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4 | <head> |
4 | <head> |
5 | <title>libev</title> |
5 | <title>libev</title> |
6 | <meta name="description" content="Pod documentation for libev" /> |
6 | <meta name="description" content="Pod documentation for libev" /> |
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7 | <meta name="inputfile" content="<standard input>" /> |
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8 | <meta name="outputfile" content="<standard output>" /> |
9 | <meta name="created" content="Tue Nov 27 21:26:46 2007" /> |
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12 | <body> |
12 | <body> |
13 | <div class="pod"> |
13 | <div class="pod"> |
14 | <!-- INDEX START --> |
14 | <!-- INDEX START --> |
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60 | <li><a href="#AUTHOR">AUTHOR</a> |
60 | <li><a href="#AUTHOR">AUTHOR</a> |
61 | </li> |
61 | </li> |
62 | </ul><hr /> |
62 | </ul><hr /> |
63 | <!-- INDEX END --> |
63 | <!-- INDEX END --> |
64 | |
64 | |
65 | <h1 id="NAME">NAME</h1><p><a href="#TOP" class="toplink">Top</a></p> |
65 | <h1 id="NAME">NAME</h1> |
66 | <div id="NAME_CONTENT"> |
66 | <div id="NAME_CONTENT"> |
67 | <p>libev - a high performance full-featured event loop written in C</p> |
67 | <p>libev - a high performance full-featured event loop written in C</p> |
68 | |
68 | |
69 | </div> |
69 | </div> |
70 | <h1 id="SYNOPSIS">SYNOPSIS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
70 | <h1 id="SYNOPSIS">SYNOPSIS</h1> |
71 | <div id="SYNOPSIS_CONTENT"> |
71 | <div id="SYNOPSIS_CONTENT"> |
72 | <pre> #include <ev.h> |
72 | <pre> #include <ev.h> |
73 | |
73 | |
74 | </pre> |
74 | </pre> |
75 | |
75 | |
76 | </div> |
76 | </div> |
77 | <h1 id="EXAMPLE_PROGRAM">EXAMPLE PROGRAM</h1><p><a href="#TOP" class="toplink">Top</a></p> |
77 | <h1 id="EXAMPLE_PROGRAM">EXAMPLE PROGRAM</h1> |
78 | <div id="EXAMPLE_PROGRAM_CONTENT"> |
78 | <div id="EXAMPLE_PROGRAM_CONTENT"> |
79 | <pre> #include <ev.h> |
79 | <pre> #include <ev.h> |
80 | |
80 | |
81 | ev_io stdin_watcher; |
81 | ev_io stdin_watcher; |
82 | ev_timer timeout_watcher; |
82 | ev_timer timeout_watcher; |
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117 | } |
117 | } |
118 | |
118 | |
119 | </pre> |
119 | </pre> |
120 | |
120 | |
121 | </div> |
121 | </div> |
122 | <h1 id="DESCRIPTION">DESCRIPTION</h1><p><a href="#TOP" class="toplink">Top</a></p> |
122 | <h1 id="DESCRIPTION">DESCRIPTION</h1> |
123 | <div id="DESCRIPTION_CONTENT"> |
123 | <div id="DESCRIPTION_CONTENT"> |
124 | <p>Libev is an event loop: you register interest in certain events (such as a |
124 | <p>Libev is an event loop: you register interest in certain events (such as a |
125 | file descriptor being readable or a timeout occuring), and it will manage |
125 | file descriptor being readable or a timeout occuring), and it will manage |
126 | these event sources and provide your program with events.</p> |
126 | these event sources and provide your program with events.</p> |
127 | <p>To do this, it must take more or less complete control over your process |
127 | <p>To do this, it must take more or less complete control over your process |
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… | |
131 | watchers</i>, which are relatively small C structures you initialise with the |
131 | watchers</i>, which are relatively small C structures you initialise with the |
132 | details of the event, and then hand it over to libev by <i>starting</i> the |
132 | details of the event, and then hand it over to libev by <i>starting</i> the |
133 | watcher.</p> |
133 | watcher.</p> |
134 | |
134 | |
135 | </div> |
135 | </div> |
136 | <h1 id="FEATURES">FEATURES</h1><p><a href="#TOP" class="toplink">Top</a></p> |
136 | <h1 id="FEATURES">FEATURES</h1> |
137 | <div id="FEATURES_CONTENT"> |
137 | <div id="FEATURES_CONTENT"> |
138 | <p>Libev supports <code>select</code>, <code>poll</code>, the linux-specific <code>epoll</code>, the |
138 | <p>Libev supports <code>select</code>, <code>poll</code>, the Linux-specific <code>epoll</code>, the |
139 | bsd-specific <code>kqueue</code> and the solaris-specific event port mechanisms |
139 | BSD-specific <code>kqueue</code> and the Solaris-specific event port mechanisms |
140 | for file descriptor events (<code>ev_io</code>), relative timers (<code>ev_timer</code>), |
140 | for file descriptor events (<code>ev_io</code>), the Linux <code>inotify</code> interface |
|
|
141 | (for <code>ev_stat</code>), relative timers (<code>ev_timer</code>), absolute timers |
141 | absolute timers with customised rescheduling (<code>ev_periodic</code>), synchronous |
142 | with customised rescheduling (<code>ev_periodic</code>), synchronous signals |
142 | signals (<code>ev_signal</code>), process status change events (<code>ev_child</code>), and |
143 | (<code>ev_signal</code>), process status change events (<code>ev_child</code>), and event |
143 | event watchers dealing with the event loop mechanism itself (<code>ev_idle</code>, |
144 | watchers dealing with the event loop mechanism itself (<code>ev_idle</code>, |
144 | <code>ev_embed</code>, <code>ev_prepare</code> and <code>ev_check</code> watchers) as well as |
145 | <code>ev_embed</code>, <code>ev_prepare</code> and <code>ev_check</code> watchers) as well as |
145 | file watchers (<code>ev_stat</code>) and even limited support for fork events |
146 | file watchers (<code>ev_stat</code>) and even limited support for fork events |
146 | (<code>ev_fork</code>).</p> |
147 | (<code>ev_fork</code>).</p> |
147 | <p>It also is quite fast (see this |
148 | <p>It also is quite fast (see this |
148 | <a href="http://libev.schmorp.de/bench.html">benchmark</a> comparing it to libevent |
149 | <a href="http://libev.schmorp.de/bench.html">benchmark</a> comparing it to libevent |
149 | for example).</p> |
150 | for example).</p> |
150 | |
151 | |
151 | </div> |
152 | </div> |
152 | <h1 id="CONVENTIONS">CONVENTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
153 | <h1 id="CONVENTIONS">CONVENTIONS</h1> |
153 | <div id="CONVENTIONS_CONTENT"> |
154 | <div id="CONVENTIONS_CONTENT"> |
154 | <p>Libev is very configurable. In this manual the default configuration will |
155 | <p>Libev is very configurable. In this manual the default configuration will |
155 | be described, which supports multiple event loops. For more info about |
156 | be described, which supports multiple event loops. For more info about |
156 | various configuration options please have a look at <strong>EMBED</strong> section in |
157 | various configuration options please have a look at <strong>EMBED</strong> section in |
157 | this manual. If libev was configured without support for multiple event |
158 | this manual. If libev was configured without support for multiple event |
158 | loops, then all functions taking an initial argument of name <code>loop</code> |
159 | loops, then all functions taking an initial argument of name <code>loop</code> |
159 | (which is always of type <code>struct ev_loop *</code>) will not have this argument.</p> |
160 | (which is always of type <code>struct ev_loop *</code>) will not have this argument.</p> |
160 | |
161 | |
161 | </div> |
162 | </div> |
162 | <h1 id="TIME_REPRESENTATION">TIME REPRESENTATION</h1><p><a href="#TOP" class="toplink">Top</a></p> |
163 | <h1 id="TIME_REPRESENTATION">TIME REPRESENTATION</h1> |
163 | <div id="TIME_REPRESENTATION_CONTENT"> |
164 | <div id="TIME_REPRESENTATION_CONTENT"> |
164 | <p>Libev represents time as a single floating point number, representing the |
165 | <p>Libev represents time as a single floating point number, representing the |
165 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
166 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
166 | the beginning of 1970, details are complicated, don't ask). This type is |
167 | the beginning of 1970, details are complicated, don't ask). This type is |
167 | called <code>ev_tstamp</code>, which is what you should use too. It usually aliases |
168 | called <code>ev_tstamp</code>, which is what you should use too. It usually aliases |
168 | to the <code>double</code> type in C, and when you need to do any calculations on |
169 | to the <code>double</code> type in C, and when you need to do any calculations on |
169 | it, you should treat it as such.</p> |
170 | it, you should treat it as such.</p> |
170 | |
171 | |
171 | </div> |
172 | </div> |
172 | <h1 id="GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
173 | <h1 id="GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</h1> |
173 | <div id="GLOBAL_FUNCTIONS_CONTENT"> |
174 | <div id="GLOBAL_FUNCTIONS_CONTENT"> |
174 | <p>These functions can be called anytime, even before initialising the |
175 | <p>These functions can be called anytime, even before initialising the |
175 | library in any way.</p> |
176 | library in any way.</p> |
176 | <dl> |
177 | <dl> |
177 | <dt>ev_tstamp ev_time ()</dt> |
178 | <dt>ev_tstamp ev_time ()</dt> |
… | |
… | |
229 | might be supported on the current system, you would need to look at |
230 | might be supported on the current system, you would need to look at |
230 | <code>ev_embeddable_backends () & ev_supported_backends ()</code>, likewise for |
231 | <code>ev_embeddable_backends () & ev_supported_backends ()</code>, likewise for |
231 | recommended ones.</p> |
232 | recommended ones.</p> |
232 | <p>See the description of <code>ev_embed</code> watchers for more info.</p> |
233 | <p>See the description of <code>ev_embed</code> watchers for more info.</p> |
233 | </dd> |
234 | </dd> |
234 | <dt>ev_set_allocator (void *(*cb)(void *ptr, size_t size))</dt> |
235 | <dt>ev_set_allocator (void *(*cb)(void *ptr, long size))</dt> |
235 | <dd> |
236 | <dd> |
236 | <p>Sets the allocation function to use (the prototype and semantics are |
237 | <p>Sets the allocation function to use (the prototype is similar - the |
237 | identical to the realloc C function). It is used to allocate and free |
238 | semantics is identical - to the realloc C function). It is used to |
238 | memory (no surprises here). If it returns zero when memory needs to be |
239 | allocate and free memory (no surprises here). If it returns zero when |
239 | allocated, the library might abort or take some potentially destructive |
240 | memory needs to be allocated, the library might abort or take some |
240 | action. The default is your system realloc function.</p> |
241 | potentially destructive action. The default is your system realloc |
|
|
242 | function.</p> |
241 | <p>You could override this function in high-availability programs to, say, |
243 | <p>You could override this function in high-availability programs to, say, |
242 | free some memory if it cannot allocate memory, to use a special allocator, |
244 | free some memory if it cannot allocate memory, to use a special allocator, |
243 | or even to sleep a while and retry until some memory is available.</p> |
245 | or even to sleep a while and retry until some memory is available.</p> |
244 | <p>Example: Replace the libev allocator with one that waits a bit and then |
246 | <p>Example: Replace the libev allocator with one that waits a bit and then |
245 | retries).</p> |
247 | retries).</p> |
… | |
… | |
285 | </pre> |
287 | </pre> |
286 | </dd> |
288 | </dd> |
287 | </dl> |
289 | </dl> |
288 | |
290 | |
289 | </div> |
291 | </div> |
290 | <h1 id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP">FUNCTIONS CONTROLLING THE EVENT LOOP</h1><p><a href="#TOP" class="toplink">Top</a></p> |
292 | <h1 id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP">FUNCTIONS CONTROLLING THE EVENT LOOP</h1> |
291 | <div id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP-2"> |
293 | <div id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP-2"> |
292 | <p>An event loop is described by a <code>struct ev_loop *</code>. The library knows two |
294 | <p>An event loop is described by a <code>struct ev_loop *</code>. The library knows two |
293 | types of such loops, the <i>default</i> loop, which supports signals and child |
295 | types of such loops, the <i>default</i> loop, which supports signals and child |
294 | events, and dynamically created loops which do not.</p> |
296 | events, and dynamically created loops which do not.</p> |
295 | <p>If you use threads, a common model is to run the default event loop |
297 | <p>If you use threads, a common model is to run the default event loop |
… | |
… | |
568 | |
570 | |
569 | |
571 | |
570 | |
572 | |
571 | |
573 | |
572 | </div> |
574 | </div> |
573 | <h1 id="ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</h1><p><a href="#TOP" class="toplink">Top</a></p> |
575 | <h1 id="ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</h1> |
574 | <div id="ANATOMY_OF_A_WATCHER_CONTENT"> |
576 | <div id="ANATOMY_OF_A_WATCHER_CONTENT"> |
575 | <p>A watcher is a structure that you create and register to record your |
577 | <p>A watcher is a structure that you create and register to record your |
576 | interest in some event. For instance, if you want to wait for STDIN to |
578 | interest in some event. For instance, if you want to wait for STDIN to |
577 | become readable, you would create an <code>ev_io</code> watcher for that:</p> |
579 | become readable, you would create an <code>ev_io</code> watcher for that:</p> |
578 | <pre> static void my_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
580 | <pre> static void my_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
… | |
… | |
741 | events but its callback has not yet been invoked). As long as a watcher |
743 | events but its callback has not yet been invoked). As long as a watcher |
742 | is pending (but not active) you must not call an init function on it (but |
744 | is pending (but not active) you must not call an init function on it (but |
743 | <code>ev_TYPE_set</code> is safe) and you must make sure the watcher is available to |
745 | <code>ev_TYPE_set</code> is safe) and you must make sure the watcher is available to |
744 | libev (e.g. you cnanot <code>free ()</code> it).</p> |
746 | libev (e.g. you cnanot <code>free ()</code> it).</p> |
745 | </dd> |
747 | </dd> |
746 | <dt>callback = ev_cb (ev_TYPE *watcher)</dt> |
748 | <dt>callback ev_cb (ev_TYPE *watcher)</dt> |
747 | <dd> |
749 | <dd> |
748 | <p>Returns the callback currently set on the watcher.</p> |
750 | <p>Returns the callback currently set on the watcher.</p> |
749 | </dd> |
751 | </dd> |
750 | <dt>ev_cb_set (ev_TYPE *watcher, callback)</dt> |
752 | <dt>ev_cb_set (ev_TYPE *watcher, callback)</dt> |
751 | <dd> |
753 | <dd> |
… | |
… | |
783 | struct my_io *w = (struct my_io *)w_; |
785 | struct my_io *w = (struct my_io *)w_; |
784 | ... |
786 | ... |
785 | } |
787 | } |
786 | |
788 | |
787 | </pre> |
789 | </pre> |
788 | <p>More interesting and less C-conformant ways of catsing your callback type |
790 | <p>More interesting and less C-conformant ways of casting your callback type |
789 | have been omitted....</p> |
791 | instead have been omitted.</p> |
|
|
792 | <p>Another common scenario is having some data structure with multiple |
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|
793 | watchers:</p> |
|
|
794 | <pre> struct my_biggy |
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|
795 | { |
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796 | int some_data; |
|
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797 | ev_timer t1; |
|
|
798 | ev_timer t2; |
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|
799 | } |
790 | |
800 | |
|
|
801 | </pre> |
|
|
802 | <p>In this case getting the pointer to <code>my_biggy</code> is a bit more complicated, |
|
|
803 | you need to use <code>offsetof</code>:</p> |
|
|
804 | <pre> #include <stddef.h> |
791 | |
805 | |
|
|
806 | static void |
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807 | t1_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
808 | { |
|
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809 | struct my_biggy big = (struct my_biggy * |
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810 | (((char *)w) - offsetof (struct my_biggy, t1)); |
|
|
811 | } |
792 | |
812 | |
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|
813 | static void |
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814 | t2_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
815 | { |
|
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816 | struct my_biggy big = (struct my_biggy * |
|
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817 | (((char *)w) - offsetof (struct my_biggy, t2)); |
|
|
818 | } |
793 | |
819 | |
794 | |
820 | |
|
|
821 | |
|
|
822 | |
|
|
823 | </pre> |
|
|
824 | |
795 | </div> |
825 | </div> |
796 | <h1 id="WATCHER_TYPES">WATCHER TYPES</h1><p><a href="#TOP" class="toplink">Top</a></p> |
826 | <h1 id="WATCHER_TYPES">WATCHER TYPES</h1> |
797 | <div id="WATCHER_TYPES_CONTENT"> |
827 | <div id="WATCHER_TYPES_CONTENT"> |
798 | <p>This section describes each watcher in detail, but will not repeat |
828 | <p>This section describes each watcher in detail, but will not repeat |
799 | information given in the last section. Any initialisation/set macros, |
829 | information given in the last section. Any initialisation/set macros, |
800 | functions and members specific to the watcher type are explained.</p> |
830 | functions and members specific to the watcher type are explained.</p> |
801 | <p>Members are additionally marked with either <i>[read-only]</i>, meaning that, |
831 | <p>Members are additionally marked with either <i>[read-only]</i>, meaning that, |
… | |
… | |
1219 | not exist" is a status change like any other. The condition "path does |
1249 | not exist" is a status change like any other. The condition "path does |
1220 | not exist" is signified by the <code>st_nlink</code> field being zero (which is |
1250 | not exist" is signified by the <code>st_nlink</code> field being zero (which is |
1221 | otherwise always forced to be at least one) and all the other fields of |
1251 | otherwise always forced to be at least one) and all the other fields of |
1222 | the stat buffer having unspecified contents.</p> |
1252 | the stat buffer having unspecified contents.</p> |
1223 | <p>Since there is no standard to do this, the portable implementation simply |
1253 | <p>Since there is no standard to do this, the portable implementation simply |
1224 | calls <code>stat (2)</code> regulalry on the path to see if it changed somehow. You |
1254 | calls <code>stat (2)</code> regularly on the path to see if it changed somehow. You |
1225 | can specify a recommended polling interval for this case. If you specify |
1255 | can specify a recommended polling interval for this case. If you specify |
1226 | a polling interval of <code>0</code> (highly recommended!) then a <i>suitable, |
1256 | a polling interval of <code>0</code> (highly recommended!) then a <i>suitable, |
1227 | unspecified default</i> value will be used (which you can expect to be around |
1257 | unspecified default</i> value will be used (which you can expect to be around |
1228 | five seconds, although this might change dynamically). Libev will also |
1258 | five seconds, although this might change dynamically). Libev will also |
1229 | impose a minimum interval which is currently around <code>0.1</code>, but thats |
1259 | impose a minimum interval which is currently around <code>0.1</code>, but thats |
1230 | usually overkill.</p> |
1260 | usually overkill.</p> |
1231 | <p>This watcher type is not meant for massive numbers of stat watchers, |
1261 | <p>This watcher type is not meant for massive numbers of stat watchers, |
1232 | as even with OS-supported change notifications, this can be |
1262 | as even with OS-supported change notifications, this can be |
1233 | resource-intensive.</p> |
1263 | resource-intensive.</p> |
1234 | <p>At the time of this writing, no specific OS backends are implemented, but |
1264 | <p>At the time of this writing, only the Linux inotify interface is |
1235 | if demand increases, at least a kqueue and inotify backend will be added.</p> |
1265 | implemented (implementing kqueue support is left as an exercise for the |
|
|
1266 | reader). Inotify will be used to give hints only and should not change the |
|
|
1267 | semantics of <code>ev_stat</code> watchers, which means that libev sometimes needs |
|
|
1268 | to fall back to regular polling again even with inotify, but changes are |
|
|
1269 | usually detected immediately, and if the file exists there will be no |
|
|
1270 | polling.</p> |
1236 | <dl> |
1271 | <dl> |
1237 | <dt>ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)</dt> |
1272 | <dt>ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)</dt> |
1238 | <dt>ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)</dt> |
1273 | <dt>ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)</dt> |
1239 | <dd> |
1274 | <dd> |
1240 | <p>Configures the watcher to wait for status changes of the given |
1275 | <p>Configures the watcher to wait for status changes of the given |
… | |
… | |
1560 | |
1595 | |
1561 | |
1596 | |
1562 | |
1597 | |
1563 | |
1598 | |
1564 | </div> |
1599 | </div> |
1565 | <h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1600 | <h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1> |
1566 | <div id="OTHER_FUNCTIONS_CONTENT"> |
1601 | <div id="OTHER_FUNCTIONS_CONTENT"> |
1567 | <p>There are some other functions of possible interest. Described. Here. Now.</p> |
1602 | <p>There are some other functions of possible interest. Described. Here. Now.</p> |
1568 | <dl> |
1603 | <dl> |
1569 | <dt>ev_once (loop, int fd, int events, ev_tstamp timeout, callback)</dt> |
1604 | <dt>ev_once (loop, int fd, int events, ev_tstamp timeout, callback)</dt> |
1570 | <dd> |
1605 | <dd> |
… | |
… | |
1617 | |
1652 | |
1618 | |
1653 | |
1619 | |
1654 | |
1620 | |
1655 | |
1621 | </div> |
1656 | </div> |
1622 | <h1 id="LIBEVENT_EMULATION">LIBEVENT EMULATION</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1657 | <h1 id="LIBEVENT_EMULATION">LIBEVENT EMULATION</h1> |
1623 | <div id="LIBEVENT_EMULATION_CONTENT"> |
1658 | <div id="LIBEVENT_EMULATION_CONTENT"> |
1624 | <p>Libev offers a compatibility emulation layer for libevent. It cannot |
1659 | <p>Libev offers a compatibility emulation layer for libevent. It cannot |
1625 | emulate the internals of libevent, so here are some usage hints:</p> |
1660 | emulate the internals of libevent, so here are some usage hints:</p> |
1626 | <dl> |
1661 | <dl> |
1627 | <dt>* Use it by including <event.h>, as usual.</dt> |
1662 | <dt>* Use it by including <event.h>, as usual.</dt> |
… | |
… | |
1637 | <dt>* The libev emulation is <i>not</i> ABI compatible to libevent, you need |
1672 | <dt>* The libev emulation is <i>not</i> ABI compatible to libevent, you need |
1638 | to use the libev header file and library.</dt> |
1673 | to use the libev header file and library.</dt> |
1639 | </dl> |
1674 | </dl> |
1640 | |
1675 | |
1641 | </div> |
1676 | </div> |
1642 | <h1 id="C_SUPPORT">C++ SUPPORT</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1677 | <h1 id="C_SUPPORT">C++ SUPPORT</h1> |
1643 | <div id="C_SUPPORT_CONTENT"> |
1678 | <div id="C_SUPPORT_CONTENT"> |
1644 | <p>Libev comes with some simplistic wrapper classes for C++ that mainly allow |
1679 | <p>Libev comes with some simplistic wrapper classes for C++ that mainly allow |
1645 | you to use some convinience methods to start/stop watchers and also change |
1680 | you to use some convinience methods to start/stop watchers and also change |
1646 | the callback model to a model using method callbacks on objects.</p> |
1681 | the callback model to a model using method callbacks on objects.</p> |
1647 | <p>To use it,</p> |
1682 | <p>To use it,</p> |
… | |
… | |
1742 | |
1777 | |
1743 | |
1778 | |
1744 | </pre> |
1779 | </pre> |
1745 | |
1780 | |
1746 | </div> |
1781 | </div> |
1747 | <h1 id="MACRO_MAGIC">MACRO MAGIC</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1782 | <h1 id="MACRO_MAGIC">MACRO MAGIC</h1> |
1748 | <div id="MACRO_MAGIC_CONTENT"> |
1783 | <div id="MACRO_MAGIC_CONTENT"> |
1749 | <p>Libev can be compiled with a variety of options, the most fundemantal is |
1784 | <p>Libev can be compiled with a variety of options, the most fundemantal is |
1750 | <code>EV_MULTIPLICITY</code>. This option determines wether (most) functions and |
1785 | <code>EV_MULTIPLICITY</code>. This option determines wether (most) functions and |
1751 | callbacks have an initial <code>struct ev_loop *</code> argument.</p> |
1786 | callbacks have an initial <code>struct ev_loop *</code> argument.</p> |
1752 | <p>To make it easier to write programs that cope with either variant, the |
1787 | <p>To make it easier to write programs that cope with either variant, the |
… | |
… | |
1803 | |
1838 | |
1804 | |
1839 | |
1805 | </pre> |
1840 | </pre> |
1806 | |
1841 | |
1807 | </div> |
1842 | </div> |
1808 | <h1 id="EMBEDDING">EMBEDDING</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1843 | <h1 id="EMBEDDING">EMBEDDING</h1> |
1809 | <div id="EMBEDDING_CONTENT"> |
1844 | <div id="EMBEDDING_CONTENT"> |
1810 | <p>Libev can (and often is) directly embedded into host |
1845 | <p>Libev can (and often is) directly embedded into host |
1811 | applications. Examples of applications that embed it include the Deliantra |
1846 | applications. Examples of applications that embed it include the Deliantra |
1812 | Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe) |
1847 | Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe) |
1813 | and rxvt-unicode.</p> |
1848 | and rxvt-unicode.</p> |
… | |
… | |
1987 | </dd> |
2022 | </dd> |
1988 | <dt>EV_USE_DEVPOLL</dt> |
2023 | <dt>EV_USE_DEVPOLL</dt> |
1989 | <dd> |
2024 | <dd> |
1990 | <p>reserved for future expansion, works like the USE symbols above.</p> |
2025 | <p>reserved for future expansion, works like the USE symbols above.</p> |
1991 | </dd> |
2026 | </dd> |
|
|
2027 | <dt>EV_USE_INOTIFY</dt> |
|
|
2028 | <dd> |
|
|
2029 | <p>If defined to be <code>1</code>, libev will compile in support for the Linux inotify |
|
|
2030 | interface to speed up <code>ev_stat</code> watchers. Its actual availability will |
|
|
2031 | be detected at runtime.</p> |
|
|
2032 | </dd> |
1992 | <dt>EV_H</dt> |
2033 | <dt>EV_H</dt> |
1993 | <dd> |
2034 | <dd> |
1994 | <p>The name of the <cite>ev.h</cite> header file used to include it. The default if |
2035 | <p>The name of the <cite>ev.h</cite> header file used to include it. The default if |
1995 | undefined is <code><ev.h></code> in <cite>event.h</cite> and <code>"ev.h"</code> in <cite>ev.c</cite>. This |
2036 | undefined is <code><ev.h></code> in <cite>event.h</cite> and <code>"ev.h"</code> in <cite>ev.c</cite>. This |
1996 | can be used to virtually rename the <cite>ev.h</cite> header file in case of conflicts.</p> |
2037 | can be used to virtually rename the <cite>ev.h</cite> header file in case of conflicts.</p> |
… | |
… | |
2051 | <dt>EV_PID_HASHSIZE</dt> |
2092 | <dt>EV_PID_HASHSIZE</dt> |
2052 | <dd> |
2093 | <dd> |
2053 | <p><code>ev_child</code> watchers use a small hash table to distribute workload by |
2094 | <p><code>ev_child</code> watchers use a small hash table to distribute workload by |
2054 | pid. The default size is <code>16</code> (or <code>1</code> with <code>EV_MINIMAL</code>), usually more |
2095 | pid. The default size is <code>16</code> (or <code>1</code> with <code>EV_MINIMAL</code>), usually more |
2055 | than enough. If you need to manage thousands of children you might want to |
2096 | than enough. If you need to manage thousands of children you might want to |
2056 | increase this value.</p> |
2097 | increase this value (<i>must</i> be a power of two).</p> |
|
|
2098 | </dd> |
|
|
2099 | <dt>EV_INOTIFY_HASHSIZE</dt> |
|
|
2100 | <dd> |
|
|
2101 | <p><code>ev_staz</code> watchers use a small hash table to distribute workload by |
|
|
2102 | inotify watch id. The default size is <code>16</code> (or <code>1</code> with <code>EV_MINIMAL</code>), |
|
|
2103 | usually more than enough. If you need to manage thousands of <code>ev_stat</code> |
|
|
2104 | watchers you might want to increase this value (<i>must</i> be a power of |
|
|
2105 | two).</p> |
2057 | </dd> |
2106 | </dd> |
2058 | <dt>EV_COMMON</dt> |
2107 | <dt>EV_COMMON</dt> |
2059 | <dd> |
2108 | <dd> |
2060 | <p>By default, all watchers have a <code>void *data</code> member. By redefining |
2109 | <p>By default, all watchers have a <code>void *data</code> member. By redefining |
2061 | this macro to a something else you can include more and other types of |
2110 | this macro to a something else you can include more and other types of |
… | |
… | |
2107 | |
2156 | |
2108 | |
2157 | |
2109 | </pre> |
2158 | </pre> |
2110 | |
2159 | |
2111 | </div> |
2160 | </div> |
2112 | <h1 id="COMPLEXITIES">COMPLEXITIES</h1><p><a href="#TOP" class="toplink">Top</a></p> |
2161 | <h1 id="COMPLEXITIES">COMPLEXITIES</h1> |
2113 | <div id="COMPLEXITIES_CONTENT"> |
2162 | <div id="COMPLEXITIES_CONTENT"> |
2114 | <p>In this section the complexities of (many of) the algorithms used inside |
2163 | <p>In this section the complexities of (many of) the algorithms used inside |
2115 | libev will be explained. For complexity discussions about backends see the |
2164 | libev will be explained. For complexity discussions about backends see the |
2116 | documentation for <code>ev_default_init</code>.</p> |
2165 | documentation for <code>ev_default_init</code>.</p> |
2117 | <p> |
2166 | <p> |
2118 | <dl> |
2167 | <dl> |
2119 | <dt>Starting and stopping timer/periodic watchers: O(log skipped_other_timers)</dt> |
2168 | <dt>Starting and stopping timer/periodic watchers: O(log skipped_other_timers)</dt> |
2120 | <dt>Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)</dt> |
2169 | <dt>Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)</dt> |
2121 | <dt>Starting io/check/prepare/idle/signal/child watchers: O(1)</dt> |
2170 | <dt>Starting io/check/prepare/idle/signal/child watchers: O(1)</dt> |
2122 | <dt>Stopping check/prepare/idle watchers: O(1)</dt> |
2171 | <dt>Stopping check/prepare/idle watchers: O(1)</dt> |
2123 | <dt>Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))</dt> |
2172 | <dt>Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))</dt> |
2124 | <dt>Finding the next timer per loop iteration: O(1)</dt> |
2173 | <dt>Finding the next timer per loop iteration: O(1)</dt> |
2125 | <dt>Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)</dt> |
2174 | <dt>Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)</dt> |
2126 | <dt>Activating one watcher: O(1)</dt> |
2175 | <dt>Activating one watcher: O(1)</dt> |
2127 | </dl> |
2176 | </dl> |
2128 | </p> |
2177 | </p> |
… | |
… | |
2130 | |
2179 | |
2131 | |
2180 | |
2132 | |
2181 | |
2133 | |
2182 | |
2134 | </div> |
2183 | </div> |
2135 | <h1 id="AUTHOR">AUTHOR</h1><p><a href="#TOP" class="toplink">Top</a></p> |
2184 | <h1 id="AUTHOR">AUTHOR</h1> |
2136 | <div id="AUTHOR_CONTENT"> |
2185 | <div id="AUTHOR_CONTENT"> |
2137 | <p>Marc Lehmann <libev@schmorp.de>.</p> |
2186 | <p>Marc Lehmann <libev@schmorp.de>.</p> |
2138 | |
2187 | |
2139 | </div> |
2188 | </div> |
2140 | </div></body> |
2189 | </div></body> |