| … | |
… | |
| 127 | .\} |
127 | .\} |
| 128 | .rm #[ #] #H #V #F C |
128 | .rm #[ #] #H #V #F C |
| 129 | .\" ======================================================================== |
129 | .\" ======================================================================== |
| 130 | .\" |
130 | .\" |
| 131 | .IX Title ""<STANDARD INPUT>" 1" |
131 | .IX Title ""<STANDARD INPUT>" 1" |
| 132 | .TH "<STANDARD INPUT>" 1 "2007-12-09" "perl v5.8.8" "User Contributed Perl Documentation" |
132 | .TH "<STANDARD INPUT>" 1 "2007-12-12" "perl v5.8.8" "User Contributed Perl Documentation" |
| 133 | .SH "NAME" |
133 | .SH "NAME" |
| 134 | libev \- a high performance full\-featured event loop written in C |
134 | libev \- a high performance full\-featured event loop written in C |
| 135 | .SH "SYNOPSIS" |
135 | .SH "SYNOPSIS" |
| 136 | .IX Header "SYNOPSIS" |
136 | .IX Header "SYNOPSIS" |
| 137 | .Vb 1 |
137 | .Vb 1 |
| … | |
… | |
| 1065 | If you cannot run the fd in non-blocking mode (for example you should not |
1065 | If you cannot run the fd in non-blocking mode (for example you should not |
| 1066 | play around with an Xlib connection), then you have to seperately re-test |
1066 | play around with an Xlib connection), then you have to seperately re-test |
| 1067 | whether a file descriptor is really ready with a known-to-be good interface |
1067 | whether a file descriptor is really ready with a known-to-be good interface |
| 1068 | such as poll (fortunately in our Xlib example, Xlib already does this on |
1068 | such as poll (fortunately in our Xlib example, Xlib already does this on |
| 1069 | its own, so its quite safe to use). |
1069 | its own, so its quite safe to use). |
|
|
1070 | .PP |
|
|
1071 | \fIThe special problem of disappearing file descriptors\fR |
|
|
1072 | .IX Subsection "The special problem of disappearing file descriptors" |
|
|
1073 | .PP |
|
|
1074 | Some backends (e.g kqueue, epoll) need to be told about closing a file |
|
|
1075 | descriptor (either by calling \f(CW\*(C`close\*(C'\fR explicitly or by any other means, |
|
|
1076 | such as \f(CW\*(C`dup\*(C'\fR). The reason is that you register interest in some file |
|
|
1077 | descriptor, but when it goes away, the operating system will silently drop |
|
|
1078 | this interest. If another file descriptor with the same number then is |
|
|
1079 | registered with libev, there is no efficient way to see that this is, in |
|
|
1080 | fact, a different file descriptor. |
|
|
1081 | .PP |
|
|
1082 | To avoid having to explicitly tell libev about such cases, libev follows |
|
|
1083 | the following policy: Each time \f(CW\*(C`ev_io_set\*(C'\fR is being called, libev |
|
|
1084 | will assume that this is potentially a new file descriptor, otherwise |
|
|
1085 | it is assumed that the file descriptor stays the same. That means that |
|
|
1086 | you \fIhave\fR to call \f(CW\*(C`ev_io_set\*(C'\fR (or \f(CW\*(C`ev_io_init\*(C'\fR) when you change the |
|
|
1087 | descriptor even if the file descriptor number itself did not change. |
|
|
1088 | .PP |
|
|
1089 | This is how one would do it normally anyway, the important point is that |
|
|
1090 | the libev application should not optimise around libev but should leave |
|
|
1091 | optimisations to libev. |
| 1070 | .IP "ev_io_init (ev_io *, callback, int fd, int events)" 4 |
1092 | .IP "ev_io_init (ev_io *, callback, int fd, int events)" 4 |
| 1071 | .IX Item "ev_io_init (ev_io *, callback, int fd, int events)" |
1093 | .IX Item "ev_io_init (ev_io *, callback, int fd, int events)" |
| 1072 | .PD 0 |
1094 | .PD 0 |
| 1073 | .IP "ev_io_set (ev_io *, int fd, int events)" 4 |
1095 | .IP "ev_io_set (ev_io *, int fd, int events)" 4 |
| 1074 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
1096 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
