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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using Microsoft.Win32.SafeHandles;
using System.Diagnostics;
using System.IO;
using System.Runtime.InteropServices;
namespace System.Threading
{
public sealed partial class Semaphore
{
private const uint AccessRights = (uint)Interop.Kernel32.MAXIMUM_ALLOWED | Interop.Kernel32.SYNCHRONIZE | Interop.Kernel32.SEMAPHORE_MODIFY_STATE;
private Semaphore(SafeWaitHandle handle)
{
SafeWaitHandle = handle;
}
private void CreateSemaphoreCore(int initialCount, int maximumCount, string name, out bool createdNew)
{
Debug.Assert(initialCount >= 0);
Debug.Assert(maximumCount >= 1);
Debug.Assert(initialCount <= maximumCount);
#if !PLATFORM_WINDOWS
if (name != null)
throw new PlatformNotSupportedException(SR.PlatformNotSupported_NamedSynchronizationPrimitives);
#endif
SafeWaitHandle myHandle = Interop.Kernel32.CreateSemaphoreEx(IntPtr.Zero, initialCount, maximumCount, name, 0, AccessRights);
int errorCode = Marshal.GetLastWin32Error();
if (myHandle.IsInvalid)
{
if (name != null && name.Length != 0 && errorCode == Interop.Errors.ERROR_INVALID_HANDLE)
throw new WaitHandleCannotBeOpenedException(
SR.Format(SR.Threading_WaitHandleCannotBeOpenedException_InvalidHandle, name));
throw Win32Marshal.GetExceptionForLastWin32Error();
}
createdNew = errorCode != Interop.Errors.ERROR_ALREADY_EXISTS;
this.SafeWaitHandle = myHandle;
}
private static OpenExistingResult OpenExistingWorker(string name, out Semaphore result)
{
#if PLATFORM_WINDOWS
if (name == null)
throw new ArgumentNullException(nameof(name));
if (name.Length == 0)
throw new ArgumentException(SR.Argument_EmptyName, nameof(name));
// Pass false to OpenSemaphore to prevent inheritedHandles
SafeWaitHandle myHandle = Interop.Kernel32.OpenSemaphore(AccessRights, false, name);
if (myHandle.IsInvalid)
{
result = null;
int errorCode = Marshal.GetLastWin32Error();
if (errorCode == Interop.Errors.ERROR_FILE_NOT_FOUND || errorCode == Interop.Errors.ERROR_INVALID_NAME)
return OpenExistingResult.NameNotFound;
if (errorCode == Interop.Errors.ERROR_PATH_NOT_FOUND)
return OpenExistingResult.PathNotFound;
if (name != null && name.Length != 0 && errorCode == Interop.Errors.ERROR_INVALID_HANDLE)
return OpenExistingResult.NameInvalid;
// this is for passed through NativeMethods Errors
throw Win32Marshal.GetExceptionForLastWin32Error();
}
result = new Semaphore(myHandle);
return OpenExistingResult.Success;
#else
throw new PlatformNotSupportedException(SR.PlatformNotSupported_NamedSynchronizationPrimitives);
#endif
}
private int ReleaseCore(int releaseCount)
{
int previousCount;
if (!Interop.Kernel32.ReleaseSemaphore(SafeWaitHandle, releaseCount, out previousCount))
throw new SemaphoreFullException();
return previousCount;
}
}
}
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