| commit | 895859550aca1c631c508190f76d22d311cb177f | [log] [tgz] |
|---|---|---|
| author | satayev <satayev@google.com> | Mon Aug 02 16:18:21 2021 +0100 |
| committer | satayev <satayev@google.com> | Tue Aug 03 16:03:28 2021 +0100 |
| tree | 068966c3ddeb0f72101eca3cc87365b85b2e6017 | |
| parent | e5834114cb5653f69f50be9883fc55839ad70a4f [diff] |
Write generated data to a temp file first. android::base::WriteStringToFile may remove the file if write fails for any reason (e.g. access or no space issues). Absense of the file would then lead to failed boot. In the case of a full disk issue, this guarantees that we keep previously generated file intact, even if we cannot write new content. This is another safe guard in addition to reserved_disk group feature. Bug: 195097326 Test: launch_cvd && atest CtsClasspathsTestCases Ignore-AOSP-First: sc-dev fix Change-Id: I629973d90393cc5b2f657440380a9be24d80fbf6
SdkExtensions module is responsible for:
The module is packaged in an apex, com.android.sdkext, and has several components:
bin/derive_classpath: a native binary that runs early in the device boot process. It reads individual classpath configs files from the system and other modules, merges them, and defines the definition of *CLASSPATH environ variables.bin/derive_sdk: native binary that runs early in the device boot process and reads metadata of other modules, to set system properties relating to the extension SDK (for instance build.version.extensions.r).javalib/framework-sdkextension.jar: this is a jar on the bootclasspath that exposes APIs to applications to query the extension SDK level.derive_sdk is a program that reads metadata stored in other apex modules, in the form of binary protobuf files in subpath etc/sdkinfo.pb inside each apex. The structure of this protobuf can be seen here. The exact steps for converting a set of metadata files to actual extension versions is likely to change over time, and should not be depended upon.
The module exposes a java class SdkExtensions in the package android.os.ext. The method getExtensionVersion(int) can be used to read the version of a particular sdk extension, e.g. getExtensionVersion(Build.VERSION_CODES.R).
derive_classpath service reads and merges individual config files in the /system/etc/classpaths/ and /apex/*/etc/classpaths. Each config stores protobuf message from classpaths.proto in a proto binary format. Exact merging algorithm that determines the order of the classpath entries is described in derive_classpath.cpp and may change over time.
For every new Android SDK level a new extension version should be defined. These are the steps necessary to do that:
derive_sdk.cpp by:GetSdkLevel with the new enum setderive_sdk_test.cpp verifying the new extensions worksSdkExtensions.getExtensionVersion API support the new extensions.RollbackManagerServiceImpl#getExtensionVersions to account for the new extension version.