Update uid process state synchronously
ActivityTaskManagerService has a mirror ActiveUids. Originally it
may be updated to an intermediate state (e.g. UidRecord.reset) and
the uid state can be accessed before the actual value is set. That
leads to unexpected behavior depends on timing.
Now the mirror ActiveUids will only be updated when the actual uid
state is decided during updating oom-adj. And by acquiring window
manager's lock when updating oom-adj, it also synchronizes other
states with activity task manager. Although an additional lock is
held, it is possible to have benefit that reduces the frequency
of lock and unlock.
Also optimize the usage of priority booster by having an alias lock
with different type declaration, then the overhead of unnecessary
nested boost injections can be eliminated.
Bug: 123502026
Test: atest ActivityManagerServiceTest
Test: Manual measure until the last boot complete receiver is done:
- Invocation of nested priority boost
Reduce ~10000 times (50%, total 0.3s) boost invocation
- Invocation of updateOomAdjLocked
~170 times total reduces ~0.05s (only compare between with and
without global lock)
Change-Id: I160f951e103835401ccaaf7c732ba407e011c39b
diff --git a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
index 5fabde4..09ef4b9 100644
--- a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
+++ b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
@@ -349,6 +349,14 @@
/* Global service lock used by the package the owns this service. */
final WindowManagerGlobalLock mGlobalLock = new WindowManagerGlobalLock();
+ /**
+ * It is the same instance as {@link mGlobalLock}, just declared as a type that the
+ * locked-region-code-injection does't recognize it. It is used to skip wrapping priority
+ * booster for places that are already in the scope of another booster (e.g. computing oom-adj).
+ *
+ * @see WindowManagerThreadPriorityBooster
+ */
+ final Object mGlobalLockWithoutBoost = mGlobalLock;
ActivityStackSupervisor mStackSupervisor;
RootActivityContainer mRootActivityContainer;
WindowManagerService mWindowManager;
@@ -6837,7 +6845,7 @@
@Override
public WindowProcessController getTopApp() {
- synchronized (mGlobalLock) {
+ synchronized (mGlobalLockWithoutBoost) {
final ActivityRecord top = mRootActivityContainer.getTopResumedActivity();
return top != null ? top.app : null;
}
@@ -6845,7 +6853,7 @@
@Override
public void rankTaskLayersIfNeeded() {
- synchronized (mGlobalLock) {
+ synchronized (mGlobalLockWithoutBoost) {
if (mRootActivityContainer != null) {
mRootActivityContainer.rankTaskLayersIfNeeded();
}
@@ -6889,28 +6897,28 @@
@Override
public void onUidActive(int uid, int procState) {
- synchronized (mGlobalLock) {
+ synchronized (mGlobalLockWithoutBoost) {
mActiveUids.put(uid, procState);
}
}
@Override
public void onUidInactive(int uid) {
- synchronized (mGlobalLock) {
+ synchronized (mGlobalLockWithoutBoost) {
mActiveUids.remove(uid);
}
}
@Override
public void onActiveUidsCleared() {
- synchronized (mGlobalLock) {
+ synchronized (mGlobalLockWithoutBoost) {
mActiveUids.clear();
}
}
@Override
public void onUidProcStateChanged(int uid, int procState) {
- synchronized (mGlobalLock) {
+ synchronized (mGlobalLockWithoutBoost) {
if (mActiveUids.get(uid) != null) {
mActiveUids.put(uid, procState);
}
@@ -6919,14 +6927,14 @@
@Override
public void onUidAddedToPendingTempWhitelist(int uid, String tag) {
- synchronized (mGlobalLock) {
+ synchronized (mGlobalLockWithoutBoost) {
mPendingTempWhitelist.put(uid, tag);
}
}
@Override
public void onUidRemovedFromPendingTempWhitelist(int uid) {
- synchronized (mGlobalLock) {
+ synchronized (mGlobalLockWithoutBoost) {
mPendingTempWhitelist.remove(uid);
}
}