hal/HalWakeLock.cpp
author Gregory Szorc <gps@mozilla.com>
Thu, 19 Feb 2015 10:58:41 -0800
changeset 245738 c97c977c92b97c9585011651b13a088f0cd4ed4f
parent 207493 932a92a16c29d31db9bb9b1bed8d9d20844ce405
child 252249 ac4464790ec4896a5188fa50cfc69ae0ffeddc08
permissions -rw-r--r--
Bug 1132771 - moz.build fixups to enable execution in no config mode Various moz.build files fail to execute when a build config is not present. Many of these are due to assuming certain CONFIG entries are present. This patch attempts to fix that and enable every moz.build to be read without a build config.

/* -*- 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 "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