Make app zygote launches more robust.

In case a process launch times out, there are paths in
ActivityManagerService that call removeProcessNameLocked() more than
once; in case such a process is using the application zygote, that can
cause the logic to remove the same ProcessRecord from the application
zygote twice, resulting in a NullPointerException.

Bug: 123758436
Test: atest android.app.cts.ServiceTest#testActivityServiceBindingLru
Change-Id: Id5462b6005a7c0601820332344af5be6d10eb319

1 files changed, 3 insertions, 1 deletions

diff --git a/services/core/java/com/android/server/am/ProcessList.java b/services/core/java/com/android/server/am/ProcessList.java
index f01305eab761..0d49e4cdc9d0 100644
--- a/services/core/java/com/android/server/am/ProcessList.java
+++ b/services/core/java/com/android/server/am/ProcessList.java
@@ -1681,7 +1681,8 @@ public final class ProcessList {
     public void killAppZygoteIfNeededLocked(AppZygote appZygote) {
         final ApplicationInfo appInfo = appZygote.getAppInfo();
         ArrayList<ProcessRecord> zygoteProcesses = mAppZygoteProcesses.get(appZygote);
-        if (zygoteProcesses.size() == 0) { // Only remove if no longer in use now
+        if (zygoteProcesses != null && zygoteProcesses.size() == 0) {
+            // Only remove if no longer in use now
             mAppZygotes.remove(appInfo.processName, appInfo.uid);
             mAppZygoteProcesses.remove(appZygote);
             mAppIsolatedUidRangeAllocator.freeUidRangeLocked(appInfo);
@@ -1703,6 +1704,7 @@ public final class ProcessList {
             ArrayList<ProcessRecord> zygoteProcesses = mAppZygoteProcesses.get(appZygote);
             zygoteProcesses.remove(app);
             if (zygoteProcesses.size() == 0) {
+                mService.mHandler.removeMessages(KILL_APP_ZYGOTE_MSG);
                 Message msg = mService.mHandler.obtainMessage(KILL_APP_ZYGOTE_MSG);
                 msg.obj = appZygote;
                 mService.mHandler.sendMessageDelayed(msg, KILL_APP_ZYGOTE_DELAY_MS);