gecko-dev/hal/HalWakeLock.cpp

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/* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/Hal.h"
#include "mozilla/HalWakeLock.h"
#include "mozilla/Services.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/dom/ContentParent.h"
#include "nsClassHashtable.h"
#include "nsDataHashtable.h"
#include "nsHashKeys.h"
#include "nsIPropertyBag2.h"
#include "nsIObserverService.h"
using namespace mozilla;
using namespace mozilla::hal;
namespace {
struct LockCount {
LockCount()
: numLocks(0)
, numHidden(0)
{}
uint32_t numLocks;
uint32_t numHidden;
nsTArray<uint64_t> processes;
};
typedef nsDataHashtable<nsUint64HashKey, LockCount> ProcessLockTable;
typedef nsClassHashtable<nsStringHashKey, ProcessLockTable> LockTable;
int sActiveListeners = 0;
StaticAutoPtr<LockTable> sLockTable;
bool sInitialized = false;
bool sIsShuttingDown = false;
WakeLockInformation
WakeLockInfoFromLockCount(const nsAString& aTopic, const LockCount& aLockCount)
{
// TODO: Once we abandon b2g18, we can switch this to use the
// WakeLockInformation constructor, which is better because it doesn't let us
// forget to assign a param. For now we have to do it this way, because
// b2g18 doesn't have the nsTArray <--> InfallibleTArray conversion (bug
// 819791).
WakeLockInformation info;
info.topic() = aTopic;
info.numLocks() = aLockCount.numLocks;
info.numHidden() = aLockCount.numHidden;
info.lockingProcesses().AppendElements(aLockCount.processes);
return info;
}
PLDHashOperator
CountWakeLocks(const uint64_t& aKey, LockCount aCount, void* aUserArg)
{
MOZ_ASSERT(aUserArg);
LockCount* totalCount = static_cast<LockCount*>(aUserArg);
totalCount->numLocks += aCount.numLocks;
totalCount->numHidden += aCount.numHidden;
// This is linear in the number of processes, but that should be small.
if (!totalCount->processes.Contains(aKey)) {
totalCount->processes.AppendElement(aKey);
}
return PL_DHASH_NEXT;
}
static PLDHashOperator
RemoveChildFromList(const nsAString& aKey, nsAutoPtr<ProcessLockTable>& aTable,
void* aUserArg)
{
MOZ_ASSERT(aUserArg);
PLDHashOperator op = PL_DHASH_NEXT;
uint64_t childID = *static_cast<uint64_t*>(aUserArg);
if (aTable->Get(childID, nullptr)) {
aTable->Remove(childID);
LockCount totalCount;
aTable->EnumerateRead(CountWakeLocks, &totalCount);
if (!totalCount.numLocks) {
op = PL_DHASH_REMOVE;
}
if (sActiveListeners) {
NotifyWakeLockChange(WakeLockInfoFromLockCount(aKey, totalCount));
}
}
return op;
}
class ClearHashtableOnShutdown MOZ_FINAL : public nsIObserver {
~ClearHashtableOnShutdown() {}
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIOBSERVER
};
NS_IMPL_ISUPPORTS(ClearHashtableOnShutdown, nsIObserver)
NS_IMETHODIMP
ClearHashtableOnShutdown::Observe(nsISupports* aSubject, const char* aTopic, const char16_t* data)
{
MOZ_ASSERT(!strcmp(aTopic, "xpcom-shutdown"));
sIsShuttingDown = true;
sLockTable = nullptr;
return NS_OK;
}
class CleanupOnContentShutdown MOZ_FINAL : public nsIObserver {
~CleanupOnContentShutdown() {}
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIOBSERVER
};
NS_IMPL_ISUPPORTS(CleanupOnContentShutdown, nsIObserver)
NS_IMETHODIMP
CleanupOnContentShutdown::Observe(nsISupports* aSubject, const char* aTopic, const char16_t* data)
{
MOZ_ASSERT(!strcmp(aTopic, "ipc:content-shutdown"));
if (sIsShuttingDown) {
return NS_OK;
}
nsCOMPtr<nsIPropertyBag2> props = do_QueryInterface(aSubject);
if (!props) {
NS_WARNING("ipc:content-shutdown message without property bag as subject");
return NS_OK;
}
uint64_t childID = 0;
nsresult rv = props->GetPropertyAsUint64(NS_LITERAL_STRING("childID"),
&childID);
if (NS_SUCCEEDED(rv)) {
sLockTable->Enumerate(RemoveChildFromList, &childID);
} else {
NS_WARNING("ipc:content-shutdown message without childID property");
}
return NS_OK;
}
void
Init()
{
sLockTable = new LockTable();
sInitialized = true;
nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
if (obs) {
obs->AddObserver(new ClearHashtableOnShutdown(), "xpcom-shutdown", false);
obs->AddObserver(new CleanupOnContentShutdown(), "ipc:content-shutdown", false);
}
}
} // anonymous namespace
namespace mozilla {
namespace hal {
WakeLockState
ComputeWakeLockState(int aNumLocks, int aNumHidden)
{
if (aNumLocks == 0) {
return WAKE_LOCK_STATE_UNLOCKED;
} else if (aNumLocks == aNumHidden) {
return WAKE_LOCK_STATE_HIDDEN;
} else {
return WAKE_LOCK_STATE_VISIBLE;
}
}
} // namespace hal
namespace hal_impl {
void
EnableWakeLockNotifications()
{
sActiveListeners++;
}
void
DisableWakeLockNotifications()
{
sActiveListeners--;
}
void
ModifyWakeLock(const nsAString& aTopic,
hal::WakeLockControl aLockAdjust,
hal::WakeLockControl aHiddenAdjust,
uint64_t aProcessID)
{
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(aProcessID != CONTENT_PROCESS_ID_UNKNOWN);
if (sIsShuttingDown) {
return;
}
if (!sInitialized) {
Init();
}
ProcessLockTable* table = sLockTable->Get(aTopic);
LockCount processCount;
LockCount totalCount;
if (!table) {
table = new ProcessLockTable();
sLockTable->Put(aTopic, table);
} else {
table->Get(aProcessID, &processCount);
table->EnumerateRead(CountWakeLocks, &totalCount);
}
MOZ_ASSERT(processCount.numLocks >= processCount.numHidden);
MOZ_ASSERT(aLockAdjust >= 0 || processCount.numLocks > 0);
MOZ_ASSERT(aHiddenAdjust >= 0 || processCount.numHidden > 0);
MOZ_ASSERT(totalCount.numLocks >= totalCount.numHidden);
MOZ_ASSERT(aLockAdjust >= 0 || totalCount.numLocks > 0);
MOZ_ASSERT(aHiddenAdjust >= 0 || totalCount.numHidden > 0);
WakeLockState oldState = ComputeWakeLockState(totalCount.numLocks, totalCount.numHidden);
bool processWasLocked = processCount.numLocks > 0;
processCount.numLocks += aLockAdjust;
processCount.numHidden += aHiddenAdjust;
totalCount.numLocks += aLockAdjust;
totalCount.numHidden += aHiddenAdjust;
if (processCount.numLocks) {
table->Put(aProcessID, processCount);
} else {
table->Remove(aProcessID);
}
if (!totalCount.numLocks) {
sLockTable->Remove(aTopic);
}
if (sActiveListeners &&
(oldState != ComputeWakeLockState(totalCount.numLocks,
totalCount.numHidden) ||
processWasLocked != (processCount.numLocks > 0))) {
WakeLockInformation info;
hal::GetWakeLockInfo(aTopic, &info);
NotifyWakeLockChange(info);
}
}
void
GetWakeLockInfo(const nsAString& aTopic, WakeLockInformation* aWakeLockInfo)
{
if (sIsShuttingDown) {
NS_WARNING("You don't want to get wake lock information during xpcom-shutdown!");
*aWakeLockInfo = WakeLockInformation();
return;
}
if (!sInitialized) {
Init();
}
ProcessLockTable* table = sLockTable->Get(aTopic);
if (!table) {
*aWakeLockInfo = WakeLockInfoFromLockCount(aTopic, LockCount());
return;
}
LockCount totalCount;
table->EnumerateRead(CountWakeLocks, &totalCount);
*aWakeLockInfo = WakeLockInfoFromLockCount(aTopic, totalCount);
}
} // hal_impl
} // mozilla