93 lines
3.0 KiB
Plaintext
93 lines
3.0 KiB
Plaintext
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// Copyright (c) 2014-2016 Khronos Group. This work is licensed under a
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// Creative Commons Attribution 4.0 International License; see
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// http://creativecommons.org/licenses/by/4.0/
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PFN_vkAllocationFunction(3)
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===========================
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Name
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----
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PFN_vkAllocationFunction - application-defined memory allocation function
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C Specification
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---------------
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// refBegin PFN_vkAllocationFunction application-defined memory allocation function
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The type of pname:pfnAllocation is:
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include::../funcpointers/PFN_vkAllocationFunction.txt[]
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Parameters
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----------
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* pname:pUserData is the value specified for
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slink:VkAllocationCallbacks.pUserData in the allocator specified by the
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application.
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* pname:size is the size in bytes of the requested allocation.
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* pname:alignment is the requested alignment of the allocation in bytes
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and must: be a power of two.
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* pname:allocationScope is a elink:VkSystemAllocationScope value
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specifying the scope of the lifetime of the allocation, as described
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<<memory-host-allocation-scope,here>>.
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Description
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-----------
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[[vkAllocationFunction_return_rules]]
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If pname:pfnAllocation is unable to allocate the requested memory,
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it must: return `NULL`. If the allocation was successful, it must: return a
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valid pointer to memory allocation containing at least pname:size bytes, and
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with the pointer value being a multiple of pname:alignment.
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[NOTE]
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.Note
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====
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Correct Vulkan operation cannot: be assumed if the application does not
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follow these rules.
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For example, pname:pfnAllocation (or pname:pfnReallocation) could cause
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termination of running Vulkan instance(s) on a failed allocation for
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debugging purposes, either directly or indirectly. In these circumstances,
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it cannot: be assumed that any part of any affected VkInstance objects are
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going to operate correctly (even flink:vkDestroyInstance), and the
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application must: ensure it cleans up properly via other means (e.g.
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process termination).
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====
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If pname:pfnAllocation returns `NULL`, and if the implementation is unable
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to continue correct processing of the current command without the requested
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allocation, it must: treat this as a run-time error, and generate
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ename:VK_ERROR_OUT_OF_HOST_MEMORY at the appropriate time for the command
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in which the condition was detected, as described in
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<<fundamentals-errorcodes, Return Codes>>.
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If the implementation is able to continue correct processing of the current
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command without the requested allocation, then it may: do so, and must:
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not generate ename:VK_ERROR_OUT_OF_HOST_MEMORY as a result of this failed
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allocation.
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// refEnd PFN_vkAllocationFunction VkAllocationCallbacks
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See Also
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--------
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slink:VkAllocationCallbacks
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Document Notes
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--------------
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For more information, see the Vulkan Specification at URL
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https://www.khronos.org/registry/vulkan/specs/1.0/xhtml/vkspec.html#PFN_vkAllocationFunction
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This page is extracted from the Vulkan Specification.
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Fixes and changes should be made to the Specification,not directly.
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include::footer.txt[]
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