Application Tasks
K
A
DAK
39
In due course the destination task will continue to execute and complete its processing of
the current message, X. The destination task will then request AMX for a message from
the message exchange three more times in succession to process messages I, J and K.
Finally, the message from task YY will be retrieved from the message exchange and
processed.
Figure 3.9-2 illustrates the situation at the destination task at the instant it begins to
process the message from task YY. Provided that no additional calls to post messages to
the message exchange have occurred, the messages will be as shown. Message queues 0,
1 and 2 are empty. Messages L and M are still pending at priority level 3. The message
from task YY is ready for processing by the destination task.
When the destination task retrieves a message from the message exchange, the message
parameters are already removed from the envelope and copied to the storage area
provided by the task, usually on the task's stack. The message parameters received by the
destination task are in exactly the same order as they were sent by the caller.
Message M
Message L
0 2 31
MESSAGE EXCHANGE
Message YY
b
be
ei
in
ng
gp
pr
ro
oc
ce
es
ss
se
ed
d
Figure 3.9-2 Message Reception