forked from boostorg/mqtt5
Korina Šimičević
c7a4fcd507
Summary: related to T12804 Reviewers: ivica Reviewed By: ivica Subscribers: miljen, iljazovic Differential Revision: https://repo.mireo.local/D28543
23 lines
1.3 KiB
Plaintext
23 lines
1.3 KiB
Plaintext
[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 async_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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