Stopped starting and killing processes directly from ATMS (27/n)

Post messages to have processes started and killed instead which
should be okay.

Bug: 80414790
Test: Existing tests pass
Change-Id: Ia435aa815c36a84947ae0f76291b1d1f9222231d

4 files changed, 44 insertions, 4 deletions

diff --git a/core/java/android/app/ActivityManagerInternal.java b/core/java/android/app/ActivityManagerInternal.java
index fddbef92cea2..50e618a577a2 100644
--- a/core/java/android/app/ActivityManagerInternal.java
+++ b/core/java/android/app/ActivityManagerInternal.java
@@ -262,4 +262,18 @@ public abstract class ActivityManagerInternal {
      * flags.
      */
     public abstract void broadcastCloseSystemDialogs(String reason);
+
+    /**
+     * Kills all background processes, except those matching any of the specified properties.
+     *
+     * @param minTargetSdk the target SDK version at or above which to preserve processes,
+     *                     or {@code -1} to ignore the target SDK
+     * @param maxProcState the process state at or below which to preserve processes,
+     *                     or {@code -1} to ignore the process state
+     */
+    public abstract void killAllBackgroundProcessesExcept(int minTargetSdk, int maxProcState);
+
+    /** Starts a given process. */
+    public abstract void startProcess(String processName, ApplicationInfo info,
+            boolean knownToBeDead, String hostingType, ComponentName hostingName);
 }
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index 2d2ac33ad82e..6a25cf13c6cf 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -20402,6 +20402,24 @@ public class ActivityManagerService extends IActivityManager.Stub
                         OP_NONE, null, false, false, -1, SYSTEM_UID, UserHandle.USER_ALL);
             }
         }
+
+        @Override
+        public void killAllBackgroundProcessesExcept(int minTargetSdk, int maxProcState) {
+            synchronized (ActivityManagerService.this) {
+                ActivityManagerService.this.killAllBackgroundProcessesExcept(
+                        minTargetSdk, maxProcState);
+            }
+        }
+
+        @Override
+        public void startProcess(String processName, ApplicationInfo info,
+                boolean knownToBeDead, String hostingType, ComponentName hostingName) {
+            synchronized (ActivityManagerService.this) {
+                startProcessLocked(processName, info, knownToBeDead, 0 /* intentFlags */,
+                        hostingType, hostingName, false /* allowWhileBooting */,
+                        false /* isolated */, true /* keepIfLarge */);
+            }
+        }
     }
 
     long inputDispatchingTimedOut(int pid, final boolean aboveSystem, String reason) {
diff --git a/services/core/java/com/android/server/am/ActivityStackSupervisor.java b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
index 44e432375894..2e36fc9385ba 100644
--- a/services/core/java/com/android/server/am/ActivityStackSupervisor.java
+++ b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
@@ -1660,8 +1660,12 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
             // restart the application.
         }
 
-        mService.mAm.startProcessLocked(r.processName, r.info.applicationInfo, true, 0,
-                "activity", r.intent.getComponent(), false, false, true);
+        // Post message to start process to avoid possible deadlock of calling into AMS with the
+        // ATMS lock held.
+        final Message msg = PooledLambda.obtainMessage(
+                ActivityManagerInternal::startProcess, mService.mAmInternal, r.processName,
+                r.info.applicationInfo, true, "activity", r.intent.getComponent());
+        mService.mH.sendMessage(msg);
     }
 
     void sendPowerHintForLaunchStartIfNeeded(boolean forceSend, ActivityRecord targetActivity) {
diff --git a/services/core/java/com/android/server/am/ActivityTaskManagerService.java b/services/core/java/com/android/server/am/ActivityTaskManagerService.java
index d1a62387726f..8ae5495cfa05 100644
--- a/services/core/java/com/android/server/am/ActivityTaskManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityTaskManagerService.java
@@ -4841,8 +4841,12 @@ public class ActivityTaskManagerService extends IActivityTaskManager.Stub {
             if (isDensityChange && displayId == DEFAULT_DISPLAY) {
                 mAppWarnings.onDensityChanged();
 
-                mAm.killAllBackgroundProcessesExcept(N,
-                        ActivityManager.PROCESS_STATE_BOUND_FOREGROUND_SERVICE);
+                // Post message to start process to avoid possible deadlock of calling into AMS with
+                // the ATMS lock held.
+                final Message msg = PooledLambda.obtainMessage(
+                        ActivityManagerInternal::killAllBackgroundProcessesExcept, mAmInternal,
+                        N, ActivityManager.PROCESS_STATE_BOUND_FOREGROUND_SERVICE);
+                mH.sendMessage(msg);
             }
         }