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Changed assignment attempt usage to object test. Used /examples/net/same_mach as guide.

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Author:halw
Date:2012-04-07T15:46:24.000000Z


git-svn-id: https://svn.eiffel.com/eiffel-org/trunk@1069 abb3cda0-5349-4a8f-a601-0c33ac3a8c38
This commit is contained in:
halw
2012-04-07 15:46:24 +00:00
parent 22942a08fa
commit 30b9ca274b
1 changed files with 53 additions and 41 deletions
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94
documentation/current/solutions/networking/eiffelnet/eiffelnet-tutorial/obtaining-finer-degree-control.wiki
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@@ -44,11 +44,17 @@ Whenever the server needs to exchange objects with one of the clients, it obtain
Procedure <eiffel>accept</eiffel> ensures synchronization with the client. When communication is established, <eiffel>accept</eiffel> creates a new socket which will be accessible through attribute <eiffel>accepted</eiffel>, whose value is here assigned to the local entity <eiffel>soc2</eiffel>. To receive objects, the server will use operations of the form introduced earlier ( [[An overview of EiffelNet Mechanisms|An overview of EiffelNet, sending and receiving object structures]] ):
<code>
struct ?= soc2.retrieved</code>
if attached {SOME_EXPECTED_TYPE} soc2.retrieved as l_temp then
-- soc2.retrieved was attached to an object of the expected type. Now that object is attached to `l_temp'
-- Proceed with normal computation, typically involving calls of the form l_temp.some_feature
else
-- soc2.retrieved was not attached to an object of the expected type.
end
</code>
applying to <eiffel>soc2</eiffel>, not <eiffel>soc1</eiffel>; this makes <eiffel>soc1</eiffel> available to accept connections with other clients, a fundamental feature of client-server mechanisms.
The operation <eiffel>soc2</eiffel>. <eiffel>close</eiffel> which terminates the above sequence closes the new socket. In principle this is not necessary, since garbage collection should eventually reclaim the socket object, and the <eiffel>dispose</eiffel> procedure of the corresponding socket class includes a call to <eiffel>close</eiffel>. But the risk exists that you run out of sockets before garbage collection reclaims all currently opened sockets, so it is preferable to include the <eiffel>close</eiffel> calls explicitly.
The operation <eiffel>soc2.close</eiffel> which terminates the above sequence closes the new socket. In principle this is not necessary, since garbage collection should eventually reclaim the socket object, and the <eiffel>dispose</eiffel> procedure of the corresponding socket class includes a call to <eiffel>close</eiffel>. But the risk exists that you run out of sockets before garbage collection reclaims all currently opened sockets, so it is preferable to include the <eiffel>close</eiffel> calls explicitly.
At the end of the processing it is necessary to close the original socket <eiffel>soc1</eiffel> but also to unlink it. The feature <eiffel>cleanup</eiffel> from class <eiffel>SOCKET</eiffel> takes care of both closing and unlinking.
@@ -67,12 +73,11 @@ creation
feature
soc1, soc2: UNIX_STREAM_SOCKET
make
-- Accept communication with client and exchange messages
local
count: INTEGER
soc1: detachable UNIX_STREAM_SOCKET
do
create soc1.make_server ("/tmp/here")
from
@@ -81,34 +86,36 @@ feature
until
count = 3
loop
process -- See below
process (soc1) -- See below
count := count + 1
end
soc1.cleanup
rescue
soc1.cleanup
if soc1 /= Void then
soc1.cleanup
end
end
process
process (soc1: UNIX_STREAM_SOCKET)
-- Receive a message, extend it, and send it back
local
our_new_list: OUR_MESSAGE
do
soc1.accept
soc2 ?= soc1.accepted
our_new_list ?= retrieved (soc2)
from
our_new_list.start
until
our_new_list.after
loop
io.putstring (our_new_list.item)
io.new_line
our_new_list.forth
end
our_new_list.extend ("%N I'm back.%N")
our_new_list.independent_store (soc2)
soc2.close
if attached soc1.accepted as l_soc2 then
if attached {OUR_MESSAGE} retrieved (l_soc2) as l_our_new_list then
from
l_our_new_list.start
until
l_our_new_list.after
loop
io.putstring (l_our_new_list.item)
io.new_line
l_our_new_list.forth
end
l_our_new_list.extend ("%N I'm back.%N")
l_our_new_list.independent_store (l_soc2)
end
soc2.close
end
end
end
@@ -129,39 +136,44 @@ creation
feature
soc1: UNIX_STREAM_SOCKET
make
-- Establish communication with server, and exchange messages
local
soc1: detachable UNIX_STREAM_SOCKET
do
create soc1.make_client ("/tmp/here")
soc1.connect
process -- See below
process (soc1) -- See below
soc1.cleanup
rescue
soc1.cleanup
if soc1 /= Void then
soc1.cleanup
end
end
process
process (soc1: UNIX_STREAM_SOCKET)
-- Build a message to server, receive answer, build
-- modified message from that answer, and print it.
local
our_list, our_new_list: OUR_MESSAGE
our_list: OUR_MESSAGE
do
create our_list.make
our_list.extend("This"); our_list.extend (" is")
our_list.extend (" our"); our_list.extend (" test")
our_list.extend("This")
our_list.extend (" is")
our_list.extend (" our")
our_list.extend (" test")
our_list.independent_store (soc1)
our_new_list ?= soc1.retrieved
from
our_new_list.start
until
our_new_list.after
loop
io.putstring (our_new_list.item)
our_new_list.forth
end
io.new_line
if attached {OUR_MESSAGE} our_list.retrieved (soc1) as l_our_new_list then
from
l_our_new_list.start
until
l_our_new_list.after
loop
io.putstring (l_our_new_list.item)
l_our_new_list.forth
end
io.new_line
end
end
end