/// <summary>
/// Explicitly frees this end of the channel.
///
/// Since both threads on the channel could try to do this simultaneously,
/// we use the ref counting on the underlying endpoints to let the last
/// free operation (the one pulling the ref count to 0) to free the associated
/// event.
/// </summary>
public unsafe static void Free(Allocation * /*EndpointCore* opt(ExHeap)!*/ endpoint)
{
// Use unchecked GetData here, since this may be called from the
// cleanup threading running in the kernel.
EndpointCore *ep = ((EndpointCore *)Allocation.GetDataUnchecked(endpoint));
if (ep->deliveryHandle != DeliveryHandle.Zero)
{
if (DeliveryHandle.Free(ep->deliveryHandle))
{
Interlocked.Decrement(ref openChannelCount);
}
}
else
{
// was never connected, just free this endpoint
AutoResetEventHandle areHandle = ep->cachedMessageEvent;
SharedHeap.KernelSharedHeap.Free(endpoint,
SharedHeap.CurrentProcessSharedHeap.EndpointPeerOwnerId);
if (areHandle.id != UIntPtr.Zero)
{
Process.kernelProcess.ReleaseHandle(areHandle.id);
}
}
}
/// <summary>
/// The peer thread might try this too, so we use the ref count of the
/// underlying memory to allow only the last freeer to also free the
/// associated auto-reset event handle. Make sure to grab the handle
/// before freeing the endpoint.
/// </summary>
unsafe private static bool TryFreeResources(
Allocation * /*EndpointCore*/ endpoint,
SharedHeap.AllocationOwnerId ownerId)
{
EndpointCore *epData =
(EndpointCore *)Allocation.GetDataUnchecked(endpoint);
AutoResetEventHandle areHandle = epData->GetAreHandle();
DeliveryHandle dh = epData->dImpHandle;
int channelId = epData->ChannelId;
bool lastRefGone = SharedHeap.KernelSharedHeap.Free(endpoint,
ownerId);
if (lastRefGone)
{
if (dh != DeliveryHandle.Zero)
{
DeliveryHandle.Dispose(dh);
}
if (areHandle.id != UIntPtr.Zero)
{
Process.kernelProcess.ReleaseHandle(areHandle.id);
}
}
return(lastRefGone);
}
internal static void Dispose(Process process,
DeliveryHandle handle)
{
Tracing.Log(Tracing.Debug, "DeliveryHandle.Dispose(id={0:x8})",
handle.id);
//
// Releasing the handle will allow the deliveryImpl to be garbage-
// collected
//
process.ReleaseHandle(handle.id);
}
/// <summary>
/// Performs the initialization of the core part of each endpoint and cross links
/// them to form a channel. Uses the given delivery mechanism.
/// </summary>
public static void Connect(
Allocation * /*EndpointCore* opt(ExHeap)!*/ imp,
Allocation * /*EndpointCore* opt(ExHeap)!*/ exp,
Allocation * /*EndpointCore* opt(ExHeap)!*/ securityEp,
string deliveryImplType)
{
if (imp == null || exp == null)
{
throw new ApplicationException("Connect called with null endpoints");
}
EndpointCore *impData = (EndpointCore *)Allocation.GetData(imp);
EndpointCore *expData = (EndpointCore *)Allocation.GetData(exp);
if (impData == null || expData == null)
{
throw new ApplicationException("SharedHeap.GetData return null");
}
Tracing.Log(Tracing.Debug, "connect {0:x8} and {1:x8}",
(UIntPtr)imp, (UIntPtr)exp);
if (!(DeliveryHandle.Create(deliveryImplType, imp, out impData->deliveryHandle) &&
DeliveryHandle.Create(deliveryImplType, exp, out expData->deliveryHandle)))
{
throw new EndpointCoreException(
"Error trying to create EndpointCore using \"" +
deliveryImplType +
"\" delivery implementation");
}
#if false
DebugStub.Print("imp handle {0,8:x} exp handle {1,8:x}\n",
__arglist((uint)impData->deliveryHandle.id, (uint)expData->deliveryHandle.id));
#endif
DeliveryImpl impDi = impData->EndpointDeliveryImpl;
DeliveryImpl expDi = expData->EndpointDeliveryImpl;
VTable.Assert(impDi != null && expDi != null);
impDi.Connect(expDi, securityEp);
// keep track of how many channels are open
Interlocked.Increment(ref openChannelCount);
#if CHANNEL_COUNT
PerfCounters.IncrementChannelsCreated();
#endif
Monitoring.Log(Monitoring.Provider.EndpointCore,
(ushort)EndpointCoreEvent.Connect, 0,
(uint)expData->ChannelId, 0, 0, 0, 0);
}
public static bool Free(DeliveryHandle handle)
{
DeliveryImpl di = GetImpl(handle);
// This is a pretty kludgy hack, but is necessary since static
// methods can't be called on an object.
switch (di.GetImplName())
{
case SingleAddrSpaceDelivery.ImplName:
return(SingleAddrSpaceDelivery.Free((SingleAddrSpaceDelivery)di));
#if PAGING
// TODO paging
#endif
default:
throw new DeliveryHandleException(
"Free of unknown channel delivery implementation \"" +
di.GetImplName() +
"\" requested");
}
}
public unsafe static bool Create(
string implName,
Allocation * /*EndpointCore* opt(ExHeap)!*/ endpoint,
out DeliveryHandle handle)
{
DeliveryImpl deliveryImpl;
switch (implName)
{
case SingleAddrSpaceDelivery.ImplName:
deliveryImpl = new SingleAddrSpaceDelivery(endpoint);
break;
#if PAGING
// TODO paging
#endif
default:
throw new DeliveryHandleException(
"Unknown channel delivery implementation \"" +
implName +
"\" requested");
}
if (!deliveryImpl.IsMechanismInitialized())
{
DebugStub.Print("Ack! IsMechInit returns false!\n");
DebugStub.Break();
handle = Zero;
return(false);
}
handle = new DeliveryHandle(
Process.kernelProcess.AllocateHandle(deliveryImpl));
#if false
unsafe {
DebugStub.WriteLine("DeliveryHandle.Create: got handle {0,8:x}\n", __arglist((uint)handle.id));
}
#endif
return(true);
}
public static void Dispose(DeliveryHandle handle)
{
Dispose(Process.kernelProcess, handle);
}
public static DeliveryImpl GetImpl(DeliveryHandle handle)
{
DeliveryImpl di = HandleTable.GetHandle(handle.id) as DeliveryImpl;
return(di);
}