private unsafe ThunksHeap(IntPtr commonStubAddress)
{
_commonStubAddress = commonStubAddress;
_allocatedBlocks = new AllocatedBlock();
InternalCalls.RhpAcquireThunkPoolLock();
IntPtr thunkStubsBlock = ThunkBlocks.GetNewThunksBlock();
InternalCalls.RhpReleaseThunkPoolLock();
if (thunkStubsBlock != IntPtr.Zero)
{
IntPtr thunkDataBlock = InternalCalls.RhpGetThunkDataBlockAddress(thunkStubsBlock);
// Address of the first thunk data cell should be at the begining of the thunks data block (page-aligned)
Debug.Assert(((nuint)(nint)thunkDataBlock % Constants.PageSize) == 0);
// Update the last pointer value in the thunks data section with the value of the common stub address
*(IntPtr *)(thunkDataBlock + (int)(Constants.PageSize - IntPtr.Size)) = commonStubAddress;
Debug.Assert(*(IntPtr *)(thunkDataBlock + (int)(Constants.PageSize - IntPtr.Size)) == commonStubAddress);
// Set the head and end of the linked list
_nextAvailableThunkPtr = thunkDataBlock;
_lastThunkPtr = _nextAvailableThunkPtr + Constants.ThunkDataSize * (Constants.NumThunksPerBlock - 1);
_allocatedBlocks._blockBaseAddress = thunkStubsBlock;
}
}
public unsafe void FreeThunk(IntPtr thunkAddress)
{
// TODO: optimize the implementation and make it lock-free
// or at least change it to a per-heap lock instead of a global lock.
IntPtr dataAddress = TryGetThunkDataAddress(thunkAddress);
if (dataAddress == IntPtr.Zero)
{
EH.FallbackFailFast(RhFailFastReason.InternalError, null);
}
#if DEBUG
if (!IsThunkInHeap(thunkAddress))
{
EH.FallbackFailFast(RhFailFastReason.InternalError, null);
}
// Debug flag indicating the thunk is no longer used
*((IntPtr *)(dataAddress + IntPtr.Size)) = new IntPtr(-1);
#endif
InternalCalls.RhpAcquireThunkPoolLock();
*((IntPtr *)(dataAddress)) = _nextAvailableThunkPtr;
_nextAvailableThunkPtr = dataAddress;
InternalCalls.RhpReleaseThunkPoolLock();
}
private unsafe ThunksHeap(IntPtr commonStubAddress)
{
_commonStubAddress = commonStubAddress;
_allocatedBlocks = new AllocatedBlock();
InternalCalls.RhpAcquireThunkPoolLock();
IntPtr thunksBlock = ThunkBlocks.GetNewThunksBlock();
InternalCalls.RhpReleaseThunkPoolLock();
if (thunksBlock != IntPtr.Zero)
{
// Update the last pointer value in the thunks data section with the value of the common stub address
*((IntPtr *)(thunksBlock + (int)(Constants.PageSize * 2 - IntPtr.Size))) = commonStubAddress;
Debug.Assert(*((IntPtr *)(thunksBlock + (int)(Constants.PageSize * 2 - IntPtr.Size))) != IntPtr.Zero);
// Set the head and end of the linked list
_nextAvailableThunkPtr = thunksBlock + (int)Constants.PageSize;
_lastThunkPtr = _nextAvailableThunkPtr + 2 * IntPtr.Size * (InternalCalls.RhpGetNumThunksPerBlock() - 1);
_allocatedBlocks._blockBaseAddress = thunksBlock;
}
}
public unsafe IntPtr AllocateThunk()
{
// TODO: optimize the implementation and make it lock-free
// or at least change it to a per-heap lock instead of a global lock.
Debug.Assert(_nextAvailableThunkPtr != IntPtr.Zero);
InternalCalls.RhpAcquireThunkPoolLock();
IntPtr nextAvailableThunkPtr = _nextAvailableThunkPtr;
IntPtr nextNextAvailableThunkPtr = *((IntPtr *)(nextAvailableThunkPtr));
if (nextNextAvailableThunkPtr == IntPtr.Zero)
{
if (!ExpandHeap())
{
InternalCalls.RhpReleaseThunkPoolLock();
return(IntPtr.Zero);
}
nextAvailableThunkPtr = _nextAvailableThunkPtr;
nextNextAvailableThunkPtr = *((IntPtr *)(nextAvailableThunkPtr));
Debug.Assert(nextNextAvailableThunkPtr != IntPtr.Zero);
}
_nextAvailableThunkPtr = nextNextAvailableThunkPtr;
InternalCalls.RhpReleaseThunkPoolLock();
Debug.Assert(nextAvailableThunkPtr != IntPtr.Zero);
#if DEBUG
// Reset debug flag indicating the thunk is now in use
*((IntPtr *)(nextAvailableThunkPtr + IntPtr.Size)) = IntPtr.Zero;
#endif
int thunkIndex = (int)(((nuint)(nint)nextAvailableThunkPtr) - ((nuint)(nint)nextAvailableThunkPtr & ~Constants.PageSizeMask));
Debug.Assert((thunkIndex % Constants.ThunkDataSize) == 0);
thunkIndex = thunkIndex / Constants.ThunkDataSize;
IntPtr thunkAddress = InternalCalls.RhpGetThunkStubsBlockAddress(nextAvailableThunkPtr) + thunkIndex * Constants.ThunkCodeSize;
return(SetThumbBit(thunkAddress));
}