4 CMake is a multi-platform build tool that can generate build files for many
5 different target platforms. See more info at http://www.cmake.org
7 CMake also allows/recommends you to do "out of source"-builds, that is,
8 the build files are separated from your sources, so there is no need to
9 create elaborate clean scripts to get a clean source tree, instead you
10 simply remove your build directory.
12 Libwebsockets has been tested to build successfully on the following platforms
13 with SSL support (both OpenSSL/wolfSSL):
20 Building the library and test apps
21 ----------------------------------
23 The project settings used by CMake to generate the platform specific build
24 files is called [CMakeLists.txt](CMakeLists.txt). CMake then uses one of its "Generators" to
25 output a Visual Studio project or Make file for instance. To see a list of
26 the available generators for your platform, simply run the "cmake" command.
28 Note that by default OpenSSL will be linked, if you don't want SSL support
29 see below on how to toggle compile options.
34 1. Install CMake 2.8 or greater: http://cmake.org/cmake/resources/software.html
35 (Most Unix distributions comes with a packaged version also)
39 3. Generate the build files (default is Make files):
48 (**NOTE**: The `build/`` directory can have any name and be located anywhere
49 on your filesystem, and that the argument `..` given to cmake is simply
50 the source directory of **libwebsockets** containing the [CMakeLists.txt](CMakeLists.txt)
51 project file. All examples in this file assumes you use "..")
54 A common option you may want to give is to set the install path, same
55 as --prefix= with autotools. It defaults to /usr/local.
56 You can do this by, eg
59 $ cmake -DCMAKE_INSTALL_PREFIX:PATH=/usr ..
63 On machines that want libraries in lib64, you can also add the
64 following to the cmake line
71 If you are building against a non-distro OpenSSL (eg, in order to get
72 access to ALPN support only in newer OpenSSL versions) the nice way to
73 express that in one cmake command is eg,
76 $ cmake .. -DOPENSSL_ROOT_DIR=/usr/local/ssl \
77 -DCMAKE_INCLUDE_DIRECTORIES_PROJECT_BEFORE=/usr/local/ssl \
81 When you run the test apps using non-distro SSL, you have to force them
82 to use your libs, not the distro ones
85 $ LD_LIBRARY_PATH=/usr/local/ssl/lib libwebsockets-test-server --ssl
88 4. Finally you can build using the generated Makefile:
98 When changing cmake options, for some reason the only way to get it to see the
99 changes sometimes is delete the contents of your build directory and do the
103 Building on Windows (Visual Studio)
104 -----------------------------------
105 1. Install CMake 2.6 or greater: http://cmake.org/cmake/resources/software.html
107 2. Install OpenSSL binaries. http://www.openssl.org/related/binaries.html
108 (Preferably in the default location to make it easier for CMake to find them)
110 3. Generate the Visual studio project by opening the Visual Studio cmd prompt:
116 cmake -G "Visual Studio 10" ..
119 (**NOTE**: There is also a cmake-gui available on Windows if you prefer that)
121 4. Now you should have a generated Visual Studio Solution in your
122 `<path to src>/build` directory, which can be used to build.
124 Setting compile options
125 -----------------------
127 To set compile time flags you can either use one of the CMake gui applications
128 or do it via command line.
132 To list avaialable options (ommit the H if you don't want the help text):
136 Then to set an option and build (for example turn off SSL support):
138 cmake -DLWS_WITH_SSL=0 ..
140 cmake -DLWS_WITH_SSL:BOOL=OFF ..
144 If you have a curses enabled build you simply type:
145 (not all packages include this, my debian install does not for example).
151 On windows CMake comes with a gui application:
152 Start -> Programs -> CMake -> CMake (cmake-gui)
154 wolfSSL/CyaSSL replacement for OpenSSL
155 --------------------------------------
156 wolfSSL/CyaSSL is a lightweight SSL library targeted at embedded systems:
157 https://www.wolfssl.com/wolfSSL/Products-wolfssl.html
159 It contains a OpenSSL compatability layer which makes it possible to pretty
160 much link to it instead of OpenSSL, giving a much smaller footprint.
162 **NOTE**: wolfssl needs to be compiled using the `--enable-opensslextra` flag for
165 Compiling libwebsockets with wolfSSL
166 ------------------------------------
169 cmake .. -DLWS_USE_WOLFSSL=1 \
170 -DLWS_WOLFSSL_INCLUDE_DIRS=/path/to/wolfssl \
171 -DLWS_WOLFSSL_LIBRARIES=/path/to/wolfssl/wolfssl.a ..
174 **NOTE**: On windows use the .lib file extension for `LWS_WOLFSSL_LIBRARIES` instead.
176 Compiling libwebsockets with CyaSSL
177 -----------------------------------
180 cmake .. -DLWS_USE_CYASSL=1 \
181 -DLWS_CYASSL_INCLUDE_DIRS=/path/to/cyassl \
182 -DLWS_CYASSL_LIBRARIES=/path/to/wolfssl/cyassl.a ..
185 **NOTE**: On windows use the .lib file extension for `LWS_CYASSL_LIBRARIES` instead.
188 Reproducing HTTP2.0 tests
189 -------------------------
191 You must have built and be running lws against a version of openssl that has
192 ALPN / NPN. Most distros still have older versions. You'll know it's right by
196 lwsts[4752]: Compiled with OpenSSL support
197 lwsts[4752]: Using SSL mode
198 lwsts[4752]: HTTP2 / ALPN enabled
203 For non-SSL HTTP2.0 upgrade
206 $ nghttp -nvasu http://localhost:7681/test.htm
209 For SSL / ALPN HTTP2.0 upgrade
212 $ nghttp -nvas https://localhost:7681/test.html
217 To enable cross compiling **libwebsockets** using CMake you need to create
218 a "Toolchain file" that you supply to CMake when generating your build files.
219 CMake will then use the cross compilers and build paths specified in this file
220 to look for dependencies and such.
222 **Libwebsockets** includes an example toolchain file [cross-arm-linux-gnueabihf.cmake](cross-arm-linux-gnueabihf.cmake)
223 you can use as a starting point.
225 The commandline to configure for cross with this would look like
228 $ cmake .. -DCMAKE_INSTALL_PREFIX:PATH=/usr \
229 -DCMAKE_TOOLCHAIN_FILE=../cross-arm-linux-gnueabihf.cmake \
230 -DWITHOUT_EXTENSIONS=1 -DWITH_SSL=0
233 The example shows how to build with no external cross lib dependencies, you
234 need to provide the cross libraries otherwise.
236 **NOTE**: start from an EMPTY build directory if you had a non-cross build in there
237 before the settings will be cached and your changes ignored.
239 Additional information on cross compilation with CMake:
240 http://www.vtk.org/Wiki/CMake_Cross_Compiling
246 Embedded server-only configuration without extensions (ie, no compression
247 on websocket connections), but with full v13 websocket features and http
248 server, built on ARM Cortex-A9:
250 Update at 8dac94d (2013-02-18)
253 $ ./configure --without-client --without-extensions --disable-debug --without-daemonize
255 Context Creation, 1024 fd limit[2]: 16720 (includes 12 bytes per fd)
256 Per-connection [3]: 72 bytes, +1328 during headers
258 .text .rodata .data .bss
262 This shows the impact of the major configuration with/without options at
263 13ba5bbc633ea962d46d using Ubuntu ARM on a PandaBoard ES.
265 These are accounting for static allocations from the library elf, there are
266 additional dynamic allocations via malloc. These are a bit old now but give
267 the right idea for relative "expense" of features.
269 Static allocations, ARM9
271 | | .text | .rodata | .data | .bss |
272 |--------------------------------|---------|---------|-------|------|
273 | All (no without) | 35024 | 9940 | 336 | 4104 |
274 | without client | 25684 | 7144 | 336 | 4104 |
275 | without client, exts | 21652 | 6288 | 288 | 4104 |
276 | without client, exts, debug[1] | 19756 | 3768 | 288 | 4104 |
277 | without server | 30304 | 8160 | 336 | 4104 |
278 | without server, exts | 25382 | 7204 | 288 | 4104 |
279 | without server, exts, debug[1] | 23712 | 4256 | 288 | 4104 |
281 [1] `--disable-debug` only removes messages below `lwsl_notice`. Since that is
282 the default logging level the impact is not noticeable, error, warn and notice
283 logs are all still there.
285 [2] `1024` fd per process is the default limit (set by ulimit) in at least Fedora
286 and Ubuntu. You can make significant savings tailoring this to actual expected
287 peak fds, ie, at a limit of `20`, context creation allocation reduces to `4432 +
290 [3] known header content is freed after connection establishment