Imported from /home/lorry/working-area/delta_python-packages_posix-ipc-tarball/posix_ipc-0.9.8.tar.gz.HEADposix_ipc-0.9.8master

7 files changed, 209 insertions, 0 deletions

diff --git a/demo3/ReadMe.txt b/demo3/ReadMe.txt
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+++ b/demo3/ReadMe.txt
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+These scripts demonstrate four message queue notification techniques.
+
+All of demos ask you to enter a message. That message is then sent to the
+queue and received in a notification handler and printed to stdout.
+
+- one_shot_signal.py and one_shot_thread.py receive their notifications via a 
+signal and thread, respectively. After one message & notification, the demo 
+exits.
+
+- repeating_signal.py and repeating_thread.py are similar, except that they
+re-register for notifications in their notification handler so you can
+enter as many messages as you like.
diff --git a/demo3/cleanup.py b/demo3/cleanup.py
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+++ b/demo3/cleanup.py
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+import posix_ipc
+import utils
+
+try:
+    posix_ipc.unlink_message_queue(utils.QUEUE_NAME)
+    s = "message queue %s removed" % utils.QUEUE_NAME
+    print (s)
+except:
+    print ("queue doesn't need cleanup")
+    
+
+
+print ("\nAll clean!")
diff --git a/demo3/one_shot_signal.py b/demo3/one_shot_signal.py
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+++ b/demo3/one_shot_signal.py
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+# Python modules
+import time
+import signal
+
+# 3rd party modules
+import posix_ipc
+
+# Utils for this demo
+import utils
+
+
+MY_SIGNAL = signal.SIGUSR1
+
+
+def handle_signal(signal_number, stack_frame):
+    message, priority = mq.receive()
+    
+    print ("Ding! Message with priority %d received: %s" % (priority, message))
+    
+
+
+# Create the message queue.
+mq = posix_ipc.MessageQueue(utils.QUEUE_NAME, posix_ipc.O_CREX)
+
+# Request notifications
+mq.request_notification(MY_SIGNAL)
+
+# Register my signal handler 
+signal.signal(MY_SIGNAL, handle_signal)
+
+# Get user input and send it to the queue.
+print ("Enter a message:")
+mq.send(utils.get_input())
+
+# The signal fires almost instantly, but if I don't pause at least 
+# briefly then the main thread may exit before the notification fires.
+print ("Sleeping for one second to allow the notification to happen.")
+time.sleep(1)
+
+print ("Destroying the message queue.")
+mq.close()
+# I could call simply mq.unlink() here but in order to demonstrate 
+# unlinking at the module level I'll do it that way.
+posix_ipc.unlink_message_queue(utils.QUEUE_NAME)
+
diff --git a/demo3/one_shot_thread.py b/demo3/one_shot_thread.py
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+++ b/demo3/one_shot_thread.py
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+# Python modules
+import time
+
+# 3rd party modules
+import posix_ipc
+
+# Utils for this demo
+import utils
+
+
+def process_notification(mq):
+    message, priority = mq.receive()
+    
+    print ("Ding! Message with priority %d received: %s" % (priority, message))
+    
+
+
+# Create the message queue.
+mq = posix_ipc.MessageQueue(utils.QUEUE_NAME, posix_ipc.O_CREX)
+
+# Request notifications
+mq.request_notification( (process_notification, mq) )
+
+# Get user input and send it to the queue.
+print ("Enter a message:")
+mq.send(utils.get_input())
+
+# The callback happens almost instantly, but if I don't pause at least 
+# briefly then the main thread may exit before the notification fires.
+print ("Sleeping for one second to allow the notification to happen.")
+time.sleep(1)
+
+print ("Destroying the message queue.")
+mq.close()
+# I could call simply mq.unlink() here but in order to demonstrate 
+# unlinking at the module level I'll do it that way.
+posix_ipc.unlink_message_queue(utils.QUEUE_NAME)
+
diff --git a/demo3/repeating_signal.py b/demo3/repeating_signal.py
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+++ b/demo3/repeating_signal.py
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+# Python modules
+import time
+import signal
+
+# 3rd party modules
+import posix_ipc
+
+# Utils for this demo
+import utils
+
+
+MY_SIGNAL = signal.SIGUSR1
+
+
+def handle_signal(signal_number, stack_frame):
+    message, priority = mq.receive()
+    
+    print ("Ding! Message with priority %d received: %s" % (priority, message))
+
+    # Re-register for notifications
+    mq.request_notification(MY_SIGNAL)
+    
+
+# Create the message queue.
+mq = posix_ipc.MessageQueue(utils.QUEUE_NAME, posix_ipc.O_CREX)
+
+# Request notifications
+mq.request_notification(MY_SIGNAL)
+
+# Register my signal handler 
+signal.signal(MY_SIGNAL, handle_signal)
+
+# Get user input and send it to the queue.
+msg = "42"
+while msg:
+    print ("\nEnter a message. A blank message will end the demo:")
+    msg = utils.get_input()
+    if msg:
+        mq.send(msg)
+
+print ("Destroying the message queue.")
+mq.close()
+# I could call simply mq.unlink() here but in order to demonstrate 
+# unlinking at the module level I'll do it that way.
+posix_ipc.unlink_message_queue(utils.QUEUE_NAME)
+
diff --git a/demo3/repeating_thread.py b/demo3/repeating_thread.py
new file mode 100644
index 0000000..e456428
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+++ b/demo3/repeating_thread.py
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+# Python modules
+import time
+
+# 3rd party modules
+import posix_ipc
+
+# Utils for this demo
+import utils
+
+
+def process_notification(mq):
+    message, priority = mq.receive()
+    
+    print ("Ding! Message with priority %d received: %s" % (priority, message))
+
+    # Re-register for notifications
+    mq.request_notification( (process_notification, mq) )
+    
+
+
+# Create the message queue.
+mq = posix_ipc.MessageQueue(utils.QUEUE_NAME, posix_ipc.O_CREX)
+
+# Request notifications
+mq.request_notification( (process_notification, mq) )
+
+# Get user input and send it to the queue.
+s = "42"
+while s:
+    print ("\nEnter a message. A blank message will end the demo:")
+    s = utils.get_input()
+    if s:
+        mq.send(s)
+
+print ("Destroying the message queue.")
+mq.close()
+# I could call simply mq.unlink() here but in order to demonstrate 
+# unlinking at the module level I'll do it that way.
+posix_ipc.unlink_message_queue(utils.QUEUE_NAME)
+
diff --git a/demo3/utils.py b/demo3/utils.py
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+++ b/demo3/utils.py
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+# Python modules
+import sys
+
+
+QUEUE_NAME = "/my_message_queue"
+
+
+PY_MAJOR_VERSION = sys.version_info[0]
+
+def get_input():
+    """Get input from user, Python 2.x and 3.x compatible"""
+    if PY_MAJOR_VERSION > 2:
+        return input()
+    else:
+        return raw_input()