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iofunc_notify_trigger()

Send notifications to queued clients

Synopsis:

#include <sys/iofunc.h>

void iofunc_notify_trigger( iofunc_notify_t *nop,
                            int count,
                            int index );

Arguments:

nop

An array of three iofunc_notify_t structures that represent (in order), the input, output, and out-of-band notification lists whose entries you want to examine; for information about this structure, see the documentation for iofunc_notify().

count

The count that you want to compare to the trigger value for the event.

index

The index into the nop array that you want to check; one of the following:

• IOFUNC_NOTIFY_INPUT
• IOFUNC_NOTIFY_OUTPUT
• IOFUNC_NOTIFY_OBAND

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The iofunc_notify_trigger() function examines all entries given in the list maintained at nop [index] to see if the event should be delivered to the client. If the specified count is greater than the trigger count for the particular notification list element, this function calls MsgDeliverEvent() to deliver the event to the client whose rcvid is stored in the notification list element, and the list element is disarmed.

Note that if the client has specified a code of SI_NOTIFY, then the value that the client specified (e.g. the value member of the struct sigevent) has the top three bits ORed with the reason for the trigger (this is the expression _NOTIFY_COND_INPUT << index), as in the following table:

index = IOFUNC_NOTIFY_INPUT

0x10000000, or _NOTIFY_COND_INPUT

index = IOFUNC_NOTIFY_OUTPUT

0x20000000, or _NOTIFY_COND_OUTPUT

index = IOFUNC_NOTIFY_OBAND

0x40000000, or _NOTIFY_COND_OBAND

If the client has specified a code of something other than SI_NOTIFY then this routine doesn't modify the value member in any way.

Examples:

See the Writing a Resource Manager chapter of Programmer's Guide.

Classification:

QNX Neutrino

See also:

iofunc_notify(), iofunc_notify_remove(), sigevent

"Handling ionotify() and select()" in the Writing a Resource Manager chapter of the Programmer's Guide.