At the moment, the whole WebAssembly compilation may run in a single
background task. On a low-end device, this can mean that the background
thread is busy for seconds and thereby blocks other tasks, see e.g.
https://crbug.com/914757.
With this CL we re-schedule compilation tasks after every 50ms. These
50ms are an arbitrary number. I don't want to introduce too much
overhead, but since this is in the background we also don't have to
make tasks super short.
Tasks which are going to compile with TurboFan will be posted with
lower priority.
This change requires changes in the CancelableTaskManager. At the
moment it is not possible that a background task posts a new task
which is managed by the same task manager as itself. The problem is
about how to deal with another thread which calls CancelAndWait
concurrently. At the moment, if a new task gets posted after the call
to CancelAndWait, then `CHECK(!canceled_)` in
CancelableTaskManager::Register will fail. If we used a lock to
synchronize the calls to CancelAndWait and Register, then there would
be a deadlock, where the thread which calls CancelAndWait waits for
the task which wants to call Register, but at the same time blocks that
task by holding the lock.
With the change here, posting a task after the call to CancelAndWait
will just immediately cancel the new task. This matches the behavior
you would get if CancelAndWait is called right after calling Register.
Bug: chromium:914757
Change-Id: I6d57aba161db8a915ec0d745658e0c28d25219a8
Reviewed-on: https://chromium-review.googlesource.com/c/1411884
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58898}
Implement similar functionality in the unit test which used this field.
One test gets slightly weaker by this.
R=mstarzinger@chromium.org
Bug: v8:8238
Change-Id: I0b047ff54f08a4549a2f78af30e21296bb1ee63f
Reviewed-on: https://chromium-review.googlesource.com/c/1327042
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57403}
1) Use own test fixture {CancelableTaskManagerTest}.
2) Avoid base::AtomicWord.
3) Use unique_ptr.
4) Fix order of expected and actual values in EXPECT_EQ.
R=mstarzinger@chromium.org
Bug: v8:8238
Change-Id: I3d29785864bbf3de58c5d9d5384b9e0065255e99
Reviewed-on: https://chromium-review.googlesource.com/c/1325967
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57378}
It's too easy to implicitly cast it to bool, as we did in several tests.
Also, move TryAbortResult out of CancelableTaskManager to avoid too much
typing when referencing one of the enum values.
R=mstarzinger@chromium.org
Bug: v8:8238
Change-Id: Ia3fa8597428876217bc86f9b8b31c21ae4846fa1
Reviewed-on: https://chromium-review.googlesource.com/c/1326027
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57363}
They were only limited to 32 bit when using the internal Hashmap. Since
this has changed alreay some time ago, we can switch to 64 bit ids and
check that we never overflow.
Bug:
Change-Id: Ia6c6d02d6b5e555c6941185a79427dc4aa2a1d62
Reviewed-on: https://chromium-review.googlesource.com/598229
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47085}
This change binds each {Cancelable} task to a so-called {CancelableTaskManager},
which is then used to handle concurrent cancelation as well as synchronizing
shutdown for already running tasks. Since ownership of tasks is transferred to
the platform executing a task (destructor), handling in the manager uses integer
ids. Note that this also mitigates (modulo integer size) the ABA problem.
All handling of {Cancelable} tasks is now encapsulated into the corresponding
manager, which is instantiated for each isolate.
R=hpayer@chromium.org
BUG=chromium:524425
LOG=N
CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg;tryserver.v8:v8_linux_gc_stress_dbg;tryserver.v8:v8_mac_gc_stress_dbg;tryserver.v8:v8_linux64_msan_rel;tryserver.v8:v8_linux64_tsan_rel;tryserver.v8:v8_mac64_asan_rel
Review URL: https://codereview.chromium.org/1409993012
Cr-Commit-Position: refs/heads/master@{#31997}
