author Andrew Osmond <>
Mon, 11 Sep 2017 08:39:30 -0400
changeset 424048 0b5841c7c3992c2c0a43cb77b51b3fd04b63b7d6
parent 418052 482d129766a98be77a6cf12934c0fb0613e22def
child 429963 5df6f8fe6c50631fe00f47b69d16b8d555d90503
permissions -rw-r--r--
Bug 1397223 - Gracefully handle failures in SurfaceCacheImpl::StartTracking. r=tnikkel, a=lizzard When the surface cache starts tracking an unlocked surface, it must insert it into the expiration tracker, so that it can be freed later if it is remains unused. ExpirationTrackerImpl::AddObjectLocked can fail due to out-of-memory conditions or during shutdown, which we previously ignored, and could leave us in a state where we think the surface is in the tracker but is not. When we later try to mark the surface as used in the tracker, it will hit a release assert because it doesn't exist. Now we handle the insertion failure by discarding the surface. Marking the surface as used can itself encounter a similar issue, and we handle it the same way.

# The Servo Parallel Browser Engine Project

[![Linux Build Status](](  [![Windows Build Status](](  [![Changelog #228](](

Servo is a prototype web browser engine written in the
[Rust]( language. It is currently developed on
64bit OS X, 64bit Linux, and Android.

Servo welcomes contribution from everyone.  See
[``]( and [``](docs/
for help getting started.

Visit the [Servo Project page]( for news and guides.

## Setting up your environment

Please select your operating system:
* [OS X](#os-x)
* [Debian-based Linuxes](#on-debian-based-linuxes)
* [Fedora](#on-fedora)
* [Arch Linux](#on-arch-linux)
* [openSUSE](#on-opensuse-linux)
* [Gentoo Linux](#on-gentoo-linux)
* [Microsoft Windows](#on-windows-msvc)
* [Android](#cross-compilation-for-android)

#### OS X
#### On OS X (homebrew)

``` sh
brew install automake pkg-config python cmake yasm
pip install virtualenv
#### On OS X (MacPorts)

``` sh
sudo port install python27 py27-virtualenv cmake yasm
#### On OS X >= 10.11 (El Capitan), you also have to install OpenSSL

``` sh
brew install openssl

export OPENSSL_INCLUDE_DIR="$(brew --prefix openssl)/include"
export OPENSSL_LIB_DIR="$(brew --prefix openssl)/lib"

./mach build ...

If you've already partially compiled servo but forgot to do this step, run `./mach clean`, set the shell variables, and recompile.

#### On Debian-based Linuxes

``` sh
sudo apt install git curl freeglut3-dev autoconf libx11-dev \
    libfreetype6-dev libgl1-mesa-dri libglib2.0-dev xorg-dev \
    gperf g++ build-essential cmake virtualenv python-pip \
    libssl1.0-dev libbz2-dev libosmesa6-dev libxmu6 libxmu-dev \
    libglu1-mesa-dev libgles2-mesa-dev libegl1-mesa-dev libdbus-1-dev

If you using a version prior to **Ubuntu 17.04** or **Debian Sid**, replace `libssl1.0-dev` with `libssl-dev`.

If you are on **Ubuntu 14.04** and encountered errors on installing these dependencies involving `libcheese`, see [#6158]( for a workaround.

If `virtualenv` does not exist, try `python-virtualenv`.

#### On Fedora

``` sh
sudo dnf install curl freeglut-devel libtool gcc-c++ libXi-devel \
    freetype-devel mesa-libGL-devel mesa-libEGL-devel glib2-devel libX11-devel libXrandr-devel gperf \
    fontconfig-devel cabextract ttmkfdir python python-virtualenv python-pip expat-devel \
    rpm-build openssl-devel cmake bzip2-devel libXcursor-devel libXmu-devel mesa-libOSMesa-devel \
    dbus-devel ncurses-devel
#### On openSUSE Linux
``` sh
sudo zypper install libX11-devel libexpat-devel libbz2-devel Mesa-libEGL-devel Mesa-libGL-devel cabextract cmake \
    dbus-1-devel fontconfig-devel freetype-devel gcc-c++ git glib2-devel gperf \
    harfbuzz-devel libOSMesa-devel libXcursor-devel libXi-devel libXmu-devel libXrandr-devel libopenssl-devel \
    python-pip python-virtualenv rpm-build glu-devel
#### On Arch Linux

``` sh
sudo pacman -S --needed base-devel git python2 python2-virtualenv python2-pip mesa cmake bzip2 libxmu glu pkg-config
#### On Gentoo Linux

sudo emerge net-misc/curl media-libs/freeglut \
    media-libs/freetype media-libs/mesa dev-util/gperf \
    dev-python/virtualenv dev-python/pip dev-libs/openssl \
    x11-libs/libXmu media-libs/glu x11-base/xorg-server
#### On Windows (MSVC)

1. Install Python for Windows ( The Windows x86-64 MSI installer is fine.
You should change the installation to install the "Add python.exe to Path" feature.

2. Install virtualenv.

 In a normal Windows Shell (cmd.exe or "Command Prompt" from the start menu), do:
pip install virtualenv
 If this does not work, you may need to reboot for the changed PATH settings (by the python installer) to take effect.

3. Install Git for Windows ( DO allow it to add git.exe to the PATH (default
settings for the installer are fine).

4. Install Visual Studio Community 2017 ( You MUST add "Visual C++" to the
list of installed components. It is not on by default.

#### Cross-compilation for Android

Pre-installed Android tools are needed. See wiki for

## The Rust compiler

Servo's build system automatically downloads a Rust compiler to build itself.
This is normally a specific revision of Rust upstream, but sometimes has a
backported patch or two.
If you'd like to know which nightly build of Rust we use, see

## Building

Servo is built with [Cargo](, the Rust package manager. We also use Mozilla's
Mach tools to orchestrate the build and other tasks.

### Normal build

To build Servo in development mode.  This is useful for development, but
the resulting binary is very slow.

``` sh
git clone
cd servo
./mach build --dev
./mach run tests/html/about-mozilla.html

Or on Windows MSVC, in a normal Command Prompt (cmd.exe):
``` cmd
git clone
cd servo
mach.bat build --dev

For benchmarking, performance testing, or
real-world use, add the `--release` flag to create an optimized build:

``` sh
./mach build --release
./mach run --release tests/html/about-mozilla.html

### Checking for build errors, without building

If you’re making changes to one crate that cause build errors in another crate,
consider this instead of a full build:

./mach check

It will run `cargo check`, which runs the analysis phase of the compiler
(and so shows build errors if any) but skips the code generation phase.
This can be a lot faster than a full build,
though of course it doesn’t produce a binary you can run.

### Building for Android target

``` sh
git clone
cd servo

export ANDROID_SDK="/path/to/sdk"
export ANDROID_NDK="/path/to/ndk"
export ANDROID_TOOLCHAIN="/path/to/toolchain"
export PATH="$PATH:/path/to/toolchain/bin"

./mach build --release --android
./mach package --release --android

Rather than setting the `ANDROID_*` environment variables every time, you can
also create a `.servobuild` file and then edit it to contain the correct paths
to the Android SDK/NDK tools:

cp servobuild.example .servobuild
# edit .servobuild

## Running

Use `./mach run [url]` to run Servo. Like so,

``` shell
./mach run

Also, don't miss the info on the [browserhtml page]( on how to run the Browser.html
full tech demo (it provides a more browser-like experience than just browsing a single
URL with servo).

### Commandline Arguments

- `-p INTERVAL` turns on the profiler and dumps info to the console every
  `INTERVAL` seconds
- `-s SIZE` sets the tile size for painting; defaults to 512
- `-z` disables all graphical output; useful for running JS / layout tests
- `-Z help` displays useful output to debug servo

### Keyboard Shortcuts

- `Ctrl`+`-` zooms out
- `Ctrl`+`=` zooms in
- `Alt`+`left arrow` goes backwards in the history
- `Alt`+`right arrow` goes forwards in the history
- `Esc` exits servo

## Developing

There are lots of mach commands you can use. You can list them with `./mach

The generated documentation can be found on