/// <summary>
/// Allocates a block of memory at least as large as the amount requested.
/// </summary>
/// <param name="bytes">The number of bytes you want to allocate.</param>
/// <returns>A pointer to a block of memory at least as large as <b>bytes</b>.</returns>
/// <exception cref="OutOfMemoryException">Thrown if the memory manager could not fulfill the request for a memory block at least as large as <b>bytes</b>.</exception>
public static IntPtr Allocate(ulong bytes)
{
if (hHeap == IntPtr.Zero)
{
throw new InvalidOperationException("heap has already been destroyed");
}
else
{
IntPtr block = SafeNativeMethods.HeapAlloc(hHeap, 0, new UIntPtr(bytes));
if (block == IntPtr.Zero)
{
throw new OutOfMemoryException("HeapAlloc returned a null pointer");
}
if (bytes > 0)
{
GC.AddMemoryPressure((long)bytes);
}
return(block);
}
}
/// <summary>
/// Allocates a block of memory at least as large as the amount requested.
/// </summary>
/// <param name="bytes">The number of bytes you want to allocate.</param>
/// <returns>A pointer to a block of memory at least as large as <b>bytes</b>.</returns>
/// <exception cref="OutOfMemoryException">Thrown if the memory manager could not fulfill the request for a memory block at least as large as <b>bytes</b>.</exception>
public static IntPtr Allocate(ulong bytes)
{
if (hHeap == IntPtr.Zero)
{
CreateHeap();
}
// Always initialize the memory to zero.
// This ensures that the behavior of Allocate is the same as AllocateLarge.
// AllocateLarge uses VirtualAlloc which is documented to initialize the allocated memory to zero.
IntPtr block = SafeNativeMethods.HeapAlloc(hHeap, NativeConstants.HEAP_ZERO_MEMORY, new UIntPtr(bytes));
if (block == IntPtr.Zero)
{
throw new OutOfMemoryException("HeapAlloc returned a null pointer");
}
if (bytes > 0)
{
MemoryPressureManager.AddMemoryPressure((long)bytes);
}
return(block);
}
