The system uses this information for interprocessor communication.
During certain critical periods, such as when a processor malfunctions or when a
processor synchronization must occurs, one processor must signal the other
processor. There are three types of program-controlled signals possible under
Emergency signals
Direct signals
External call signals
have generated the system as an
macro. The macro expansion code destroys the contents of registers
15. The macro expansion loads register
loads register 1 with the function code, and uses registers 14 and 15 for linkage.
Note: If you have not generated the system as an
gram treats the SIGNAL macro as a no-operation.
The SIGNAL macro causes all signaling requests to be sent to the external inter
ruption handler so that error analysis and recovery attempts are centralized.
The format of the SIGNAL macro and the functions that you can perform using
each type of signal are:
label SIGNAL CLKCHK
,CONTROL=SERIAL]
EXTEND
QUIESCE
XTNDEXIT
APR
[
,CONTROL=[PARALLEL]]
DISPATCH =
RESTART
[
,CONTROL=[PARALLEL]]
START =
where:
label
is any desired label.
CP in Attached Processor and Multiprocessor Modes 211