| … | |
… | |
| 26 | Libev supports select, poll, the linux-specific epoll and the bsd-specific |
26 | Libev supports select, poll, the linux-specific epoll and the bsd-specific |
| 27 | kqueue mechanisms for file descriptor events, relative timers, absolute |
27 | kqueue mechanisms for file descriptor events, relative timers, absolute |
| 28 | timers with customised rescheduling, signal events, process status change |
28 | timers with customised rescheduling, signal events, process status change |
| 29 | events (related to SIGCHLD), and event watchers dealing with the event |
29 | events (related to SIGCHLD), and event watchers dealing with the event |
| 30 | loop mechanism itself (idle, prepare and check watchers). It also is quite |
30 | loop mechanism itself (idle, prepare and check watchers). It also is quite |
| 31 | fast (see a L<benchmark|http://libev.schmorp.de/bench.html> comparing it |
31 | fast (see this L<benchmark|http://libev.schmorp.de/bench.html> comparing |
| 32 | to libevent). |
32 | it to libevent for example). |
| 33 | |
33 | |
| 34 | =head1 CONVENTIONS |
34 | =head1 CONVENTIONS |
| 35 | |
35 | |
| 36 | Libev is very configurable. In this manual the default configuration |
36 | Libev is very configurable. In this manual the default configuration |
| 37 | will be described, which supports multiple event loops. For more info |
37 | will be described, which supports multiple event loops. For more info |
| 38 | about various configuraiton options please have a look at the file |
38 | about various configuration options please have a look at the file |
| 39 | F<README.embed> in the libev distribution. If libev was configured without |
39 | F<README.embed> in the libev distribution. If libev was configured without |
| 40 | support for multiple event loops, then all functions taking an initial |
40 | support for multiple event loops, then all functions taking an initial |
| 41 | argument of name C<loop> (which is always of type C<struct ev_loop *>) |
41 | argument of name C<loop> (which is always of type C<struct ev_loop *>) |
| 42 | will not have this argument. |
42 | will not have this argument. |
| 43 | |
43 | |
| … | |
… | |
| 71 | not a problem. |
71 | not a problem. |
| 72 | |
72 | |
| 73 | =item ev_set_allocator (void *(*cb)(void *ptr, long size)) |
73 | =item ev_set_allocator (void *(*cb)(void *ptr, long size)) |
| 74 | |
74 | |
| 75 | Sets the allocation function to use (the prototype is similar to the |
75 | Sets the allocation function to use (the prototype is similar to the |
| 76 | realloc function). It is used to allocate and free memory (no surprises |
76 | realloc C function, the semantics are identical). It is used to allocate |
| 77 | here). If it returns zero when memory needs to be allocated, the library |
77 | and free memory (no surprises here). If it returns zero when memory |
| 78 | might abort or take some potentially destructive action. The default is |
78 | needs to be allocated, the library might abort or take some potentially |
| 79 | your system realloc function. |
79 | destructive action. The default is your system realloc function. |
| 80 | |
80 | |
| 81 | You could override this function in high-availability programs to, say, |
81 | You could override this function in high-availability programs to, say, |
| 82 | free some memory if it cannot allocate memory, to use a special allocator, |
82 | free some memory if it cannot allocate memory, to use a special allocator, |
| 83 | or even to sleep a while and retry until some memory is available. |
83 | or even to sleep a while and retry until some memory is available. |
| 84 | |
84 | |
| … | |
… | |
| 86 | |
86 | |
| 87 | Set the callback function to call on a retryable syscall error (such |
87 | Set the callback function to call on a retryable syscall error (such |
| 88 | as failed select, poll, epoll_wait). The message is a printable string |
88 | as failed select, poll, epoll_wait). The message is a printable string |
| 89 | indicating the system call or subsystem causing the problem. If this |
89 | indicating the system call or subsystem causing the problem. If this |
| 90 | callback is set, then libev will expect it to remedy the sitution, no |
90 | callback is set, then libev will expect it to remedy the sitution, no |
| 91 | matter what, when it returns. That is, libev will geenrally retry the |
91 | matter what, when it returns. That is, libev will generally retry the |
| 92 | requested operation, or, if the condition doesn't go away, do bad stuff |
92 | requested operation, or, if the condition doesn't go away, do bad stuff |
| 93 | (such as abort). |
93 | (such as abort). |
| 94 | |
94 | |
| 95 | =back |
95 | =back |
| 96 | |
96 | |
| … | |
… | |
| 100 | types of such loops, the I<default> loop, which supports signals and child |
100 | types of such loops, the I<default> loop, which supports signals and child |
| 101 | events, and dynamically created loops which do not. |
101 | events, and dynamically created loops which do not. |
| 102 | |
102 | |
| 103 | If you use threads, a common model is to run the default event loop |
103 | If you use threads, a common model is to run the default event loop |
| 104 | in your main thread (or in a separate thrad) and for each thread you |
104 | in your main thread (or in a separate thrad) and for each thread you |
| 105 | create, you also create another event loop. Libev itself does no lockign |
105 | create, you also create another event loop. Libev itself does no locking |
| 106 | whatsoever, so if you mix calls to different event loops, make sure you |
106 | whatsoever, so if you mix calls to the same event loop in different |
| 107 | lock (this is usually a bad idea, though, even if done right). |
107 | threads, make sure you lock (this is usually a bad idea, though, even if |
|
|
108 | done correctly, because its hideous and inefficient). |
| 108 | |
109 | |
| 109 | =over 4 |
110 | =over 4 |
| 110 | |
111 | |
| 111 | =item struct ev_loop *ev_default_loop (unsigned int flags) |
112 | =item struct ev_loop *ev_default_loop (unsigned int flags) |
| 112 | |
113 | |
