WAIT

General Format

WAIT FOR { THREAD Thread-Id }           { LAST THREAD      }      [Remaining-Phrase]     [ ON EXCEPTION Imperative-Statement-1 ]      [ NOT ON EXCEPTION Imperative-Statement-2 ]      [END-WAIT]

Remaining-Phrases are optional and can appear in any order.

{ BEFORE TIME Timeout }   { TEST ONLY           }     THREAD IN Thread-2     SIZE IN Size-Item     STATUS IN status-item

Syntax rules

1.	Thread-Id and Thread-2 are usage HANDLE or HANDLE OF THREAD data items.

2.	Size-Item and, Status-Item are numeric data items.

3.	Size-Item, Status-Item and Thread-2 cannot be indexed or reference modified.

4.	Status-Item is a two-character group item defined as, PIC X(02), or PIC 9(02).

General rules

1.	The WAIT statement waits for a thread to terminate or send a message. The thread used to wait is one of the following:

A.	FOR THREAD thread-ID specifies the thread identified by thread-ID.

B.	FOR LAST THREAD specifies the last thread.

2.	If a message is available when the WAIT statement executes, then WAIT statement finishes immediately.

3.

When BEFORE TIME is specified, the WAIT statement will time-out after the specified hundredths of seconds. If this happens, the destination item (dest-item) is not updated. If timeout is zero, then the WAIT statement times out immediately if a message is not available. Specifying TEST ONLY is equivalent to specifying a timeout value of zero.

4.	The thread ID of the sending or terminating thread is put into thread-2 by WAIT.

5.	The size of the message sent is placed in size-item.

6.	The status of the WAIT statement is placed in status-item as defined below:

"00"	Success - message received
"10"	Exception - thread does not exist or terminated
"99"	Exception - timed-out

7.	There is no control in Size Item and Status Item, the result is setted in according with MOVE statment.

8.	If the WAIT statement is successful, statement-2 executes otherwise, statement-1 executes.

Examples

Wait for a thread to finish, in this sample the other thread has its hanlde in loop-thread-handle

wait for thread loop-thread-handle      on exception        display message " Loop thread finished, finishing this thread now"        goback end-wait