WebSVN – HelenOS – Diff – //branches/dd/uspace/srv/devmap/devmap.c

 #include <fibril_sync.h>
 #include <stdlib.h>
 #include <string.h>
 #include <ipc/devmap.h>
-#define NAME  "devmap"
+#define NAME          "devmap"
+#define NULL_DEVICES  256
 /** Representation of device driver.
+ *
  * Each driver is responsible for a set of devices.
+ *
     char *name;
     /** Device driver handling this device */
     devmap_driver_t *driver;
 } devmap_device_t;
-/** Pending lookup structure. */
-typedef struct {
-    link_t link;
-    char *name;              /**< Device name */
-    ipc_callid_t callid;     /**< Call ID waiting for the lookup */
-} pending_req_t;
 LIST_INITIALIZE(devices_list);
 LIST_INITIALIZE(drivers_list);
-LIST_INITIALIZE(pending_req);
 /* Locking order:
  *  drivers_list_mutex
  *  devices_list_mutex
  *  (devmap_driver_t *)->devices_mutex
  *  create_handle_mutex
  **/
 static FIBRIL_MUTEX_INITIALIZE(devices_list_mutex);
+static FIBRIL_CONDVAR_INITIALIZE(devices_list_cv);
 static FIBRIL_MUTEX_INITIALIZE(drivers_list_mutex);
 static FIBRIL_MUTEX_INITIALIZE(create_handle_mutex);
+static FIBRIL_MUTEX_INITIALIZE(null_devices_mutex);
 static dev_handle_t last_handle = 0;
+static devmap_device_t *null_devices[NULL_DEVICES];
 static dev_handle_t devmap_create_handle(void)
+{
     /* TODO: allow reusing old handles after their unregistration
      * and implement some version of LRU algorithm, avoid overflow
     return device;
+}
 /**
- *
  * Unregister device and free it. It's assumed that driver's device list is
  * already locked.
- *
  */
 static int devmap_device_unregister_core(devmap_device_t *device)
+{
     list_remove(&(device->devices));
     list_remove(&(device->driver_devices));
     return EOK;
+}
 /**
- *
  * Read info about new driver and add it into linked list of registered
  * drivers.
- *
  */
 static void devmap_driver_register(devmap_driver_t **odriver)
+{
     *odriver = NULL;
     free(driver);
     return EOK;
+}
-/** Process pending lookup requests */
-static void process_pending_lookup(void)
-{
-    link_t *cur;
-loop:
-    for (cur = pending_req.next; cur != &pending_req; cur = cur->next) {
-        pending_req_t *pr = list_get_instance(cur, pending_req_t, link);
-        const devmap_device_t *dev = devmap_device_find_name(pr->name);
-        if (!dev)
-            continue;
-        ipc_answer_1(pr->callid, EOK, dev->handle);
-        free(pr->name);
-        list_remove(cur);
-        free(pr);
-        goto loop;
-    }
-}
 /** Register instance of device
+ *
  */
 static void devmap_device_register(ipc_callid_t iid, ipc_call_t *icall,
     devmap_driver_t *driver)
     fibril_mutex_lock(&device->driver->devices_mutex);
     list_append(&device->driver_devices, &device->driver->devices);
     fibril_mutex_unlock(&device->driver->devices_mutex);
+    fibril_condvar_broadcast(&devices_list_cv);
     fibril_mutex_unlock(&devices_list_mutex);
     ipc_answer_1(iid, EOK, device->handle);
+}
         free(name);
         return;
+    }
     name[size] = '\0';
+    fibril_mutex_lock(&devices_list_mutex);
+    const devmap_device_t *dev;
+recheck:
     /*
-     * Find device name in linked list of known devices.
+     * Find device name in the list of known devices.
      */
-    const devmap_device_t *dev = devmap_device_find_name(name);
+    dev = devmap_device_find_name(name);
     /*
      * Device was not found.
      */
     if (dev == NULL) {
         if (IPC_GET_ARG1(*icall) & IPC_FLAG_BLOCKING) {
-            /* Blocking lookup, add to pending list */
+            /* Blocking lookup */
-            pending_req_t *pr = (pending_req_t *) malloc(sizeof(pending_req_t));
-            if (!pr) {
-                ipc_answer_0(iid, ENOMEM);
+            fibril_condvar_wait(&devices_list_cv,
-                free(name);
+                &devices_list_mutex);
-                return;
+            goto recheck;
-            }
-            pr->name = name;
-            pr->callid = iid;
-            list_append(&pr->link, &pending_req);
-            return;
+        }
         ipc_answer_0(iid, ENOENT);
         free(name);
+        fibril_mutex_unlock(&devices_list_mutex);
         return;
+    }
+    fibril_mutex_unlock(&devices_list_mutex);
     ipc_answer_1(iid, EOK, dev->handle);
     free(name);
+}
     fibril_mutex_unlock(&devices_list_mutex);
     ipc_answer_1(iid, EOK, pos);
+}
-/** Initialize device mapper.
- *
- *
- */
-static bool devmap_init()
+static void devmap_null_create(ipc_callid_t iid, ipc_call_t *icall)
+{
+    fibril_mutex_lock(&null_devices_mutex);
+    unsigned int i;
+    bool fnd = false;
+    for (i = 0; i < NULL_DEVICES; i++) {
+        if (null_devices[i] == NULL) {
+            fnd = true;
+            break;
+        }
+    }
+    if (!fnd) {
+        fibril_mutex_unlock(&null_devices_mutex);
+        ipc_answer_0(iid, ENOMEM);
+        return;
+    }
     /* Create NULL device entry */
     devmap_device_t *device = (devmap_device_t *) malloc(sizeof(devmap_device_t));
-    if (device == NULL)
+    if (device == NULL) {
+        fibril_mutex_unlock(&null_devices_mutex);
+        ipc_answer_0(iid, ENOMEM);
-        return false;
+        return;
+    }
+    char null[DEVMAP_NAME_MAXLEN];
+    snprintf(null, DEVMAP_NAME_MAXLEN, "null%u", i);
-    device->name = str_dup("null");
+    device->name = str_dup(null);
     if (device->name == NULL) {
+        fibril_mutex_unlock(&null_devices_mutex);
         free(device);
+        ipc_answer_0(iid, ENOMEM);
-        return false;
+        return;
+    }
     list_initialize(&(device->devices));
     list_initialize(&(device->driver_devices));
     /* Get unique device handle */
     device->handle = devmap_create_handle();
     device->driver = NULL;
-    /* Insert device into list of all devices  */
+    /* Insert device into list of all devices
+       and into null devices array */
     list_append(&device->devices, &devices_list);
+    null_devices[i] = device;
     fibril_mutex_unlock(&devices_list_mutex);
+    fibril_mutex_unlock(&null_devices_mutex);
+    ipc_answer_1(iid, EOK, (ipcarg_t) i);
+}
+static void devmap_null_destroy(ipc_callid_t iid, ipc_call_t *icall)
+{
+    fibril_mutex_lock(&null_devices_mutex);
+    ipcarg_t i = IPC_GET_ARG1(*icall);
+    if (null_devices[i] == NULL) {
+        ipc_answer_0(iid, ENOENT);
+        return;
+    }
+    devmap_device_unregister_core(null_devices[i]);
+    null_devices[i] = NULL;
+    fibril_mutex_unlock(&null_devices_mutex);
+    ipc_answer_0(iid, EOK);
+}
+/** Initialize device mapper.
+ *
+ *
+ */
+static bool devmap_init(void)
+{
+    fibril_mutex_lock(&null_devices_mutex);
+    unsigned int i;
+    for (i = 0; i < NULL_DEVICES; i++)
+        null_devices[i] = NULL;
+    fibril_mutex_unlock(&null_devices_mutex);
     return true;
+}
 /** Handle connection with device driver.
             if (!(callid & IPC_CALLID_NOTIFICATION))
                 ipc_answer_0(callid, ENOENT);
+        }
+    }
-    if (NULL != driver) {
+    if (driver != NULL) {
         /*
          * Unregister the device driver and all its devices.
          */
         devmap_driver_unregister(driver);
         driver = NULL;
             devmap_get_handle(callid, &call);
             break;
         case DEVMAP_DEVICE_GET_NAME:
             devmap_get_name(callid, &call);
             break;
+        case DEVMAP_DEVICE_NULL_CREATE:
+            devmap_null_create(callid, &call);
+            break;
+        case DEVMAP_DEVICE_NULL_DESTROY:
+            devmap_null_destroy(callid, &call);
+            break;
         case DEVMAP_DEVICE_GET_COUNT:
             devmap_get_count(callid, &call);
             break;
         case DEVMAP_DEVICE_GET_DEVICES:
             devmap_get_devices(callid, &call);
     if (!devmap_init()) {
         printf(NAME ": Error while initializing service\n");
         return -1;
+    }
-    /* Set a handler of incomming connections and
+    /* Set a handler of incomming connections */
-       pending operations */
-    async_set_pending(process_pending_lookup);
     async_set_client_connection(devmap_connection);
     /* Register device mapper at naming service */
     ipcarg_t phonead;
     if (ipc_connect_to_me(PHONE_NS, SERVICE_DEVMAP, 0, 0, &phonead) != 0)

Subversion Repositories HelenOS

(root)//branches/dd/uspace/srv/devmap/devmap.c – Rev 4537 → 4668