Top Description Fields Methods
org.lwjgl.vulkan

public Interface VkAllocationFunctionI

extends CallbackI
Known Direct Implementers
org.lwjgl.vulkan.VkAllocationFunction
Annotations
@FunctionalInterface
@NativeType:PFN_vkAllocationFunction
Imports
org.lwjgl.system.*, org.lwjgl.system.libffi.*
Application-defined memory allocation function.
C Specification

The type of pfnAllocation is:


typedef void* (VKAPI_PTR *PFN_vkAllocationFunction)(
    void*                                       pUserData,
    size_t                                      size,
    size_t                                      alignment,
    VkSystemAllocationScope                     allocationScope);
Description

If pfnAllocation is unable to allocate the requested memory, it must return NULL. If the allocation was successful, it must return a valid pointer to memory allocation containing at least size bytes, and with the pointer value being a multiple of alignment.

Note

Correct Vulkan operation cannot be assumed if the application does not follow these rules.

For example, pfnAllocation (or pfnReallocation) could cause termination of running Vulkan instance(s) on a failed allocation for debugging purposes, either directly or indirectly. In these circumstances, it cannot be assumed that any part of any affected VkInstance objects are going to operate correctly (even DestroyInstance), and the application must ensure it cleans up properly via other means (e.g. process termination).

If pfnAllocation returns NULL, and if the implementation is unable to continue correct processing of the current command without the requested allocation, it must treat this as a runtime error, and generate ERROR_OUT_OF_HOST_MEMORY at the appropriate time for the command in which the condition was detected, as described in Return Codes.

If the implementation is able to continue correct processing of the current command without the requested allocation, then it may do so, and must not generate ERROR_OUT_OF_HOST_MEMORY as a result of this failed allocation.

See Also

VkAllocationCallbacks

Field Summary

Modifier and TypeField and Description
public static final FFICIF
CIF

Method Summary

Modifier and TypeMethod and Description
public default void
callback(long
a pointer to the memory used for the function's return value.

If the function is declared as returning void, then this value is garbage and should not be used.

Otherwise, the callback must fill the object to which this points, following the same special promotion behavior as LibFFI#ffi_call. That is, in most cases, ret points to an object of exactly the size of the type specified when CIF was constructed. However, integral types narrower than the system register size are widened. In these cases your program may assume that ret points to an ffi_arg object.

ret, long
a vector of pointers to memory holding the arguments to the function
args)

Implements org.lwjgl.system.CallbackI.callback.

The Java method that will be called from native code when the native callback function is invoked.
public default FFICIF
getCallInterface()

Implements org.lwjgl.system.CallbackI.getCallInterface.

Returns the libffi Call Interface for this callback function.
public long
invoke(long
the value specified for VkAllocationCallbacks::pUserData in the allocator specified by the application.
pUserData, long
the size in bytes of the requested allocation.
size, long
the requested alignment of the allocation in bytes and must be a power of two.
alignment, int
a VkSystemAllocationScope value specifying the allocation scope of the lifetime of the allocation, as described here.
allocationScope)

Application-defined memory allocation function.

Inherited from org.lwjgl.system.CallbackI:
address

Field Detail

CIFback to summary
public static final FFICIF CIF

Method Detail

callbackback to summary
public default void callback(long ret, long args)

Implements org.lwjgl.system.CallbackI.callback.

Doc from org.lwjgl.system.CallbackI.callback.

The Java method that will be called from native code when the native callback function is invoked.

Parameters
ret:long

a pointer to the memory used for the function's return value.

If the function is declared as returning void, then this value is garbage and should not be used.

Otherwise, the callback must fill the object to which this points, following the same special promotion behavior as LibFFI#ffi_call. That is, in most cases, ret points to an object of exactly the size of the type specified when CIF was constructed. However, integral types narrower than the system register size are widened. In these cases your program may assume that ret points to an ffi_arg object.

args:long

a vector of pointers to memory holding the arguments to the function

Annotations
@Override
getCallInterfaceback to summary
public default FFICIF getCallInterface()

Implements org.lwjgl.system.CallbackI.getCallInterface.

Doc from org.lwjgl.system.CallbackI.getCallInterface.

Returns the libffi Call Interface for this callback function. [INTERNAL API]

Returns:FFICIF

the CIF structure for this callback function

Annotations
@Override
invokeback to summary
public long invoke(long pUserData, long size, long alignment, int allocationScope)

Application-defined memory allocation function.

Parameters
pUserData:long

the value specified for VkAllocationCallbacks::pUserData in the allocator specified by the application.

size:long

the size in bytes of the requested allocation.

alignment:long

the requested alignment of the allocation in bytes and must be a power of two.

allocationScope:int

a VkSystemAllocationScope value specifying the allocation scope of the lifetime of the allocation, as described here.

Annotations
@NativeType:void *