X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Forg%2Fvamsas%2Fclient%2Fsimpleclient%2FClientsFile.java;h=d0fe34034e9ebc01be2ffe05dddab7cad3b5fee7;hb=37e460acf0f82dfb3dfeeb022a84f737759921ba;hp=8f938f6569aa64b4e3fbbded18ec0165a0546da0;hpb=60d3fb8b4c31842b601284e79906e8f8bc63c4f8;p=vamsas.git

diff --git a/src/org/vamsas/client/simpleclient/ClientsFile.java b/src/org/vamsas/client/simpleclient/ClientsFile.java
index 8f938f6..d0fe340 100644
--- a/src/org/vamsas/client/simpleclient/ClientsFile.java
+++ b/src/org/vamsas/client/simpleclient/ClientsFile.java
@@ -17,7 +17,7 @@ import java.io.OutputStream;
 import java.util.Vector;
 
 /**
- * @author jim Handler for the clientsFile within a vamsas session.
+ * @author jim Handler for the clientsFile within a vamsas session thread.
  */
 public class ClientsFile {
   private File filelist;
@@ -36,24 +36,36 @@ public class ClientsFile {
 
   private Lock listlock = null;
 
+  protected boolean lockList(Lock extantlock) {
+    if (listlock!=null && !listlock.isLocked()) {
+      listlock.release();// tidy up invalid lock
+    }
+    listlock=extantlock;
+    return lockList();
+  }
   /**
    * Get a lock for the ClientsFile
    * 
    * @return true if lock was made
    */
   protected boolean lockList() {
-    if (listlock != null && listlock.isLocked())
-      return true;
+    if (listlock != null)
+      if (listlock.isLocked())
+        return true;
+      else 
+        // lock failed for some reason.
+        listlock.release();
     listlock = null;
     if (filelist != null) {
       if (filelist.exists()) {
         // TODO: see if we need to loop-wait for locks or they just block until
         // lock is made...
-        // do {
-        // listlock = new Lock(filelist); // TODO: wait around if we can't get
-        // the lock.
-        // } while (!listlock.isLocked());
-        listlock = new Lock(filelist);
+        do {
+          if (listlock!=null)
+            listlock.release();
+          listlock = new Lock(filelist); // TODO: wait around if we can't get the lock.
+        } while (!listlock.isLocked());
+        // listlock = new Lock(filelist);
         return listlock.isLocked();
       }
     } else
@@ -69,22 +81,11 @@ public class ClientsFile {
    * 
    * @return true if lock was released.
    */
-  protected boolean unlockList() {
+  protected void unlockList() {
     if (listlock != null) {
-
-      if (listlock.isLocked()) {
-        try {
-          listlock.lock.release();
-        } catch (IOException e) {
-          // TODO Deal with unlock Lock.release exception!
-          e.printStackTrace(System.err);
-        }
-      }
-
+      listlock.release();    
       listlock = null;
-      return true;
     }
-    return false;
   }
 
   /**
@@ -122,18 +123,57 @@ public class ClientsFile {
     return null;
   }
   /**
-   * get the clientList from the file. May return false if lock failed!
+   * get the clientList from the file. May return null if lock failed!
    * @return clientList
    */
   public ClientHandle[] retrieveClientList() {
     if (lockList()) {
       ClientHandle[] clients = retrieveClientHandles();
-      if (unlockList())
-        return clients;
+      unlockList();
+      return clients;
     }
     return null;
   }
-
+  /**
+   * get list from the locked ClientList.
+   * @param extantlock
+   * @return clientList or null if lock failed (or file was empty)
+   */
+  public ClientHandle[] retrieveClientList(Lock extantlock) {
+    if (lockList(extantlock)) {
+      ClientHandle[] clients = retrieveClientHandles();
+      unlockList();
+      return clients;
+    }
+    return null;
+  }
+  /**
+   * adds clientHandle me to the clientList under an existing lock extantLock.
+   * @param me
+   * @param extantLock
+   * @return client index in list or 0 if lock was invalid or addClient operation failed.
+   */
+  public int addClient(ClientHandle me, Lock extantLock) {
+    return addClient(me, true, extantLock);
+  }
+  
+  /**
+   * adds clientHandle me to the clientList under an existing lock.
+   * @param me - clientHandle
+   * @param disambig - if true then add will fail if an identical clientHandle already exists
+   * @param extantLock - existing lock
+   * @return client index in list or 0 if addClient (or the lock) failed.
+   */
+  
+  public int addClient(ClientHandle me, boolean disambig, Lock extantLock) {
+    if (lockList(extantLock)) {
+      syncnum = addClient(me, disambig);
+      unlockList();
+      return syncnum;
+    }
+    return 0;
+  }
+  
   /**
    * adds the ClientHandle to the list - if it is not unique, then the
    * ClientHandle object is modified to make it unique in the list. returns the
@@ -151,14 +191,15 @@ public class ClientsFile {
 
   /**
    * removes 'me' from the session ClientList without complaint if 'me' isn't in the clientList already.
-   * @param me
+   * @param me client handle to be removed
+   * @param clientlock existing lock passed from watcher.
    */
-  public void removeClient(ClientHandle me) {
+  public void removeClient(ClientHandle me, Lock clientlock) {
     int mynum=-1;
-    if (lockList()) {
+    if (lockList(clientlock)) {
       ClientHandle[] clients = retrieveClientHandles();
       if (clients != null) {
-        if (clients[syncnum-1]!=me) {
+        if ((syncnum<=0 || syncnum>clients.length) || clients[syncnum-1]!=me) {
           for (int i = 0, j = clients.length; i < j; i++) 
             if (clients[i].equals(me)) {
               mynum=i;
@@ -172,7 +213,7 @@ public class ClientsFile {
           for (int k=0,i = 0, j = clients.length; i < j; i++)
             if (i!=mynum)
               newlist[k++] = clients[i];
-          if (!putClientList(clients))
+          if (!putClientList(newlist))
             throw new Error("Failed to write new clientList!"); // failed to put the clientList to disk.
         }
       }
@@ -187,7 +228,7 @@ public class ClientsFile {
    * Note: Caller is left to release the lock on the ClientList.
    * @param me
    * @param disambiguate -
-   *          flag indicating if the URN for me should be disambiguate to
+   *          flag indicating if the URN for me should be disambiguated to
    *          differentiate between sessions.
    * @return index of clientHandle in new list, or -1-position of existing
    *         clientHandle (if disambiguate is true)