ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/libev/ev.pod
(Generate patch)

Comparing libev/ev.pod (file contents):
Revision 1.58 by root, Wed Nov 28 11:31:34 2007 UTC vs.
Revision 1.61 by root, Thu Nov 29 12:21:05 2007 UTC

… …
163C<ev_embeddable_backends () & ev_supported_backends ()>, likewise for 163C<ev_embeddable_backends () & ev_supported_backends ()>, likewise for
164recommended ones. 164recommended ones.
165 165
166See the description of C<ev_embed> watchers for more info. 166See the description of C<ev_embed> watchers for more info.
167 167
168=item ev_set_allocator (void *(*cb)(void *ptr, size_t size)) 168=item ev_set_allocator (void *(*cb)(void *ptr, long size))
169 169
170Sets the allocation function to use (the prototype and semantics are 170Sets the allocation function to use (the prototype is similar - the
171identical to the realloc C function). It is used to allocate and free 171semantics is identical - to the realloc C function). It is used to
172memory (no surprises here). If it returns zero when memory needs to be 172allocate and free memory (no surprises here). If it returns zero when
173allocated, the library might abort or take some potentially destructive 173memory needs to be allocated, the library might abort or take some
174action. The default is your system realloc function. 174potentially destructive action. The default is your system realloc
175function.
175 176
176You could override this function in high-availability programs to, say, 177You could override this function in high-availability programs to, say,
177free some memory if it cannot allocate memory, to use a special allocator, 178free some memory if it cannot allocate memory, to use a special allocator,
178or even to sleep a while and retry until some memory is available. 179or even to sleep a while and retry until some memory is available.
179 180
… …
915=item ev_timer_again (loop) 916=item ev_timer_again (loop)
916 917
917This will act as if the timer timed out and restart it again if it is 918This will act as if the timer timed out and restart it again if it is
918repeating. The exact semantics are: 919repeating. The exact semantics are:
919 920
921If the timer is pending, its pending status is cleared.
922
920If the timer is started but nonrepeating, stop it. 923If the timer is started but nonrepeating, stop it (as if it timed out).
921 924
922If the timer is repeating, either start it if necessary (with the repeat 925If the timer is repeating, either start it if necessary (with the
923value), or reset the running timer to the repeat value. 926C<repeat> value), or reset the running timer to the C<repeat> value.
924 927
925This sounds a bit complicated, but here is a useful and typical 928This sounds a bit complicated, but here is a useful and typical
926example: Imagine you have a tcp connection and you want a so-called 929example: Imagine you have a tcp connection and you want a so-called idle
927idle timeout, that is, you want to be called when there have been, 930timeout, that is, you want to be called when there have been, say, 60
928say, 60 seconds of inactivity on the socket. The easiest way to do 931seconds of inactivity on the socket. The easiest way to do this is to
929this is to configure an C<ev_timer> with C<after>=C<repeat>=C<60> and calling 932configure an C<ev_timer> with a C<repeat> value of C<60> and then call
930C<ev_timer_again> each time you successfully read or write some data. If 933C<ev_timer_again> each time you successfully read or write some data. If
931you go into an idle state where you do not expect data to travel on the 934you go into an idle state where you do not expect data to travel on the
932socket, you can stop the timer, and again will automatically restart it if 935socket, you can C<ev_timer_stop> the timer, and C<ev_timer_again> will
933need be. 936automatically restart it if need be.
934 937
935You can also ignore the C<after> value and C<ev_timer_start> altogether 938That means you can ignore the C<after> value and C<ev_timer_start>
936and only ever use the C<repeat> value: 939altogether and only ever use the C<repeat> value and C<ev_timer_again>:
937 940
938 ev_timer_init (timer, callback, 0., 5.); 941 ev_timer_init (timer, callback, 0., 5.);
939 ev_timer_again (loop, timer); 942 ev_timer_again (loop, timer);
940 ... 943 ...
941 timer->again = 17.; 944 timer->again = 17.;
942 ev_timer_again (loop, timer); 945 ev_timer_again (loop, timer);
943 ... 946 ...
944 timer->again = 10.; 947 timer->again = 10.;
945 ev_timer_again (loop, timer); 948 ev_timer_again (loop, timer);
946 949
947This is more efficient then stopping/starting the timer eahc time you want 950This is more slightly efficient then stopping/starting the timer each time
948to modify its timeout value. 951you want to modify its timeout value.
949 952
950=item ev_tstamp repeat [read-write] 953=item ev_tstamp repeat [read-write]
951 954
952The current C<repeat> value. Will be used each time the watcher times out 955The current C<repeat> value. Will be used each time the watcher times out
953or C<ev_timer_again> is called and determines the next timeout (if any), 956or C<ev_timer_again> is called and determines the next timeout (if any),
… …
1221The path does not need to exist: changing from "path exists" to "path does 1224The path does not need to exist: changing from "path exists" to "path does
1222not exist" is a status change like any other. The condition "path does 1225not exist" is a status change like any other. The condition "path does
1223not exist" is signified by the C<st_nlink> field being zero (which is 1226not exist" is signified by the C<st_nlink> field being zero (which is
1224otherwise always forced to be at least one) and all the other fields of 1227otherwise always forced to be at least one) and all the other fields of
1225the stat buffer having unspecified contents. 1228the stat buffer having unspecified contents.
1229
1230The path I<should> be absolute and I<must not> end in a slash. If it is
1231relative and your working directory changes, the behaviour is undefined.
1226 1232
1227Since there is no standard to do this, the portable implementation simply 1233Since there is no standard to do this, the portable implementation simply
1228calls C<stat (2)> regularly on the path to see if it changed somehow. You 1234calls C<stat (2)> regularly on the path to see if it changed somehow. You
1229can specify a recommended polling interval for this case. If you specify 1235can specify a recommended polling interval for this case. If you specify
1230a polling interval of C<0> (highly recommended!) then a I<suitable, 1236a polling interval of C<0> (highly recommended!) then a I<suitable,

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines