/// <summary>
/// Allocates a block of memory from the default process heap.
/// </summary>
/// <param name="size">The size of the memory to allocate.</param>
/// <param name="allocationFlags">The memory allocation flags.</param>
/// <returns>A pointer to the allocated block of memory.</returns>
public static IntPtr Allocate(ulong size, MemoryAllocationFlags allocationFlags)
{
if (hHeap == IntPtr.Zero)
{
InitializeHeap();
}
bool zeroFill = (allocationFlags & MemoryAllocationFlags.ZeroFill) == MemoryAllocationFlags.ZeroFill;
IntPtr block = SafeNativeMethods.HeapAlloc(hHeap, zeroFill ? NativeConstants.HEAP_ZERO_MEMORY : 0U, new UIntPtr(size));
if (block == IntPtr.Zero)
{
if ((allocationFlags & MemoryAllocationFlags.ReturnZeroOnOutOfMemory) == MemoryAllocationFlags.ReturnZeroOnOutOfMemory)
{
return(IntPtr.Zero);
}
else
{
throw new OutOfMemoryException();
}
}
if (size > 0L)
{
MemoryPressureManager.AddMemoryPressure((long)size);
}
return(block);
}
/// <summary>
/// Frees a block of memory previously allocated with Allocate().
/// </summary>
/// <param name="block">The block to free.</param>
/// <exception cref="InvalidOperationException">There was an error freeing the block.</exception>
public static void Free(IntPtr block)
{
if (Memory.hHeap != IntPtr.Zero)
{
long bytes = (long)SafeNativeMethods.HeapSize(hHeap, 0, block);
bool result = SafeNativeMethods.HeapFree(hHeap, 0, block);
if (!result)
{
int error = Marshal.GetLastWin32Error();
throw new InvalidOperationException("HeapFree returned an error: " + error.ToString(CultureInfo.InvariantCulture));
}
if (bytes > 0)
{
MemoryPressureManager.RemoveMemoryPressure(bytes);
}
}
else
{
#if REPORTLEAKS
throw new InvalidOperationException("memory leak! check the debug output for more info, and http://blogs.msdn.com/ricom/archive/2004/12/10/279612.aspx to track it down");
#endif
}
}
/// <summary>
/// Frees the block of memory allocated by AllocateExecutable().
/// </summary>
/// <param name="hMem">The block to free.</param>
/// <param name="size">The size of the allocated block.</param>
public static void FreeExecutable(IntPtr hMem, long size)
{
if (!SafeNativeMethods.VirtualFree(hMem, UIntPtr.Zero, NativeConstants.MEM_RELEASE))
{
int error = Marshal.GetLastWin32Error();
throw new InvalidOperationException("VirtualFree returned an error: " + error.ToString(CultureInfo.InvariantCulture));
}
if (size > 0L)
{
MemoryPressureManager.RemoveMemoryPressure(size);
}
}
/// <summary>
/// Frees a block of memory previous allocated with AllocateLarge().
/// </summary>
/// <param name="block">The block to free.</param>
/// <param name="bytes">The size of the block.</param>
public static void FreeLarge(IntPtr block, ulong bytes)
{
if (!SafeNativeMethods.VirtualFree(block, UIntPtr.Zero, NativeConstants.MEM_RELEASE))
{
int error = Marshal.GetLastWin32Error();
throw new InvalidOperationException("VirtualFree returned an error: " + error.ToString(CultureInfo.InvariantCulture));
}
if (bytes > 0)
{
MemoryPressureManager.RemoveMemoryPressure((long)bytes);
}
}
/// <summary>
/// Allocates a block of memory with the PAGE_EXECUTE permission.
/// </summary>
/// <param name="size">The size of the memory to allocate.</param>
/// <returns>A pointer to the allocated block of memory.</returns>
public static IntPtr AllocateExecutable(long size)
{
IntPtr block = SafeNativeMethods.VirtualAlloc(IntPtr.Zero, new UIntPtr((ulong)size), NativeConstants.MEM_COMMIT, NativeConstants.PAGE_EXECUTE_READWRITE);
if (block == IntPtr.Zero)
{
throw new OutOfMemoryException("VirtualAlloc returned a null pointer");
}
if (size > 0L)
{
MemoryPressureManager.AddMemoryPressure(size);
}
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 bytes</returns>
/// <remarks>
/// This method uses an alternate method for allocating memory (VirtualAlloc in Windows). The allocation
/// granularity is the page size of the system (usually 4K). Blocks allocated with this method may also
/// be protected using the ProtectBlock method.
/// </remarks>
public static IntPtr AllocateLarge(ulong bytes)
{
IntPtr block = SafeNativeMethods.VirtualAlloc(IntPtr.Zero, new UIntPtr(bytes),
NativeConstants.MEM_COMMIT, NativeConstants.PAGE_READWRITE);
if (block == IntPtr.Zero)
{
throw new OutOfMemoryException("VirtualAlloc returned a null pointer");
}
if (bytes > 0)
{
MemoryPressureManager.AddMemoryPressure((long)bytes);
}
return(block);
}
/// <summary>
/// Frees the block of memory allocated by Allocate().
/// </summary>
/// <param name="hMem">The block to free.</param>
public static void Free(IntPtr hMem)
{
if (hHeap != IntPtr.Zero)
{
long size = Size(hMem);
if (!SafeNativeMethods.HeapFree(hHeap, 0, hMem))
{
int error = Marshal.GetLastWin32Error();
throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, "HeapFree returned an error 0x{0:X8}", error));
}
if (size > 0L)
{
MemoryPressureManager.RemoveMemoryPressure(size);
}
}
}
/// <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);
}
/// <summary>
/// Resizes the memory block previously allocated by Allocate().
/// </summary>
/// <param name="pv">The pointer to the block to resize.</param>
/// <param name="newSize">The new size of the block.</param>
/// <returns>The pointer to the resized block.</returns>
public static IntPtr ReAlloc(IntPtr pv, long newSize)
{
if (hHeap == IntPtr.Zero)
{
InitializeHeap();
}
IntPtr block;
long oldSize = Size(pv);
try
{
UIntPtr bytes = new UIntPtr((ulong)newSize);
block = SafeNativeMethods.HeapReAlloc(hHeap, 0U, pv, bytes);
}
catch (OverflowException ex)
{
throw new OutOfMemoryException(string.Format(CultureInfo.InvariantCulture, "Overflow while trying to allocate {0:N} bytes", newSize), ex);
}
if (block == IntPtr.Zero)
{
throw new OutOfMemoryException(string.Format(CultureInfo.InvariantCulture, "HeapAlloc returned a null pointer while trying to allocate {0:N} bytes", newSize));
}
if (oldSize > 0L)
{
MemoryPressureManager.RemoveMemoryPressure(oldSize);
}
if (newSize > 0)
{
MemoryPressureManager.AddMemoryPressure(newSize);
}
return(block);
}
/// <summary>
/// Resizes the memory block previously allocated by Allocate().
/// </summary>
/// <param name="pv">The pointer to the block to resize.</param>
/// <param name="newSize">The new size of the block.</param>
/// <returns>The pointer to the resized block.</returns>
public static IntPtr ReAlloc(IntPtr pv, int newSize)
{
if (hHeap == IntPtr.Zero)
{
InitializeHeap();
}
IntPtr block;
long oldSize = Size(pv);
try
{
UIntPtr bytes = new UIntPtr((ulong)newSize);
block = SafeNativeMethods.HeapReAlloc(hHeap, 0U, pv, bytes);
}
catch (OverflowException)
{
throw new OutOfMemoryException();
}
if (block == IntPtr.Zero)
{
throw new OutOfMemoryException();
}
if (oldSize > 0L)
{
MemoryPressureManager.RemoveMemoryPressure(oldSize);
}
if (newSize > 0)
{
MemoryPressureManager.AddMemoryPressure(newSize);
}
return(block);
}
