From 2db234db5f5c2e55e025bb67e1557a84a4b118cd Mon Sep 17 00:00:00 2001 From: yingleiw Date: Thu, 10 Mar 2022 17:33:30 -0800 Subject: [PATCH] resolve possible Imf lock and a11y mLock deadlock When IMF calls into A11yManagerService, A11yMannagerService will post the call to main handler so the function call returns without holding the a11y mLock. Fix: 218182733 Test: atest AccessibilityImeTest Change-Id: I3f7fcb1906b4084b2458ce2b65bb6fec8e9c6ae1 --- .../AccessibilityManagerService.java | 62 ++++++++++++------- 1 file changed, 41 insertions(+), 21 deletions(-) diff --git a/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java b/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java index 249ee16afaae2..61e3da8aae51e 100644 --- a/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java +++ b/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java @@ -322,28 +322,28 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub @Override public void setImeSessionEnabled(SparseArray sessions, boolean enabled) { - mService.setImeSessionEnabled(sessions, enabled); + mService.scheduleSetImeSessionEnabled(sessions, enabled); } @Override public void unbindInput() { - mService.unbindInput(); + mService.scheduleUnbindInput(); } @Override public void bindInput(InputBinding binding) { - mService.bindInput(binding); + mService.scheduleBindInput(binding); } @Override public void createImeSession(ArraySet ignoreSet) { - mService.createImeSession(ignoreSet); + mService.scheduleCreateImeSession(ignoreSet); } @Override public void startInput(IBinder startInputToken, IInputContext inputContext, EditorInfo editorInfo, boolean restarting) { - mService.startInput(startInputToken, inputContext, editorInfo, restarting); + mService.scheduleStartInput(startInputToken, inputContext, editorInfo, restarting); } } @@ -4377,12 +4377,16 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub * * @param binding Information given to an accessibility service about a client connecting to it. */ - public void bindInput(InputBinding binding) { - AccessibilityUserState userState; + public void scheduleBindInput(InputBinding binding) { + mMainHandler.sendMessage(obtainMessage(AccessibilityManagerService::bindInput, this, + binding)); + } + + private void bindInput(InputBinding binding) { synchronized (mLock) { // Keep records of these in case new Accessibility Services are enabled. mInputBinding = binding; - userState = getCurrentUserStateLocked(); + AccessibilityUserState userState = getCurrentUserStateLocked(); for (int i = userState.mBoundServices.size() - 1; i >= 0; i--) { final AccessibilityServiceConnection service = userState.mBoundServices.get(i); if (service.requestImeApis()) { @@ -4395,11 +4399,13 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub /** * Unbind input for accessibility services which request ime capabilities. */ - public void unbindInput() { - AccessibilityUserState userState; - // TODO(b/218182733): Resolve the Imf lock and mLock possible deadlock + public void scheduleUnbindInput() { + mMainHandler.sendMessage(obtainMessage(AccessibilityManagerService::unbindInput, this)); + } + + private void unbindInput() { synchronized (mLock) { - userState = getCurrentUserStateLocked(); + AccessibilityUserState userState = getCurrentUserStateLocked(); for (int i = userState.mBoundServices.size() - 1; i >= 0; i--) { final AccessibilityServiceConnection service = userState.mBoundServices.get(i); if (service.requestImeApis()) { @@ -4412,16 +4418,21 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub /** * Start input for accessibility services which request ime capabilities. */ - public void startInput(IBinder startInputToken, IInputContext inputContext, + public void scheduleStartInput(IBinder startInputToken, IInputContext inputContext, + EditorInfo editorInfo, boolean restarting) { + mMainHandler.sendMessage(obtainMessage(AccessibilityManagerService::startInput, this, + startInputToken, inputContext, editorInfo, restarting)); + } + + private void startInput(IBinder startInputToken, IInputContext inputContext, EditorInfo editorInfo, boolean restarting) { - AccessibilityUserState userState; synchronized (mLock) { // Keep records of these in case new Accessibility Services are enabled. mStartInputToken = startInputToken; mInputContext = inputContext; mEditorInfo = editorInfo; mRestarting = restarting; - userState = getCurrentUserStateLocked(); + AccessibilityUserState userState = getCurrentUserStateLocked(); for (int i = userState.mBoundServices.size() - 1; i >= 0; i--) { final AccessibilityServiceConnection service = userState.mBoundServices.get(i); if (service.requestImeApis()) { @@ -4435,11 +4446,15 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub * Request input sessions from all accessibility services which request ime capabilities and * whose id is not in the ignoreSet */ - public void createImeSession(ArraySet ignoreSet) { - AccessibilityUserState userState; + public void scheduleCreateImeSession(ArraySet ignoreSet) { + mMainHandler.sendMessage(obtainMessage(AccessibilityManagerService::createImeSession, + this, ignoreSet)); + } + + private void createImeSession(ArraySet ignoreSet) { synchronized (mLock) { mInputSessionRequested = true; - userState = getCurrentUserStateLocked(); + AccessibilityUserState userState = getCurrentUserStateLocked(); for (int i = userState.mBoundServices.size() - 1; i >= 0; i--) { final AccessibilityServiceConnection service = userState.mBoundServices.get(i); if ((!ignoreSet.contains(service.mId)) && service.requestImeApis()) { @@ -4455,10 +4470,15 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub * @param sessions Sessions to enable or disable. * @param enabled True if enable the sessions or false if disable the sessions. */ - public void setImeSessionEnabled(SparseArray sessions, boolean enabled) { - AccessibilityUserState userState; + public void scheduleSetImeSessionEnabled(SparseArray sessions, + boolean enabled) { + mMainHandler.sendMessage(obtainMessage(AccessibilityManagerService::setImeSessionEnabled, + this, sessions, enabled)); + } + + private void setImeSessionEnabled(SparseArray sessions, boolean enabled) { synchronized (mLock) { - userState = getCurrentUserStateLocked(); + AccessibilityUserState userState = getCurrentUserStateLocked(); for (int i = userState.mBoundServices.size() - 1; i >= 0; i--) { final AccessibilityServiceConnection service = userState.mBoundServices.get(i); if (sessions.contains(service.mId) && service.requestImeApis()) {