libuv is a multi-platform support library with a focus on asynchronous I/O. It
was primarily developed for use by Node.js, but it's also
used by Luvit, Julia,
pyuv, and others.
Feature highlights
Full-featured event loop backed by epoll, kqueue, IOCP, event ports.
Asynchronous TCP and UDP sockets
Asynchronous DNS resolution
Asynchronous file and file system operations
File system events
ANSI escape code controlled TTY
IPC with socket sharing, using Unix domain sockets or named pipes (Windows)
Child processes
Thread pool
Signal handling
High resolution clock
Threading and synchronization primitives
Versioning
Starting with version 1.0.0 libuv follows the semantic versioning
scheme. The API change and backwards compatibility rules are those indicated by
SemVer. libuv will keep a stable ABI across major releases.
libuv is licensed under the MIT license. Check the LICENSE file.
The documentation is licensed under the CC BY 4.0 license. Check the LICENSE-docs file.
Starting with libuv 1.7.0, binaries for Windows are also provided. This is to
be considered EXPERIMENTAL.
Before verifying the git tags or signature files, importing the relevant keys
is necessary. Key IDs are listed in the
MAINTAINERS
file, but are also available as git blob objects for easier use.
Git tags are signed with the developer's key, they can be verified as follows:
$ git verify-tag v1.6.1
Starting with libuv 1.7.0, the tarballs stored in the
downloads site are signed and an accompanying
signature file sit alongside each. Once both the release tarball and the
signature file are downloaded, the file can be verified as follows:
$ gpg --verify libuv-1.7.0.tar.gz.sign
Build Instructions
For GCC there are two build methods: via autotools or via GYP.
GYP is a meta-build system which can generate MSVS, Makefile, and XCode
backends. It is best used for integration into other projects.
To build with autotools:
$ sh autogen.sh
$ ./configure
$ make
$ make check
$ make install
Python 2.6 or 2.7 as it is required
by GYP.
If python is not in your path, set the environment variable PYTHON to its
location. For example: set PYTHON=C:\Python27\python.exe
Visual Studio 2015 Update 3, all editions
including the Community edition (remember to select
"Common Tools for Visual C++ 2015" feature during installation).
Visual Studio 2017, any edition (including the Build Tools SKU).
Required Components: "MSbuild", "VC++ 2017 v141 toolset" and one of the
Windows SDKs (10 or 8.1).
Basic Unix tools required for some tests,
Git for Windows includes Git Bash
and tools which can be included in the global PATH.
To build, launch a git shell (e.g. Cmd or PowerShell), run vcbuild.bat
(to build with VS2017 you need to explicitly add a vs2017 argument),
which will checkout the GYP code into build/gyp, generate uv.sln
as well as the necesery related project files, and start building.
> vcbuild
Or:
> vcbuild vs2017
To run the tests:
> vcbuild test
To see all the options that could passed to vcbuild:
> vcbuild help
vcbuild.bat [debug/release] [test/bench] [clean] [noprojgen] [nobuild] [vs2017] [x86/x64] [static/shared]
Examples:
vcbuild.bat : builds debug build
vcbuild.bat test : builds debug build and runs tests
vcbuild.bat release bench: builds release build and runs benchmarks
Unix
For Debug builds (recommended) run:
$ ./gyp_uv.py -f make
$ make -C out
For Release builds run:
$ ./gyp_uv.py -f make
$ BUILDTYPE=Release make -C out
Run ./gyp_uv.py -f make -Dtarget_arch=x32 to build x32 binaries.
Make sure that you specify the architecture you wish to build for in the
"ARCHS" flag. You can specify more than one by delimiting with a space
(e.g. "x86_64 i386").
Android
Run:
For arm
$ source ./android-configure-arm NDK_PATH gyp [API_LEVEL]
$ make -C out
or for arm64
$ source ./android-configure-arm64 NDK_PATH gyp [API_LEVEL]
$ make -C out
or for x86
$ source ./android-configure-x86 NDK_PATH gyp [API_LEVEL]
$ make -C out
or for x86_64
$ source ./android-configure-x86_64 NDK_PATH gyp [API_LEVEL]
$ make -C out
The default API level is 24, but a different one can be selected as follows:
$ source ./android-configure-arm ~/android-ndk-r15b gyp 21
$ make -C out
Note for UNIX users: compile your project with -D_LARGEFILE_SOURCE and
-D_FILE_OFFSET_BITS=64. GYP builds take care of that automatically.
Using Ninja
To use ninja for build on ninja supported platforms, run:
This invocation will cause the run-tests driver to fork and execute TEST_NAME in a child process:
$ ./out/Debug/run-tests TEST_NAME
This invocation will cause the run-tests driver to execute the test within the run-tests process:
$ ./out/Debug/run-tests TEST_NAME TEST_NAME
Debugging tools
When running the test from within the run-tests process (run-tests TEST_NAME TEST_NAME), tools like gdb and valgrind work normally.
When running the test from a child of the run-tests process (run-tests TEST_NAME), use these tools in a fork-aware manner.
AIX compilation using IBM XL C/C++ requires version 12.1 or greater.
AIX support for filesystem events requires the non-default IBM bos.ahafs
package to be installed. This package provides the AIX Event Infrastructure
that is detected by autoconf.
IBM documentation
describes the package in more detail.
AIX support for filesystem events is not compiled when building with gyp.
z/OS Notes
z/OS creates System V semaphores and message queues. These persist on the system
after the process terminates unless the event loop is closed.
Use the ipcrm command to manually clear up System V resources.
Overview
libuv is a multi-platform support library with a focus on asynchronous I/O. It was primarily developed for use by Node.js, but it's also used by Luvit, Julia, pyuv, and others.
Feature highlights
Full-featured event loop backed by epoll, kqueue, IOCP, event ports.
Asynchronous TCP and UDP sockets
Asynchronous DNS resolution
Asynchronous file and file system operations
File system events
ANSI escape code controlled TTY
IPC with socket sharing, using Unix domain sockets or named pipes (Windows)
Child processes
Thread pool
Signal handling
High resolution clock
Threading and synchronization primitives
Versioning
Starting with version 1.0.0 libuv follows the semantic versioning scheme. The API change and backwards compatibility rules are those indicated by SemVer. libuv will keep a stable ABI across major releases.
The ABI/API changes can be tracked here.
Licensing
libuv is licensed under the MIT license. Check the LICENSE file. The documentation is licensed under the CC BY 4.0 license. Check the LICENSE-docs file.
Community
Documentation
Official documentation
Located in the docs/ subdirectory. It uses the Sphinx framework, which makes it possible to build the documentation in multiple formats.
Show different supported building options:
Build documentation as HTML:
Build documentation as HTML and live reload it when it changes (this requires sphinx-autobuild to be installed and is only supported on Unix):
Build documentation as man pages:
Build documentation as ePub:
NOTE: Windows users need to use make.bat instead of plain 'make'.
Documentation can be browsed online here.
The tests and benchmarks also serve as API specification and usage examples.
Other resources
These resources are not handled by libuv maintainers and might be out of date. Please verify it before opening new issues.
Downloading
libuv can be downloaded either from the GitHub repository or from the downloads site.
Starting with libuv 1.7.0, binaries for Windows are also provided. This is to be considered EXPERIMENTAL.
Before verifying the git tags or signature files, importing the relevant keys is necessary. Key IDs are listed in the MAINTAINERS file, but are also available as git blob objects for easier use.
Importing a key the usual way:
Importing a key from a git blob object:
Verifying releases
Git tags are signed with the developer's key, they can be verified as follows:
Starting with libuv 1.7.0, the tarballs stored in the downloads site are signed and an accompanying signature file sit alongside each. Once both the release tarball and the signature file are downloaded, the file can be verified as follows:
Build Instructions
For GCC there are two build methods: via autotools or via GYP. GYP is a meta-build system which can generate MSVS, Makefile, and XCode backends. It is best used for integration into other projects.
To build with autotools:
To build with CMake:
To build with GYP, first run:
Windows
Prerequisites:
PYTHON
to its location. For example:set PYTHON=C:\Python27\python.exe
PATH
.To build, launch a git shell (e.g. Cmd or PowerShell), run
vcbuild.bat
(to build with VS2017 you need to explicitly add avs2017
argument), which will checkout the GYP code intobuild/gyp
, generateuv.sln
as well as the necesery related project files, and start building.Or:
To run the tests:
To see all the options that could passed to
vcbuild
:Unix
For Debug builds (recommended) run:
For Release builds run:
Run
./gyp_uv.py -f make -Dtarget_arch=x32
to build x32 binaries.OS X
Run:
Using Homebrew:
Note to OS X users:
Make sure that you specify the architecture you wish to build for in the "ARCHS" flag. You can specify more than one by delimiting with a space (e.g. "x86_64 i386").
Android
Run:
For arm
or for arm64
or for x86
or for x86_64
The default API level is 24, but a different one can be selected as follows:
Note for UNIX users: compile your project with
-D_LARGEFILE_SOURCE
and-D_FILE_OFFSET_BITS=64
. GYP builds take care of that automatically.Using Ninja
To use ninja for build on ninja supported platforms, run:
Running tests
Build
Build (includes tests):
Run all tests
Run one test
The list of all tests is in
test/test-list.h
.This invocation will cause the
run-tests
driver to fork and executeTEST_NAME
in a child process:This invocation will cause the
run-tests
driver to execute the test within therun-tests
process:Debugging tools
When running the test from within the
run-tests
process (run-tests TEST_NAME TEST_NAME
), tools like gdb and valgrind work normally. When running the test from a child of therun-tests
process (run-tests TEST_NAME
), use these tools in a fork-aware manner.Fork-aware gdb
Use the follow-fork-mode setting:
Fork-aware valgrind
Use the
--trace-children=yes
parameter:Running benchmarks
See the section on running tests. The benchmark driver is
out/Debug/run-benchmarks
and the benchmarks are listed intest/benchmark-list.h
.Supported Platforms
Check the SUPPORTED_PLATFORMS file.
AIX Notes
AIX compilation using IBM XL C/C++ requires version 12.1 or greater.
AIX support for filesystem events requires the non-default IBM
bos.ahafs
package to be installed. This package provides the AIX Event Infrastructure that is detected byautoconf
. IBM documentation describes the package in more detail.AIX support for filesystem events is not compiled when building with
gyp
.z/OS Notes
z/OS creates System V semaphores and message queues. These persist on the system after the process terminates unless the event loop is closed.
Use the
ipcrm
command to manually clear up System V resources.Patches
See the guidelines for contributing.