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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" /> |
7 | <meta name="inputfile" content="<standard input>" /> |
7 | <meta name="inputfile" content="<standard input>" /> |
8 | <meta name="outputfile" content="<standard output>" /> |
8 | <meta name="outputfile" content="<standard output>" /> |
9 | <meta name="created" content="Tue Nov 27 20:23:27 2007" /> |
9 | <meta name="created" content="Thu Nov 29 13:21:20 2007" /> |
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11 | <link rel="stylesheet" href="http://res.tst.eu/pod.css"/></head> |
12 | <body> |
12 | <body> |
13 | <div class="pod"> |
13 | <div class="pod"> |
14 | <!-- INDEX START --> |
14 | <!-- INDEX START --> |
15 | <h3 id="TOP">Index</h3> |
15 | <h3 id="TOP">Index</h3> |
16 | |
16 | |
17 | <ul><li><a href="#NAME">NAME</a></li> |
17 | <ul><li><a href="#NAME">NAME</a></li> |
18 | <li><a href="#SYNOPSIS">SYNOPSIS</a></li> |
18 | <li><a href="#SYNOPSIS">SYNOPSIS</a></li> |
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19 | <li><a href="#EXAMPLE_PROGRAM">EXAMPLE PROGRAM</a></li> |
19 | <li><a href="#DESCRIPTION">DESCRIPTION</a></li> |
20 | <li><a href="#DESCRIPTION">DESCRIPTION</a></li> |
20 | <li><a href="#FEATURES">FEATURES</a></li> |
21 | <li><a href="#FEATURES">FEATURES</a></li> |
21 | <li><a href="#CONVENTIONS">CONVENTIONS</a></li> |
22 | <li><a href="#CONVENTIONS">CONVENTIONS</a></li> |
22 | <li><a href="#TIME_REPRESENTATION">TIME REPRESENTATION</a></li> |
23 | <li><a href="#TIME_REPRESENTATION">TIME REPRESENTATION</a></li> |
23 | <li><a href="#GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</a></li> |
24 | <li><a href="#GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</a></li> |
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59 | <li><a href="#AUTHOR">AUTHOR</a> |
60 | <li><a href="#AUTHOR">AUTHOR</a> |
60 | </li> |
61 | </li> |
61 | </ul><hr /> |
62 | </ul><hr /> |
62 | <!-- INDEX END --> |
63 | <!-- INDEX END --> |
63 | |
64 | |
64 | <h1 id="NAME">NAME</h1><p><a href="#TOP" class="toplink">Top</a></p> |
65 | <h1 id="NAME">NAME</h1> |
65 | <div id="NAME_CONTENT"> |
66 | <div id="NAME_CONTENT"> |
66 | <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> |
67 | |
68 | |
68 | </div> |
69 | </div> |
69 | <h1 id="SYNOPSIS">SYNOPSIS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
70 | <h1 id="SYNOPSIS">SYNOPSIS</h1> |
70 | <div id="SYNOPSIS_CONTENT"> |
71 | <div id="SYNOPSIS_CONTENT"> |
71 | <pre> #include <ev.h> |
72 | <pre> #include <ev.h> |
72 | |
73 | |
73 | </pre> |
74 | </pre> |
74 | |
75 | |
75 | </div> |
76 | </div> |
76 | <h1 id="DESCRIPTION">DESCRIPTION</h1><p><a href="#TOP" class="toplink">Top</a></p> |
77 | <h1 id="EXAMPLE_PROGRAM">EXAMPLE PROGRAM</h1> |
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78 | <div id="EXAMPLE_PROGRAM_CONTENT"> |
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79 | <pre> #include <ev.h> |
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80 | |
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81 | ev_io stdin_watcher; |
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82 | ev_timer timeout_watcher; |
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83 | |
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84 | /* called when data readable on stdin */ |
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85 | static void |
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86 | stdin_cb (EV_P_ struct ev_io *w, int revents) |
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87 | { |
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88 | /* puts ("stdin ready"); */ |
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89 | ev_io_stop (EV_A_ w); /* just a syntax example */ |
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90 | ev_unloop (EV_A_ EVUNLOOP_ALL); /* leave all loop calls */ |
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91 | } |
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92 | |
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93 | static void |
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94 | timeout_cb (EV_P_ struct ev_timer *w, int revents) |
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95 | { |
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96 | /* puts ("timeout"); */ |
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97 | ev_unloop (EV_A_ EVUNLOOP_ONE); /* leave one loop call */ |
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98 | } |
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99 | |
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100 | int |
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101 | main (void) |
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102 | { |
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103 | struct ev_loop *loop = ev_default_loop (0); |
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104 | |
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105 | /* initialise an io watcher, then start it */ |
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106 | ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ); |
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107 | ev_io_start (loop, &stdin_watcher); |
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108 | |
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109 | /* simple non-repeating 5.5 second timeout */ |
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110 | ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.); |
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111 | ev_timer_start (loop, &timeout_watcher); |
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112 | |
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113 | /* loop till timeout or data ready */ |
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114 | ev_loop (loop, 0); |
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115 | |
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116 | return 0; |
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117 | } |
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118 | |
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119 | </pre> |
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120 | |
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121 | </div> |
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122 | <h1 id="DESCRIPTION">DESCRIPTION</h1> |
77 | <div id="DESCRIPTION_CONTENT"> |
123 | <div id="DESCRIPTION_CONTENT"> |
78 | <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 |
79 | 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 |
80 | these event sources and provide your program with events.</p> |
126 | these event sources and provide your program with events.</p> |
81 | <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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85 | 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 |
86 | 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 |
87 | watcher.</p> |
133 | watcher.</p> |
88 | |
134 | |
89 | </div> |
135 | </div> |
90 | <h1 id="FEATURES">FEATURES</h1><p><a href="#TOP" class="toplink">Top</a></p> |
136 | <h1 id="FEATURES">FEATURES</h1> |
91 | <div id="FEATURES_CONTENT"> |
137 | <div id="FEATURES_CONTENT"> |
92 | <p>Libev supports select, poll, the linux-specific epoll and the bsd-specific |
138 | <p>Libev supports <code>select</code>, <code>poll</code>, the Linux-specific <code>epoll</code>, the |
93 | kqueue mechanisms for file descriptor events, relative timers, absolute |
139 | BSD-specific <code>kqueue</code> and the Solaris-specific event port mechanisms |
94 | timers with customised rescheduling, signal events, process status change |
140 | for file descriptor events (<code>ev_io</code>), the Linux <code>inotify</code> interface |
95 | events (related to SIGCHLD), and event watchers dealing with the event |
141 | (for <code>ev_stat</code>), relative timers (<code>ev_timer</code>), absolute timers |
96 | loop mechanism itself (idle, prepare and check watchers). It also is quite |
142 | with customised rescheduling (<code>ev_periodic</code>), synchronous signals |
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143 | (<code>ev_signal</code>), process status change events (<code>ev_child</code>), and event |
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144 | watchers dealing with the event loop mechanism itself (<code>ev_idle</code>, |
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145 | <code>ev_embed</code>, <code>ev_prepare</code> and <code>ev_check</code> watchers) as well as |
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146 | file watchers (<code>ev_stat</code>) and even limited support for fork events |
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147 | (<code>ev_fork</code>).</p> |
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148 | <p>It also is quite fast (see this |
97 | fast (see this <a href="http://libev.schmorp.de/bench.html">benchmark</a> comparing |
149 | <a href="http://libev.schmorp.de/bench.html">benchmark</a> comparing it to libevent |
98 | it to libevent for example).</p> |
150 | for example).</p> |
99 | |
151 | |
100 | </div> |
152 | </div> |
101 | <h1 id="CONVENTIONS">CONVENTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
153 | <h1 id="CONVENTIONS">CONVENTIONS</h1> |
102 | <div id="CONVENTIONS_CONTENT"> |
154 | <div id="CONVENTIONS_CONTENT"> |
103 | <p>Libev is very configurable. In this manual the default configuration |
155 | <p>Libev is very configurable. In this manual the default configuration will |
104 | will be described, which supports multiple event loops. For more info |
156 | be described, which supports multiple event loops. For more info about |
105 | about various configuration options please have a look at the file |
157 | various configuration options please have a look at <strong>EMBED</strong> section in |
106 | <cite>README.embed</cite> in the libev distribution. If libev was configured without |
158 | this manual. If libev was configured without support for multiple event |
107 | support for multiple event loops, then all functions taking an initial |
159 | loops, then all functions taking an initial argument of name <code>loop</code> |
108 | argument of name <code>loop</code> (which is always of type <code>struct ev_loop *</code>) |
160 | (which is always of type <code>struct ev_loop *</code>) will not have this argument.</p> |
109 | will not have this argument.</p> |
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110 | |
161 | |
111 | </div> |
162 | </div> |
112 | <h1 id="TIME_REPRESENTATION">TIME REPRESENTATION</h1><p><a href="#TOP" class="toplink">Top</a></p> |
163 | <h1 id="TIME_REPRESENTATION">TIME REPRESENTATION</h1> |
113 | <div id="TIME_REPRESENTATION_CONTENT"> |
164 | <div id="TIME_REPRESENTATION_CONTENT"> |
114 | <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 |
115 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
166 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
116 | 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 |
117 | 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 |
118 | 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 |
119 | it, you should treat it as such.</p> |
170 | it, you should treat it as such.</p> |
120 | |
171 | |
121 | </div> |
172 | </div> |
122 | <h1 id="GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
173 | <h1 id="GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</h1> |
123 | <div id="GLOBAL_FUNCTIONS_CONTENT"> |
174 | <div id="GLOBAL_FUNCTIONS_CONTENT"> |
124 | <p>These functions can be called anytime, even before initialising the |
175 | <p>These functions can be called anytime, even before initialising the |
125 | library in any way.</p> |
176 | library in any way.</p> |
126 | <dl> |
177 | <dl> |
127 | <dt>ev_tstamp ev_time ()</dt> |
178 | <dt>ev_tstamp ev_time ()</dt> |
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140 | version of the library your program was compiled against.</p> |
191 | version of the library your program was compiled against.</p> |
141 | <p>Usually, it's a good idea to terminate if the major versions mismatch, |
192 | <p>Usually, it's a good idea to terminate if the major versions mismatch, |
142 | as this indicates an incompatible change. Minor versions are usually |
193 | as this indicates an incompatible change. Minor versions are usually |
143 | compatible to older versions, so a larger minor version alone is usually |
194 | compatible to older versions, so a larger minor version alone is usually |
144 | not a problem.</p> |
195 | not a problem.</p> |
145 | <p>Example: make sure we haven't accidentally been linked against the wrong |
196 | <p>Example: Make sure we haven't accidentally been linked against the wrong |
146 | version:</p> |
197 | version.</p> |
147 | <pre> assert (("libev version mismatch", |
198 | <pre> assert (("libev version mismatch", |
148 | ev_version_major () == EV_VERSION_MAJOR |
199 | ev_version_major () == EV_VERSION_MAJOR |
149 | && ev_version_minor () >= EV_VERSION_MINOR)); |
200 | && ev_version_minor () >= EV_VERSION_MINOR)); |
150 | |
201 | |
151 | </pre> |
202 | </pre> |
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181 | recommended ones.</p> |
232 | recommended ones.</p> |
182 | <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> |
183 | </dd> |
234 | </dd> |
184 | <dt>ev_set_allocator (void *(*cb)(void *ptr, long size))</dt> |
235 | <dt>ev_set_allocator (void *(*cb)(void *ptr, long size))</dt> |
185 | <dd> |
236 | <dd> |
186 | <p>Sets the allocation function to use (the prototype is similar to the |
237 | <p>Sets the allocation function to use (the prototype is similar - the |
187 | realloc C function, the semantics are identical). It is used to allocate |
238 | semantics is identical - to the realloc C function). It is used to |
188 | and free memory (no surprises here). If it returns zero when memory |
239 | allocate and free memory (no surprises here). If it returns zero when |
189 | needs to be allocated, the library might abort or take some potentially |
240 | memory needs to be allocated, the library might abort or take some |
190 | destructive action. The default is your system realloc function.</p> |
241 | potentially destructive action. The default is your system realloc |
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242 | function.</p> |
191 | <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, |
192 | 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, |
193 | 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> |
194 | <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 |
195 | retries: better than mine).</p> |
247 | retries).</p> |
196 | <pre> static void * |
248 | <pre> static void * |
197 | persistent_realloc (void *ptr, long size) |
249 | persistent_realloc (void *ptr, size_t size) |
198 | { |
250 | { |
199 | for (;;) |
251 | for (;;) |
200 | { |
252 | { |
201 | void *newptr = realloc (ptr, size); |
253 | void *newptr = realloc (ptr, size); |
202 | |
254 | |
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219 | indicating the system call or subsystem causing the problem. If this |
271 | indicating the system call or subsystem causing the problem. If this |
220 | callback is set, then libev will expect it to remedy the sitution, no |
272 | callback is set, then libev will expect it to remedy the sitution, no |
221 | matter what, when it returns. That is, libev will generally retry the |
273 | matter what, when it returns. That is, libev will generally retry the |
222 | requested operation, or, if the condition doesn't go away, do bad stuff |
274 | requested operation, or, if the condition doesn't go away, do bad stuff |
223 | (such as abort).</p> |
275 | (such as abort).</p> |
224 | <p>Example: do the same thing as libev does internally:</p> |
276 | <p>Example: This is basically the same thing that libev does internally, too.</p> |
225 | <pre> static void |
277 | <pre> static void |
226 | fatal_error (const char *msg) |
278 | fatal_error (const char *msg) |
227 | { |
279 | { |
228 | perror (msg); |
280 | perror (msg); |
229 | abort (); |
281 | abort (); |
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235 | </pre> |
287 | </pre> |
236 | </dd> |
288 | </dd> |
237 | </dl> |
289 | </dl> |
238 | |
290 | |
239 | </div> |
291 | </div> |
240 | <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> |
241 | <div id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP-2"> |
293 | <div id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP-2"> |
242 | <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 |
243 | 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 |
244 | events, and dynamically created loops which do not.</p> |
296 | events, and dynamically created loops which do not.</p> |
245 | <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 |
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365 | <dd> |
417 | <dd> |
366 | <p>Similar to <code>ev_default_loop</code>, but always creates a new event loop that is |
418 | <p>Similar to <code>ev_default_loop</code>, but always creates a new event loop that is |
367 | always distinct from the default loop. Unlike the default loop, it cannot |
419 | always distinct from the default loop. Unlike the default loop, it cannot |
368 | handle signal and child watchers, and attempts to do so will be greeted by |
420 | handle signal and child watchers, and attempts to do so will be greeted by |
369 | undefined behaviour (or a failed assertion if assertions are enabled).</p> |
421 | undefined behaviour (or a failed assertion if assertions are enabled).</p> |
370 | <p>Example: try to create a event loop that uses epoll and nothing else.</p> |
422 | <p>Example: Try to create a event loop that uses epoll and nothing else.</p> |
371 | <pre> struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
423 | <pre> struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
372 | if (!epoller) |
424 | if (!epoller) |
373 | fatal ("no epoll found here, maybe it hides under your chair"); |
425 | fatal ("no epoll found here, maybe it hides under your chair"); |
374 | |
426 | |
375 | </pre> |
427 | </pre> |
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468 | be handled here by queueing them when their watcher gets executed. |
520 | be handled here by queueing them when their watcher gets executed. |
469 | - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
521 | - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
470 | were used, return, otherwise continue with step *. |
522 | were used, return, otherwise continue with step *. |
471 | |
523 | |
472 | </pre> |
524 | </pre> |
473 | <p>Example: queue some jobs and then loop until no events are outsanding |
525 | <p>Example: Queue some jobs and then loop until no events are outsanding |
474 | anymore.</p> |
526 | anymore.</p> |
475 | <pre> ... queue jobs here, make sure they register event watchers as long |
527 | <pre> ... queue jobs here, make sure they register event watchers as long |
476 | ... as they still have work to do (even an idle watcher will do..) |
528 | ... as they still have work to do (even an idle watcher will do..) |
477 | ev_loop (my_loop, 0); |
529 | ev_loop (my_loop, 0); |
478 | ... jobs done. yeah! |
530 | ... jobs done. yeah! |
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497 | example, libev itself uses this for its internal signal pipe: It is not |
549 | example, libev itself uses this for its internal signal pipe: It is not |
498 | visible to the libev user and should not keep <code>ev_loop</code> from exiting if |
550 | visible to the libev user and should not keep <code>ev_loop</code> from exiting if |
499 | no event watchers registered by it are active. It is also an excellent |
551 | no event watchers registered by it are active. It is also an excellent |
500 | way to do this for generic recurring timers or from within third-party |
552 | way to do this for generic recurring timers or from within third-party |
501 | libraries. Just remember to <i>unref after start</i> and <i>ref before stop</i>.</p> |
553 | libraries. Just remember to <i>unref after start</i> and <i>ref before stop</i>.</p> |
502 | <p>Example: create a signal watcher, but keep it from keeping <code>ev_loop</code> |
554 | <p>Example: Create a signal watcher, but keep it from keeping <code>ev_loop</code> |
503 | running when nothing else is active.</p> |
555 | running when nothing else is active.</p> |
504 | <pre> struct dv_signal exitsig; |
556 | <pre> struct ev_signal exitsig; |
505 | ev_signal_init (&exitsig, sig_cb, SIGINT); |
557 | ev_signal_init (&exitsig, sig_cb, SIGINT); |
506 | ev_signal_start (myloop, &exitsig); |
558 | ev_signal_start (loop, &exitsig); |
507 | evf_unref (myloop); |
559 | evf_unref (loop); |
508 | |
560 | |
509 | </pre> |
561 | </pre> |
510 | <p>Example: for some weird reason, unregister the above signal handler again.</p> |
562 | <p>Example: For some weird reason, unregister the above signal handler again.</p> |
511 | <pre> ev_ref (myloop); |
563 | <pre> ev_ref (loop); |
512 | ev_signal_stop (myloop, &exitsig); |
564 | ev_signal_stop (loop, &exitsig); |
513 | |
565 | |
514 | </pre> |
566 | </pre> |
515 | </dd> |
567 | </dd> |
516 | </dl> |
568 | </dl> |
517 | |
569 | |
518 | |
570 | |
519 | |
571 | |
520 | |
572 | |
521 | |
573 | |
522 | </div> |
574 | </div> |
523 | <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> |
524 | <div id="ANATOMY_OF_A_WATCHER_CONTENT"> |
576 | <div id="ANATOMY_OF_A_WATCHER_CONTENT"> |
525 | <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 |
526 | 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 |
527 | 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> |
528 | <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) |
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691 | 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 |
692 | 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 |
693 | <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 |
694 | libev (e.g. you cnanot <code>free ()</code> it).</p> |
746 | libev (e.g. you cnanot <code>free ()</code> it).</p> |
695 | </dd> |
747 | </dd> |
696 | <dt>callback = ev_cb (ev_TYPE *watcher)</dt> |
748 | <dt>callback ev_cb (ev_TYPE *watcher)</dt> |
697 | <dd> |
749 | <dd> |
698 | <p>Returns the callback currently set on the watcher.</p> |
750 | <p>Returns the callback currently set on the watcher.</p> |
699 | </dd> |
751 | </dd> |
700 | <dt>ev_cb_set (ev_TYPE *watcher, callback)</dt> |
752 | <dt>ev_cb_set (ev_TYPE *watcher, callback)</dt> |
701 | <dd> |
753 | <dd> |
… | |
… | |
733 | struct my_io *w = (struct my_io *)w_; |
785 | struct my_io *w = (struct my_io *)w_; |
734 | ... |
786 | ... |
735 | } |
787 | } |
736 | |
788 | |
737 | </pre> |
789 | </pre> |
738 | <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 |
739 | have been omitted....</p> |
791 | instead have been omitted.</p> |
|
|
792 | <p>Another common scenario is having some data structure with multiple |
|
|
793 | watchers:</p> |
|
|
794 | <pre> struct my_biggy |
|
|
795 | { |
|
|
796 | int some_data; |
|
|
797 | ev_timer t1; |
|
|
798 | ev_timer t2; |
|
|
799 | } |
740 | |
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> |
741 | |
805 | |
|
|
806 | static void |
|
|
807 | t1_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
808 | { |
|
|
809 | struct my_biggy big = (struct my_biggy * |
|
|
810 | (((char *)w) - offsetof (struct my_biggy, t1)); |
|
|
811 | } |
742 | |
812 | |
|
|
813 | static void |
|
|
814 | t2_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
815 | { |
|
|
816 | struct my_biggy big = (struct my_biggy * |
|
|
817 | (((char *)w) - offsetof (struct my_biggy, t2)); |
|
|
818 | } |
743 | |
819 | |
744 | |
820 | |
|
|
821 | |
|
|
822 | |
|
|
823 | </pre> |
|
|
824 | |
745 | </div> |
825 | </div> |
746 | <h1 id="WATCHER_TYPES">WATCHER TYPES</h1><p><a href="#TOP" class="toplink">Top</a></p> |
826 | <h1 id="WATCHER_TYPES">WATCHER TYPES</h1> |
747 | <div id="WATCHER_TYPES_CONTENT"> |
827 | <div id="WATCHER_TYPES_CONTENT"> |
748 | <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 |
749 | information given in the last section. Any initialisation/set macros, |
829 | information given in the last section. Any initialisation/set macros, |
750 | functions and members specific to the watcher type are explained.</p> |
830 | functions and members specific to the watcher type are explained.</p> |
751 | <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, |
… | |
… | |
811 | <dt>int events [read-only]</dt> |
891 | <dt>int events [read-only]</dt> |
812 | <dd> |
892 | <dd> |
813 | <p>The events being watched.</p> |
893 | <p>The events being watched.</p> |
814 | </dd> |
894 | </dd> |
815 | </dl> |
895 | </dl> |
816 | <p>Example: call <code>stdin_readable_cb</code> when STDIN_FILENO has become, well |
896 | <p>Example: Call <code>stdin_readable_cb</code> when STDIN_FILENO has become, well |
817 | readable, but only once. Since it is likely line-buffered, you could |
897 | readable, but only once. Since it is likely line-buffered, you could |
818 | attempt to read a whole line in the callback:</p> |
898 | attempt to read a whole line in the callback.</p> |
819 | <pre> static void |
899 | <pre> static void |
820 | stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
900 | stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
821 | { |
901 | { |
822 | ev_io_stop (loop, w); |
902 | ev_io_stop (loop, w); |
823 | .. read from stdin here (or from w->fd) and haqndle any I/O errors |
903 | .. read from stdin here (or from w->fd) and haqndle any I/O errors |
… | |
… | |
872 | </dd> |
952 | </dd> |
873 | <dt>ev_timer_again (loop)</dt> |
953 | <dt>ev_timer_again (loop)</dt> |
874 | <dd> |
954 | <dd> |
875 | <p>This will act as if the timer timed out and restart it again if it is |
955 | <p>This will act as if the timer timed out and restart it again if it is |
876 | repeating. The exact semantics are:</p> |
956 | repeating. The exact semantics are:</p> |
|
|
957 | <p>If the timer is pending, its pending status is cleared.</p> |
877 | <p>If the timer is started but nonrepeating, stop it.</p> |
958 | <p>If the timer is started but nonrepeating, stop it (as if it timed out).</p> |
878 | <p>If the timer is repeating, either start it if necessary (with the repeat |
959 | <p>If the timer is repeating, either start it if necessary (with the |
879 | value), or reset the running timer to the repeat value.</p> |
960 | <code>repeat</code> value), or reset the running timer to the <code>repeat</code> value.</p> |
880 | <p>This sounds a bit complicated, but here is a useful and typical |
961 | <p>This sounds a bit complicated, but here is a useful and typical |
881 | example: Imagine you have a tcp connection and you want a so-called |
962 | example: Imagine you have a tcp connection and you want a so-called idle |
882 | idle timeout, that is, you want to be called when there have been, |
963 | timeout, that is, you want to be called when there have been, say, 60 |
883 | say, 60 seconds of inactivity on the socket. The easiest way to do |
964 | seconds of inactivity on the socket. The easiest way to do this is to |
884 | this is to configure an <code>ev_timer</code> with <code>after</code>=<code>repeat</code>=<code>60</code> and calling |
965 | configure an <code>ev_timer</code> with a <code>repeat</code> value of <code>60</code> and then call |
885 | <code>ev_timer_again</code> each time you successfully read or write some data. If |
966 | <code>ev_timer_again</code> each time you successfully read or write some data. If |
886 | you go into an idle state where you do not expect data to travel on the |
967 | you go into an idle state where you do not expect data to travel on the |
887 | socket, you can stop the timer, and again will automatically restart it if |
968 | socket, you can <code>ev_timer_stop</code> the timer, and <code>ev_timer_again</code> will |
888 | need be.</p> |
969 | automatically restart it if need be.</p> |
889 | <p>You can also ignore the <code>after</code> value and <code>ev_timer_start</code> altogether |
970 | <p>That means you can ignore the <code>after</code> value and <code>ev_timer_start</code> |
890 | and only ever use the <code>repeat</code> value:</p> |
971 | altogether and only ever use the <code>repeat</code> value and <code>ev_timer_again</code>:</p> |
891 | <pre> ev_timer_init (timer, callback, 0., 5.); |
972 | <pre> ev_timer_init (timer, callback, 0., 5.); |
892 | ev_timer_again (loop, timer); |
973 | ev_timer_again (loop, timer); |
893 | ... |
974 | ... |
894 | timer->again = 17.; |
975 | timer->again = 17.; |
895 | ev_timer_again (loop, timer); |
976 | ev_timer_again (loop, timer); |
896 | ... |
977 | ... |
897 | timer->again = 10.; |
978 | timer->again = 10.; |
898 | ev_timer_again (loop, timer); |
979 | ev_timer_again (loop, timer); |
899 | |
980 | |
900 | </pre> |
981 | </pre> |
901 | <p>This is more efficient then stopping/starting the timer eahc time you want |
982 | <p>This is more slightly efficient then stopping/starting the timer each time |
902 | to modify its timeout value.</p> |
983 | you want to modify its timeout value.</p> |
903 | </dd> |
984 | </dd> |
904 | <dt>ev_tstamp repeat [read-write]</dt> |
985 | <dt>ev_tstamp repeat [read-write]</dt> |
905 | <dd> |
986 | <dd> |
906 | <p>The current <code>repeat</code> value. Will be used each time the watcher times out |
987 | <p>The current <code>repeat</code> value. Will be used each time the watcher times out |
907 | or <code>ev_timer_again</code> is called and determines the next timeout (if any), |
988 | or <code>ev_timer_again</code> is called and determines the next timeout (if any), |
908 | which is also when any modifications are taken into account.</p> |
989 | which is also when any modifications are taken into account.</p> |
909 | </dd> |
990 | </dd> |
910 | </dl> |
991 | </dl> |
911 | <p>Example: create a timer that fires after 60 seconds.</p> |
992 | <p>Example: Create a timer that fires after 60 seconds.</p> |
912 | <pre> static void |
993 | <pre> static void |
913 | one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
994 | one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
914 | { |
995 | { |
915 | .. one minute over, w is actually stopped right here |
996 | .. one minute over, w is actually stopped right here |
916 | } |
997 | } |
… | |
… | |
918 | struct ev_timer mytimer; |
999 | struct ev_timer mytimer; |
919 | ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
1000 | ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
920 | ev_timer_start (loop, &mytimer); |
1001 | ev_timer_start (loop, &mytimer); |
921 | |
1002 | |
922 | </pre> |
1003 | </pre> |
923 | <p>Example: create a timeout timer that times out after 10 seconds of |
1004 | <p>Example: Create a timeout timer that times out after 10 seconds of |
924 | inactivity.</p> |
1005 | inactivity.</p> |
925 | <pre> static void |
1006 | <pre> static void |
926 | timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1007 | timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
927 | { |
1008 | { |
928 | .. ten seconds without any activity |
1009 | .. ten seconds without any activity |
… | |
… | |
1044 | <p>The current reschedule callback, or <code>0</code>, if this functionality is |
1125 | <p>The current reschedule callback, or <code>0</code>, if this functionality is |
1045 | switched off. Can be changed any time, but changes only take effect when |
1126 | switched off. Can be changed any time, but changes only take effect when |
1046 | the periodic timer fires or <code>ev_periodic_again</code> is being called.</p> |
1127 | the periodic timer fires or <code>ev_periodic_again</code> is being called.</p> |
1047 | </dd> |
1128 | </dd> |
1048 | </dl> |
1129 | </dl> |
1049 | <p>Example: call a callback every hour, or, more precisely, whenever the |
1130 | <p>Example: Call a callback every hour, or, more precisely, whenever the |
1050 | system clock is divisible by 3600. The callback invocation times have |
1131 | system clock is divisible by 3600. The callback invocation times have |
1051 | potentially a lot of jittering, but good long-term stability.</p> |
1132 | potentially a lot of jittering, but good long-term stability.</p> |
1052 | <pre> static void |
1133 | <pre> static void |
1053 | clock_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
1134 | clock_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
1054 | { |
1135 | { |
… | |
… | |
1058 | struct ev_periodic hourly_tick; |
1139 | struct ev_periodic hourly_tick; |
1059 | ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1140 | ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1060 | ev_periodic_start (loop, &hourly_tick); |
1141 | ev_periodic_start (loop, &hourly_tick); |
1061 | |
1142 | |
1062 | </pre> |
1143 | </pre> |
1063 | <p>Example: the same as above, but use a reschedule callback to do it:</p> |
1144 | <p>Example: The same as above, but use a reschedule callback to do it:</p> |
1064 | <pre> #include <math.h> |
1145 | <pre> #include <math.h> |
1065 | |
1146 | |
1066 | static ev_tstamp |
1147 | static ev_tstamp |
1067 | my_scheduler_cb (struct ev_periodic *w, ev_tstamp now) |
1148 | my_scheduler_cb (struct ev_periodic *w, ev_tstamp now) |
1068 | { |
1149 | { |
… | |
… | |
1070 | } |
1151 | } |
1071 | |
1152 | |
1072 | ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1153 | ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1073 | |
1154 | |
1074 | </pre> |
1155 | </pre> |
1075 | <p>Example: call a callback every hour, starting now:</p> |
1156 | <p>Example: Call a callback every hour, starting now:</p> |
1076 | <pre> struct ev_periodic hourly_tick; |
1157 | <pre> struct ev_periodic hourly_tick; |
1077 | ev_periodic_init (&hourly_tick, clock_cb, |
1158 | ev_periodic_init (&hourly_tick, clock_cb, |
1078 | fmod (ev_now (loop), 3600.), 3600., 0); |
1159 | fmod (ev_now (loop), 3600.), 3600., 0); |
1079 | ev_periodic_start (loop, &hourly_tick); |
1160 | ev_periodic_start (loop, &hourly_tick); |
1080 | |
1161 | |
… | |
… | |
1141 | <dd> |
1222 | <dd> |
1142 | <p>The process exit/trace status caused by <code>rpid</code> (see your systems |
1223 | <p>The process exit/trace status caused by <code>rpid</code> (see your systems |
1143 | <code>waitpid</code> and <code>sys/wait.h</code> documentation for details).</p> |
1224 | <code>waitpid</code> and <code>sys/wait.h</code> documentation for details).</p> |
1144 | </dd> |
1225 | </dd> |
1145 | </dl> |
1226 | </dl> |
1146 | <p>Example: try to exit cleanly on SIGINT and SIGTERM.</p> |
1227 | <p>Example: Try to exit cleanly on SIGINT and SIGTERM.</p> |
1147 | <pre> static void |
1228 | <pre> static void |
1148 | sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1229 | sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1149 | { |
1230 | { |
1150 | ev_unloop (loop, EVUNLOOP_ALL); |
1231 | ev_unloop (loop, EVUNLOOP_ALL); |
1151 | } |
1232 | } |
… | |
… | |
1168 | <p>The path does not need to exist: changing from "path exists" to "path does |
1249 | <p>The path does not need to exist: changing from "path exists" to "path does |
1169 | not exist" is a status change like any other. The condition "path does |
1250 | not exist" is a status change like any other. The condition "path does |
1170 | not exist" is signified by the <code>st_nlink</code> field being zero (which is |
1251 | not exist" is signified by the <code>st_nlink</code> field being zero (which is |
1171 | otherwise always forced to be at least one) and all the other fields of |
1252 | otherwise always forced to be at least one) and all the other fields of |
1172 | the stat buffer having unspecified contents.</p> |
1253 | the stat buffer having unspecified contents.</p> |
|
|
1254 | <p>The path <i>should</i> be absolute and <i>must not</i> end in a slash. If it is |
|
|
1255 | relative and your working directory changes, the behaviour is undefined.</p> |
1173 | <p>Since there is no standard to do this, the portable implementation simply |
1256 | <p>Since there is no standard to do this, the portable implementation simply |
1174 | calls <code>stat (2)</code> regulalry on the path to see if it changed somehow. You |
1257 | calls <code>stat (2)</code> regularly on the path to see if it changed somehow. You |
1175 | can specify a recommended polling interval for this case. If you specify |
1258 | can specify a recommended polling interval for this case. If you specify |
1176 | a polling interval of <code>0</code> (highly recommended!) then a <i>suitable, |
1259 | a polling interval of <code>0</code> (highly recommended!) then a <i>suitable, |
1177 | unspecified default</i> value will be used (which you can expect to be around |
1260 | unspecified default</i> value will be used (which you can expect to be around |
1178 | five seconds, although this might change dynamically). Libev will also |
1261 | five seconds, although this might change dynamically). Libev will also |
1179 | impose a minimum interval which is currently around <code>0.1</code>, but thats |
1262 | impose a minimum interval which is currently around <code>0.1</code>, but thats |
1180 | usually overkill.</p> |
1263 | usually overkill.</p> |
1181 | <p>This watcher type is not meant for massive numbers of stat watchers, |
1264 | <p>This watcher type is not meant for massive numbers of stat watchers, |
1182 | as even with OS-supported change notifications, this can be |
1265 | as even with OS-supported change notifications, this can be |
1183 | resource-intensive.</p> |
1266 | resource-intensive.</p> |
1184 | <p>At the time of this writing, no specific OS backends are implemented, but |
1267 | <p>At the time of this writing, only the Linux inotify interface is |
1185 | if demand increases, at least a kqueue and inotify backend will be added.</p> |
1268 | implemented (implementing kqueue support is left as an exercise for the |
|
|
1269 | reader). Inotify will be used to give hints only and should not change the |
|
|
1270 | semantics of <code>ev_stat</code> watchers, which means that libev sometimes needs |
|
|
1271 | to fall back to regular polling again even with inotify, but changes are |
|
|
1272 | usually detected immediately, and if the file exists there will be no |
|
|
1273 | polling.</p> |
1186 | <dl> |
1274 | <dl> |
1187 | <dt>ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)</dt> |
1275 | <dt>ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)</dt> |
1188 | <dt>ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)</dt> |
1276 | <dt>ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)</dt> |
1189 | <dd> |
1277 | <dd> |
1190 | <p>Configures the watcher to wait for status changes of the given |
1278 | <p>Configures the watcher to wait for status changes of the given |
… | |
… | |
1274 | <p>Initialises and configures the idle watcher - it has no parameters of any |
1362 | <p>Initialises and configures the idle watcher - it has no parameters of any |
1275 | kind. There is a <code>ev_idle_set</code> macro, but using it is utterly pointless, |
1363 | kind. There is a <code>ev_idle_set</code> macro, but using it is utterly pointless, |
1276 | believe me.</p> |
1364 | believe me.</p> |
1277 | </dd> |
1365 | </dd> |
1278 | </dl> |
1366 | </dl> |
1279 | <p>Example: dynamically allocate an <code>ev_idle</code>, start it, and in the |
1367 | <p>Example: Dynamically allocate an <code>ev_idle</code> watcher, start it, and in the |
1280 | callback, free it. Alos, use no error checking, as usual.</p> |
1368 | callback, free it. Also, use no error checking, as usual.</p> |
1281 | <pre> static void |
1369 | <pre> static void |
1282 | idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1370 | idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1283 | { |
1371 | { |
1284 | free (w); |
1372 | free (w); |
1285 | // now do something you wanted to do when the program has |
1373 | // now do something you wanted to do when the program has |
… | |
… | |
1510 | |
1598 | |
1511 | |
1599 | |
1512 | |
1600 | |
1513 | |
1601 | |
1514 | </div> |
1602 | </div> |
1515 | <h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1603 | <h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1> |
1516 | <div id="OTHER_FUNCTIONS_CONTENT"> |
1604 | <div id="OTHER_FUNCTIONS_CONTENT"> |
1517 | <p>There are some other functions of possible interest. Described. Here. Now.</p> |
1605 | <p>There are some other functions of possible interest. Described. Here. Now.</p> |
1518 | <dl> |
1606 | <dl> |
1519 | <dt>ev_once (loop, int fd, int events, ev_tstamp timeout, callback)</dt> |
1607 | <dt>ev_once (loop, int fd, int events, ev_tstamp timeout, callback)</dt> |
1520 | <dd> |
1608 | <dd> |
… | |
… | |
1567 | |
1655 | |
1568 | |
1656 | |
1569 | |
1657 | |
1570 | |
1658 | |
1571 | </div> |
1659 | </div> |
1572 | <h1 id="LIBEVENT_EMULATION">LIBEVENT EMULATION</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1660 | <h1 id="LIBEVENT_EMULATION">LIBEVENT EMULATION</h1> |
1573 | <div id="LIBEVENT_EMULATION_CONTENT"> |
1661 | <div id="LIBEVENT_EMULATION_CONTENT"> |
1574 | <p>Libev offers a compatibility emulation layer for libevent. It cannot |
1662 | <p>Libev offers a compatibility emulation layer for libevent. It cannot |
1575 | emulate the internals of libevent, so here are some usage hints:</p> |
1663 | emulate the internals of libevent, so here are some usage hints:</p> |
1576 | <dl> |
1664 | <dl> |
1577 | <dt>* Use it by including <event.h>, as usual.</dt> |
1665 | <dt>* Use it by including <event.h>, as usual.</dt> |
… | |
… | |
1587 | <dt>* The libev emulation is <i>not</i> ABI compatible to libevent, you need |
1675 | <dt>* The libev emulation is <i>not</i> ABI compatible to libevent, you need |
1588 | to use the libev header file and library.</dt> |
1676 | to use the libev header file and library.</dt> |
1589 | </dl> |
1677 | </dl> |
1590 | |
1678 | |
1591 | </div> |
1679 | </div> |
1592 | <h1 id="C_SUPPORT">C++ SUPPORT</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1680 | <h1 id="C_SUPPORT">C++ SUPPORT</h1> |
1593 | <div id="C_SUPPORT_CONTENT"> |
1681 | <div id="C_SUPPORT_CONTENT"> |
1594 | <p>Libev comes with some simplistic wrapper classes for C++ that mainly allow |
1682 | <p>Libev comes with some simplistic wrapper classes for C++ that mainly allow |
1595 | you to use some convinience methods to start/stop watchers and also change |
1683 | you to use some convinience methods to start/stop watchers and also change |
1596 | the callback model to a model using method callbacks on objects.</p> |
1684 | the callback model to a model using method callbacks on objects.</p> |
1597 | <p>To use it,</p> |
1685 | <p>To use it,</p> |
… | |
… | |
1692 | |
1780 | |
1693 | |
1781 | |
1694 | </pre> |
1782 | </pre> |
1695 | |
1783 | |
1696 | </div> |
1784 | </div> |
1697 | <h1 id="MACRO_MAGIC">MACRO MAGIC</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1785 | <h1 id="MACRO_MAGIC">MACRO MAGIC</h1> |
1698 | <div id="MACRO_MAGIC_CONTENT"> |
1786 | <div id="MACRO_MAGIC_CONTENT"> |
1699 | <p>Libev can be compiled with a variety of options, the most fundemantal is |
1787 | <p>Libev can be compiled with a variety of options, the most fundemantal is |
1700 | <code>EV_MULTIPLICITY</code>. This option determines wether (most) functions and |
1788 | <code>EV_MULTIPLICITY</code>. This option determines wether (most) functions and |
1701 | callbacks have an initial <code>struct ev_loop *</code> argument.</p> |
1789 | callbacks have an initial <code>struct ev_loop *</code> argument.</p> |
1702 | <p>To make it easier to write programs that cope with either variant, the |
1790 | <p>To make it easier to write programs that cope with either variant, the |
… | |
… | |
1753 | |
1841 | |
1754 | |
1842 | |
1755 | </pre> |
1843 | </pre> |
1756 | |
1844 | |
1757 | </div> |
1845 | </div> |
1758 | <h1 id="EMBEDDING">EMBEDDING</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1846 | <h1 id="EMBEDDING">EMBEDDING</h1> |
1759 | <div id="EMBEDDING_CONTENT"> |
1847 | <div id="EMBEDDING_CONTENT"> |
1760 | <p>Libev can (and often is) directly embedded into host |
1848 | <p>Libev can (and often is) directly embedded into host |
1761 | applications. Examples of applications that embed it include the Deliantra |
1849 | applications. Examples of applications that embed it include the Deliantra |
1762 | Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe) |
1850 | Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe) |
1763 | and rxvt-unicode.</p> |
1851 | and rxvt-unicode.</p> |
… | |
… | |
1937 | </dd> |
2025 | </dd> |
1938 | <dt>EV_USE_DEVPOLL</dt> |
2026 | <dt>EV_USE_DEVPOLL</dt> |
1939 | <dd> |
2027 | <dd> |
1940 | <p>reserved for future expansion, works like the USE symbols above.</p> |
2028 | <p>reserved for future expansion, works like the USE symbols above.</p> |
1941 | </dd> |
2029 | </dd> |
|
|
2030 | <dt>EV_USE_INOTIFY</dt> |
|
|
2031 | <dd> |
|
|
2032 | <p>If defined to be <code>1</code>, libev will compile in support for the Linux inotify |
|
|
2033 | interface to speed up <code>ev_stat</code> watchers. Its actual availability will |
|
|
2034 | be detected at runtime.</p> |
|
|
2035 | </dd> |
1942 | <dt>EV_H</dt> |
2036 | <dt>EV_H</dt> |
1943 | <dd> |
2037 | <dd> |
1944 | <p>The name of the <cite>ev.h</cite> header file used to include it. The default if |
2038 | <p>The name of the <cite>ev.h</cite> header file used to include it. The default if |
1945 | undefined is <code><ev.h></code> in <cite>event.h</cite> and <code>"ev.h"</code> in <cite>ev.c</cite>. This |
2039 | undefined is <code><ev.h></code> in <cite>event.h</cite> and <code>"ev.h"</code> in <cite>ev.c</cite>. This |
1946 | can be used to virtually rename the <cite>ev.h</cite> header file in case of conflicts.</p> |
2040 | can be used to virtually rename the <cite>ev.h</cite> header file in case of conflicts.</p> |
… | |
… | |
2001 | <dt>EV_PID_HASHSIZE</dt> |
2095 | <dt>EV_PID_HASHSIZE</dt> |
2002 | <dd> |
2096 | <dd> |
2003 | <p><code>ev_child</code> watchers use a small hash table to distribute workload by |
2097 | <p><code>ev_child</code> watchers use a small hash table to distribute workload by |
2004 | pid. The default size is <code>16</code> (or <code>1</code> with <code>EV_MINIMAL</code>), usually more |
2098 | pid. The default size is <code>16</code> (or <code>1</code> with <code>EV_MINIMAL</code>), usually more |
2005 | than enough. If you need to manage thousands of children you might want to |
2099 | than enough. If you need to manage thousands of children you might want to |
2006 | increase this value.</p> |
2100 | increase this value (<i>must</i> be a power of two).</p> |
|
|
2101 | </dd> |
|
|
2102 | <dt>EV_INOTIFY_HASHSIZE</dt> |
|
|
2103 | <dd> |
|
|
2104 | <p><code>ev_staz</code> watchers use a small hash table to distribute workload by |
|
|
2105 | inotify watch id. The default size is <code>16</code> (or <code>1</code> with <code>EV_MINIMAL</code>), |
|
|
2106 | usually more than enough. If you need to manage thousands of <code>ev_stat</code> |
|
|
2107 | watchers you might want to increase this value (<i>must</i> be a power of |
|
|
2108 | two).</p> |
2007 | </dd> |
2109 | </dd> |
2008 | <dt>EV_COMMON</dt> |
2110 | <dt>EV_COMMON</dt> |
2009 | <dd> |
2111 | <dd> |
2010 | <p>By default, all watchers have a <code>void *data</code> member. By redefining |
2112 | <p>By default, all watchers have a <code>void *data</code> member. By redefining |
2011 | this macro to a something else you can include more and other types of |
2113 | this macro to a something else you can include more and other types of |
… | |
… | |
2057 | |
2159 | |
2058 | |
2160 | |
2059 | </pre> |
2161 | </pre> |
2060 | |
2162 | |
2061 | </div> |
2163 | </div> |
2062 | <h1 id="COMPLEXITIES">COMPLEXITIES</h1><p><a href="#TOP" class="toplink">Top</a></p> |
2164 | <h1 id="COMPLEXITIES">COMPLEXITIES</h1> |
2063 | <div id="COMPLEXITIES_CONTENT"> |
2165 | <div id="COMPLEXITIES_CONTENT"> |
2064 | <p>In this section the complexities of (many of) the algorithms used inside |
2166 | <p>In this section the complexities of (many of) the algorithms used inside |
2065 | libev will be explained. For complexity discussions about backends see the |
2167 | libev will be explained. For complexity discussions about backends see the |
2066 | documentation for <code>ev_default_init</code>.</p> |
2168 | documentation for <code>ev_default_init</code>.</p> |
2067 | <p> |
2169 | <p> |
2068 | <dl> |
2170 | <dl> |
2069 | <dt>Starting and stopping timer/periodic watchers: O(log skipped_other_timers)</dt> |
2171 | <dt>Starting and stopping timer/periodic watchers: O(log skipped_other_timers)</dt> |
2070 | <dt>Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)</dt> |
2172 | <dt>Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)</dt> |
2071 | <dt>Starting io/check/prepare/idle/signal/child watchers: O(1)</dt> |
2173 | <dt>Starting io/check/prepare/idle/signal/child watchers: O(1)</dt> |
2072 | <dt>Stopping check/prepare/idle watchers: O(1)</dt> |
2174 | <dt>Stopping check/prepare/idle watchers: O(1)</dt> |
2073 | <dt>Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))</dt> |
2175 | <dt>Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))</dt> |
2074 | <dt>Finding the next timer per loop iteration: O(1)</dt> |
2176 | <dt>Finding the next timer per loop iteration: O(1)</dt> |
2075 | <dt>Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)</dt> |
2177 | <dt>Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)</dt> |
2076 | <dt>Activating one watcher: O(1)</dt> |
2178 | <dt>Activating one watcher: O(1)</dt> |
2077 | </dl> |
2179 | </dl> |
2078 | </p> |
2180 | </p> |
… | |
… | |
2080 | |
2182 | |
2081 | |
2183 | |
2082 | |
2184 | |
2083 | |
2185 | |
2084 | </div> |
2186 | </div> |
2085 | <h1 id="AUTHOR">AUTHOR</h1><p><a href="#TOP" class="toplink">Top</a></p> |
2187 | <h1 id="AUTHOR">AUTHOR</h1> |
2086 | <div id="AUTHOR_CONTENT"> |
2188 | <div id="AUTHOR_CONTENT"> |
2087 | <p>Marc Lehmann <libev@schmorp.de>.</p> |
2189 | <p>Marc Lehmann <libev@schmorp.de>.</p> |
2088 | |
2190 | |
2089 | </div> |
2191 | </div> |
2090 | </div></body> |
2192 | </div></body> |