Consolidate temp files in Unix implementations

System.IO.Pipes and System.IO.MemoryMappedFiles both create temporary files, and end up doing so in inconsistent locations.  This commit changes them to use a consistently named location under the temporary path, e.g. /tmp/.dotnet/corefx/pipes/* and /tmp/.dotnet/corefx/maps/*

Author: stephentoub

src/Common/src/System/IO/PersistedFiles.Names.Unix.cs

@@ -0,0 +1,16 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace System.IO
+{
+    internal static partial class PersistedFiles
+    {
+        // Temporary data, /tmp/.dotnet/corefx
+        // User-persisted data, ~/.dotnet/corefx/
+        // System-persisted data, /etc/dotnet/corefx/
+
+        internal const string TopLevelDirectory = "dotnet";
+        internal const string TopLevelHiddenDirectory = "." + TopLevelDirectory;
+        internal const string SecondLevelDirectory = "corefx";
+    }
+}

src/Common/src/System/IO/PersistedFiles.Unix.cs

@@ -5,14 +5,8 @@
 
 namespace System.IO
 {
-    internal static class PersistedFiles
+    internal static partial class PersistedFiles
     {
-        // If we ever need system persisted data, /etc/dotnet/corefx/
-        private const string TopLevelDirectory = "dotnet";
-        // User persisted data, ~/.dotnet/corefx/
-        private const string TopLevelUserDirectory = "." + TopLevelDirectory;
-        private const string SecondLevelDirectory = "corefx";
-
         private static string s_userProductDirectory;
 
         /// <summary>
@@ -79,7 +73,7 @@ private static void EnsureUserDirectories()
 
             s_userProductDirectory = Path.Combine(
                 userHomeDirectory,
-                TopLevelUserDirectory,
+                TopLevelHiddenDirectory,
                 SecondLevelDirectory);
         }
     }

src/System.IO.MemoryMappedFiles/src/System.IO.MemoryMappedFiles.csproj

@@ -198,6 +198,9 @@
     <Compile Include="$(CommonPath)\Interop\OSX\libc\Interop.SysConfNames.cs">
       <Link>Common\Interop\OSX\Interop.SysConfNames.cs</Link>
     </Compile>
+    <Compile Include="$(CommonPath)\System\IO\PersistedFiles.Names.Unix.cs">
+      <Link>Common\System\IO\PersistedFiles.Names.Unix.cs</Link>
+    </Compile>
   </ItemGroup>
   <!-- Resource files -->
   <ItemGroup>

src/System.IO.MemoryMappedFiles/src/System/IO/MemoryMappedFiles/MemoryMappedFile.Unix.BackingObject_File.cs

@@ -9,8 +9,9 @@ public partial class MemoryMappedFile
     {
         private static FileStream CreateSharedBackingObject(Interop.libc.MemoryMappedProtections protections, long capacity)
         {
-            string path = TmpPathPrefix + Guid.NewGuid().ToString("N") + ".tmp";
-
+            Directory.CreateDirectory(s_tempMapsDirectory);
+            string path = Path.Combine(s_tempMapsDirectory, Guid.NewGuid().ToString("N"));
+            
             FileAccess access =
                 (protections & (Interop.libc.MemoryMappedProtections.PROT_READ | Interop.libc.MemoryMappedProtections.PROT_WRITE)) != 0 ? FileAccess.ReadWrite :
                 (protections & (Interop.libc.MemoryMappedProtections.PROT_WRITE)) != 0 ? FileAccess.Write :
@@ -37,6 +38,10 @@ private static FileStream CreateSharedBackingObject(Interop.libc.MemoryMappedPro
         // ---- PAL layer ends here ----
         // -----------------------------
 
-        private static readonly string TmpPathPrefix = Path.Combine(Path.GetTempPath(), MemoryMapObjectFilePrefix);
+        private static readonly string s_tempMapsDirectory = Path.Combine(
+            Path.GetTempPath(),
+            PersistedFiles.TopLevelHiddenDirectory,
+            PersistedFiles.SecondLevelDirectory,
+            "maps");
     }
 }

src/System.IO.MemoryMappedFiles/src/System/IO/MemoryMappedFiles/MemoryMappedFile.Unix.BackingObject_Memory.cs

@@ -11,7 +11,7 @@ private static FileStream CreateSharedBackingObject(
             Interop.libc.MemoryMappedProtections protections, long capacity)
         {
             // The POSIX shared memory object name must begin with '/'.  After that we just want something short and unique.
-            string mapName = "/" + MemoryMapObjectFilePrefix + Guid.NewGuid().ToString("N");
+            string mapName = "/corefx_map_" + Guid.NewGuid().ToString("N");
 
             // Determine the flags to use when creating the shared memory object
             Interop.libc.OpenFlags flags = (protections & Interop.libc.MemoryMappedProtections.PROT_WRITE) != 0 ?

src/System.IO.MemoryMappedFiles/src/System/IO/MemoryMappedFiles/MemoryMappedFile.Unix.cs

@@ -122,9 +122,7 @@ private static Exception CreateNamedMapsNotSupportedException()
         {
             return new PlatformNotSupportedException(SR.PlatformNotSupported_NamedMaps);
         }
-
-        private const string MemoryMapObjectFilePrefix = "corefx_mmf_";
-
+        
         private static FileAccess TranslateProtectionsToFileAccess(Interop.libc.MemoryMappedProtections protections)
         {
             return

src/System.IO.Pipes/src/System.IO.Pipes.csproj

@@ -139,10 +139,6 @@
     <Compile Include="System\IO\Pipes\PipeStreamAsyncResult.cs" />
   </ItemGroup>
   <ItemGroup Condition=" '$(TargetsUnix)' == 'true' ">
-    <Compile Include="$(CommonPath)\System\NotImplemented.cs">
-      <!-- TODO: Remove once implemented -->
-      <Link>Common\System\NotImplemented.cs</Link>
-    </Compile>
     <Compile Include="Microsoft\Win32\SafeHandles\SafePipeHandle.Unix.cs" />
     <Compile Include="System\IO\Pipes\AnonymousPipeServerStream.Unix.cs" />
     <Compile Include="System\IO\Pipes\NamedPipeClientStream.Unix.cs" />
@@ -199,6 +195,9 @@
     <Compile Include="$(CommonPath)\Interop\Unix\System.Native\Interop.Stat.cs">
       <Link>Common\Interop\Unix\Interop.Stat.cs</Link>
     </Compile>
+    <Compile Include="$(CommonPath)\System\IO\PersistedFiles.Names.Unix.cs">
+      <Link>Common\System\IO\PersistedFiles.Names.Unix.cs</Link>
+    </Compile>
   </ItemGroup>
   <!-- Linux -->
   <ItemGroup Condition="'$(TargetsLinux)' == 'true'">

src/System.IO.Pipes/src/System/IO/Pipes/PipeStream.Unix.cs

@@ -20,8 +20,6 @@ public abstract partial class PipeStream : Stream
         // Windows, but can't assume a valid handle on Unix.
         internal const bool CheckOperationsRequiresSetHandle = false;
 
-        private static readonly string PipeDirectoryPath = Path.Combine(Path.GetTempPath(), "corefxnamedpipes");
-
         internal static string GetPipePath(string serverName, string pipeName)
         {
             if (serverName != "." && serverName != Interop.libc.gethostname())
@@ -38,35 +36,8 @@ internal static string GetPipePath(string serverName, string pipeName)
                 throw new PlatformNotSupportedException();
             }
 
-            // Make sure we have the directory in which to put the pipe paths
-            while (true)
-            {
-                int result = Interop.libc.mkdir(PipeDirectoryPath, (int)Interop.libc.Permissions.S_IRWXU);
-                if (result >= 0)
-                {
-                    // directory created
-                    break;
-                }
-
-                Interop.ErrorInfo errorInfo = Interop.Sys.GetLastErrorInfo();
-                if (errorInfo.Error == Interop.Error.EINTR)
-                {
-                    // I/O was interrupted, try again
-                    continue;
-                }
-                else if (errorInfo.Error == Interop.Error.EEXIST)
-                {
-                    // directory already exists
-                    break;
-                }
-                else
-                {
-                    throw Interop.GetExceptionForIoErrno(errorInfo, PipeDirectoryPath, isDirectory: true);
-                }
-            }
-
             // Return the pipe path
-            return Path.Combine(PipeDirectoryPath, pipeName);
+            return Path.Combine(GetPipeDirectoryPath(), pipeName);
         }
 
         /// <summary>Throws an exception if the supplied handle does not represent a valid pipe.</summary>
@@ -255,6 +226,59 @@ public virtual PipeTransmissionMode ReadMode
         // ---- PAL layer ends here ----
         // -----------------------------
 
+        private static string s_pipeDirectoryPath;
+
+        private static string GetPipeDirectoryPath()
+        {
+            string path = s_pipeDirectoryPath;
+            if (path == null)
+            {
+                // Create the pipes temporary directory, e.g. "/tmp/.dotnet/corefx/pipes".
+                // We don't have access to Directory.CreateDirectory (which handles creating
+                // all levels of the directory full path specified), so we create each nested
+                // level individually (though we assume that the temp path already exists).
+
+                path = Path.GetTempPath();
+
+                path = Path.Combine(path, PersistedFiles.TopLevelHiddenDirectory);
+                CreateDirectory(path);
+
+                path = Path.Combine(path, PersistedFiles.SecondLevelDirectory);
+                CreateDirectory(path);
+
+                const string PipesFeatureName = "pipes";
+                path = Path.Combine(path, PipesFeatureName);
+                CreateDirectory(path);
+
+                s_pipeDirectoryPath = path;
+            }
+            return path;
+        }
+
+        private static void CreateDirectory(string directoryPath)
+        {
+            while (true)
+            {
+                int result = Interop.libc.mkdir(directoryPath, (int)Interop.libc.Permissions.S_IRWXU);
+
+                // If successful created, we're done.
+                if (result >= 0)
+                    return;
+
+                // If the directory already exists, consider it a success.
+                Interop.ErrorInfo errorInfo = Interop.Sys.GetLastErrorInfo();
+                if (errorInfo.Error == Interop.Error.EEXIST)
+                    return;
+
+                // If the I/O was interrupted, try again.
+                if (errorInfo.Error == Interop.Error.EINTR)
+                    continue;
+
+                // Otherwise, fail.
+                throw Interop.GetExceptionForIoErrno(errorInfo, directoryPath, isDirectory: true);
+            }
+        }
+
         internal static Interop.libc.OpenFlags TranslateFlags(PipeDirection direction, PipeOptions options, HandleInheritability inheritability)
         {
             // Translate direction

src/System.Security.Cryptography.X509Certificates/src/System.Security.Cryptography.X509Certificates.csproj

@@ -219,6 +219,9 @@
     <Compile Include="$(CommonPath)\System\IO\PersistedFiles.Unix.cs">
       <Link>Common\System\IO\PersistedFiles.Unix.cs</Link>
     </Compile>
+    <Compile Include="$(CommonPath)\System\IO\PersistedFiles.Names.Unix.cs">
+      <Link>Common\System\IO\PersistedFiles.Names.Unix.cs</Link>
+    </Compile>
   </ItemGroup>
   <ItemGroup>
     <None Include="project.json" />