 HELP: alarm
 { $class-description "An alarm. Can be passed to " { $link cancel-alarm } "." } ;
 
+HELP: current-alarm
+{ $description "A symbol that contains the currently executing alarm, availble only to the alarm quotation. One use for this symbol is if a repeated alarm wishes to cancel itself from executing in the future."
+}
+{ $examples
+    { $unchecked-example
+        """USING: alarms calendar io threads ;"""
+        """["""
+        """    "Hi, this should only get printed once..." print flush"""
+        """    current-alarm get cancel-alarm"""
+        """] 1 seconds every"""
+        ""
+    }
+} ;
+
 HELP: add-alarm
 { $values { "quot" quotation } { "start" duration } { "interval" { $maybe "duration/f" } } { "alarm" alarm } }
-{ $description "Creates and registers an alarm to start at " { $snippet "start" } " offset from the current time. If " { $snippet "interval" } " is " { $link f } ", this will be a one-time alarm, otherwise it will fire with the given frequency, with scheduling happening before the quotation is called in order to ensure that the next event will happen on time. The quotation will be called from the alarm thread." } ;
+{ $description "Creates and registers an alarm to start at " { $snippet "start" } " offset from the current time. If " { $snippet "interval" } " is " { $link f } ", this will be a one-time alarm, otherwise it will fire with the given frequency, with scheduling happening before the quotation is called in order to ensure that the next event will happen on time. The quotation will be called from a new thread spawned by the alarm thread. If a repeated alarm's quotation throws an exception, the alarm will not be rescheduled." } ;
 
 HELP: later
 { $values { "quot" quotation } { "duration" duration } { "alarm" alarm } }

{ $subsections every }
"Register a one-time alarm:"
{ $subsections later }
"Low-level interface to add alarms:"
{ $subsections add-alarm }
"Cancelling an alarm:"

{ $values
     { "quot" quotation } { "duration" duration }
     { "alarm" alarm } }
{ $description "Creates and registers an alarm which calls the quotation repeatedly, using " { $snippet "dt" } " as the frequency. If the quotation throws an exception that is not caught inside it, the alarm scheduler will cancel the alarm and will not reschedule it again." }
{ $examples
    { $unchecked-example
        "USING: alarms io calendar ;"
