::SHE+ILA:: Inter-task Messaging

More about ::SHE+ILA:: Inter-task Messaging

The easiest way to send a message to another task is :
::YOURSEG::[1] <<? "doodat";
This sends the message "doodat" via the first queue in segment ::YOURSEG::. By default, if the task waiting on the queue ::YOURSEG::[1] is idle, it will be triggered by the arrival of a message. It will eventually return a reply to its caller (which is itself waiting, indicated by the FBI operator "<<?", "insert into queue and wait"). This is similar to IAS's "QIOW$" Queue I/O and Wait, and SDL's Sendmsg() call. If we don't expect a reply we would use "<<", the FBI "insert into queue" operator, and maybe a later {? ... ?} wait-for-event block (like IAS's QIO$ followed by WT$LOR, or MS-Windows MsgWaitForSingleObject() on an event flag);
An alternative mechanism for inter-task communication is "shared variables" using intrinsic record-locking.