Merge "Update createHintSession API doc and add error slog" into main
diff --git a/core/java/android/os/PerformanceHintManager.java b/core/java/android/os/PerformanceHintManager.java
index 977ef60..bcea797 100644
--- a/core/java/android/os/PerformanceHintManager.java
+++ b/core/java/android/os/PerformanceHintManager.java
@@ -55,15 +55,20 @@
      * duration.
      *
      * @param tids The list of threads to be associated with this session. They must be part of
-     *     this process' thread group.
+     *     this process' thread group
      * @param initialTargetWorkDurationNanos The desired duration in nanoseconds for the new
-     *     session.
+     *     session
      * @return the new session if it is supported on this device, null if hint session is not
-     *     supported on this device.
+     *     supported on this device or the tid doesn't belong to the application
+     * @throws IllegalArgumentException if the thread id list is empty, or
+     *                                  initialTargetWorkDurationNanos is non-positive
      */
     @Nullable
     public Session createHintSession(@NonNull int[] tids, long initialTargetWorkDurationNanos) {
-        Preconditions.checkNotNull(tids, "tids cannot be null");
+        Objects.requireNonNull(tids, "tids cannot be null");
+        if (tids.length == 0) {
+            throw new IllegalArgumentException("thread id list can't be empty.");
+        }
         Preconditions.checkArgumentPositive(initialTargetWorkDurationNanos,
                 "the hint target duration should be positive.");
         long nativeSessionPtr = nativeCreateSession(mNativeManagerPtr, tids,
@@ -75,7 +80,7 @@
     /**
      * Get preferred update rate information for this device.
      *
-     * @return the preferred update rate supported by device software.
+     * @return the preferred update rate supported by device software
      */
     public long getPreferredUpdateRateNanos() {
         return nativeGetPreferredUpdateRateNanos(mNativeManagerPtr);
@@ -209,7 +214,7 @@
         /**
          * Sends performance hints to inform the hint session of changes in the workload.
          *
-         * @param hint The hint to send to the session.
+         * @param hint The hint to send to the session
          *
          * @hide
          */
@@ -230,11 +235,11 @@
          * Note that this is not an oneway method.
          *
          * @param tids The list of threads to be associated with this session. They must be
-         *     part of this app's thread group.
+         *     part of this app's thread group
          *
-         * @throws IllegalStateException if the hint session is not in the foreground.
-         * @throws IllegalArgumentException if the thread id list is empty.
-         * @throws SecurityException if any thread id doesn't belong to the application.
+         * @throws IllegalStateException if the hint session is not in the foreground
+         * @throws IllegalArgumentException if the thread id list is empty
+         * @throws SecurityException if any thread id doesn't belong to the application
          */
         public void setThreads(@NonNull int[] tids) {
             if (mNativeSessionPtr == 0) {
diff --git a/core/tests/coretests/src/android/os/PerformanceHintManagerTest.java b/core/tests/coretests/src/android/os/PerformanceHintManagerTest.java
index 2c03fdc..b0826ab 100644
--- a/core/tests/coretests/src/android/os/PerformanceHintManagerTest.java
+++ b/core/tests/coretests/src/android/os/PerformanceHintManagerTest.java
@@ -69,6 +69,24 @@
     }
 
     @Test
+    public void testCreateHintSession_noTids() {
+        assertThrows(NullPointerException.class, () -> {
+            mPerformanceHintManager.createHintSession(
+                    null, DEFAULT_TARGET_NS);
+        });
+        assertThrows(IllegalArgumentException.class, () -> {
+            mPerformanceHintManager.createHintSession(
+                    new int[]{}, DEFAULT_TARGET_NS);
+        });
+    }
+
+    @Test
+    public void testCreateHintSession_invalidTids() {
+        assertNull(mPerformanceHintManager.createHintSession(
+                new int[]{-1}, DEFAULT_TARGET_NS));
+    }
+
+    @Test
     public void testGetPreferredUpdateRateNanos() {
         if (createSession() != null) {
             assertTrue(mPerformanceHintManager.getPreferredUpdateRateNanos() > 0);
diff --git a/services/core/java/com/android/server/power/hint/HintManagerService.java b/services/core/java/com/android/server/power/hint/HintManagerService.java
index 1a91d25..8dcf3e0 100644
--- a/services/core/java/com/android/server/power/hint/HintManagerService.java
+++ b/services/core/java/com/android/server/power/hint/HintManagerService.java
@@ -304,7 +304,8 @@
         return mService;
     }
 
-    private boolean checkTidValid(int uid, int tgid, int [] tids) {
+    // returns the first invalid tid or null if not found
+    private Integer checkTidValid(int uid, int tgid, int [] tids) {
         // Make sure all tids belongs to the same UID (including isolated UID),
         // tids can belong to different application processes.
         List<Integer> isolatedPids = null;
@@ -326,19 +327,24 @@
             if (isolatedPids == null) {
                 // To avoid deadlock, do not call into AMS if the call is from system.
                 if (uid == Process.SYSTEM_UID) {
-                    return false;
+                    return threadId;
                 }
                 isolatedPids = mAmInternal.getIsolatedProcesses(uid);
                 if (isolatedPids == null) {
-                    return false;
+                    return threadId;
                 }
             }
             if (isolatedPids.contains(pidOfThreadId)) {
                 continue;
             }
-            return false;
+            return threadId;
         }
-        return true;
+        return null;
+    }
+
+    private String formatTidCheckErrMsg(int callingUid, int[] tids, Integer invalidTid) {
+        return "Tid" + invalidTid + " from list " + Arrays.toString(tids)
+                + " doesn't belong to the calling application" + callingUid;
     }
 
     @VisibleForTesting
@@ -356,8 +362,11 @@
             final int callingTgid = Process.getThreadGroupLeader(Binder.getCallingPid());
             final long identity = Binder.clearCallingIdentity();
             try {
-                if (!checkTidValid(callingUid, callingTgid, tids)) {
-                    throw new SecurityException("Some tid doesn't belong to the application");
+                final Integer invalidTid = checkTidValid(callingUid, callingTgid, tids);
+                if (invalidTid != null) {
+                    final String errMsg = formatTidCheckErrMsg(callingUid, tids, invalidTid);
+                    Slogf.w(TAG, errMsg);
+                    throw new SecurityException(errMsg);
                 }
 
                 long halSessionPtr = mNativeWrapper.halCreateHintSession(callingTgid, callingUid,
@@ -561,8 +570,11 @@
                 final int callingTgid = Process.getThreadGroupLeader(Binder.getCallingPid());
                 final long identity = Binder.clearCallingIdentity();
                 try {
-                    if (!checkTidValid(callingUid, callingTgid, tids)) {
-                        throw new SecurityException("Some tid doesn't belong to the application.");
+                    final Integer invalidTid = checkTidValid(callingUid, callingTgid, tids);
+                    if (invalidTid != null) {
+                        final String errMsg = formatTidCheckErrMsg(callingUid, tids, invalidTid);
+                        Slogf.w(TAG, errMsg);
+                        throw new SecurityException(errMsg);
                     }
                 } finally {
                     Binder.restoreCallingIdentity(identity);