Android/frameworks_base
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

DO NOT MERGE Don't lock listener delivery

Browse Source 
Previous versions of GNSS listeners commited to not holding locks even
when running directly unfortunately. We do some extra work to avoid
holding locks while running listeners.

Bug: 151291181
Test: manual
Change-Id: I0b7f46c30df2f97ce11db45b69443a9994885309
This commit is contained in:
Soonil Nagarkar
2020-03-18 19:17:52 -07:00
parent 2490ec4d13
commit 8aea09fecd
1 changed files with 23 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
location/java/android/location/AbstractListenerManager.java
View File

@@ -85,11 +85,13 @@ abstract class AbstractListenerManager<TRequest, TListener> {
}
}
@GuardedBy("mListeners")
private final ArrayMap<Object, Registration<TRequest, TListener>> mListeners =
private final Object mLock = new Object();
@GuardedBy("mLock")
private volatile ArrayMap<Object, Registration<TRequest, TListener>> mListeners =
new ArrayMap<>();
@GuardedBy("mListeners")
@GuardedBy("mLock")
@Nullable
private TRequest mMergedRequest;
@@ -129,10 +131,16 @@ abstract class AbstractListenerManager<TRequest, TListener> {
throws RemoteException {
Preconditions.checkNotNull(registration);
synchronized (mListeners) {
synchronized (mLock) {
boolean initialRequest = mListeners.isEmpty();
Registration<TRequest, TListener> oldRegistration = mListeners.put(key, registration);
ArrayMap<Object, Registration<TRequest, TListener>> newListeners = new ArrayMap<>(
mListeners.size() + 1);
newListeners.putAll(mListeners);
Registration<TRequest, TListener> oldRegistration = newListeners.put(key,
registration);
mListeners = newListeners;
if (oldRegistration != null) {
oldRegistration.unregister();
}
@@ -151,8 +159,12 @@ abstract class AbstractListenerManager<TRequest, TListener> {
}
public void removeListener(Object listener) throws RemoteException {
synchronized (mListeners) {
Registration<TRequest, TListener> oldRegistration = mListeners.remove(listener);
synchronized (mLock) {
ArrayMap<Object, Registration<TRequest, TListener>> newListeners = new ArrayMap<>(
mListeners);
Registration<TRequest, TListener> oldRegistration = newListeners.remove(listener);
mListeners = newListeners;
if (oldRegistration == null) {
return;
}
@@ -190,18 +202,16 @@ abstract class AbstractListenerManager<TRequest, TListener> {
}
protected void execute(Consumer<TListener> operation) {
synchronized (mListeners) {
for (Registration<TRequest, TListener> registration : mListeners.values()) {
registration.execute(operation);
}
for (Registration<TRequest, TListener> registration : mListeners.values()) {
registration.execute(operation);
}
}
@GuardedBy("mListeners")
@GuardedBy("mLock")
@SuppressWarnings("unchecked")
@Nullable
private TRequest mergeRequests() {
Preconditions.checkState(Thread.holdsLock(mListeners));
Preconditions.checkState(Thread.holdsLock(mLock));
if (mListeners.isEmpty()) {
return null;