override the flags completely if it is found in the environment. This is
useful to try out specific backends to test their performance, or to work
around bugs.
+.ie n .IP """EVFLAG_FORKCHECK""" 4
+.el .IP "\f(CWEVFLAG_FORKCHECK\fR" 4
+.IX Item "EVFLAG_FORKCHECK"
+Instead of calling \f(CW\*(C`ev_default_fork\*(C'\fR or \f(CW\*(C`ev_loop_fork\*(C'\fR manually after
+a fork, you can also make libev check for a fork in each iteration by
+enabling this flag.
+.Sp
+This works by calling \f(CW\*(C`getpid ()\*(C'\fR on every iteration of the loop,
+and thus this might slow down your event loop if you do a lot of loop
+iterations and little real work, but is usually not noticable (on my
+Linux system for example, \f(CW\*(C`getpid\*(C'\fR is actually a simple 5\-insn sequence
+without a syscall and thus \fIvery\fR fast, but my Linux system also has
+\&\f(CW\*(C`pthread_atfork\*(C'\fR which is even faster).
+.Sp
+The big advantage of this flag is that you can forget about fork (and
+forget about forgetting to tell libev about forking) when you use this
+flag.
+.Sp
+This flag setting cannot be overriden or specified in the \f(CW\*(C`LIBEV_FLAGS\*(C'\fR
+environment variable.
.ie n .IP """EVBACKEND_SELECT"" (value 1, portable select backend)" 4
.el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4
.IX Item "EVBACKEND_SELECT (value 1, portable select backend)"
now_floor = mn_now;
rtmn_diff = ev_rt_now - mn_now;
+ /* pid check not overridable via env */
+#ifndef _WIN32
+ if (flags & EVFLAG_FORKCHECK)
+ curpid = getpid ();
+#endif
+
if (!(flags & EVFLAG_NOENV)
&& !enable_secure ()
&& getenv ("LIBEV_FLAGS"))
? EVUNLOOP_ONE
: EVUNLOOP_CANCEL;
+ call_pending (EV_A); /* in case we recurse, ensure ordering stays nice and clean */
+
while (activecnt)
{
+#ifndef _WIN32
+ if (expect_false (curpid)) /* penalise the forking check even more */
+ if (expect_false (getpid () != curpid))
+ {
+ curpid = getpid ();
+ postfork = 1;
+ }
+#endif
+
#if EV_FORK_ENABLE
/* we might have forked, so queue fork handlers */
if (expect_false (postfork))
#define EVFLAG_AUTO 0x00000000UL /* not quite a mask */
/* flag bits */
#define EVFLAG_NOENV 0x01000000UL /* do NOT consult environment */
+#define EVFLAG_FORKCHECK 0x02000000UL /* check for a fork in each iteration */
/* method bits to be ored together */
#define EVBACKEND_SELECT 0x00000001UL /* about anywhere */
#define EVBACKEND_POLL 0x00000002UL /* !win */
<meta name="description" content="Pod documentation for libev" />
<meta name="inputfile" content="<standard input>" />
<meta name="outputfile" content="<standard output>" />
- <meta name="created" content="Thu Nov 29 13:21:20 2007" />
+ <meta name="created" content="Thu Nov 29 18:28:02 2007" />
<meta name="generator" content="Pod::Xhtml 1.57" />
<link rel="stylesheet" href="http://res.tst.eu/pod.css"/></head>
<body>
override the flags completely if it is found in the environment. This is
useful to try out specific backends to test their performance, or to work
around bugs.</p>
+ </dd>
+ <dt><code>EVFLAG_FORKCHECK</code></dt>
+ <dd>
+ <p>Instead of calling <code>ev_default_fork</code> or <code>ev_loop_fork</code> manually after
+a fork, you can also make libev check for a fork in each iteration by
+enabling this flag.</p>
+ <p>This works by calling <code>getpid ()</code> on every iteration of the loop,
+and thus this might slow down your event loop if you do a lot of loop
+iterations and little real work, but is usually not noticable (on my
+Linux system for example, <code>getpid</code> is actually a simple 5-insn sequence
+without a syscall and thus <i>very</i> fast, but my Linux system also has
+<code>pthread_atfork</code> which is even faster).</p>
+ <p>The big advantage of this flag is that you can forget about fork (and
+forget about forgetting to tell libev about forking) when you use this
+flag.</p>
+ <p>This flag setting cannot be overriden or specified in the <code>LIBEV_FLAGS</code>
+environment variable.</p>
</dd>
<dt><code>EVBACKEND_SELECT</code> (value 1, portable select backend)</dt>
<dd>
useful to try out specific backends to test their performance, or to work
around bugs.
+=item C<EVFLAG_FORKCHECK>
+
+Instead of calling C<ev_default_fork> or C<ev_loop_fork> manually after
+a fork, you can also make libev check for a fork in each iteration by
+enabling this flag.
+
+This works by calling C<getpid ()> on every iteration of the loop,
+and thus this might slow down your event loop if you do a lot of loop
+iterations and little real work, but is usually not noticable (on my
+Linux system for example, C<getpid> is actually a simple 5-insn sequence
+without a syscall and thus I<very> fast, but my Linux system also has
+C<pthread_atfork> which is even faster).
+
+The big advantage of this flag is that you can forget about fork (and
+forget about forgetting to tell libev about forking) when you use this
+flag.
+
+This flag setting cannot be overriden or specified in the C<LIBEV_FLAGS>
+environment variable.
+
=item C<EVBACKEND_SELECT> (value 1, portable select backend)
This is your standard select(2) backend. Not I<completely> standard, as
VARx(ev_tstamp, mn_now) /* monotonic clock "now" */
VARx(ev_tstamp, rtmn_diff) /* difference realtime - monotonic time */
VARx(int, backend)
+VARx(int, activecnt) /* total number of active events ("refcount") */
VARx(ev_tstamp, backend_fudge) /* assumed typical timer resolution */
VAR (backend_modify, void (*backend_modify)(EV_P_ int fd, int oev, int nev))
VAR (backend_poll , void (*backend_poll)(EV_P_ ev_tstamp timeout))
VARx(int, backend_fd)
+#if !defined(_WIN32) || EV_GENWRAP
+VARx(pid_t, curpid)
+#endif
+
VARx(int, postfork) /* true if we need to recreate kernel state after fork */
-VARx(int, activecnt) /* total number of active events ("refcount") */
#if EV_USE_SELECT || EV_GENWRAP
VARx(void *, vec_ri)
#define mn_now ((loop)->mn_now)
#define rtmn_diff ((loop)->rtmn_diff)
#define backend ((loop)->backend)
+#define activecnt ((loop)->activecnt)
#define backend_fudge ((loop)->backend_fudge)
#define backend_modify ((loop)->backend_modify)
#define backend_poll ((loop)->backend_poll)
#define backend_fd ((loop)->backend_fd)
+#define curpid ((loop)->curpid)
#define postfork ((loop)->postfork)
-#define activecnt ((loop)->activecnt)
#define vec_ri ((loop)->vec_ri)
#define vec_ro ((loop)->vec_ro)
#define vec_wi ((loop)->vec_wi)
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