From 71fd3dc69476bf6b925b32e1d00add6bb09df537 Mon Sep 17 00:00:00 2001
From: Li Li <dualli@google.com>
Date: Mon, 24 May 2021 12:44:29 -0700
Subject: [PATCH] Freezer kill reason in App Process Kill Stats

The reason code is helpful for developers to understand why an app is
killed. It is also valuable to better quantify the benefit and impact
of App Freezer.

Bug: 183714099
Bug: 179715791
Test: dumpsys activity exit-info shows subreasons.

Change-Id: Iea808cdc8adbe9d84663071dc849d00ea28a9f7d
---
 .../java/android/app/ApplicationExitInfo.java | 30 +++++++++++++++++++
 .../android/server/am/CachedAppOptimizer.java |  8 ++---
 2 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/core/java/android/app/ApplicationExitInfo.java b/core/java/android/app/ApplicationExitInfo.java
index 4f94c9b5045b6..d54452fb3004c 100644
--- a/core/java/android/app/ApplicationExitInfo.java
+++ b/core/java/android/app/ApplicationExitInfo.java
@@ -334,6 +334,26 @@ public final class ApplicationExitInfo implements Parcelable {
      */
     public static final int SUBREASON_CACHED_IDLE_FORCED_APP_STANDBY = 18;
 
+    /**
+     * The process was killed because it fails to freeze/unfreeze binder
+     * or query binder frozen info while being frozen.
+     * this would be set only when the reason is {@link #REASON_FREEZER}.
+     *
+     * For internal use only.
+     * @hide
+     */
+    public static final int SUBREASON_FREEZER_BINDER_IOCTL = 19;
+
+    /**
+     * The process was killed because it receives sync binder transactions
+     * while being frozen.
+     * this would be set only when the reason is {@link #REASON_FREEZER}.
+     *
+     * For internal use only.
+     * @hide
+     */
+    public static final int SUBREASON_FREEZER_BINDER_TRANSACTION = 20;
+
     // If there is any OEM code which involves additional app kill reasons, it should
     // be categorized in {@link #REASON_OTHER}, with subreason code starting from 1000.
 
@@ -491,6 +511,8 @@ public final class ApplicationExitInfo implements Parcelable {
         SUBREASON_IMPERCEPTIBLE,
         SUBREASON_REMOVE_LRU,
         SUBREASON_ISOLATED_NOT_NEEDED,
+        SUBREASON_FREEZER_BINDER_IOCTL,
+        SUBREASON_FREEZER_BINDER_TRANSACTION,
     })
     @Retention(RetentionPolicy.SOURCE)
     public @interface SubReason {}
@@ -1032,6 +1054,8 @@ public final class ApplicationExitInfo implements Parcelable {
         pw.println(prefix + "  user=" + UserHandle.getUserId(mPackageUid));
         pw.println(prefix + "  process=" + mProcessName);
         pw.println(prefix + "  reason=" + mReason + " (" + reasonCodeToString(mReason) + ")");
+        pw.println(prefix + "  subreason=" + mSubReason + " (" + subreasonToString(mSubReason)
+                + ")");
         pw.println(prefix + "  status=" + mStatus);
         pw.println(prefix + "  importance=" + mImportance);
         pw.print(prefix + "  pss="); DebugUtils.printSizeValue(pw, mPss << 10); pw.println();
@@ -1055,6 +1079,8 @@ public final class ApplicationExitInfo implements Parcelable {
         sb.append(" process=").append(mProcessName);
         sb.append(" reason=").append(mReason).append(" (")
                 .append(reasonCodeToString(mReason)).append(")");
+        sb.append(" subreason=").append(mSubReason).append(" (")
+                .append(subreasonToString(mSubReason)).append(")");
         sb.append(" status=").append(mStatus);
         sb.append(" importance=").append(mImportance);
         sb.append(" pss="); DebugUtils.sizeValueToString(mPss << 10, sb);
@@ -1137,6 +1163,10 @@ public final class ApplicationExitInfo implements Parcelable {
                 return "REMOVE LRU";
             case SUBREASON_ISOLATED_NOT_NEEDED:
                 return "ISOLATED NOT NEEDED";
+            case SUBREASON_FREEZER_BINDER_IOCTL:
+                return "FREEZER BINDER IOCTL";
+            case SUBREASON_FREEZER_BINDER_TRANSACTION:
+                return "FREEZER BINDER TRANSACTION";
             default:
                 return "UNKNOWN";
         }
diff --git a/services/core/java/com/android/server/am/CachedAppOptimizer.java b/services/core/java/com/android/server/am/CachedAppOptimizer.java
index 1ddd899505b0d..966e746b3c738 100644
--- a/services/core/java/com/android/server/am/CachedAppOptimizer.java
+++ b/services/core/java/com/android/server/am/CachedAppOptimizer.java
@@ -927,7 +927,7 @@ public final class CachedAppOptimizer {
                         + " received sync transactions while frozen, killing");
                 app.killLocked("Sync transaction while in frozen state",
                         ApplicationExitInfo.REASON_OTHER,
-                        ApplicationExitInfo.SUBREASON_INVALID_STATE, true);
+                        ApplicationExitInfo.SUBREASON_FREEZER_BINDER_TRANSACTION, true);
                 processKilled = true;
             }
 
@@ -940,7 +940,7 @@ public final class CachedAppOptimizer {
                     + app.processName + ". Killing it. Exception: " + e);
             app.killLocked("Unable to query binder frozen stats",
                     ApplicationExitInfo.REASON_OTHER,
-                    ApplicationExitInfo.SUBREASON_INVALID_STATE, true);
+                    ApplicationExitInfo.SUBREASON_FREEZER_BINDER_IOCTL, true);
             processKilled = true;
         }
 
@@ -957,7 +957,7 @@ public final class CachedAppOptimizer {
                     + ". Killing it");
             app.killLocked("Unable to unfreeze",
                     ApplicationExitInfo.REASON_OTHER,
-                    ApplicationExitInfo.SUBREASON_INVALID_STATE, true);
+                    ApplicationExitInfo.SUBREASON_FREEZER_BINDER_IOCTL, true);
             return;
         }
 
@@ -1342,7 +1342,7 @@ public final class CachedAppOptimizer {
                         synchronized (mAm) {
                             proc.killLocked("Unable to freeze binder interface",
                                     ApplicationExitInfo.REASON_OTHER,
-                                    ApplicationExitInfo.SUBREASON_INVALID_STATE, true);
+                                    ApplicationExitInfo.SUBREASON_FREEZER_BINDER_IOCTL, true);
                         }
                     });
                 }