.Sp
Here are the gory details of what \f(CW\*(C`ev_loop\*(C'\fR does:
.Sp
-.Vb 18
+.Vb 19
+\& - Before the first iteration, call any pending watchers.
\& * If there are no active watchers (reference count is zero), return.
-\& - Queue prepare watchers and then call all outstanding watchers.
+\& - Queue all prepare watchers and then call all outstanding watchers.
\& - If we have been forked, recreate the kernel state.
\& - Update the kernel state with all outstanding changes.
\& - Update the "event loop time".
of lower priority, but only once, using idle watchers to keep the event
loop from blocking if lower-priority coroutines are active, thus mapping
low-priority coroutines to idle/background tasks).
+.PP
+It is recommended to give \f(CW\*(C`ev_check\*(C'\fR watchers highest (\f(CW\*(C`EV_MAXPRI\*(C'\fR)
+priority, to ensure that they are being run before any other watchers
+after the poll. Also, \f(CW\*(C`ev_check\*(C'\fR watchers (and \f(CW\*(C`ev_prepare\*(C'\fR watchers,
+too) should not activate (\*(L"feed\*(R") events into libev. While libev fully
+supports this, they will be called before other \f(CW\*(C`ev_check\*(C'\fR watchers did
+their job. As \f(CW\*(C`ev_check\*(C'\fR watchers are often used to embed other event
+loops those other event loops might be in an unusable state until their
+\&\f(CW\*(C`ev_check\*(C'\fR watcher ran (always remind yourself to coexist peacefully with
+others).
.IP "ev_prepare_init (ev_prepare *, callback)" 4
.IX Item "ev_prepare_init (ev_prepare *, callback)"
.PD 0
}
#endif
- /* queue check watchers (and execute them) */
+ /* queue prepare watchers (and execute them) */
if (expect_false (preparecnt))
{
queue_events (EV_A_ (W *)prepares, preparecnt, EV_PREPARE);
<meta name="description" content="Pod documentation for libev" />
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+ <meta name="created" content="Sat Dec 8 23:11:11 2007" />
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<body>
libev watchers. However, a pair of <code>ev_prepare</code>/<code>ev_check</code> watchers is
usually a better approach for this kind of thing.</p>
<p>Here are the gory details of what <code>ev_loop</code> does:</p>
-<pre> * If there are no active watchers (reference count is zero), return.
- - Queue prepare watchers and then call all outstanding watchers.
+<pre> - Before the first iteration, call any pending watchers.
+ * If there are no active watchers (reference count is zero), return.
+ - Queue all prepare watchers and then call all outstanding watchers.
- If we have been forked, recreate the kernel state.
- Update the kernel state with all outstanding changes.
- Update the "event loop time".
of lower priority, but only once, using idle watchers to keep the event
loop from blocking if lower-priority coroutines are active, thus mapping
low-priority coroutines to idle/background tasks).</p>
+<p>It is recommended to give <code>ev_check</code> watchers highest (<code>EV_MAXPRI</code>)
+priority, to ensure that they are being run before any other watchers
+after the poll. Also, <code>ev_check</code> watchers (and <code>ev_prepare</code> watchers,
+too) should not activate ("feed") events into libev. While libev fully
+supports this, they will be called before other <code>ev_check</code> watchers did
+their job. As <code>ev_check</code> watchers are often used to embed other event
+loops those other event loops might be in an unusable state until their
+<code>ev_check</code> watcher ran (always remind yourself to coexist peacefully with
+others).</p>
<dl>
<dt>ev_prepare_init (ev_prepare *, callback)</dt>
<dt>ev_check_init (ev_check *, callback)</dt>
Here are the gory details of what C<ev_loop> does:
+ - Before the first iteration, call any pending watchers.
* If there are no active watchers (reference count is zero), return.
- - Queue prepare watchers and then call all outstanding watchers.
+ - Queue all prepare watchers and then call all outstanding watchers.
- If we have been forked, recreate the kernel state.
- Update the kernel state with all outstanding changes.
- Update the "event loop time".
loop from blocking if lower-priority coroutines are active, thus mapping
low-priority coroutines to idle/background tasks).
+It is recommended to give C<ev_check> watchers highest (C<EV_MAXPRI>)
+priority, to ensure that they are being run before any other watchers
+after the poll. Also, C<ev_check> watchers (and C<ev_prepare> watchers,
+too) should not activate ("feed") events into libev. While libev fully
+supports this, they will be called before other C<ev_check> watchers did
+their job. As C<ev_check> watchers are often used to embed other event
+loops those other event loops might be in an unusable state until their
+C<ev_check> watcher ran (always remind yourself to coexist peacefully with
+others).
+
=over 4
=item ev_prepare_init (ev_prepare *, callback)
projects / software / libev.git / commitdiff