Use Mutex to prevent simultaneous SCSS compilation for multi target projects

AspNetCore.SassCompiler.Tasks/CompileSass.cs

@@ -4,8 +4,10 @@
 using System.IO;
 using System.Linq;
 using System.Runtime.Serialization;
+using System.Security.Cryptography;
 using System.Text;
 using System.Text.RegularExpressions;
+using System.Threading;
 using Microsoft.Build.Framework;
 using Microsoft.Build.Utilities;
 
@@ -30,6 +32,10 @@ public string Snapshot
 
         public string Configuration { get; set; }
 
+        public string TargetFramework { get; set; }
+
+        public string TargetFrameworks { get; set; }
+
         [Output]
         public ITaskItem[] GeneratedFiles { get; set; } = Array.Empty<ITaskItem>();
 
@@ -271,6 +277,49 @@ private IEnumerable<ITaskItem> GenerateCss(SassCompilerOptions options)
         }
 
         private (bool Success, string Output, string Error) GenerateCss(string arguments)
+        {
+            if (string.IsNullOrWhiteSpace(TargetFrameworks))
+            {
+                return CompileCss(arguments);
+            }
+
+            var mutexName = GetMutexName();
+
+            Log.LogMessage(MessageImportance.Normal,
+                $"TargetFramework: '{TargetFramework}'; TargetFrameworks: '{TargetFrameworks}'; using mutex {mutexName}");
+
+            using var mutex = new Mutex(false, mutexName);
+
+            try
+            {
+                mutex.WaitOne();
+            }
+            catch (AbandonedMutexException)
+            {
+                return (false, string.Empty, $"Mutex {mutexName} was abandoned");
+            }
+
+            try
+            {
+                return CompileCss(arguments);
+            }
+            finally
+            {
+                mutex.ReleaseMutex();
+            }
+
+            string GetMutexName()
+            {
+                using var sha256 = SHA256.Create();
+
+                var hash = sha256.ComputeHash(Encoding.UTF8.GetBytes(arguments));
+                var hashString = BitConverter.ToString(hash).Replace("-", "");
+
+                return $"{nameof(AspNetCore)}.{nameof(SassCompiler)}_{hashString}";
+            }
+        }
+
+        private (bool Success, string Output, string Error) CompileCss(string arguments)
         {
             var compiler = new Process();
             compiler.StartInfo = new ProcessStartInfo
@@ -290,11 +339,11 @@ private IEnumerable<ITaskItem> GenerateCss(SassCompilerOptions options)
             {
                 error += e.Data + Environment.NewLine;
             };
-            
+
             compiler.Start();
 
             compiler.BeginErrorReadLine();
-            
+
             var output = compiler.StandardOutput.ReadToEnd();
 
             compiler.WaitForExit();

AspNetCore.SassCompiler/build/AspNetCore.SassCompiler.targets

@@ -1,5 +1,5 @@
-<Project>
-  
+<Project>
+
   <PropertyGroup Condition="'$(SassCompilerIncludeRuntime)' == 'true'">
     <SassCompilerEnableWatcher>$(SassCompilerIncludeRuntime)</SassCompilerEnableWatcher>
     <SassCompilerRuntimeCopyToPublishDirectory>PreserveNewest</SassCompilerRuntimeCopyToPublishDirectory>
@@ -12,12 +12,16 @@
   <UsingTask TaskName="AspNetCore.SassCompiler.CompileSass"
              AssemblyFile="$(SassCompilerTasksAssembly)" />
 
-  <Target Name="Compile Sass" BeforeTargets="Build;ResolveScopedCssInputs;BundleMinify;ResolveProjectStaticWebAssets" Condition="'$(DesignTimeBuild)' != 'true'">
+  <Target Name="Compile Sass"
+          BeforeTargets="Build;ResolveScopedCssInputs;BundleMinify;ResolveProjectStaticWebAssets"
+          Condition="'$(DesignTimeBuild)' != 'true'">
     <CompileSass AppsettingsFile="$(SassCompilerAppsettingsJson)"
                  SassCompilerFile="$(SassCompilerSassCompilerJson)"
                  Command="$(SassCompilerBuildCommand)"
                  Snapshot="$(SassCompilerBuildSnapshot)"
-                 Configuration="$(SassCompilerConfiguration)">
+                 Configuration="$(SassCompilerConfiguration)"
+                 TargetFramework="$(TargetFramework)"
+                 TargetFrameworks="$(TargetFrameworks)">
       <Output TaskParameter="GeneratedFiles"
               ItemName="CompiledCssFiles" />
     </CompileSass>