Called just prior to invoking IMalloc::Alloc.

ULONG PreAlloc(

ULONG cbRequest
//The byte count passed to IMalloc::Alloc



The number of bytes in the allocation request the caller is passing to IMalloc::Alloc.

Return Value

The byte count actually passed to IMalloc::Alloc, which should be greater than or equal to the value of cbRequest.


The IMallocSpy::PreAlloc implementation may extend and/or modify the allocation to store debug-specific information with the allocation.

PreAlloc can force memory allocation failure by returning 0, allowing testing to ensure that the application handles allocation failure gracefully in all cases. In this case PostAlloc is not called and Alloc returns NULL. Forcing allocation failure is effective only if cbRequest is not equal to 0. If PreAlloc is forcing failure by returning NULL, PostAlloc is not called. However, if IMalloc::Alloc encounters a real memory failure and returns NULL, PostAlloc is called.

The call to PreAlloc through the return from PostAlloc is guaranteed to be thread safe.

See Also

IMalloc::Alloc, IMallocSpy::PostAlloc, CoRegisterMallocSpy, CoRevokeMallocSpy

Software for developers
Delphi Components
.Net Components
Software for Android Developers
More information resources
Unix Manual Pages
Delphi Examples
Databases for Amazon shops developers
Amazon Categories Database
Browse Nodes Database