[GNUnet-SVN] r21366 - gnunet/src/lockmanager

[gnunet]

Author: harsha
Date: 2012-05-09 09:09:30 +0200 (Wed, 09 May 2012)
New Revision: 21366

Modified:
   gnunet/src/lockmanager/gnunet-service-lockmanager.c
Log:
added list processing

Modified: gnunet/src/lockmanager/gnunet-service-lockmanager.c
===================================================================
--- gnunet/src/lockmanager/gnunet-service-lockmanager.c 2012-05-08 22:42:02 UTC 
(rev 21365)
+++ gnunet/src/lockmanager/gnunet-service-lockmanager.c 2012-05-09 07:09:30 UTC 
(rev 21366)
@@ -26,6 +26,7 @@
 
 #include "platform.h"
 #include "gnunet_common.h"
+#include "gnunet_container_lib.h"
 #include "gnunet_protocols.h"
 #include "gnunet_service_lib.h"
 #include "gnunet_server_lib.h"
@@ -42,7 +43,323 @@
 
 #define TIMEOUT TIME_REL_MINS(3)
 
+
 /**
+ * Doubly linked list of clients waiting for a lock
+ */
+struct WaitList
+{
+  /**
+   * The next client structure
+   */
+  struct WaitList *next;
+  
+  /**
+   * The prev client structure
+   */
+  struct WaitList *prev;
+
+  /**
+   * Pointer to the client
+   */
+  struct GNUNET_SERVER_Client *client;
+};
+
+
+/**
+ * A Lock element for a doubly linked list
+ */
+struct LockList
+{
+  /**
+   * The next element pointer
+   */
+  struct LockList *next;
+
+  /**
+   * Pointer to the previous element
+   */
+  struct LockList *prev;
+
+  /**
+   * The client whizch is currently holding this lock
+   */
+  struct GNUNET_SERVER_Client *client;
+
+  /**
+   * List head of clients waiting for this lock
+   */
+  struct WaitList *wait_list_head;
+
+  /**
+   * List tail of clients waiting for this lock
+   */
+  struct WaitList *wait_list_tail;
+
+  /**
+   * The name of the locking domain this lock belongs to
+   */
+  char *domain_name;
+
+  /**
+   * The number of this lock
+   */
+  uint32_t lock_num;
+};
+
+
+/**
+ * Doubly linked list of clients having connections to us
+ */
+struct ClientList
+{
+  /**
+   * The next client structure
+   */
+  struct ClientList *next;
+
+  /**
+   * The previous client structure
+   */
+  struct ClientList *prev;
+
+  /**
+   * Pointer to the client
+   */
+  struct GNUNET_SERVER_Client *client;
+};
+
+
+/**
+ * Head of the doubly linked list of the currently held locks
+ */
+static struct LockList *ll_head;
+
+/**
+ * Tail of the doubly linked list of the currently held locks
+ */
+static struct LockList *ll_tail;
+
+/**
+ * Head of the doubly linked list of clients currently connected
+ */
+static struct ClientList *cl_head;
+
+/**
+ * Tail of the doubly linked list of clients currently connected
+ */
+static struct ClientList *cl_tail;
+
+
+
+/**
+ * Function to search for a lock in lock_list matching the given domain_name 
and
+ * lock number
+ *
+ * @param domain_name the name of the locking domain
+ * @param lock_num the number of the lock
+ * @param ret this will be the pointer to the corresponding Lock if found; else
+ *         it will be the last element in the locks list
+ * @return GNUNET_YES if a matching lock is present in lock_list; GNUNET_NO if 
not
+ */
+static int
+ll_find_lock (const char *domain_name,
+           const uint32_t lock_num,
+           struct LockList **ret)
+{
+  struct LockList *current_lock;
+
+  current_lock = ll_head;
+  
+  while (NULL != current_lock)
+    {
+      if ( (0 == strcmp (domain_name, current_lock->domain_name))
+           && (lock_num == current_lock->lock_num))
+        {
+          *ret = current_lock;
+          return GNUNET_YES;
+        }
+
+      current_lock = current_lock->next;
+    }
+  
+  *ret = current_lock;
+  return GNUNET_NO;
+}
+
+
+/**
+ * Function to append a lock to the global lock list
+ *
+ * @param domain_name the name of the locking domain
+ * @param domain_name_len the length of the domain name
+ * @param lock_num the number of the lock
+ * @param tail the pointer to the tail of the global lock list
+ */
+static void
+ll_add_lock (const char *domain_name,
+          size_t domain_name_len,
+          const uint32_t lock_num)
+{
+  struct LockList *lock;
+
+  lock = GNUNET_malloc (sizeof (struct LockList));
+  lock->domain_name = GNUNET_malloc (domain_name_len);
+  strncpy (lock->domain_name, domain_name, domain_name_len);
+  lock->lock_num = lock_num;
+  
+  GNUNET_CONTAINER_DLL_insert_tail (ll_head,
+                                    ll_tail,
+                                    lock);
+}
+
+
+/**
+ * Function to delete a lock from the lock list
+ *
+ * @param lock the lock to be deleted
+ */
+static void
+ll_remove_lock (struct LockList *lock)
+{
+  GNUNET_assert (NULL != ll_head);
+  GNUNET_CONTAINER_DLL_remove (ll_head,
+                               ll_tail,
+                               lock);
+  GNUNET_free (lock->domain_name);
+  GNUNET_free (lock);
+}
+
+
+/**
+ * Find a client in the waiting list of a lock
+ *
+ * @param lock the LockList entry of a lock
+ * @param client the client to look for
+ * @param ret where to store the matched wait list entry
+ * @return GNUNET_YES if a match is found; GNUNET_NO if not
+ */
+static int
+ll_wl_find_client (struct LockList *lock,
+                   const struct GNUNET_SERVER_Client *client,
+                   struct WaitList **ret)
+{
+  struct WaitList *current_wl_entry;
+
+  current_wl_entry = lock->wait_list_head;
+
+  while (NULL != current_wl_entry)
+    {
+      if (client == current_wl_entry->client)
+        {
+          *ret = current_wl_entry;
+          return GNUNET_YES;
+        }
+      current_wl_entry = current_wl_entry->next;
+    }
+  *ret = current_wl_entry;
+  return GNUNET_NO;
+}
+
+
+/**
+ * Add a client to the wait list of a lock
+ *
+ * @param lock the lock list entry of a lock
+ * @param client the client to queue for the lock's wait list
+ */
+static void
+ll_wl_add_client (struct LockList *lock,
+                  struct GNUNET_SERVER_Client *client)
+{
+  struct WaitList *wl_entry;
+
+  wl_entry = GNUNET_malloc (sizeof (struct WaitList));
+  wl_entry->client = client;
+  GNUNET_CONTAINER_DLL_insert_tail (lock->wait_list_head,
+                                    lock->wait_list_tail,
+                                    wl_entry);
+}
+
+
+static void
+ll_wl_remove_client (struct LockList *lock,
+                     struct WaitList *wl_client)
+{
+  GNUNET_CONTAINER_DLL_remove (lock->wait_list_head,
+                               lock->wait_list_tail,
+                               wl_client);
+
+  GNUNET_free (wl_client);
+}
+
+
+/**
+ * Search for a client in the client list
+ *
+ * @param client the client to be searched for
+ * @param ret will be pointing to the matched list entry (if there is a match);
+ *          else to the tail of the client list
+ * @return GNUNET_YES if the client is present; GNUNET_NO if not
+ */
+static int
+cl_find_client (const struct GNUNET_SERVER_Client *client,
+                struct ClientList **ret)
+{
+  struct ClientList *current;
+
+  current = cl_head;
+
+  while (NULL != current)
+    {
+      if (client == current->client)
+        {
+          *ret = current;
+          return GNUNET_YES;
+        }
+
+      current = current->next;
+    }
+  
+  *ret = current;
+  return GNUNET_NO;
+}
+
+
+/**
+ * Append a client to the client list
+ *
+ * @param client the client to be appended to the list
+ */
+static void
+cl_add_client (struct GNUNET_SERVER_Client *client)
+{
+  struct ClientList *new_client;
+
+  new_client = GNUNET_malloc (sizeof (struct ClientList));
+  new_client->client = client;
+  GNUNET_CONTAINER_DLL_insert_tail (cl_head,
+                                    cl_tail,
+                                    new_client);
+}
+
+
+/**
+ * Delete the given client from the client list
+ *
+ * @param client the client list entry to delete
+ */
+static void
+cl_remove_client (struct ClientList *client)
+{
+  GNUNET_CONTAINER_DLL_remove (cl_head,
+                               cl_tail,
+                               client);
+  GNUNET_free (client);
+}
+
+
+/**
  * Transmit notify for sending message to client
  *
  * @param cls the message to send