add prepare watcher

[software/libev.git] / ev.h

diff --git a/ev.h b/ev.h
index 34670609a13cbde1107b9c25166b72c94b8db8dc..3c550e2e8d993954b365eeb0df15c76c8f73b5fd 100644 (file)
--- a/ev.h
+++ b/ev.h
@@ -1,3 +1,32 @@
+/*
+ * Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *
+ *     * Redistributions in binary form must reproduce the above
+ *       copyright notice, this list of conditions and the following
+ *       disclaimer in the documentation and/or other materials provided
+ *       with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+

 #ifndef EV_H
 #define EV_H
 
 #ifndef EV_H
 #define EV_H
 


@@ -5,32 +34,78 @@ typedef double ev_tstamp;
 
 /* eventmask, revents, events... */
 #define EV_UNDEF   -1 /* guaranteed to be invalid */
 
 /* eventmask, revents, events... */
 #define EV_UNDEF   -1 /* guaranteed to be invalid */

-#define EV_NONE    0
-#define EV_READ    1
-#define EV_WRITE   2
-#define EV_TIMEOUT 4
-#define EV_SIGNAL  8
+#define EV_NONE    0x00
+#define EV_READ    0x01
+#define EV_WRITE   0x02
+#define EV_TIMEOUT 0x04
+#define EV_SIGNAL  0x08
+#define EV_IDLE    0x10
+#define EV_CHECK   0x20
+#define EV_PREPARE 0x40
+#define EV_ERROR   (0x7f|0x80)
+
+/* can be used to add custom fields to all watchers */
+#ifndef EV_COMMON
+# define EV_COMMON void *data
+#endif
+#ifndef EV_PROTOTYPES
+# define EV_PROTOTYPES 1
+#endif
+
+/*
+ * struct member types:
+ * private: you can look at them, but not change them, and they might not mean anything to you.
+ * ro: can be read anytime, but only changed when the watcher isn't active
+ * rw: can be read and modified anytime, even when the watcher is active
+ */

 
 /* shared by all watchers */
 #define EV_WATCHER(type)                       \
   int active; /* private */                    \
   int pending; /* private */                   \
 
 /* shared by all watchers */
 #define EV_WATCHER(type)                       \
   int active; /* private */                    \
   int pending; /* private */                   \

-  void *data; /* rw */                         \
-  void (*cb)(struct type *, int revents) /* rw */
+  EV_COMMON; /* rw */                          \
+  void (*cb)(struct type *, int revents); /* rw */ /* gets invoked with an eventmask */

 
 #define EV_WATCHER_LIST(type)                  \
   EV_WATCHER (type);                           \
   struct type *next /* private */
 
 
 #define EV_WATCHER_LIST(type)                  \
   EV_WATCHER (type);                           \
   struct type *next /* private */
 

+#define EV_WATCHER_TIME(type)                  \
+  EV_WATCHER (type);                           \
+  ev_tstamp at     /* private */
+
+/* base class, nothing to see here unless you subclass */
+struct ev_watcher {
+  EV_WATCHER (ev_watcher);
+};
+
+/* base class, nothing to see here unless you subclass */
+struct ev_watcher_list {
+  EV_WATCHER_LIST (ev_watcher_list);
+};
+
+/* base class, nothing to see here unless you subclass */
+struct ev_watcher_time {
+  EV_WATCHER_TIME (ev_watcher_time);
+};
+
+/* invoked after a specific time, repeatable (based on monotonic clock) */

 struct ev_timer
 {
 struct ev_timer
 {

-  EV_WATCHER_LIST (ev_timer);
+  EV_WATCHER_TIME (ev_timer);

 
 

-  ev_tstamp at;     /* private */

   ev_tstamp repeat; /* rw */
   ev_tstamp repeat; /* rw */

-  unsigned char is_abs; /* ro */

 };
 
 };
 

+/* invoked at some specific time, possibly repeating at regular intervals (based on UTC) */
+struct ev_periodic
+{
+  EV_WATCHER_TIME (ev_periodic);
+
+  ev_tstamp interval; /* rw */
+};
+
+/* invoked when fd is either EV_READable or EV_WRITEable */

 struct ev_io
 {
   EV_WATCHER_LIST (ev_io);
 struct ev_io
 {
   EV_WATCHER_LIST (ev_io);


@@ -39,6 +114,7 @@ struct ev_io
   int events; /* ro */
 };
 
   int events; /* ro */
 };
 

+/* invoked when the given signal has been received */

 struct ev_signal
 {
   EV_WATCHER_LIST (ev_signal);
 struct ev_signal
 {
   EV_WATCHER_LIST (ev_signal);


@@ -46,42 +122,99 @@ struct ev_signal
   int signum; /* ro */
 };
 
   int signum; /* ro */
 };
 

+/* invoked when the nothing else needs to be done, keeps the process from blocking */
+struct ev_idle
+{
+  EV_WATCHER (ev_idle);
+};
+
+/* invoked for each run of the mainloop, just before the blocking call */
+/* you can still change events in any way you like */
+struct ev_prepare
+{
+  EV_WATCHER (ev_prepare);
+};
+
+/* invoked for each run of the mainloop, just after the blocking call */
+struct ev_check
+{
+  EV_WATCHER (ev_check);
+};
+

 #define EVMETHOD_NONE   0
 #define EVMETHOD_SELECT 1
 #define EVMETHOD_EPOLL  2
 #define EVMETHOD_NONE   0
 #define EVMETHOD_SELECT 1
 #define EVMETHOD_EPOLL  2

-int ev_init (int flags);
+#if EV_PROTOTYPES

 extern int ev_method;
 extern int ev_method;

+int ev_init (int flags); /* returns ev_method */

 
 

+/* these three calls are suitable for plugging into pthread_atfork */

 void ev_prefork (void);
 void ev_postfork_parent (void);
 void ev_postfork_child (void);
 
 extern ev_tstamp ev_now; /* time w.r.t. timers and the eventloop, updated after each poll */
 ev_tstamp ev_time (void);
 void ev_prefork (void);
 void ev_postfork_parent (void);
 void ev_postfork_child (void);
 
 extern ev_tstamp ev_now; /* time w.r.t. timers and the eventloop, updated after each poll */
 ev_tstamp ev_time (void);

+#endif

 
 #define EVLOOP_NONBLOCK        1 /* do not block/wait */
 #define EVLOOP_ONESHOT 2 /* block *once* only */
 
 #define EVLOOP_NONBLOCK        1 /* do not block/wait */
 #define EVLOOP_ONESHOT 2 /* block *once* only */

+#if EV_PROTOTYPES

 void ev_loop (int flags);
 void ev_loop (int flags);

-extern int ev_loop_done; /* set to 1 to break out of event loop */
+extern int ev_loop_done; /* set to 1 to break out of event loop, set to 2 to break out of all event loops */
+
+/* convinience function, wait for a single event, without registering an event watcher */
+/* if timeout is < 0, do wait indefinitely */
+void ev_once (int fd, int events, ev_tstamp timeout, void (*cb)(int revents, void *arg), void *arg);
+#endif

 
 /* these may evaluate ev multiple times, and the other arguments at most once */
 
 /* these may evaluate ev multiple times, and the other arguments at most once */

-#define evw_init(ev,cb_,data_)             do { (ev)->active = 0; (ev)->cb = (cb_); (ev)->data = (void *)data_; } while (0)
+/* either use evw_init + evXXX_set, or the evXXX_init macro, below, to first initialise a watcher */
+#define evw_init(ev,cb_)                   do { (ev)->active = 0; (ev)->pending = 0; (ev)->cb = (cb_); } while (0)

 
 #define evio_set(ev,fd_,events_)           do { (ev)->fd = (fd_); (ev)->events = (events_); } while (0)
 
 #define evio_set(ev,fd_,events_)           do { (ev)->fd = (fd_); (ev)->events = (events_); } while (0)

-#define evtimer_set_rel(ev,after_,repeat_) do { (ev)->at = (after_); (ev)->repeat = (repeat_); (ev)->is_abs = 0; } while (0)
-#define evtimer_set_abs(ev,at_,repeat_)    do { (ev)->at = (at_); (ev)->repeat = (repeat_); (ev)->is_abs = 1; } while (0)
+#define evtimer_set(ev,after_,repeat_)     do { (ev)->at = (after_); (ev)->repeat = (repeat_); } while (0)
+#define evperiodic_set(ev,at_,interval_)   do { (ev)->at = (at_); (ev)->interval = (interval_); } while (0)

 #define evsignal_set(ev,signum_)           do { (ev)->signum = (signum_); } while (0)
 #define evsignal_set(ev,signum_)           do { (ev)->signum = (signum_); } while (0)

+#define evidle_set(ev)                     /* nop, yes, this is a serious in-joke */
+#define evprepare_set(ev)                  /* nop, yes, this is a serious in-joke */
+#define evcheck_set(ev)                    /* nop, yes, this is a serious in-joke */
+
+#define evio_init(ev,cb,fd,events)         do { evw_init ((ev), (cb)); evio_set ((ev),(fd),(events)); } while (0)
+#define evtimer_init(ev,cb,after,repeat)   do { evw_init ((ev), (cb)); evtimer_set ((ev),(after),(repeat)); } while (0)
+#define evperiodic_init(ev,cb,at,interval) do { evw_init ((ev), (cb)); evperiodic_set ((ev),(at),(interval)); } while (0)
+#define evsignal_init(ev,cb,signum)        do { evw_init ((ev), (cb)); evsignal_set ((ev), (signum)); } while (0)
+#define evidle_init(ev,cb)                 do { evw_init ((ev), (cb)); evidle_set ((ev)); } while (0)
+#define evprepare_init(ev,cb)              do { evw_init ((ev), (cb)); evprepare_set ((ev)); } while (0)
+#define evcheck_init(ev,cb)                do { evw_init ((ev), (cb)); evcheck_set ((ev)); } while (0)

 
 #define ev_is_active(ev) (0 + (ev)->active) /* true when the watcher has been started */
 
 
 #define ev_is_active(ev) (0 + (ev)->active) /* true when the watcher has been started */
 

-void evio_start (struct ev_io *w);
-void evio_stop  (struct ev_io *w);
+/* stopping (enabling, adding) a watcher does nothing if it is already running */
+/* stopping (disabling, deleting) a watcher does nothing unless its already running */
+#if EV_PROTOTYPES
+void evio_start       (struct ev_io *w);
+void evio_stop        (struct ev_io *w);
+
+void evtimer_start    (struct ev_timer *w);
+void evtimer_stop     (struct ev_timer *w);
+void evtimer_again    (struct ev_timer *w); /* stops if active and no repeat, restarts if active and repeating, starts if inactive and repeating */

 
 

-void evtimer_start (struct ev_timer *w);
-void evtimer_stop  (struct ev_timer *w);
+void evperiodic_start (struct ev_periodic *w);
+void evperiodic_stop  (struct ev_periodic *w);

 
 

-void evsignal_start (struct ev_signal *w);
-void evsignal_stop  (struct ev_signal *w);
+void evsignal_start   (struct ev_signal *w);
+void evsignal_stop    (struct ev_signal *w);
+
+void evidle_start     (struct ev_idle *w);
+void evidle_stop      (struct ev_idle *w);
+
+void evprepare_start  (struct ev_prepare *w);
+void evprepare_stop   (struct ev_prepare *w);
+
+void evcheck_start    (struct ev_check *w);
+void evcheck_stop     (struct ev_check *w);
+#endif

 
 #endif
 
 
 #endif