@notify

@notify[/any][/all] <object>[/<attribute>][=<number>]
@notify/setq <object>[/<attribute>]=<qreg1>,<qval1>[,...]

This command notifies a semaphore, allowing commands queued for that semaphore to be executed.

The semaphore counter is stored before waiting commands are released. If the database cannot confirm a counter change, affected work stays reserved and further semaphore changes are refused until reconciliation succeeds. A later attempt verifies the stored count before completing or abandoning the uncertain operation. Conflicting counts or incomplete semaphore flags require administrator repair.

If the /any switch is given, then all semaphores associated with <object> are @notified. Otherwise, only the specified semaphore <attribute> (or SEMAPHORE if no attribute is specified) is @notified.

If the /all switch is given, then all queue entries associated with the selected semaphore(s) are executed. Otherwise, only the first <number> of queue entries are run. If no <number> is given, then only one queue entry is run.

If the /all switch was not used, and there were not enough queue entries waiting to satisfy the requested <number>, then the semaphore becomes negative, and subsequent @waits will not block until it reaches 0 again.

You may not specify both the /any switch and a specific attribute. Similarly, you may not specify both the /all switch and a number.

Updating waiting registers

@notify/setq is a special form of @notify: It requires that a queue entry exists and is waiting on <object>[/<attr>]. When this is the case, then @notify/setq will modify the Q-registers of the extant queue entry.

/setq supercedes all other switches: You cannot @notify/all/setq or @notify/any/setq - it deals with just one queue entry.

Example

> @wait me=think Hello, %q0!
> @notify/setq me=0,Walker
Hello, Walker!

::: seealso