diff options
Diffstat (limited to 'ev.3')
| -rw-r--r-- | ev.3 | 52 |
1 files changed, 49 insertions, 3 deletions
@@ -132,7 +132,7 @@ .\" ======================================================================== .\" .IX Title "EV 1" -.TH EV 1 "2008-03-13" "perl v5.10.0" "User Contributed Perl Documentation" +.TH EV 1 "2008-04-02" "perl v5.10.0" "User Contributed Perl Documentation" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l @@ -406,6 +406,10 @@ flags. If that is troubling you, check \f(CW\*(C`ev_backend ()\*(C'\fR afterward If you don't know what event loop to use, use the one returned from this function. .Sp +Note that this function is \fInot\fR thread-safe, so if you want to use it +from multiple threads, you have to lock (note also that this is unlikely, +as loops cannot bes hared easily between threads anyway). +.Sp The default loop is the only loop that can handle \f(CW\*(C`ev_signal\*(C'\fR and \&\f(CW\*(C`ev_child\*(C'\fR watchers, and to do this, it always registers a handler for \f(CW\*(C`SIGCHLD\*(C'\fR. If this is a problem for your app you can either @@ -602,6 +606,10 @@ always distinct from the default loop. Unlike the default loop, it cannot handle signal and child watchers, and attempts to do so will be greeted by undefined behaviour (or a failed assertion if assertions are enabled). .Sp +Note that this function \fIis\fR thread-safe, and the recommended way to use +libev with threads is indeed to create one loop per thread, and using the +default loop in the \*(L"main\*(R" or \*(L"initial\*(R" thread. +.Sp Example: Try to create a event loop that uses epoll and nothing else. .Sp .Vb 3 @@ -1221,6 +1229,19 @@ To support fork in your programs, you either have to call enable \f(CW\*(C`EVFLAG_FORKCHECK\*(C'\fR, or resort to \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR or \&\f(CW\*(C`EVBACKEND_POLL\*(C'\fR. .PP +\fIThe special problem of \s-1SIGPIPE\s0\fR +.IX Subsection "The special problem of SIGPIPE" +.PP +While not really specific to libev, it is easy to forget about \s-1SIGPIPE:\s0 +when reading from a pipe whose other end has been closed, your program +gets send a \s-1SIGPIPE\s0, which, by default, aborts your program. For most +programs this is sensible behaviour, for daemons, this is usually +undesirable. +.PP +So when you encounter spurious, unexplained daemon exits, make sure you +ignore \s-1SIGPIPE\s0 (and maybe make sure you log the exit status of your daemon +somewhere, as that would have given you a big clue). +.PP \fIWatcher-Specific Functions\fR .IX Subsection "Watcher-Specific Functions" .IP "ev_io_init (ev_io *, callback, int fd, int events)" 4 @@ -1738,6 +1759,18 @@ to fall back to regular polling again even with inotify, but changes are usually detected immediately, and if the file exists there will be no polling. .PP +\fI\s-1ABI\s0 Issues (Largefile Support)\fR +.IX Subsection "ABI Issues (Largefile Support)" +.PP +Libev by default (unless the user overrides this) uses the default +compilation environment, which means that on systems with optionally +disabled large file support, you get the 32 bit version of the stat +structure. When using the library from programs that change the \s-1ABI\s0 to +use 64 bit file offsets the programs will fail. In that case you have to +compile libev with the same flags to get binary compatibility. This is +obviously the case with any flags that change the \s-1ABI\s0, but the problem is +most noticably with ev_stat and largefile support. +.PP \fIInotify\fR .IX Subsection "Inotify" .PP @@ -2385,6 +2418,19 @@ section below on what exactly this means). This call incurs the overhead of a syscall only once per loop iteration, so while the overhead might be noticable, it doesn't apply to repeated calls to \f(CW\*(C`ev_async_send\*(C'\fR. +.IP "bool = ev_async_pending (ev_async *)" 4 +.IX Item "bool = ev_async_pending (ev_async *)" +Returns a non-zero value when \f(CW\*(C`ev_async_send\*(C'\fR has been called on the +watcher but the event has not yet been processed (or even noted) by the +event loop. +.Sp +\&\f(CW\*(C`ev_async_send\*(C'\fR sets a flag in the watcher and wakes up the loop. When +the loop iterates next and checks for the watcher to have become active, +it will reset the flag again. \f(CW\*(C`ev_async_pending\*(C'\fR can be used to very +quickly check wether invoking the loop might be a good idea. +.Sp +Not that this does \fInot\fR check wether the watcher itself is pending, only +wether it has been requested to make this watcher pending. .SH "OTHER FUNCTIONS" .IX Header "OTHER FUNCTIONS" There are some other functions of possible interest. Described. Here. Now. @@ -3225,6 +3271,6 @@ Marc Lehmann <libev@schmorp.de>. .SH "POD ERRORS" .IX Header "POD ERRORS" Hey! \fBThe above document had some coding errors, which are explained below:\fR -.IP "Around line 2951:" 4 -.IX Item "Around line 2951:" +.IP "Around line 2996:" 4 +.IX Item "Around line 2996:" You forgot a '=back' before '=head2' |