btrace

README 中文版

btrace for Android

btrace for iOS

btrace for HarmonyOS

Major Update

We are proud to announce the launch of btrace 3.0, introducing an industry-first high-performance synchronized sampling-based tracing solution. Additionally, the new version now provides comprehensive iOS tracing capabilities. We have also extended btrace to HarmonyOS, providing on-device SDK and command-line tooling to capture trace data and quickly locate performance issues for HarmonyOS apps.

btrace for Android

Integration

Add dependencies in app/build.gradle file:

dependencies {
    if (enable_btrace == 'true') {
        implementation 'com.bytedance.btrace:rhea-inhouse:3.0.0'
    } else {
        implementation 'com.bytedance.btrace:rhea-inhouse-noop:3.0.0'
    }
}

Add enable_btrace switch in the gradle.properties file:

# Turn on this switch when you want to build app that support tracing.
enable_btrace=false

Add initialization code in attachBaseContext() method of your Application:

public class MyApp extends Application {

    @Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(base);
        // When rhea-inhouse-noop is used, RheaTrace3.init() has empty implementation.
        RheaTrace3.init(base);
    }
}

Usage

To use btrace 3.0, follow these instructions:

1. Make sure that your computer has integrated adb and Java and Python3 environment.
2. Connect your phone to your computer and make sure it can recognized by adb devices.
3. Install the APK that integrates btrace 3.0 on your phone.
4. Download the latest script from "Script Management" below to your computer.
5. In the directory where the computer script is located, execute the following command:

java -jar rhea-trace-shell.jar -a ${your_package_name} -t 10 -o output.pb -r sched

6. Open the generated trace file in https://ui.perfetto.dev/ for detailed analysis.

Script Management

Parameters Description

Required Parameters

Optional Parameters

Known Issues

btrace for iOS

Record trace data offline without Instruments to help find performance issue of your app.

Installation

Clone source code, and add the following lines to your Podfile:

pod 'BTrace', :subspecs => ['Core', 'Debug'], :path => 'xxx/btrace-iOS'
pod 'fishhook', :git => 'https://github.com/facebook/fishhook.git', :branch => 'main'

Install command line tool:

# using homebrew
brew install libusbmuxd
brew install poetry

# install from the BTraceTool directory
poetry install

Usage

Activate the virtual environment before executing commands.

# activate from the BTraceTool directory
poetry shell
# or 
poetry env activate

Record

Note that if '-l' is not specified, app must have been launched before recording.

python3 -m btrace record [-h] [-i DEVICE_ID] [-b BUNDLE_ID] [-o OUTPUT] [-t TIME_LIMIT] [-d DSYM_PATH] [-m] [-l] [-s]

Options

Examples

python3 -m btrace record -i xxx -b xxx -d /xxxDebug-iphoneos/xxx.app
python3 -m btrace record -i xxx -b xxx -d /xxxDebug-iphoneos/xxx.dSYM

Stop

ctrl + c

Parse

When should the 'parse' command used?

• '-d' option is not specified in the 'record' command.
• reopen the parsed data

python3 -m btrace parse [-h] [-d DSYM_PATH] [-f] [-s] file_path

Options

Examples

btrace parse -d /xxx.dSYM xxx.sqlite
btrace parse -d /xxx.app xxx.sqlite

btrace for HarmonyOS

Record trace data for HarmonyOS apps to help find performance issues.

Integration

Add the on-device SDK to your HarmonyOS project via ohpm:

ohpm install @bytedance/btrace

Initialize the offline server as early as possible during app startup:

import { OfflineServer } from '@bytedance/btrace'

OfflineServer.Init()

Command-Line Tool Installation

Prerequisites

• JDK 11 or above is required, with environment variables configured properly.
• The hdc tool is required to operate apps on the device. Add it to your PATH:

export PATH="/Applications/DevEco-Studio.app/Contents/sdk/default/openharmony/toolchains:$PATH"

• Parsing native symbols requires llvm-addr2line. Add it to your PATH:

export PATH="/Applications/DevEco-Studio.app/Contents/sdk/default/openharmony/native/llvm/bin:$PATH"

Install

1. Download the latest harmony-trace-cli jar and place it under ~/.oh_trace_cli directory.

Note: The download artifacts will be published with the official release. Please stay tuned.

Usage

Run the following command in the directory where harmony-trace-cli.jar is located:

java -jar harmony-trace-cli.jar -b ${your_bundle_name} -t 10

The above command starts tracing for the given bundle from its current foreground page, samples all threads for 10 seconds, saves the result to the current directory and automatically generates a flame graph.

Stop

ctrl + c

Stops the tracing and automatically exports the trace file from the app sandbox.

Parameters Description

Required Parameters

Optional Parameters

Known Issues

• CLI is currently macOS-only: the harmony-trace-cli command-line tool only supports macOS at the moment; Windows / Linux support will be added in future releases.
• On-device symbol resolution can be slow: the SDK currently performs symbol resolution on-device, which is relatively time-consuming. After the trace capture finishes, exporting from the device and writing to disk may take noticeably longer; we will continue to optimize this.
• System library symbols must be supplied manually: the SDK cannot currently resolve symbols of HarmonyOS system libraries on-device. To recover the symbols, users need to supply the directory containing the matching .so files via -N, --native_path, and the CLI tool will perform symbolication offline.

Technology Principle

If you are interested in the internal details of btrace 3.0, you can refer to the document: btrace 3.0 Internal Principle in Detail! .

Feedback

We've made a lot of improvements in btrace 3.0, including better error prompts. There might still be some cases where the prompts aren't accurate enough or the messages aren't clear. If you run into any issues, just give us a shout in the Lark group below, and we'll do our best to help you out. We always appreciate any other feedback or suggestions you might have too, thanks you!

Contributes

Contributing Guide

License

Apache License