dragon.mpbridge.queues.DragonSimpleQueue

class DragonSimpleQueue

Bases: PatchedDragonNativeQueue

A simplified queue co-located on the same node by default as the creating process

__init__(*args, ctx=None, **kwargs)

Init method

Parameters:

• maxsize (int , optional) – sets the upperbound limit on the number of items that can be placed in the queue, defaults to 100

• m_uid (int , optional) – The m_uid of the memory pool to use, defaults to _DEF_MUID

• block_size (int , optional) – Block size for the underlying channel, defaults to 64 kbytes

• joinable (bool , optional) – If this queue should be joinable, defaults to False

• policy (object , optional) – policy object, defaults to POLICY_USER

• _ext_channel (instance of dragon.channel, optional) – non-local externally managed channel for testing purposes only, defaults to None

Raises:

• QueueError – If something goes wrong during creation

• ValueError – If a parameter is wrong

• NotImplementedError – If a joinable queue is used with an external channel

Methods

__init__(*args[, ctx])	Init method
close()	Indicate that no more data will be put on this queue by the current process.
empty()	Return True if the queue is empty, False otherwise.
get([block, timeout])	Remove and return an item from the queue.
put(obj[, block, timeout])	Puts the serialization of an object onto the queue.

__init__(*args, ctx=None, **kwargs)

Init method

Parameters:

• maxsize (int , optional) – sets the upperbound limit on the number of items that can be placed in the queue, defaults to 100

• m_uid (int , optional) – The m_uid of the memory pool to use, defaults to _DEF_MUID

• block_size (int , optional) – Block size for the underlying channel, defaults to 64 kbytes

• joinable (bool , optional) – If this queue should be joinable, defaults to False

• policy (object , optional) – policy object, defaults to POLICY_USER

• _ext_channel (instance of dragon.channel, optional) – non-local externally managed channel for testing purposes only, defaults to None

Raises:

• QueueError – If something goes wrong during creation

• ValueError – If a parameter is wrong

• NotImplementedError – If a joinable queue is used with an external channel

close() → None

Indicate that no more data will be put on this queue by the current process. The refcount of the background channel will be released and the channel might be removed, if no other processes are holding it. This version includes a patch for the multiprocessing unit tests.

empty() → bool

Return True if the queue is empty, False otherwise. This might not be reliable

Raises:

ValueError – If the queue is closed

Returns:

Wether or not the queue is empty

Return type:

bool

get(block: bool = True, timeout: float = None) → object

Remove and return an item from the queue.

Parameters:

• block (bool , optional) – Make this call blocking, defaults to True

• timeout (float , optional) – number of seconds to block, defaults to None

Raises:

• ValueError – If queue is closed

• queue.Empty – If queue is empty

Returns:

The next item in the queue

Return type:

object

put(obj, block=True, timeout=None) → None

Puts the serialization of an object onto the queue. This version includes patches for the multiprocessing unit tests

Parameters:

• obj – object to serialize and put

• block – Whether to block

• timeout – Timeout, if blocking. None means infinity, default

Returns:

None