Optimize blinear closed file cleanup logic

shiroha-server/src/main/java/io/nanachiyo0721/shiroha/data/BufferedLinearRegionFile.java

@@ -459,6 +459,9 @@ public class BufferedLinearRegionFile implements io.nanachiyo0721.shiroha.data.R
                         return;
                     }
 
+                    // remove from flusher
+                    this.markClosed();
+
                     IOException failure = null;
 
                     // final sync so no buffered data is lost; holding syncLock also guarantees no
@@ -473,8 +476,6 @@ public class BufferedLinearRegionFile implements io.nanachiyo0721.shiroha.data.R
                     }
 
                     try {
-                        this.markClosed();
-
                         this.swapFileChannel.close();
                     } catch (IOException ex) {
                         if (failure == null) failure = ex;
@@ -488,9 +489,6 @@ public class BufferedLinearRegionFile implements io.nanachiyo0721.shiroha.data.R
                         else failure.addSuppressed(e);
                     }
 
-                    // finalize
-                    this.markClosed();
-
                     if (failure != null) {
                         throw failure;
                     }

shiroha-server/src/main/java/io/nanachiyo0721/shiroha/data/BufferedLinearRegionFileFlusher.java

@@ -62,7 +62,6 @@ public class BufferedLinearRegionFileFlusher implements Runnable {
             copied = this.inManagement.toArray(new BufferedLinearRegionFile[0]);
         }
 
-        final List<BufferedLinearRegionFile> toRemove = new ObjectArrayList<>();
         for (BufferedLinearRegionFile file : copied) {
             // try acquiring the read lock
             if (!file.softReadLock()) {
@@ -80,8 +79,7 @@ public class BufferedLinearRegionFileFlusher implements Runnable {
             }
 
             if (closed) {
-                // add to pending remove list so that we could clean the closed file correctly
-                toRemove.add(file);
+                // closed already, should be removed soon
                 continue;
             }
 
@@ -109,13 +107,6 @@ public class BufferedLinearRegionFileFlusher implements Runnable {
                 });
             }
         }
-
-        synchronized (this) {
-            // clean closed files
-            for (BufferedLinearRegionFile file : toRemove) {
-                this.inManagement.remove(file);
-            }
-        }
     }
 
     public void removeFile(BufferedLinearRegionFile fileToRemove) {