WebSVN – HelenOS – Diff – /branches/tracing/uspace/srv/vfs/vfs_register.c

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
 #include <bool.h>
-#include <futex.h>
+#include <fibril_sync.h>
-#include <libadt/list.h>
+#include <adt/list.h>
 #include <as.h>
 #include <assert.h>
 #include <atomic.h>
 #include "vfs.h"
+FIBRIL_CONDVAR_INITIALIZE(fs_head_cv);
-atomic_t fs_head_futex = FUTEX_INITIALIZER;
+FIBRIL_MUTEX_INITIALIZE(fs_head_lock);
-link_t fs_head;
+LIST_INITIALIZE(fs_head);
 atomic_t fs_handle_next = {
     .count = 1
 };
         ipc_answer_0(callid, ENOMEM);
         ipc_answer_0(rid, ENOMEM);
         return;
+    }
     link_initialize(&fs_info->fs_link);
-    futex_initialize(&fs_info->phone_futex, 1);
+    fibril_mutex_initialize(&fs_info->phone_lock);
     rc = ipc_data_write_finalize(callid, &fs_info->vfs_info, size);
     if (rc != EOK) {
         dprintf("Failed to deliver the VFS info into our AS, rc=%d.\n",
             rc);
         ipc_answer_0(callid, EINVAL);
         ipc_answer_0(rid, EINVAL);
         return;
+    }
-    futex_down(&fs_head_futex);
+    fibril_mutex_lock(&fs_head_lock);
-    fibril_inc_sercount();
     /*
      * Check for duplicit registrations.
      */
     if (fs_name_to_handle(fs_info->vfs_info.name, false)) {
         /*
          * We already register a fs like this.
          */
         dprintf("FS is already registered.\n");
-        fibril_dec_sercount();
-        futex_up(&fs_head_futex);
+        fibril_mutex_unlock(&fs_head_lock);
         free(fs_info);
         ipc_answer_0(callid, EEXISTS);
         ipc_answer_0(rid, EEXISTS);
         return;
+    }
      */
     callid = async_get_call(&call);
     if (IPC_GET_METHOD(call) != IPC_M_CONNECT_TO_ME) {
         dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));
         list_remove(&fs_info->fs_link);
-        fibril_dec_sercount();
-        futex_up(&fs_head_futex);
+        fibril_mutex_unlock(&fs_head_lock);
         free(fs_info);
         ipc_answer_0(callid, EINVAL);
         ipc_answer_0(rid, EINVAL);
         return;
+    }
      */
     if (!ipc_share_in_receive(&callid, &size)) {
         dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));
         list_remove(&fs_info->fs_link);
-        fibril_dec_sercount();
-        futex_up(&fs_head_futex);
+        fibril_mutex_unlock(&fs_head_lock);
         ipc_hangup(fs_info->phone);
         free(fs_info);
         ipc_answer_0(callid, EINVAL);
         ipc_answer_0(rid, EINVAL);
         return;
      * We can only send the client address space area PLB_SIZE bytes long.
      */
     if (size != PLB_SIZE) {
         dprintf("Client suggests wrong size of PFB, size = %d\n", size);
         list_remove(&fs_info->fs_link);
-        fibril_dec_sercount();
-        futex_up(&fs_head_futex);
+        fibril_mutex_unlock(&fs_head_lock);
         ipc_hangup(fs_info->phone);
         free(fs_info);
         ipc_answer_0(callid, EINVAL);
         ipc_answer_0(rid, EINVAL);
         return;
      * system a global file system handle.
      */
     fs_info->fs_handle = (fs_handle_t) atomic_postinc(&fs_handle_next);
     ipc_answer_1(rid, EOK, (ipcarg_t) fs_info->fs_handle);
-    fibril_dec_sercount();
+    fibril_condvar_broadcast(&fs_head_cv);
-    futex_up(&fs_head_futex);
+    fibril_mutex_unlock(&fs_head_lock);
     dprintf("\"%.*s\" filesystem successfully registered, handle=%d.\n",
         FS_NAME_MAXLEN, fs_info->vfs_info.name, fs_info->fs_handle);
-    /* Process pending mount requests possibly waiting
-     * for this filesystem implementation.
-     */
-    vfs_process_pending_mount();
+}
 /** For a given file system handle, implement policy for allocating a phone.
+ *
  * @param handle    File system handle.
  * @return      Phone over which a multi-call request can be safely
  *          sent. Return 0 if no phone was found.
  */
 int vfs_grab_phone(fs_handle_t handle)
+{
+    int phone;
     /*
-     * For now, we don't try to be very clever and very fast.
+     * For now, we don't try to be very clever and very fast.  We simply
-     * We simply lookup the phone in the fs_head list. We currently don't
+     * lookup the phone in the fs_head list and duplicate it.  The duplicate
-     * open any additional phones (even though that itself would be pretty
+     * phone will be returned to the client and the client will use it for
-     * straightforward; housekeeping multiple open phones to a FS task would
-     * be more demanding). Instead, we simply take the respective
+     * communication.  In the future, we should cache the connections so
-     * phone_futex and keep it until vfs_release_phone().
+     * that they do not have to be reestablished over and over again.
      */
-    futex_down(&fs_head_futex);
+    fibril_mutex_lock(&fs_head_lock);
     link_t *cur;
     fs_info_t *fs;
     for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
         fs = list_get_instance(cur, fs_info_t, fs_link);
         if (fs->fs_handle == handle) {
-            futex_up(&fs_head_futex);
+            fibril_mutex_unlock(&fs_head_lock);
-            /*
-             * For now, take the futex unconditionally.
-             * Oh yeah, serialization rocks.
+            fibril_mutex_lock(&fs->phone_lock);
-             * It will be up'ed in vfs_release_phone().
+            phone = ipc_connect_me_to(fs->phone, 0, 0, 0);
-             */
-            futex_down(&fs->phone_futex);
+            fibril_mutex_unlock(&fs->phone_lock);
-            /*
-             * Avoid deadlock with other fibrils in the same thread
-             * by disabling fibril preemption.
-             */
-            fibril_inc_sercount();
+            assert(phone > 0);
-            return fs->phone;
+            return phone;
+        }
+    }
-    futex_up(&fs_head_futex);
+    fibril_mutex_unlock(&fs_head_lock);
     return 0;
+}
-/** Tell VFS that the phone is in use for any request.
+/** Tell VFS that the phone is not needed anymore.
+ *
  * @param phone     Phone to FS task.
  */
 void vfs_release_phone(int phone)
+{
-    bool found = false;
-    /*
-     * Undo the fibril_inc_sercount() done in vfs_grab_phone().
+    /* TODO: implement connection caching */
-     */
-    fibril_dec_sercount();
-    futex_down(&fs_head_futex);
-    link_t *cur;
-    for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
-        fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);
-        if (fs->phone == phone) {
+    ipc_hangup(phone);
-            found = true;
-            futex_up(&fs_head_futex);
-            futex_up(&fs->phone_futex);
-            return;
-        }
-    }
-    futex_up(&fs_head_futex);
-    /*
-     * Not good to get here.
-     */
-    assert(found == true);
+}
 /** Convert file system name to its handle.
+ *
  * @param name      File system name.
- * @param lock      If true, the function will down and up the
+ * @param lock      If true, the function will lock and unlock the
- *          fs_head_futex.
+ *          fs_head_lock.
+ *
  * @return      File system handle or zero if file system not found.
  */
 fs_handle_t fs_name_to_handle(char *name, bool lock)
+{
     int handle = 0;
     if (lock)
-        futex_down(&fs_head_futex);
+        fibril_mutex_lock(&fs_head_lock);
     link_t *cur;
     for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
         fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);
         if (str_cmp(fs->vfs_info.name, name) == 0) {
             handle = fs->fs_handle;
             break;
+        }
+    }
     if (lock)
-        futex_up(&fs_head_futex);
+        fibril_mutex_unlock(&fs_head_lock);
     return handle;
+}
 /**
  * @}

Subversion Repositories HelenOS

(root)/branches/tracing/uspace/srv/vfs/vfs_register.c – Rev 4377 → 4692