disable zero copy partial write combined with multibuffering (#1163) #1168
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FlorianReimold
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Jul 31, 2023
FlorianReimold
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Jul 31, 2023
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Pull request type
Please check the type of change your PR introduces:
What is the current behavior?
See issue #1163
Fixes #1163
What is the new behavior?
If the publisher multibuffering feature is activated (
CPublisher::ShmSetBufferCount), multiple memory files are used as ring buffers and cyclically written.The new zero copy (
CPublisher::ShmEnableZeroCopy) mode on the other hand allows to write partial content (modify the the content) of a memory file, this leads to much higher data throughput if just a few byte of a payload needs to be changed on every publication.This partial / differential write makes no sense if multiple memory files are handled by a single publisher. In this case, each of these files must be written completely to ensure consistent payload data. So, the partial write variant is now blocked in the described multibuffering mode.
Does this introduce a breaking change?
Cherry-pick to: