoline function & it's following JITed code. In AOT we
have exactly one ffi trampoline per target/native-signature/exceptional-return
combination.
=> This CL ensures we have only one such function.
Furthermore each `Pointer.fromFunction()` will currently perform 2
runtime calls in JIT: One to create a `Function` object, the other to
JIT that function & register callback metadata.
=> This CL ensures we won't do a runtime call to get a function, instead
do it at compile-time (as in AOT)
Furthermore we eagerly assign a callback-id to the unique/deduped ffi
trampoline callbacks. Only when the application requests a pointer, do
we populate metadata on the `Thread` object.
This CL doesn't (yet) change the fact that in JIT mode we have
isolate-specific jit trampolines (that will call now shared ffi trampoline
functions).
We also avoid baking in C++ runtime function pointers in generated
code. As a result we can now preserve ffi trampolines across AppJIT
serialization.
As a nice side-effect, we remove 100 lines of code.
TEST=ffi{,_2}/ffi_callback_unique_test
Issue https://github.com/dart-lang/sdk/issues/50611
Change-Id: I458831a47b041a088086f28f825de2a3849f6adc
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/273420
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
This CL introduces new embedding APIs for supporting heap sample
profiling. A registered sampling callback is invoked approximately every
N bytes based on an exponential distribution, providing information
about the isolate group the allocation occurred in, the user visible
name of the allocated object type, a weak persistent handle to the
allocated object, and the size of the allocation.
Sampling is triggered using artificial TLAB boundaries to cause
allocations to be sampled to take the allocation slow path where the
registered callback can be invoked with the allocation information.
Only new space allocations are currently traced, with old space
allocation support to be added in a future CL.
TEST=Dart_HeapSampling
Change-Id: I22bcdeec6e823bc1ab44898d4c596fbed7169fa1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/264520
Commit-Queue: Ben Konyi <bkonyi@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Enable concurrent marking for IA32.
This removes the last write barrier relying on different alignment offsets for old and new space.
TEST=ci
Change-Id: Ib1c13124002392cf1c3ec264643325ec471a6918
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/262280
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: 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>
`MournFinalized` runs during marking and can add objects to the store
buffer. These objects are stored in the threads' store buffer block.
This block needs to be released to the central store buffer in order for
the objects' addresses to be updated during compacting.
TEST=runtime/vm/object_test.cc
TEST=tools/test.py vm/cc/Finalizer_Regress_48843
Closes: https://github.com/dart-lang/sdk/issues/48843
Change-Id: Ib2424929c86fee730d3f09fbd2f9f6c97f31abfd
Cq-Include-Trybots: luci.dart.try:vm-canary-linux-debug-try,vm-kernel-linux-debug-x64-try,vm-kernel-linux-debug-x64c-try,vm-kernel-mac-debug-x64-try,vm-kernel-win-debug-x64-try,vm-kernel-linux-release-x64-try,vm-kernel-linux-product-x64-try,vm-kernel-linux-debug-ia32-try,vm-kernel-linux-release-ia32-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/243262
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
If the popular store buffer targets are copied instead of promoted, the store buffer won't shrink and a second scavenge will occur that does promote them.
TEST=ci
Change-Id: I09fd7f263a2a9e99179af7ee58bc93335c4f5d05
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/241203
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Previously all arrays were excluded from WB elimination pass
to avoid invariant restoration code creating excessive work
for the GC and to avoid dealing with card marking in the
invariant restoration code.
It seems reasonable to enable this for small arrays of up to 8
elements. The cut of point of 8 elements was chosen based on the
cut of point for literal<N> specialisations provided by the
core library for creating small literal arrays.
TEST=vm/cc/IRTest_WriteBarrierElimination_Arrays
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-dwarf-linux-product-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64c-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-linux-release-simarm_x64-try,vm-kernel-precomp-linux-release-x64-try
Change-Id: I2b3169865f07c3ff95820c1bc6718943e96bd33b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/229903
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
Implements a backend targeting RV32GC and RV64GC, based on Linux standardizing around GC. The assembler is written to make it easy to disable usage of C, but because the sizes of some instruction sequences are compile-time constants, an additional build configuration would need to be defined to make use of it.
The assembler and disassembler cover every RV32/64GC instruction. The simulator covers all instructions except accessing CSRs and the floating point state accessible through such, include accrued exceptions and dynamic rounding mode.
Quirks:
- RISC-V is a compare-and-branch architecture, but some existing "architecture-independent" parts of the Dart compiler assume a condition code architecture. To avoid rewriting these parts, we use a peephole in the assembler to map to compare-and-branch. See Assembler::BranchIf. Luckily nothing depended on taking multiple branches on the same condition code set.
- There are no hardware overflow checks, so we must use Hacker's Delight style software checks. Often these are very cheap: if the sign of one operand is known, a single branch is needed.
- The ranges of RISC-V branches and jumps are such that we use 3 levels of generation for forward branches, instead of the 2 levels of near and far branches used on ARM[64]. Nearly all code is handled by the first two levels with 20-bits of range, with enormous regex matchers triggering the third level that uses aupic+jalr to get 32-bits of range.
- For PC-relative calls in AOT, we always generate auipc+jalr pairs with 32-bits of range, so we never generate trampolines.
- Only a subset of registers are available in some compressed instructions, so we assign the most popular uses to these registers. In particular, THR, TMP[2], CODE and PP. This has the effect of assigning CODE and PP to volatile registers in the C calling convention, whereas they are assigned preserved registers on the other architectures. As on ARM64, PP is untagged; this is so short indices can be accessed with a compressed instruction.
- There are no push or pop instructions, so combining pushes and pops is preferred so we can update SP once.
- The C calling convention has a strongly aligned stack, but unlike on ARM64 we don't need to use an alternate stack pointer. The author ensured language was added to the RISC-V psABI making the OS responsible for realigning the stack pointer for signal handlers, allowing Dart to leave the stack pointer misaligned from the C calling convention's point of view until a foreign call.
- We don't bother with the link register tracking done on ARM[64]. Instead we make use of an alternate link register to avoid inline spilling in the write barrier.
Unimplemented:
- non-trivial FFI cases
- Compressed pointers - No intention to implement.
- Unboxed SIMD - We might make use of the V extension registers when the V extension is ratified.
- BigInt intrinsics
TEST=existing tests for IL level, new tests for assembler/disassembler/simulator
Bug: https://github.com/dart-lang/sdk/issues/38587
Bug: https://github.com/dart-lang/sdk/issues/48164
Change-Id: I991d1df4be5bf55efec5371b767b332d37dfa3e0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/217289
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
TSAN instruments C++ code by adding prologue/epilogue code which
maintains a shadow stack. Using setjmp()/longjmp() is intercepted by
TSAN and correspondingly unwinds the shadow stack.
When Dart VM throws exceptions we call the JumpToFrame stub
from C++ which will directly reset the stack to the exception handler
catch entry. This leaves the TSAN shadow stack unchanged.
This means whenever an exception is thrown we leak frames in TSAN's
shadow stack. Due to using a fixed-size shadow stack, it will cause a
buffer-overflow in TSAN when too many such frame leaks happen. This can
cause arbitrary memory to be overriden, leading to awkward crashes.
This is especially an issue on the "iso-stres" builder because it
launches - in the same process - *many* small tests, more easily hitting
that limit.
This CL will workaround the TSAN issue by making runtime call save it's
state via setjmp() and make exception throughing process go via
longjmp() (which TSAN will intercept) before actually calling the
JumpToFrame stub.
=> This will ensure the TSAN shadow stack is correctly maintained.
The [jmp_buf]'s encoding of register state is non-trivial (e.g. it uses
XOR'ing of the actual saved state under certain glibc versions). So we
store any state we need to pass to the target of the `longjmp()` on the
[Thread] instead of overriding the [jmp_buf]s register state with the
arguments.
Issue https://github.com/dart-lang/sdk/issues/47472#issuecomment-948235479
TEST=vm/dart{,_2}/regress47472_test.dart
Change-Id: Ifbf6580aa15bcce54d0584cdc3cd18cc19be0a9c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/222300
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
Add a GCReason for store buffer overflow instead of using a separate print.
This is a pure refactoring that doesn't change GC policy.
TEST=ci
Change-Id: Idcd95b0701a36f45ebaa02db2c2fac9a9081d7c6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/215102
Reviewed-by: Liam Appelbe <liama@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
1) double.truncate() now simply calls toInt(), omitting
truncateToDouble() call.
2) double.floor() and ceil() are now intrinsified on arm64 and AOT/x64
and generated using DoubleToInteger instruction.
3) DoubleToInteger instruction is extended to support floor and ceil.
On arm64 DoubleToInteger is implemented using fcvtms and fcvtps
instructions. On x64 DoubleToInteger is implemented using roundsd
under a check if it is supported (with a fallback to a stub and a
runtime call).
AOT/x64:
Before: BenchFloor(RunTime): 318.82148549569655 us.
After: BenchFloor(RunTime): 133.29430189936687 us.
TEST=ci
Closes https://github.com/dart-lang/sdk/issues/46876
Closes https://github.com/dart-lang/sdk/issues/46650
Change-Id: I16ca18faf97954f8e8e25f0b72a2bbfac5bdc672
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/212381
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
In the unoptimized code unboxed double inputs are now unboxed in the
instruction prologue, and unboxed double output is boxed in the
instruction epilogue. Double values are still always boxed on the
expression stack in the unoptimized mode.
Support for unboxed doubles in unoptimized code allows us to have
one implementation of double and dart:math built-in functions,
shared across optimized and unoptimized modes.
TEST=ci
Issue: https://github.com/dart-lang/sdk/issues/46650
Change-Id: Ic1e42b72ee80cb2c12019b7abab8111240b05efd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/211302
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
This reverts commit 1796160606.
Reason for revert: Still seeing failures.
Original change's description:
> Reland "[ package:dds ] Add support for caching CPU samples based on UserTag"
>
> This reverts commit 4160747ef6.
>
> It seems like 9397b8ff05 should have fixed the original failures we were seeing and the failing bots in question seem to be passing when running try jobs.
>
> TBR=asiva@ (discussed offline)
>
> TEST=Existing service tests + get_cached_cpu_samples_test
> Change-Id: I1c50c0e79375df819a0bd68e68ac28c3064874c8
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/208441
> Reviewed-by: Ben Konyi <bkonyi@google.com>
> Commit-Queue: Ben Konyi <bkonyi@google.com>
TBR=bkonyi@google.com,asiva@google.com
Change-Id: Ic522ab61b430673533c94ecd0c91bee569a0add6
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/208960
Reviewed-by: Ben Konyi <bkonyi@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>
This reverts commit 4160747ef6.
It seems like 9397b8ff05 should have fixed the original failures we were seeing and the failing bots in question seem to be passing when running try jobs.
TBR=asiva@ (discussed offline)
TEST=Existing service tests + get_cached_cpu_samples_test
Change-Id: I1c50c0e79375df819a0bd68e68ac28c3064874c8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/208441
Reviewed-by: Ben Konyi <bkonyi@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>
DDS can be configured to listen for CPU sample events and cache samples
that were collected while certain UserTags are active. These cached
samples are stored in a ring buffer and are stored until the isolate
shuts down.
TEST=pkg/dds/test/get_cached_cpu_samples_test.dart
Change-Id: Ib20770f59f1672c703413486f87795b3bb23f676
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/207206
Commit-Queue: Ben Konyi <bkonyi@google.com>
Reviewed-by: Kenzie Schmoll <kenzieschmoll@google.com>
Alexander Aprelev