Add Directory.CreateTempSubdirectory

src/libraries/Common/src/Interop/Unix/Interop.IOErrors.cs

@@ -45,6 +45,14 @@ internal static long CheckIo(long result, string? path = null, bool isDirectory
         return result;
     }
 
+    /// <summary>
+    /// Throws an IOException using the last error info (errno).
+    /// </summary>
+    internal static void ThrowIOExceptionForLastError()
+    {
+        ThrowExceptionForIoErrno(Sys.GetLastErrorInfo(), path: null, isDirectory: false);
+    }
+
     /// <summary>
     /// Validates the result of system call that returns greater than or equal to 0 on success
     /// and less than 0 on failure, with errno set to the error code.

src/libraries/Common/src/Interop/Unix/System.Native/Interop.MkdTemp.cs

@@ -0,0 +1,14 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Runtime.InteropServices;
+
+internal static partial class Interop
+{
+    internal static partial class Sys
+    {
+        [LibraryImport(Libraries.SystemNative, EntryPoint = "SystemNative_MkdTemp", SetLastError = true)]
+        internal static unsafe partial byte* MkdTemp(byte* template);
+    }
+}

src/libraries/Common/src/Interop/Unix/System.Native/Interop.MksTemps.cs

@@ -9,8 +9,8 @@ internal static partial class Interop
     internal static partial class Sys
     {
         [LibraryImport(Libraries.SystemNative, EntryPoint = "SystemNative_MksTemps", SetLastError = true)]
-        internal static partial IntPtr MksTemps(
-            byte[] template,
+        internal static unsafe partial IntPtr MksTemps(
+            byte* template,
             int suffixlen);
     }
 }

src/libraries/Common/src/Interop/Windows/Kernel32/Interop.CreateDirectory.cs

@@ -14,15 +14,15 @@ internal static partial class Kernel32
         /// </summary>
         [LibraryImport(Libraries.Kernel32, EntryPoint = "CreateDirectoryW", SetLastError = true, StringMarshalling = StringMarshalling.Utf16)]
         [return: MarshalAs(UnmanagedType.Bool)]
-        private static partial bool CreateDirectoryPrivate(
+        private static unsafe partial bool CreateDirectoryPrivate(
             string path,
-            ref SECURITY_ATTRIBUTES lpSecurityAttributes);
+            SECURITY_ATTRIBUTES* lpSecurityAttributes);
 
-        internal static bool CreateDirectory(string path, ref SECURITY_ATTRIBUTES lpSecurityAttributes)
+        internal static unsafe bool CreateDirectory(string path, SECURITY_ATTRIBUTES* lpSecurityAttributes)
         {
             // We always want to add for CreateDirectory to get around the legacy 248 character limitation
             path = PathInternal.EnsureExtendedPrefix(path);
-            return CreateDirectoryPrivate(path, ref lpSecurityAttributes);
+            return CreateDirectoryPrivate(path, lpSecurityAttributes);
         }
     }
 }

src/libraries/Common/src/System/IO/FileSystem.DirectoryCreation.Windows.cs

@@ -88,7 +88,7 @@ public static unsafe void CreateDirectory(string fullPath, byte[]? securityDescr
                     string name = stackDir[stackDir.Count - 1];
                     stackDir.RemoveAt(stackDir.Count - 1);
 
-                    r = Interop.Kernel32.CreateDirectory(name, ref secAttrs);
+                    r = Interop.Kernel32.CreateDirectory(name, &secAttrs);
                     if (!r && (firstError == 0))
                     {
                         int currentError = Marshal.GetLastWin32Error();

src/libraries/Common/src/System/IO/PathInternal.Unix.cs

@@ -16,6 +16,7 @@ internal static partial class PathInternal
         internal const char PathSeparator = ':';
         internal const string DirectorySeparatorCharAsString = "/";
         internal const string ParentDirectoryPrefix = @"../";
+        internal const string DirectorySeparators = DirectorySeparatorCharAsString;
 
         internal static int GetRootLength(ReadOnlySpan<char> path)
         {

src/libraries/Common/src/System/IO/PathInternal.Windows.cs

@@ -54,6 +54,7 @@ internal static partial class PathInternal
         internal const string UncNTPathPrefix = @"\??\UNC\";
         internal const string DevicePathPrefix = @"\\.\";
         internal const string ParentDirectoryPrefix = @"..\";
+        internal const string DirectorySeparators = @"\/";
 
         internal const int MaxShortPath = 260;
         internal const int MaxShortDirectoryPath = 248;

src/libraries/Common/src/System/IO/TempFileCollection.cs

@@ -24,6 +24,7 @@ class TempFileCollection : ICollection, IDisposable
         private string _basePath;
         private readonly string _tempDir;
         private readonly Hashtable _files;
+        private bool _createdTempDirectory;
 
         public TempFileCollection() : this(null, false)
         {
@@ -127,7 +128,7 @@ private void EnsureTempNameCreated()
                 do
                 {
                     _basePath = Path.Combine(
-                        string.IsNullOrEmpty(TempDir) ? Path.GetTempPath() : TempDir,
+                        string.IsNullOrEmpty(TempDir) ? GetTempDirectory() : TempDir,
                         Path.GetFileNameWithoutExtension(Path.GetRandomFileName()));
                     tempFileName = _basePath + ".tmp";
 
@@ -150,6 +151,19 @@ private void EnsureTempNameCreated()
             }
         }
 
+#if NET7_0_OR_GREATER
+        private string GetTempDirectory()
+        {
+            _createdTempDirectory = true;
+            return Directory.CreateTempSubdirectory().FullName;
+        }
+#else
+        private static string GetTempDirectory()
+        {
+            return Path.GetTempPath();
+        }
+#endif
+
         public bool KeepFiles { get; set; }
 
         private bool KeepFile(string fileName)
@@ -177,6 +191,8 @@ private static void Delete(string fileName)
 
         internal void SafeDelete()
         {
+            bool allFilesDeleted = true;
+
             if (_files != null && _files.Count > 0)
             {
                 string[] fileNames = new string[_files.Count];
@@ -188,8 +204,28 @@ internal void SafeDelete()
                         Delete(fileName);
                         _files.Remove(fileName);
                     }
+                    else
+                    {
+                        allFilesDeleted = false;
+                    }
                 }
             }
+
+            // if we created a temp directory, delete it and clear the basePath, so a new directory will be created for the next request.
+            if (_createdTempDirectory && allFilesDeleted)
+            {
+                try
+                {
+                    Directory.Delete(Path.GetDirectoryName(BasePath));
+                }
+                catch
+                {
+                    // Ignore all exceptions
+                }
+
+                _createdTempDirectory = false;
+                _basePath = null;
+            }
         }
     }
 }

src/libraries/Microsoft.Extensions.Configuration/tests/FunctionalTests/DisposableFileSystem.cs

@@ -14,9 +14,13 @@ public class DisposableFileSystem : IDisposable
 
         public DisposableFileSystem()
         {
-            RootPath = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
-            CreateFolder("");
-            DirectoryInfo = new DirectoryInfo(RootPath);
+#if NETCOREAPP
+            DirectoryInfo = Directory.CreateTempSubdirectory();
+#else
+            DirectoryInfo = new DirectoryInfo(Path.Combine(Path.GetTempPath(), Path.GetRandomFileName()));
+            DirectoryInfo.Create();
+#endif
+            RootPath = DirectoryInfo.FullName;
         }
 
         public string RootPath { get; }

src/libraries/Microsoft.Extensions.FileSystemGlobbing/tests/TestUtility/DisposableFileSystem.cs

@@ -10,9 +10,13 @@ public class DisposableFileSystem : IDisposable
     {
         public DisposableFileSystem()
         {
-            RootPath = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
-            Directory.CreateDirectory(RootPath);
-            DirectoryInfo = new DirectoryInfo(RootPath);
+#if NETCOREAPP
+            DirectoryInfo = Directory.CreateTempSubdirectory();
+#else
+            DirectoryInfo = new DirectoryInfo(Path.Combine(Path.GetTempPath(), Path.GetRandomFileName()));
+            DirectoryInfo.Create();
+#endif
+            RootPath = DirectoryInfo.FullName;
         }
 
         public string RootPath { get; }

src/libraries/System.CodeDom/tests/System/CodeDom/TempFileCollectionTests.cs

@@ -277,8 +277,13 @@ private static string TempDirectory()
         {
             if (s_tempDirectory == null)
             {
+#if NETCOREAPP
+                string tempDirectory = Directory.CreateTempSubdirectory().FullName;
+#else
                 string tempDirectory = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
                 Directory.CreateDirectory(tempDirectory);
+#endif
+
                 s_tempDirectory = tempDirectory;
             }
             return s_tempDirectory;

src/libraries/System.ComponentModel.Composition/tests/System/ComponentModel/Composition/Hosting/DirectoryCatalogDebuggerProxyTests.cs

@@ -164,9 +164,7 @@ private DirectoryCatalog CreateDirectoryCatalog(string path, string filter)
 
         private string GetTemporaryDirectory(string location = null)
         {
-            string tempDirectory = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
-            Directory.CreateDirectory(tempDirectory);
-            return tempDirectory;
+            return Directory.CreateTempSubdirectory().FullName;
         }
     }
 
@@ -193,16 +191,12 @@ public static string GetRootTemporaryDirectory()
 
         public static string GetNewTemporaryDirectory()
         {
-            string tempDirectory = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
-            Directory.CreateDirectory(tempDirectory);
-            return tempDirectory;
+            return Directory.CreateTempSubdirectory().FullName;
         }
 
         public static string GetTemporaryDirectory()
         {
-            string tempDirectory = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
-            Directory.CreateDirectory(tempDirectory);
-            return tempDirectory;
+            return Directory.CreateTempSubdirectory().FullName;
         }
     }
 }

src/libraries/System.IO.FileSystem/tests/Directory/CreateTempSubdirectory.cs

@@ -0,0 +1,112 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Microsoft.DotNet.RemoteExecutor;
+using Xunit;
+
+namespace System.IO.Tests
+{
+    public class Directory_CreateTempSubdirectory : FileSystemTest
+    {
+        public static TheoryData<string> CreateTempSubdirectoryData
+        {
+            get
+            {
+                var result = new TheoryData<string>() { null, "", "myDir", "my.Dir", "H\u00EBllo" };
+                if (!OperatingSystem.IsWindows())
+                {
+                    // ensure we can use backslashes on Unix since that isn't a directory separator
+                    result.Add(@"my\File");
+                    result.Add(@"\");
+                }
+                return result;
+            }
+        }
+
+        [Theory]
+        [MemberData(nameof(CreateTempSubdirectoryData))]
+        public void CreateTempSubdirectory(string prefix)
+        {
+            DirectoryInfo tmpDir = Directory.CreateTempSubdirectory(prefix);
+            try
+            {
+                Assert.True(tmpDir.Exists);
+                Assert.Equal(-1, tmpDir.FullName.IndexOfAny(Path.GetInvalidPathChars()));
+                Assert.Empty(Directory.GetFileSystemEntries(tmpDir.FullName));
+                Assert.Equal(Path.TrimEndingDirectorySeparator(Path.GetTempPath()), tmpDir.Parent.FullName);
+
+                if (!string.IsNullOrEmpty(prefix))
+                {
+                    Assert.StartsWith(prefix, tmpDir.Name);
+                    int expectedNameLength = prefix.Length + (OperatingSystem.IsWindows() ? 12 : 6);
+                    Assert.Equal(expectedNameLength, tmpDir.Name.Length);
+                }
+
+                if (!OperatingSystem.IsWindows())
+                {
+                    UnixFileMode userRWX = UnixFileMode.UserRead | UnixFileMode.UserWrite | UnixFileMode.UserExecute;
+                    Assert.Equal(userRWX, tmpDir.UnixFileMode);
+                }
+
+                // Ensure a file can be written to the directory
+                string tempFile = Path.Combine(tmpDir.FullName, "newFile");
+                using (FileStream fs = File.Create(tempFile, bufferSize: 1024, FileOptions.DeleteOnClose))
+                {
+                    Assert.Equal(0, fs.Length);
+                }
+            }
+            finally
+            {
+                tmpDir.Delete(recursive: true);
+            }
+        }
+
+        [ConditionalFact(typeof(RemoteExecutor), nameof(RemoteExecutor.IsSupported))]
+        public void CreateTempSubdirectoryTempUnicode()
+        {
+            RemoteExecutor.Invoke(() =>
+            {
+                DirectoryInfo tempPathWithUnicode = new DirectoryInfo(Path.Combine(Path.GetTempPath(), Path.GetRandomFileName() + "\u00F6"));
+                tempPathWithUnicode.Create();
+
+                string tempEnvVar = OperatingSystem.IsWindows() ? "TMP" : "TMPDIR";
+                Environment.SetEnvironmentVariable(tempEnvVar, tempPathWithUnicode.FullName);
+
+                try
+                {
+                    DirectoryInfo tmpDir = Directory.CreateTempSubdirectory();
+                    Assert.True(tmpDir.Exists);
+                    Assert.Equal(tempPathWithUnicode.FullName, tmpDir.Parent.FullName);
+
+                    Environment.SetEnvironmentVariable(tempEnvVar, tempPathWithUnicode.Parent.FullName);
+                }
+                finally
+                {
+                    tempPathWithUnicode.Delete(recursive: true);
+                }
+            }).Dispose();
+        }
+
+        public static TheoryData<string> InvalidPrefixData
+        {
+            get
+            {
+                var result = new TheoryData<string>() { "/", "myDir/", "my/Dir" };
+                if (OperatingSystem.IsWindows())
+                {
+                    result.Add(@"\");
+                    result.Add(@"myDir\");
+                    result.Add(@"my\Dir");
+                }
+                return result;
+            }
+        }
+
+        [Theory]
+        [MemberData(nameof(InvalidPrefixData))]
+        public void CreateTempSubdirectoryThrowsWithPrefixContainingDirectorySeparator(string prefix)
+        {
+            AssertExtensions.Throws<ArgumentException>("prefix", () => Directory.CreateTempSubdirectory(prefix));
+        }
+    }
+}

src/libraries/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj

@@ -19,6 +19,7 @@
     <Compile Include="Base\SymbolicLinks\BaseSymbolicLinks.cs" />
     <Compile Include="Base\SymbolicLinks\BaseSymbolicLinks.FileSystem.cs" />
     <Compile Include="Base\SymbolicLinks\BaseSymbolicLinks.FileSystemInfo.cs" />
+    <Compile Include="Directory\CreateTempSubdirectory.cs" />
     <Compile Include="Directory\EnumerableTests.cs" />
     <Compile Include="Directory\SymbolicLinks.cs" />
     <Compile Include="DirectoryInfo\SymbolicLinks.cs" />

src/libraries/System.Private.CoreLib/src/Resources/Strings.resx

@@ -2710,6 +2710,9 @@
   <data name="IO_UnknownFileName" xml:space="preserve">
     <value>[Unknown]</value>
   </data>
+  <data name="IO_MaxAttemptsReached" xml:space="preserve">
+    <value>Unable to complete the operation after the maximum number of attempts.</value>
+  </data>
   <data name="Lazy_CreateValue_NoParameterlessCtorForT" xml:space="preserve">
     <value>The lazily-initialized type does not have a public, parameterless constructor.</value>
   </data>
@@ -3988,4 +3991,7 @@
   <data name="FileNotFound_AssemblyNotFound" xml:space="preserve">
     <value>Cannot load assembly '{0}'. No metadata found for this assembly.</value>
   </data>
+  <data name="Argument_DirectorySeparatorInvalid" xml:space="preserve">
+    <value>The value may not contain directory separator characters.</value>
+  </data>
 </root>

src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems

@@ -2093,6 +2093,9 @@
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.MkDir.cs">
       <Link>Common\Interop\Unix\System.Native\Interop.MkDir.cs</Link>
     </Compile>
+    <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.MkdTemp.cs">
+      <Link>Common\Interop\Unix\System.Native\Interop.MkdTemp.cs</Link>
+    </Compile>
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.MksTemps.cs">
       <Link>Common\Interop\Unix\System.Native\Interop.MksTemps.cs</Link>
     </Compile>