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3 files changed, 147 insertions, 1 deletions
diff --git a/updater_sample/README.md b/updater_sample/README.md index 3f211ddba..f6c63a7b6 100644 --- a/updater_sample/README.md +++ b/updater_sample/README.md @@ -65,6 +65,32 @@ purpose only. 6. Push OTA packages to the device. +## Sample App State vs UpdateEngine Status + +UpdateEngine provides status for different stages of update application +process. But it lacks of proper status codes when update fails. + +This creates two problems: + +1. If sample app is unbound from update_engine (MainActivity is paused, destroyed), + app doesn't receive onStatusUpdate and onPayloadApplicationCompleted notifications. + If app binds to update_engine after update is completed, + only onStatusUpdate is called, but status becomes IDLE in most cases. + And there is no way to know if update was successful or not. + +2. This sample app demostrates suspend/resume using update_engins's + `cancel` and `applyPayload` (which picks up from where it left). + When `cancel` is called, status is set to `IDLE`, which doesn't allow + tracking suspended state properly. + +To solve these problems sample app implements its own separate update +state - `UpdaterState`. To solve the first problem, sample app persists +`UpdaterState` on a device. When app is resumed, it checks if `UpdaterState` +matches the update_engine's status (as onStatusUpdate is guaranteed to be called). +If they doesn't match, sample app calls `applyPayload` again with the same +parameters, and handles update completion properly using `onPayloadApplicationCompleted` +callback. The second problem is solved by adding `PAUSED` updater state. + ## Sending HTTP headers from UpdateEngine Sometimes OTA package server might require some HTTP headers to be present, @@ -76,6 +102,44 @@ as of writing this sample app, these headers are `Authorization` and `User-Agent which HTTP headers are supported. +## Used update_engine APIs + +### UpdateEngine#bind + +Binds given callbacks to update_engine. When update_engine successfully +initialized, it's guaranteed to invoke callback onStatusUpdate. + +### UpdateEngine#applyPayload + +Start an update attempt to download an apply the provided `payload_url` if +no other update is running. The extra `key_value_pair_headers` will be +included when fetching the payload. + +### UpdateEngine#cancel + +Cancel the ongoing update. The update could be running or suspended, but it +can't be canceled after it was done. + +### UpdateEngine#resetStatus + +Reset the already applied update back to an idle state. This method can +only be called when no update attempt is going on, and it will reset the +status back to idle, deleting the currently applied update if any. + +### Callback: onStatusUpdate + +Called whenever the value of `status` or `progress` changes. For +`progress` values changes, this method will be called only if it changes significantly. +At this time of writing this doc, delta for `progress` is `0.005`. + +`onStatusUpdate` is always called when app binds to update_engine, +except when update_engine fails to initialize. + +### Callback: onPayloadApplicationComplete + +Called whenever an update attempt is completed. + + ## Development - [x] Create a UI with list of configs, current version, @@ -90,6 +154,10 @@ which HTTP headers are supported. - [x] Add demo for passing HTTP headers to `UpdateEngine#applyPayload` - [x] [Package compatibility check](https://source.android.com/devices/architecture/vintf/match-rules) - [x] Deferred switch slot demo +- [x] Add UpdateManager; extract update logic from MainActivity +- [x] Add Sample app update state (separate from update_engine status) +- [-] Add smart update completion detection using onStatusUpdate +- [ ] Add pause/resume demo - [ ] Add demo for passing NETWORK_ID to `UpdateEngine#applyPayload` - [ ] Verify system partition checksum for package - [?] Add non-A/B updates demo diff --git a/updater_sample/src/com/example/android/systemupdatersample/UpdateManager.java b/updater_sample/src/com/example/android/systemupdatersample/UpdateManager.java index c4c8c9c27..f5c2ea5ab 100644 --- a/updater_sample/src/com/example/android/systemupdatersample/UpdateManager.java +++ b/updater_sample/src/com/example/android/systemupdatersample/UpdateManager.java @@ -384,11 +384,85 @@ public class UpdateManager { updateEngineApplyPayload(builder.build()); } + /** + * Verifies if mUpdaterState matches mUpdateEngineStatus. + * If they don't match, runs applyPayload to trigger onPayloadApplicationComplete + * callback, which updates mUpdaterState. + */ + private void ensureCorrectUpdaterState() { + // When mUpdaterState is one of IDLE, PAUSED, ERROR, SLOT_SWITCH_REQUIRED + // then mUpdateEngineStatus must be IDLE. + // When mUpdaterState is RUNNING, + // then mUpdateEngineStatus must not be IDLE or UPDATED_NEED_REBOOT. + // When mUpdaterState is REBOOT_REQUIRED, + // then mUpdateEngineStatus must be UPDATED_NEED_REBOOT. + int state = mUpdaterState.get(); + int updateEngineStatus = mUpdateEngineStatus.get(); + if (state == UpdaterState.IDLE + || state == UpdaterState.ERROR + || state == UpdaterState.PAUSED + || state == UpdaterState.SLOT_SWITCH_REQUIRED) { + ensureUpdateEngineStatusIdle(state, updateEngineStatus); + } else if (state == UpdaterState.RUNNING) { + ensureUpdateEngineStatusRunning(state, updateEngineStatus); + } else if (state == UpdaterState.REBOOT_REQUIRED) { + ensureUpdateEngineStatusReboot(state, updateEngineStatus); + } + } + + private void ensureUpdateEngineStatusIdle(int state, int updateEngineStatus) { + if (updateEngineStatus == UpdateEngine.UpdateStatusConstants.IDLE) { + return; + } + // It might happen when update is started not from the sample app. + // To make the sample app simple, we won't handle this case. + throw new RuntimeException("When mUpdaterState is " + state + + " mUpdateEngineStatus expected to be " + + UpdateEngine.UpdateStatusConstants.IDLE + + ", but it is " + updateEngineStatus); + } + + private void ensureUpdateEngineStatusRunning(int state, int updateEngineStatus) { + if (updateEngineStatus != UpdateEngine.UpdateStatusConstants.UPDATED_NEED_REBOOT + && updateEngineStatus != UpdateEngine.UpdateStatusConstants.IDLE) { + return; + } + // Re-apply latest update. It makes update_engine to invoke + // onPayloadApplicationComplete callback. The callback notifies + // if update was successful or not. + updateEngineReApplyPayload(); + } + + private void ensureUpdateEngineStatusReboot(int state, int updateEngineStatus) { + if (updateEngineStatus == UpdateEngine.UpdateStatusConstants.UPDATED_NEED_REBOOT) { + return; + } + // This might happen when update is installed by other means, + // and sample app is not aware of it. To make the sample app simple, + // we won't handle this case. + throw new RuntimeException("When mUpdaterState is " + state + + " mUpdateEngineStatus expected to be " + + UpdateEngine.UpdateStatusConstants.UPDATED_NEED_REBOOT + + ", but it is " + updateEngineStatus); + } + + /** + * Invoked by update_engine whenever update status or progress changes. + * It's also guaranteed to be invoked when app binds to the update_engine, except + * when update_engine fails to initialize (as defined in + * system/update_engine/binder_service_android.cc in + * function BinderUpdateEngineAndroidService::bind). + * + * @param status one of {@link UpdateEngine.UpdateStatusConstants}. + * @param progress a number from 0.0 to 1.0. + */ private void onStatusUpdate(int status, float progress) { int previousStatus = mUpdateEngineStatus.get(); mUpdateEngineStatus.set(status); mProgress.set(progress); + ensureCorrectUpdaterState(); + getOnProgressUpdateCallback().ifPresent(callback -> callback.accept(progress)); if (previousStatus != status) { @@ -413,7 +487,7 @@ public class UpdateManager { } /** - * Helper class to delegate {@code update_engine} callbacks to UpdateManager + * Helper class to delegate {@code update_engine} callback invocations to UpdateManager. */ class UpdateEngineCallbackImpl extends UpdateEngineCallback { @Override diff --git a/updater_sample/src/com/example/android/systemupdatersample/ui/MainActivity.java b/updater_sample/src/com/example/android/systemupdatersample/ui/MainActivity.java index 0b571cc81..1de72c2d6 100644 --- a/updater_sample/src/com/example/android/systemupdatersample/ui/MainActivity.java +++ b/updater_sample/src/com/example/android/systemupdatersample/ui/MainActivity.java @@ -108,12 +108,16 @@ public class MainActivity extends Activity { @Override protected void onResume() { super.onResume(); + // TODO(zhomart) load saved states + // Binding to UpdateEngine invokes onStatusUpdate callback, + // persisted updater state has to be loaded and prepared beforehand. this.mUpdateManager.bind(); } @Override protected void onPause() { this.mUpdateManager.unbind(); + // TODO(zhomart) save state super.onPause(); } |