Interface VkAllocationFunctionI
- All Known Implementing Classes:
VkAllocationFunction
- Functional Interface:
- This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
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
-
Nested Class Summary
Nested classes/interfaces inherited from interface org.lwjgl.system.Pointer
Pointer.Default
-
Field Summary
Fields inherited from interface org.lwjgl.system.Pointer
BITS32, BITS64, CLONG_SHIFT, CLONG_SIZE, POINTER_SHIFT, POINTER_SIZE
-
Method Summary
Modifier and TypeMethodDescriptiondefault void
callback
(long ret, long args) The Java method that will be called from native code when the native callback function is invoked.default FFICIF
Returns the libffi Call Interface for this callback function.long
invoke
(long pUserData, long size, long alignment, int allocationScope) Application-defined memory allocation function.
-
Field Details
-
CIF
-
-
Method Details
-
getCallInterface
Description copied from interface:CallbackI
Returns the libffi Call Interface for this callback function. [INTERNAL API]- Specified by:
getCallInterface
in interfaceCallbackI
- Returns:
- the CIF structure for this callback function
-
callback
default void callback(long ret, long args) Description copied from interface:CallbackI
The Java method that will be called from native code when the native callback function is invoked.- Specified by:
callback
in interfaceCallbackI
- Parameters:
ret
- 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(org.lwjgl.system.libffi.FFICIF, long, java.nio.ByteBuffer, org.lwjgl.PointerBuffer)
. That is, in most cases,ret
points to an object of exactly the size of the type specified whenCIF
was constructed. However, integral types narrower than the system register size are widened. In these cases your program may assume thatret
points to anffi_arg
object.args
- a vector of pointers to memory holding the arguments to the function
-
invoke
long invoke(long pUserData, long size, long alignment, int allocationScope) Application-defined memory allocation function.- Parameters:
pUserData
- the value specified forVkAllocationCallbacks
::pUserData
in the allocator specified by the application.size
- the size in bytes of the requested allocation.alignment
- the requested alignment of the allocation in bytes and must be a power of two.allocationScope
- aVkSystemAllocationScope
value specifying the allocation scope of the lifetime of the allocation, as described here.
-