Date: Sat, 24 Nov 2007 10:10:26 +0000 Subject: [PATCH] include embedding doc in main doc --- ev.html | 294 +++++++++++++++++++++++++++++++++++++++++++++++++++++++- ev.pod | 19 ++-- 2 files changed, 299 insertions(+), 14 deletions(-) diff --git a/ev.html b/ev.html index 8c61bc2..9dd27c1 100644 --- a/ev.html +++ b/ev.html @@ -6,7 +6,7 @@ - + @@ -41,6 +41,17 @@

EMBEDDING +

FILESETS +
+
PREPROCESSOR SYMBOLS/MACROS
EXAMPLES

AUTHOR

@@ -1401,12 +1412,291 @@ the constructor.

io.start (fd, ev::READ); } + + + +

EMBEDDING

Top

Libev can (and often is) directly embedded into host +applications. Examples of applications that embed it include the Deliantra +Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe) +and rxvt-unicode.

The goal is to enable you to just copy the neecssary files into your +source directory without having to change even a single line in them, so +you can easily upgrade by simply copying (or having a checked-out copy of +libev somewhere in your source tree).

+ +

FILESETS

Depending on what features you need you need to include one or more sets of files +in your app.

+ +

CORE EVENT LOOP

To include only the libev core (all the ev_* functions), with manual +configuration (no autoconf):

  #define EV_STANDALONE 1
+  #include "ev.c"
+
+

This will automatically include ev.h, too, and should be done in a +single C source file only to provide the function implementations. To use +it, do the same for ev.h in all files wishing to use this API (best +done by writing a wrapper around ev.h that you can include instead and +where you can put other configuration options):

  #define EV_STANDALONE 1
+  #include "ev.h"
+
+

Both header files and implementation files can be compiled with a C++ +compiler (at least, thats a stated goal, and breakage will be treated +as a bug).

You need the following files in your source tree, or in a directory +in your include path (e.g. in libev/ when using -Ilibev):

  ev.h
+  ev.c
+  ev_vars.h
+  ev_wrap.h
+
+  ev_win32.c      required on win32 platforms only
+
+  ev_select.c     only when select backend is enabled (which is is by default)
+  ev_poll.c       only when poll backend is enabled (disabled by default)
+  ev_epoll.c      only when the epoll backend is enabled (disabled by default)
+  ev_kqueue.c     only when the kqueue backend is enabled (disabled by default)
+  ev_port.c       only when the solaris port backend is enabled (disabled by default)
+
+

ev.c includes the backend files directly when enabled, so you only need +to compile a single file.

+ +

LIBEVENT COMPATIBILITY API

To include the libevent compatibility API, also include:

  #include "event.c"
+
+

in the file including ev.c, and:

  #include "event.h"
+
+

in the files that want to use the libevent API. This also includes ev.h.

You need the following additional files for this:

  event.h
+  event.c
+
+

+ +

AUTOCONF SUPPORT

Instead of using EV_STANDALONE=1 and providing your config in +whatever way you want, you can also m4_include([libev.m4]) in your +configure.ac and leave EV_STANDALONE off. ev.c will then include +config.h and configure itself accordingly.

For this of course you need the m4 file:

  libev.m4
+
+

+ +

PREPROCESSOR SYMBOLS/MACROS

Libev can be configured via a variety of preprocessor symbols you have to define +before including any of its files. The default is not to build for multiplicity +and only include the select backend.

EV_STANDALONE

Must always be 1 if you do not use autoconf configuration, which +keeps libev from including config.h, and it also defines dummy +implementations for some libevent functions (such as logging, which is not +supported). It will also not define any of the structs usually found in +event.h that are not directly supported by the libev core alone.

EV_USE_MONOTONIC

If defined to be 1, libev will try to detect the availability of the +monotonic clock option at both compiletime and runtime. Otherwise no use +of the monotonic clock option will be attempted. If you enable this, you +usually have to link against librt or something similar. Enabling it when +the functionality isn't available is safe, though, althoguh you have +to make sure you link against any libraries where the clock_gettime +function is hiding in (often -lrt).

EV_USE_REALTIME

If defined to be 1, libev will try to detect the availability of the +realtime clock option at compiletime (and assume its availability at +runtime if successful). Otherwise no use of the realtime clock option will +be attempted. This effectively replaces gettimeofday by clock_get +(CLOCK_REALTIME, ...) and will not normally affect correctness. See tzhe note about libraries +in the description of EV_USE_MONOTONIC, though.

EV_USE_SELECT

If undefined or defined to be 1, libev will compile in support for the +select(2) backend. No attempt at autodetection will be done: if no +other method takes over, select will be it. Otherwise the select backend +will not be compiled in.

EV_SELECT_USE_FD_SET

If defined to 1, then the select backend will use the system fd_set +structure. This is useful if libev doesn't compile due to a missing +NFDBITS or fd_mask definition or it misguesses the bitset layout on +exotic systems. This usually limits the range of file descriptors to some +low limit such as 1024 or might have other limitations (winsocket only +allows 64 sockets). The FD_SETSIZE macro, set before compilation, might +influence the size of the fd_set used.

EV_SELECT_IS_WINSOCKET

When defined to 1, the select backend will assume that +select/socket/connect etc. don't understand file descriptors but +wants osf handles on win32 (this is the case when the select to +be used is the winsock select). This means that it will call +_get_osfhandle on the fd to convert it to an OS handle. Otherwise, +it is assumed that all these functions actually work on fds, even +on win32. Should not be defined on non-win32 platforms.

EV_USE_POLL

If defined to be 1, libev will compile in support for the poll(2) +backend. Otherwise it will be enabled on non-win32 platforms. It +takes precedence over select.

EV_USE_EPOLL

If defined to be 1, libev will compile in support for the Linux +epoll(7) backend. Its availability will be detected at runtime, +otherwise another method will be used as fallback. This is the +preferred backend for GNU/Linux systems.

EV_USE_KQUEUE

If defined to be 1, libev will compile in support for the BSD style +kqueue(2) backend. Its actual availability will be detected at runtime, +otherwise another method will be used as fallback. This is the preferred +backend for BSD and BSD-like systems, although on most BSDs kqueue only +supports some types of fds correctly (the only platform we found that +supports ptys for example was NetBSD), so kqueue might be compiled in, but +not be used unless explicitly requested. The best way to use it is to find +out wether kqueue supports your type of fd properly and use an embedded +kqueue loop.

EV_USE_PORT

If defined to be 1, libev will compile in support for the Solaris +10 port style backend. Its availability will be detected at runtime, +otherwise another method will be used as fallback. This is the preferred +backend for Solaris 10 systems.

EV_USE_DEVPOLL

reserved for future expansion, works like the USE symbols above.

EV_H

The name of the ev.h header file used to include it. The default if +undefined is <ev.h> in event.h and "ev.h" in ev.c. This +can be used to virtually rename the ev.h header file in case of conflicts.

EV_CONFIG_H

If EV_STANDALONE isn't 1, this variable can be used to override +ev.c's idea of where to find the config.h file, similarly to +EV_H, above.

EV_EVENT_H

Similarly to EV_H, this macro can be used to override event.c's idea +of how the event.h header can be found.

EV_PROTOTYPES

If defined to be 0, then ev.h will not define any function +prototypes, but still define all the structs and other symbols. This is +occasionally useful if you want to provide your own wrapper functions +around libev functions.

EV_MULTIPLICITY

If undefined or defined to 1, then all event-loop-specific functions +will have the struct ev_loop * as first argument, and you can create +additional independent event loops. Otherwise there will be no support +for multiple event loops and there is no first event loop pointer +argument. Instead, all functions act on the single default loop.

EV_PERIODICS

If undefined or defined to be 1, then periodic timers are supported, +otherwise not. This saves a few kb of code.

EV_COMMON

By default, all watchers have a void *data member. By redefining +this macro to a something else you can include more and other types of +members. You have to define it each time you include one of the files, +though, and it must be identical each time.

For example, the perl EV module uses something like this:

  #define EV_COMMON                       \
+    SV *self; /* contains this struct */  \
+    SV *cb_sv, *fh /* note no trailing ";" */
+
+

EV_CB_DECLARE(type)

EV_CB_INVOKE(watcher,revents)

ev_set_cb(ev,cb)

Can be used to change the callback member declaration in each watcher, +and the way callbacks are invoked and set. Must expand to a struct member +definition and a statement, respectively. See the ev.v header file for +their default definitions. One possible use for overriding these is to +avoid the ev_loop pointer as first argument in all cases, or to use method +calls instead of plain function calls in C++.

+ +

EXAMPLES

For a real-world example of a program the includes libev +verbatim, you can have a look at the EV perl module +(http://software.schmorp.de/pkg/EV.html). It has the libev files in +the libev/ subdirectory and includes them in the EV/EVAPI.h (public +interface) and EV.xs (implementation) files. Only the EV.xs file +will be compiled. It is pretty complex because it provides its own header +file.

The usage in rxvt-unicode is simpler. It has a ev_cpp.h header file +that everybody includes and which overrides some autoconf choices:

   #define EV_USE_POLL 0
+   #define EV_MULTIPLICITY 0
+   #define EV_PERIODICS 0
+   #define EV_CONFIG_H <config.h>
+
+   #include "ev++.h"
+
+

And a ev_cpp.C implementation file that contains libev proper and is compiled:

   #include "rxvttoolkit.h"
+
+   /* darwin has problems with its header files in C++, requiring this namespace juggling */
+   using namespace ev;
+
+   #include "ev.c"
+
+
+
+

AUTHOR

Top

Marc Lehmann <libev@schmorp.de>.

diff --git a/ev.pod b/ev.pod index 05bac98..30439ef 100644 --- a/ev.pod +++ b/ev.pod @@ -1675,22 +1675,17 @@ file. The usage in rxvt-unicode is simpler. It has a F header file that everybody includes and which overrides some autoconf choices: - #define EV_USE_POLL 0 - #define EV_MULTIPLICITY 0 - #define EV_PERIODICS 0 - #define EV_CONFIG_H + #define EV_USE_POLL 0 + #define EV_MULTIPLICITY 0 + #define EV_PERIODICS 0 + #define EV_CONFIG_H - #include "ev++.h" + #include "ev++.h" And a F implementation file that contains libev proper and is compiled: - #include "rxvttoolkit.h" - - /* darwin has problems with its header files in C++, requiring this namespace juggling */ - using namespace ev; - - #include "ev.c" - + #include "ev_cpp.h" + #include "ev.c" =head1 AUTHOR -- 2.43.0