# This patch file was generated by NetBeans IDE
# This patch can be applied using context Tools: Apply Diff Patch action on respective folder.
# It uses platform neutral UTF-8 encoding.
# Above lines and this line are ignored by the patching process.
Index: projects/projectapi/src/org/netbeans/api/project/ProjectManager.java
--- projects/projectapi/src/org/netbeans/api/project/ProjectManager.java Base (1.38)
+++ projects/projectapi/src/org/netbeans/api/project/ProjectManager.java Locally Modified (Based On 1.38)
@@ -41,6 +41,7 @@
 
 package org.netbeans.api.project;
 
+import java.io.File;
 import java.io.IOException;
 import java.lang.ref.Reference;
 import java.util.Arrays;
@@ -50,6 +51,7 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.WeakHashMap;
+import java.util.concurrent.Executor;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import org.netbeans.modules.projectapi.SimpleFileOwnerQueryImplementation;
@@ -61,7 +63,10 @@
 import org.openide.filesystems.FileChangeListener;
 import org.openide.filesystems.FileEvent;
 import org.openide.filesystems.FileObject;
+import org.openide.filesystems.FileStateInvalidException;
+import org.openide.filesystems.FileSystem;
 import org.openide.filesystems.FileUtil;
+import org.openide.util.Exceptions;
 import org.openide.util.Lookup;
 import org.openide.util.LookupEvent;
 import org.openide.util.LookupListener;
@@ -107,7 +112,37 @@
         return DEFAULT;
     }
     
-    private static final Mutex MUTEX = new Mutex();
+    private static final Executor FS_EXEC = new Executor() {
+        public void execute(final Runnable command) {
+            FileSystem fs = null;
+            for (File f : File.listRoots()) {
+                FileObject fo = FileUtil.toFileObject(f);
+                if (fo != null) {
+                    try {
+                        fs = fo.getFileSystem();
+                        break;
+                    } catch (FileStateInvalidException ex) {
+                        LOG.log(Level.WARNING, "Cannot find filesystem for " + f, ex); // NOI18N
+                    }
+                }
+            }
+            
+            if (fs != null) {
+                try {
+                    fs.runAtomicAction(new FileSystem.AtomicAction() {
+                        public void run() throws IOException {
+                            command.run();
+                        }
+                    });
+                } catch (IOException ex) {
+                    throw (IllegalStateException)new IllegalStateException().initCause(ex);
+                }
+            } else {
+                command.run();
+            }
+        }
+    };
+    private static final Mutex MUTEX = new Mutex(new Mutex.Privileged(), FS_EXEC);
     /**
      * Get a read/write lock to be used for all project metadata accesses.
      * All methods relating to recognizing and loading projects, saving them,
Index: projects/projectapi/test/unit/src/org/netbeans/api/project/ProjectManagerTest.java
--- projects/projectapi/test/unit/src/org/netbeans/api/project/ProjectManagerTest.java Base (1.15)
+++ projects/projectapi/test/unit/src/org/netbeans/api/project/ProjectManagerTest.java Locally Modified (Based On 1.15)
@@ -51,7 +51,12 @@
 import java.util.logging.Level;
 import org.netbeans.junit.NbTestCase;
 import org.netbeans.modules.projectapi.TimedWeakReference;
+import org.openide.filesystems.FileAttributeEvent;
+import org.openide.filesystems.FileChangeListener;
+import org.openide.filesystems.FileEvent;
 import org.openide.filesystems.FileObject;
+import org.openide.filesystems.FileRenameEvent;
+import org.openide.util.Mutex;
 import org.openide.util.test.MockLookup;
 
 /* XXX tests needed:
@@ -67,7 +72,8 @@
  * Test ProjectManager find and save functionality.
  * @author Jesse Glick
  */
-public class ProjectManagerTest extends NbTestCase {
+public class ProjectManagerTest extends NbTestCase 
+implements FileChangeListener {
     
     static {
         // For easier testing.
@@ -92,6 +98,9 @@
     protected void setUp() throws Exception {
         super.setUp();
         scratch = TestUtil.makeScratchDir(this);
+        
+        scratch.getFileSystem().addFileChangeListener(this);
+        
         goodproject = scratch.createFolder("good");
         goodproject.createFolder("testproject");
         goodproject2 = scratch.createFolder("good2");
@@ -106,6 +115,8 @@
     }
     
     protected void tearDown() throws Exception {
+        scratch.getFileSystem().removeFileChangeListener(this);
+        
         scratch = null;
         goodproject = null;
         badproject = null;
@@ -343,6 +354,22 @@
         assertNotNull("now p3 is recognized as a non-broken project", pm.findProject(p3));
         assertEquals("p1 still recognized as a project", proj1, pm.findProject(p1));
     }
+    public void testClearNonProjectCacheInWriteAccess() throws Exception {
+        ProjectManager.mutex().writeAccess(new Mutex.ExceptionAction<Void>() {
+            public Void run() throws Exception {
+                testClearNonProjectCache();
+                return null;
+            }
+        });
+    }
+    public void testClearNonProjectCacheInReadAccess() throws Exception {
+        ProjectManager.mutex().readAccess(new Mutex.ExceptionAction<Void>() {
+            public Void run() throws Exception {
+                testClearNonProjectCache();
+                return null;
+            }
+        });
+    }
     
     public void testLoadExceptionWithConcurrentLoad() throws Exception {
         TestUtil.BROKEN_PROJECT_LOAD_LOCK = new Object();
@@ -473,4 +500,32 @@
         assertTrue("An IllegalStateException was thrown when calling notifyDeleted twice.", wasException);
     }
     
+    private void assertNoAccess() {
+        assertFalse("No read access", ProjectManager.mutex().isReadAccess());
+        assertFalse("No write access", ProjectManager.mutex().isWriteAccess());
 }
+    
+    public void fileFolderCreated(FileEvent fe) {
+        assertNoAccess();
+    }
+
+    public void fileDataCreated(FileEvent fe) {
+        assertNoAccess();
+    }
+
+    public void fileChanged(FileEvent fe) {
+        assertNoAccess();
+    }
+
+    public void fileDeleted(FileEvent fe) {
+        assertNoAccess();
+    }
+
+    public void fileRenamed(FileRenameEvent fe) {
+        assertNoAccess();
+    }
+
+    public void fileAttributeChanged(FileAttributeEvent fe) {
+        assertNoAccess();
+    }
+}