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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "mozilla/ipc/IdleSchedulerChild.h"
#include "mozilla/ipc/IdleSchedulerParent.h"
#include "mozilla/ipc/PBackgroundChild.h"
#include "mozilla/Atomics.h"
#include "mozilla/IdlePeriodState.h"
#include "mozilla/Telemetry.h"
#include "BackgroundChild.h"
namespace mozilla::ipc {
static IdleSchedulerChild* sMainThreadIdleScheduler = nullptr;
static bool sIdleSchedulerDestroyed = false;
IdleSchedulerChild::~IdleSchedulerChild() {
if (sMainThreadIdleScheduler == this) {
sMainThreadIdleScheduler = nullptr;
sIdleSchedulerDestroyed = true;
}
MOZ_ASSERT(!mIdlePeriodState);
}
void IdleSchedulerChild::Init(IdlePeriodState* aIdlePeriodState) {
mIdlePeriodState = aIdlePeriodState;
RefPtr<IdleSchedulerChild> scheduler = this;
auto resolve =
[&](std::tuple<mozilla::Maybe<SharedMemoryHandle>, uint32_t>&& aResult) {
if (std::get<0>(aResult)) {
mActiveCounter.SetHandle(std::move(*std::get<0>(aResult)), false);
mActiveCounter.Map(sizeof(int32_t));
mChildId = std::get<1>(aResult);
if (mChildId && mIdlePeriodState && mIdlePeriodState->IsActive()) {
SetActive();
}
}
};
auto reject = [&](ResponseRejectReason) {};
SendInitForIdleUse(std::move(resolve), std::move(reject));
}
IPCResult IdleSchedulerChild::RecvIdleTime(uint64_t aId, TimeDuration aBudget) {
if (mIdlePeriodState) {
mIdlePeriodState->SetIdleToken(aId, aBudget);
}
return IPC_OK();
}
void IdleSchedulerChild::SetActive() {
if (mChildId && CanSend() && mActiveCounter.memory()) {
++(static_cast<Atomic<int32_t>*>(
mActiveCounter.memory())[NS_IDLE_SCHEDULER_INDEX_OF_ACTIVITY_COUNTER]);
++(static_cast<Atomic<int32_t>*>(mActiveCounter.memory())[mChildId]);
}
}
bool IdleSchedulerChild::SetPaused() {
if (mChildId && CanSend() && mActiveCounter.memory()) {
--(static_cast<Atomic<int32_t>*>(mActiveCounter.memory())[mChildId]);
// The following expression reduces the global activity count and checks if
// it drops below the cpu counter limit.
return (static_cast<Atomic<int32_t>*>(
mActiveCounter
.memory())[NS_IDLE_SCHEDULER_INDEX_OF_ACTIVITY_COUNTER])-- ==
static_cast<Atomic<int32_t>*>(
mActiveCounter.memory())[NS_IDLE_SCHEDULER_INDEX_OF_CPU_COUNTER];
}
return false;
}
RefPtr<IdleSchedulerChild::MayGCPromise> IdleSchedulerChild::MayGCNow() {
if (mIsRequestingGC || mIsDoingGC) {
return MayGCPromise::CreateAndResolve(false, __func__);
}
mIsRequestingGC = true;
return SendRequestGC()->Then(
GetMainThreadSerialEventTarget(), __func__,
[self = RefPtr(this)](bool aIgnored) {
// Only one of these may be true at a time.
MOZ_ASSERT(!(self->mIsRequestingGC && self->mIsDoingGC));
// The parent process always says yes, sometimes after a delay.
if (self->mIsRequestingGC) {
self->mIsRequestingGC = false;
self->mIsDoingGC = true;
return MayGCPromise::CreateAndResolve(true, __func__);
}
return MayGCPromise::CreateAndResolve(false, __func__);
},
[self = RefPtr(this)](ResponseRejectReason reason) {
self->mIsRequestingGC = false;
return MayGCPromise::CreateAndReject(reason, __func__);
});
}
void IdleSchedulerChild::StartedGC() {
// Only one of these may be true at a time.
MOZ_ASSERT(!(mIsRequestingGC && mIsDoingGC));
// If mRequestingGC was true then when the outstanding GC request returns
// it'll see that the GC has already started.
mIsRequestingGC = false;
if (!mIsDoingGC) {
if (CanSend()) {
SendStartedGC();
}
mIsDoingGC = true;
}
}
void IdleSchedulerChild::DoneGC() {
if (mIsDoingGC) {
if (CanSend()) {
SendDoneGC();
}
mIsDoingGC = false;
}
}
IdleSchedulerChild* IdleSchedulerChild::GetMainThreadIdleScheduler() {
MOZ_ASSERT(NS_IsMainThread());
if (sMainThreadIdleScheduler) {
return sMainThreadIdleScheduler;
}
if (sIdleSchedulerDestroyed) {
return nullptr;
}
ipc::PBackgroundChild* background =
ipc::BackgroundChild::GetOrCreateForCurrentThread();
if (background) {
// this is nulled out on our destruction, so we don't need to worry
sMainThreadIdleScheduler = new ipc::IdleSchedulerChild();
MOZ_ALWAYS_TRUE(
background->SendPIdleSchedulerConstructor(sMainThreadIdleScheduler));
}
return sMainThreadIdleScheduler;
}
} // namespace mozilla::ipc