forked from boostorg/mqtt5
Korina Šimičević
b42014f379
Summary: related to T15996 - docs are now buildable with b2 (in a very simplified way) like mysql docs - change Async.MQTT5 -> Boost.MQTT5, async_mqtt5 namespace to boost::mqtt5 namespace - once changes are approved, Ill update all tabs to 4 spaces in .qbk files Reviewers: ivica Reviewed By: ivica Subscribers: iljazovic, miljen Differential Revision: https://repo.mireo.local/D33373
29 lines
1.6 KiB
Plaintext
29 lines
1.6 KiB
Plaintext
[/
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Copyright (c) 2023-2024 Ivica Siladic, Bruno Iljazovic, Korina Simicevic
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Distributed under the Boost Software License, Version 1.0.
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(See accompanying file LICENSE or copy at http://www.boost.org/LICENSE_1_0.txt)
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]
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[section:allocators Allocators]
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Every asynchronous operation has an associated allocator
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designed to provide the operation with a consistent and stable memory source for the duration of its execution.
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This allocated memory, referred to as per-operation stable memory resources (POSMs),
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remains retained for the lifetime of the operation, ensuring its availability whenever needed.
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Asynchronous operations may utilise POSMs in numerous ways.
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See __ASIO_ALLOCATORS__ and __ASIO_CUSTOM_MEMORY_ALLOCATION__ for more information.
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The __Client__ supports and utilises allocators associated with `async_xxx`'s handlers
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to store the state associated with the operation.
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Specifically, the allocator is used to reserve memory for MQTT Control Packet bytes
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(__PUBLISH__, __SUBSCRIBE__,...) created by each `async_xxx` operation request.
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Moreover, the __Client__'s internal packet queue
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(described in the section ['Efficient bandwidth usage with packet queuing] in [link mqtt5.optimising_communication Optimising communication])
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associates the allocator of the first packet in the queue to the low-level __Asio__ function
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`async_write` on the transport layer.
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Lastly, the __Client__ uses [@boost:doc/html/boost_asio/reference/recycling_allocator.html `boost::asio::recycling_allocator`]
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to allocate memory for its internal operations and components.
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[endsect][/allocators]
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