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authorroot <root>2010-03-10 08:19:38 +0000
committerroot <root>2010-03-10 08:19:38 +0000
commit1e97f470d7efb51562242a32fa3145e02c19b030 (patch)
tree3fce0950088557fc8b18c41e0ee7ce634910f9ba
parent0bcdefb16b27d722ed252e7922f63c5caf2d801e (diff)
more minimal tuning, add truly minimal example
-rw-r--r--Changes4
-rw-r--r--ev.c63
-rw-r--r--ev.h27
-rw-r--r--ev.pod49
4 files changed, 116 insertions, 27 deletions
diff --git a/Changes b/Changes
index 57f6cb8..9997f15 100644
--- a/Changes
+++ b/Changes
@@ -1,8 +1,9 @@
Revision history for libev, a high-performance and full-featured event loop.
+TODO: accept() documentation
- ev_embed_stop did not correctly stop the watcher (very good
testcase by Vladimir Timofeev).
- - applied win32 fixes by Michael Lenaghan.
+ - applied win32 fixes by Michael Lenaghan (also James Mansion).
- remove dependency on sys/queue.h on freebsd (patch by Vanilla Hsu).
- configure now prepends -O3, not appends it, so one can still
override it.
@@ -14,6 +15,7 @@ Revision history for libev, a high-performance and full-featured event loop.
- implement EV_AVOID_STDIO option.
- do not use sscanf to parse linux version number (smaller, faster,
no sscanf dependency).
+ - new EV_CHILD_ENABLE and EV_SIGNAL_ENABLE configurable settings.
3.9 Thu Dec 31 07:59:59 CET 2009
- signalfd is no longer used by default and has to be requested
diff --git a/ev.c b/ev.c
index d0a160a..2a66b60 100644
--- a/ev.c
+++ b/ev.c
@@ -209,12 +209,13 @@ extern "C" {
#elif defined (MAX_SIG)
# define EV_NSIG (MAX_SIG+1)
#elif defined (SIGARRAYSIZE)
-# define EV_NSIG SIGARRAYSIZE /* Assume ary[SIGARRAYSIZE] */
+# define EV_NSIG (SIGARRAYSIZE) /* Assume ary[SIGARRAYSIZE] */
#elif defined (_sys_nsig)
# define EV_NSIG (_sys_nsig) /* Solaris 2.5 */
#else
# error "unable to find value for NSIG, please report"
-/* to make it compile regardless, just remove the above line */
+/* to make it compile regardless, just remove the above line, */
+/* but consider reporting it, too! :) */
# define EV_NSIG 65
#endif
@@ -994,7 +995,7 @@ fd_kill (EV_P_ int fd)
}
}
-/* check whether the given fd is atcually valid, for error recovery */
+/* check whether the given fd is actually valid, for error recovery */
inline_size int
fd_valid (int fd)
{
@@ -1046,6 +1047,20 @@ fd_rearm_all (EV_P)
}
}
+/* used to prepare libev internal fd's */
+/* this is not fork-safe */
+inline_speed void
+fd_intern (int fd)
+{
+#ifdef _WIN32
+ unsigned long arg = 1;
+ ioctlsocket (EV_FD_TO_WIN32_HANDLE (fd), FIONBIO, &arg);
+#else
+ fcntl (fd, F_SETFD, FD_CLOEXEC);
+ fcntl (fd, F_SETFL, O_NONBLOCK);
+#endif
+}
+
/*****************************************************************************/
/*
@@ -1207,26 +1222,14 @@ static ANSIG signals [EV_NSIG - 1];
/*****************************************************************************/
-/* used to prepare libev internal fd's */
-/* this is not fork-safe */
-inline_speed void
-fd_intern (int fd)
-{
-#ifdef _WIN32
- unsigned long arg = 1;
- ioctlsocket (EV_FD_TO_WIN32_HANDLE (fd), FIONBIO, &arg);
-#else
- fcntl (fd, F_SETFD, FD_CLOEXEC);
- fcntl (fd, F_SETFL, O_NONBLOCK);
-#endif
-}
+#if EV_SIGNAL_ENABLE || EV_ASYNC_ENABLE
static void noinline
evpipe_init (EV_P)
{
if (!ev_is_active (&pipe_w))
{
-#if EV_USE_EVENTFD
+# if EV_USE_EVENTFD
evfd = eventfd (0, EFD_NONBLOCK | EFD_CLOEXEC);
if (evfd < 0 && errno == EINVAL)
evfd = eventfd (0, 0);
@@ -1238,7 +1241,7 @@ evpipe_init (EV_P)
ev_io_set (&pipe_w, evfd, EV_READ);
}
else
-#endif
+# endif
{
while (pipe (evpipe))
ev_syserr ("(libev) error creating signal/async pipe");
@@ -1259,6 +1262,7 @@ evpipe_write (EV_P_ EV_ATOMIC_T *flag)
if (!*flag)
{
int old_errno = errno; /* save errno because write might clobber it */
+ char dummy;
*flag = 1;
@@ -1270,7 +1274,7 @@ evpipe_write (EV_P_ EV_ATOMIC_T *flag)
}
else
#endif
- write (evpipe [1], &old_errno, 1);
+ write (evpipe [1], &dummy, 1);
errno = old_errno;
}
@@ -1381,12 +1385,13 @@ sigfdcb (EV_P_ ev_io *iow, int revents)
}
#endif
+#endif
+
/*****************************************************************************/
+#if EV_CHILD_ENABLE
static WL childs [EV_PID_HASHSIZE];
-#ifndef _WIN32
-
static ev_signal childev;
#ifndef WIFCONTINUED
@@ -1664,8 +1669,10 @@ loop_init (EV_P_ unsigned int flags)
ev_prepare_init (&pending_w, pendingcb);
+#if EV_SIGNAL_ENABLE || EV_ASYNC_ENABLE
ev_init (&pipe_w, pipecb);
ev_set_priority (&pipe_w, EV_MAXPRI);
+#endif
}
}
@@ -1925,8 +1932,10 @@ ev_loop_verify (EV_P)
array_verify (EV_A_ (W *)checks, checkcnt);
# if 0
+#if EV_CHILD_ENABLE
for (w = (ev_child *)childs [chain & (EV_PID_HASHSIZE - 1)]; w; w = (ev_child *)((WL)w)->next)
for (signum = EV_NSIG; signum--; ) if (signals [signum].pending)
+#endif
# endif
#endif
}
@@ -1952,7 +1961,7 @@ ev_default_loop (unsigned int flags)
if (ev_backend (EV_A))
{
-#ifndef _WIN32
+#if EV_CHILD_ENABLE
ev_signal_init (&childev, childcb, SIGCHLD);
ev_set_priority (&childev, EV_MAXPRI);
ev_signal_start (EV_A_ &childev);
@@ -1975,7 +1984,7 @@ ev_default_destroy (void)
ev_default_loop_ptr = 0;
-#ifndef _WIN32
+#if EV_CHILD_ENABLE
ev_ref (EV_A); /* child watcher */
ev_signal_stop (EV_A_ &childev);
#endif
@@ -2727,6 +2736,8 @@ ev_periodic_again (EV_P_ ev_periodic *w)
# define SA_RESTART 0
#endif
+#if EV_SIGNAL_ENABLE
+
void noinline
ev_signal_start (EV_P_ ev_signal *w)
{
@@ -2842,6 +2853,10 @@ ev_signal_stop (EV_P_ ev_signal *w)
EV_FREQUENT_CHECK;
}
+#endif
+
+#if EV_CHILD_ENABLE
+
void
ev_child_start (EV_P_ ev_child *w)
{
@@ -2874,6 +2889,8 @@ ev_child_stop (EV_P_ ev_child *w)
EV_FREQUENT_CHECK;
}
+#endif
+
#if EV_STAT_ENABLE
# ifdef _WIN32
diff --git a/ev.h b/ev.h
index 06ff8cc..661ff98 100644
--- a/ev.h
+++ b/ev.h
@@ -74,14 +74,26 @@ typedef double ev_tstamp;
# define EV_FORK_ENABLE 1
#endif
-#ifndef EV_EMBED_ENABLE
-# define EV_EMBED_ENABLE 1
+#ifndef EV_SIGNAL_ENABLE
+# define EV_SIGNAL_ENABLE 1
+#endif
+
+#ifndef EV_CHILD_ENABLE
+# ifdef _WIN32
+# define EV_CHILD_ENABLE 0
+# else
+# define EV_CHILD_ENABLE 1
+#endif
#endif
#ifndef EV_ASYNC_ENABLE
# define EV_ASYNC_ENABLE 1
#endif
+#ifndef EV_EMBED_ENABLE
+# define EV_EMBED_ENABLE 1
+#endif
+
#ifndef EV_WALK_ENABLE
# define EV_WALK_ENABLE 0 /* not yet */
#endif
@@ -93,6 +105,11 @@ typedef double ev_tstamp;
/*****************************************************************************/
+#if EV_CHILD_ENABLE && !EV_SIGNAL_ENABLE
+# undef EV_SIGNAL_ENABLE
+# define EV_SIGNAL_ENABLE 1
+#endif
+
#if EV_STAT_ENABLE
# ifdef _WIN32
# include <time.h>
@@ -632,7 +649,9 @@ void ev_resume (EV_P);
/* accepts any ev_watcher type */
void ev_feed_event (EV_P_ void *w, int revents);
void ev_feed_fd_event (EV_P_ int fd, int revents);
+#if EV_SIGNAL_ENABLE
void ev_feed_signal_event (EV_P_ int signum);
+#endif
void ev_invoke (EV_P_ void *w, int revents);
int ev_clear_pending (EV_P_ void *w);
@@ -653,12 +672,16 @@ void ev_periodic_again (EV_P_ ev_periodic *w);
#endif
/* only supported in the default loop */
+#if EV_SIGNAL_ENABLE
void ev_signal_start (EV_P_ ev_signal *w);
void ev_signal_stop (EV_P_ ev_signal *w);
+#endif
/* only supported in the default loop */
+# if EV_CHILD_ENABLE
void ev_child_start (EV_P_ ev_child *w);
void ev_child_stop (EV_P_ ev_child *w);
+# endif
# if EV_STAT_ENABLE
void ev_stat_start (EV_P_ ev_stat *w);
diff --git a/ev.pod b/ev.pod
index f13391d..8c586e7 100644
--- a/ev.pod
+++ b/ev.pod
@@ -3868,11 +3868,21 @@ defined to be C<0>, then they are not.
If undefined or defined to be C<1>, then fork watchers are supported. If
defined to be C<0>, then they are not.
+=item EV_SIGNAL_ENABLE
+
+If undefined or defined to be C<1>, then signal watchers are supported. If
+defined to be C<0>, then they are not.
+
=item EV_ASYNC_ENABLE
If undefined or defined to be C<1>, then async watchers are supported. If
defined to be C<0>, then they are not.
+=item EV_CHILD_ENABLE
+
+If undefined or defined to be C<1> (and C<_WIN32> is not defined), then
+child watchers are supported. If defined to be C<0>, then they are not.
+
=item EV_MINIMAL
If you need to shave off some kilobytes of code at the expense of some
@@ -3883,13 +3893,50 @@ the default 4-heap.
You can save even more by disabling watcher types you do not need
and setting C<EV_MAXPRI> == C<EV_MINPRI>. Also, disabling C<assert>
-(C<-DNDEBUG>) will usually reduce code size a lot.
+(C<-DNDEBUG>) will usually reduce code size a lot. Disabling inotify,
+eventfd and signalfd will further help, and disabling backends one doesn't
+need (e.g. poll, epoll, kqueue, ports) will help further.
Defining C<EV_MINIMAL> to C<2> will additionally reduce the core API to
provide a bare-bones event library. See C<ev.h> for details on what parts
of the API are still available, and do not complain if this subset changes
over time.
+This example set of settings reduces the compiled size of libev from 24Kb
+to 8Kb on my GNU/Linux amd64 system (and leaves little in - there is also
+an effect on the amount of memory used). With an intelligent-enough linker
+further unused functions might be left out as well automatically.
+
+ // tuning and API changes
+ #define EV_MINIMAL 2
+ #define EV_MULTIPLICITY 0
+ #define EV_MINPRI 0
+ #define EV_MAXPRI 0
+
+ // OS-specific backends
+ #define EV_USE_INOTIFY 0
+ #define EV_USE_EVENTFD 0
+ #define EV_USE_SIGNALFD 0
+ #define EV_USE_REALTIME 0
+ #define EV_USE_MONOTONIC 0
+ #define EV_USE_CLOCK_SYSCALL 0
+
+ // disable all backends except select
+ #define EV_USE_POLL 0
+ #define EV_USE_PORT 0
+ #define EV_USE_KQUEUE 0
+ #define EV_USE_EPOLL 0
+
+ // disable all watcher types that cna be disabled
+ #define EV_STAT_ENABLE 0
+ #define EV_PERIODIC_ENABLE 0
+ #define EV_IDLE_ENABLE 0
+ #define EV_FORK_ENABLE 0
+ #define EV_SIGNAL_ENABLE 0
+ #define EV_CHILD_ENABLE 0
+ #define EV_ASYNC_ENABLE 0
+ #define EV_EMBED_ENABLE 0
+
=item EV_AVOID_STDIO
If this is set to C<1> at compiletime, then libev will avoid using stdio