IMalloc::Realloc - OLE Programmer's Reference

OLE Programmer's Reference

Home Index About

Custom Search

IMalloc::Realloc

Changes the size of a previously allocated memory block.

oid *Realloc(

void *pv,	//The memory block to be reallocated
ULONG cb	//The size of the memory block in bytes
);

Parameters
pv
[in] Points to the memory block to be reallocated. It can be a NULL pointer, as discussed in the following Comments section.

[in] Specifies the size of the memory block (in bytes) to be reallocated. It can be zero, as discussed in the following remarks.

Return Values
Reallocated memory block

Memory block successfully reallocated.

NULL

Insufficient memory or cb is zero and pv is not NULL.

Comments
The initial contents of the returned memory block are undefined - there is no guarantee that the block has been initialized, so you should initialize it in your code. The allocated block may be larger than cb bytes because of the space required for alignment and for maintenance information.

The pv argument points to the beginning of the memory block. If pv is NULL, IMalloc::Realloc allocates a new memory block in the same way as IMalloc::Alloc. If pv is not NULL, it should be a pointer returned by a prior call to IMalloc::Alloc.
The cb argument specifies the size (in bytes) of the new block. The contents of the block are unchanged up to the shorter of the new and old sizes, although the new block can be in a different location. Because the new block can be in a different memory location, the pointer returned by IMalloc::Realloc is not guaranteed to be the pointer passed through the pv argument. If pv is not NULL and cb is zero, then the memory pointed to by pv is freed.

IMalloc::Realloc returns a void pointer to the reallocated (and possibly moved) memory block. The return value is NULL if the size is zero and the buffer argument is not NULL, or if there is not enough memory available to expand the block to the given size. In the first case, the original block is freed; in the second, the original block is unchanged.

The storage space pointed to by the return value is guaranteed to be suitably aligned for storage of any type of object. To get a pointer to a type other than void, use a type cast on the return value.

See Also

IMalloc::Alloc, IMalloc::Free

Last news from Greatis Software

    Nostalgia .Net     .Net is powerful, but not all-powerful, so sometimes we need to use Win32 API for our .Net applications. It's simple enough with Platform Invoke if you have Win32 skill, but we do not always have time to dig the ancient documentation, declare the special types that are compatible with Win32, find the values of the Win32's constants and so on. Nostalgia .Net offers several simple-to-use classes, and components that will allow you to forget about the headache of Win32 and just use the power of Win32 in your application the same way as you use the native. Net classes. More »

Recommended software for developers

    Ultimate Pack     Component pack for Delphi and C++ Builder that contains runtime form designer, runtime object inspector, print suite and much more for the very special price. More »

    Form Designer .Net     Unique runtime form design solution that allows to edit any form in .Net WinForms application at runtime with full source codes for only 300 euro! More »

    Print Suite .Net     Print Suite .Net is a set of components for easy printing texts, images and grids from your WinForms applications. Full C# source codes are available More »

    Gradient Controls .Net     Gradient Controls .Net offers controls with gradient background feature. Labels, panels and so on... Full C# source codes are available More »

    Greatis iGrid     iGrid plots drawing grid right over your desktop, so you can use it everywhere, with any drawing application without any special plugins for different graphic editors. More »

All the contacts and projects

Dmitry Vasiliev (just.dmitry)

More Online Helps

Win32 Programmer's Reference
Win32 Multimedia Programmer's Reference
OLE Programmer's Reference
Microsoft Windows Pen API Programmer's Reference
Microsoft Windows Sockets 2 Reference
Microsoft Windows Telephony API (TAPI) Programmer's Reference
Unix Manual Pages

greatis just4fun network