#5273 Returned to use named mutex, because the named semaphore doesn'…

…t support bu UNIX based systems

src/Libraries/Nop.Services/Media/PictureService.cs

@@ -578,21 +578,23 @@ public virtual async Task<string> GetPictureSeNameAsync(string name)
             if (await GeneratedThumbExistsAsync(thumbFilePath, thumbFileName))
                 return (await GetThumbUrlAsync(thumbFileName, storeLocation), picture);
 
-            //the named semaphore helps to avoid creating the same files in different threads,
+            //the named mutex helps to avoid creating the same files in different threads,
             //and does not decrease performance significantly, because the code is blocked only for the specific file.
-            using (var semaphore = new Semaphore(1, 1, thumbFileName))
+            //you should be very careful, mutexes cannot be used in with the await operation
+            //we can't use semaphore here, because it produces PlatformNotSupportedException exception on UNIX based systems
+            using (var mutex = new Mutex(false, thumbFileName))
             {
-                semaphore.WaitOne();
+                mutex.WaitOne();
 
                 try
                 {
                     //check, if the file was created, while we were waiting for the release of the mutex.
-                    if (!await GeneratedThumbExistsAsync(thumbFilePath, thumbFileName))
+                    if (!GeneratedThumbExistsAsync(thumbFilePath, thumbFileName).Result)
                     {
-                        pictureBinary ??= await LoadPictureBinaryAsync(picture);
+                        pictureBinary ??= LoadPictureBinaryAsync(picture).Result;
 
                         if ((pictureBinary?.Length ?? 0) == 0)
-                            return showDefaultPicture ? (await GetDefaultPictureUrlAsync(targetSize, defaultPictureType, storeLocation), picture) : (string.Empty, picture);
+                            return showDefaultPicture ? (GetDefaultPictureUrlAsync(targetSize, defaultPictureType, storeLocation).Result, picture) : (string.Empty, picture);
 
                         byte[] pictureBinaryResized;
                         if (targetSize != 0)
@@ -605,18 +607,18 @@ public virtual async Task<string> GetPictureSeNameAsync(string name)
                                 Size = CalculateDimensions(image.Size(), targetSize)
                             }));
 
-                            pictureBinaryResized = await EncodeImageAsync(image, imageFormat);
+                            pictureBinaryResized = EncodeImageAsync(image, imageFormat).Result;
                         }
                         else
                             //create a copy of pictureBinary
                             pictureBinaryResized = pictureBinary.ToArray();
 
-                        await SaveThumbAsync(thumbFilePath, thumbFileName, picture.MimeType, pictureBinaryResized);
+                        SaveThumbAsync(thumbFilePath, thumbFileName, picture.MimeType, pictureBinaryResized).Wait();
                     }
                 }
                 finally
                 {
-                    semaphore.Release();
+                    mutex.ReleaseMutex();
                 }
             }
 

src/Libraries/Nop.Services/Media/RoxyFileman/DatabaseRoxyFilemanService.cs

@@ -278,11 +278,13 @@ protected virtual async Task SavePictureByVirtualPathAsync(Picture picture, int
             if (_fileProvider.FileExists(thumbFilePath))
                 return;
 
-            //the named semaphore helps to avoid creating the same files in different threads,
+            //the named mutex helps to avoid creating the same files in different threads,
             //and does not decrease performance significantly, because the code is blocked only for the specific file.
-            using var semaphore = new Semaphore(1, 1, thumbFileName);
+            //you should be very careful, mutexes cannot be used in with the await operation
+            //we can't use semaphore here, because it produces PlatformNotSupportedException exception on UNIX based systems
+            using var mutex = new Mutex(false, thumbFileName);
 
-            semaphore.WaitOne();
+            mutex.WaitOne();
 
             try
             {
@@ -302,7 +304,7 @@ protected virtual async Task SavePictureByVirtualPathAsync(Picture picture, int
                             Size = CalculateDimensions(size, targetSize)
                         }));
 
-                        pictureBinaryResized = await EncodeImageAsync(image, imageFormat);
+                        pictureBinaryResized = EncodeImageAsync(image, imageFormat).Result;
                     }
                     else
                     {
@@ -311,12 +313,12 @@ protected virtual async Task SavePictureByVirtualPathAsync(Picture picture, int
                     }
 
                     //save
-                    await _fileProvider.WriteAllBytesAsync(thumbFilePath, pictureBinaryResized);
+                    _fileProvider.WriteAllBytesAsync(thumbFilePath, pictureBinaryResized).Wait();
                 }
             }
             finally
             {
-                semaphore.Release();
+                mutex.ReleaseMutex();
             }
         }