EVadd_select

Synopsis

void EVadd_select (int type,int fd, void (*function)
(char *), NULL, char* arg, int dir );
void EVdel_select (int type, int fd, void (*function)
(char *), NULL, char* arg, int dir );

Description

EVadd_select adds an event callback handler of type type .For all types, function is a pointer to a user-supplied callback function that takes a single pointer argument. The arg parameter specifies the argument.type can be any of the following: EV_SELECT0 or EV_SELECT -- Calls function when the event indicated by the dir parameter occurs in fd , a file descriptor.Of the two types, EV_SELECT0 is the one you typically specify. EV_SELECT0 specifies that the handler should be invoked only when there are no outstanding push/pop contexts. You should use EV_SELECT0 when the callback uses the routines OMpush_ctx/OMpop_ctx. Otherwise, you can use EV_SELECT. EV_SELECT specifies that the handler can be called in the middle of a push/pop context, but in this case, it should not begin a new context. EV_PRE0 or EV_PRE -- Calls function right before waiting for events. The fd and dir parameters have no meaning and should be set to 0.Of the two types, EV_PRE0 is the one you typically specify. EV_PRE0 specifies that the handler should be invoked only when there are no outstanding push/pop contexts. You should use EV_PRE0 when the callback creates its own push/pop context. Otherwise, you can use EV_PRE. EV_PRE specifies that the handler can be called in the middle of a push/pop context. EV_POST -- Calls function right after having waited for events. The fd and dir parameters have no meaning and should be set to 0. EV_POLL or EV_TIMEOUT -- Calls function when there are no events. EV_POLL calls the function immediately. EV_TIMEOUT calls the function after a certain number of milliseconds, which you specify with the dir parameter. The fd parameter has no meaning and should be set to 0. For EV_POLL, the dir parameter has no meaning and should be set to 0.EVdel_select deletes an event callback handler. The parameters to EVdel_select must match those of the EVadd_select that created the handler.

Arguments

type

An event type, as described above:EV_SELECT0EV_SELECTEV_PRE0EV_PREEV_POSTEV_POLLEV_TIMEOUT     

fd

A file descriptor. fd has meaning only when type is EV_SELECT0 or EV_SELECT. Otherwise, it should be 0.

function

A pointer to a user-supplied callback function. The function should take a single pointer argument.

NULL

The fourth argument should be NULL.

arg

The argument passed to function .

dir

When the type is EV_SELECT0 or EV_SELECT, a further refinement of the event type: EV_SEL_IN -- The event handler should be invoked when input data is available in fd . EV_SEL_OUT -- The event handler should be invoked when output can be sent to fd . EV_SEL_EX -- The event handler should be invoked when an exception has occurred in fd . When the type is EV_TIMEOUT, dir specifies the number of milliseconds to wait before invoking the event handler.For other types, dir has no meaning and should be 0.

Examples

none.

See Also

none.