diff options
Diffstat (limited to 'portato')
| -rw-r--r-- | portato/ipc.pyx | 35 |
1 files changed, 32 insertions, 3 deletions
diff --git a/portato/ipc.pyx b/portato/ipc.pyx index 4a06102..e9340cf 100644 --- a/portato/ipc.pyx +++ b/portato/ipc.pyx @@ -11,12 +11,21 @@ # Written by René 'Necoro' Neumann <necoro@necoro.net> class MessageQueueError(Exception): + """ + Base class for different queue errors. + """ pass class MessageQueueRemovedError (MessageQueueError): + """ + This class is used iff the queue is already removed. + """ pass cdef class MessageQueue (object): + """ + A simple interface to the SysV message queues. + """ CREAT = IPC_CREAT EXCL = IPC_EXCL @@ -25,12 +34,18 @@ cdef class MessageQueue (object): cdef readonly key_t key def __init__ (self, key = None, int flags = 0): + """ + Create a new MessageQueue instance. Depending on the passed in flags, + different behavior occurs. See man msgget for the details. + + If key is None, a random key is created. + """ if (flags & IPC_EXCL) and not (flags & IPC_CREAT): - raise MessageQueueError("EXCL must be combined with CREAT.") + raise ValueError("EXCL must be combined with CREAT.") if key is None and not (flags & IPC_EXCL): - raise MessageQueueError("The key can only be None if EXCL is set.") + raise ValueError("The key can only be None if EXCL is set.") # make sure there is nothing ... obscure flags &= (IPC_CREAT | IPC_EXCL) @@ -55,11 +70,14 @@ cdef class MessageQueue (object): elif errno == ENOENT: raise MessageQueueError("Queue does not exist and CREAT is not set.") elif errno == ENOMEM or errno == ENOSPC: - raise MessageQueueError("Insufficient ressources.") + raise MemoryError("Insufficient ressources.") else: raise OSError(errno, strerror(errno)) def remove (self): + """ + Removes the message queue. + """ cdef msqid_ds info cdef int ret @@ -74,6 +92,12 @@ cdef class MessageQueue (object): raise OSError(errno, strerror(errno)) def send (self, message, int type = 1): + """ + Sends a message with a specific type. + + The type must be larger zero. + Also note, that this is always blocking. + """ cdef msg_data * msg cdef int ret cdef long size = len(message) @@ -109,6 +133,11 @@ cdef class MessageQueue (object): PyMem_Free(msg) def receive (self): + """ + Receives a message from the queue and returns the (msg, type) pair. + + Note that this method is always blocking. + """ cdef msg_data * msg cdef int ret cdef object retTuple |