Changeset fc02cc41 in mainline for uspace/srv/devmap/devmap.c

Timestamp:

2009-06-10T19:15:00Z (15 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

ba2a055

Parents:

95ba2b8

Message:

get back fine-grained locking (which was removed in commit 4458), but this time with proper fibril synchronization

File:

• uspace/srv/devmap/devmap.c (modified) (25 diffs)

uspace/srv/devmap/devmap.c

@@ -42 +42 @@
 #include <errno.h>
 #include <bool.h>
+#include <fibril_sync.h>
 #include <stdlib.h>
 #include <string.h>
@@ -62 +63 @@
         /** Device driver name */
         char *name;
+        /** Fibril mutex for list of devices owned by this driver */
+        fibril_mutex_t devices_mutex;
 } devmap_driver_t;
 
@@ -92 +95 @@
 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_MUTEX_INITIALIZE(drivers_list_mutex);
+static FIBRIL_MUTEX_INITIALIZE(create_handle_mutex);
+
 static dev_handle_t last_handle = 0;
 
@@ -100 +114 @@
          */
         
+        fibril_mutex_lock(&create_handle_mutex);
         last_handle++;
+        fibril_mutex_unlock(&create_handle_mutex);
         
         return last_handle;
@@ -134 +150 @@
 static devmap_device_t *devmap_device_find_handle(dev_handle_t handle)
 {
+        fibril_mutex_lock(&devices_list_mutex);
+        
         link_t *item = (&devices_list)->next;
         devmap_device_t *device = NULL;
@@ -144 +162 @@
         }
         
-        if (item == &devices_list)
+        if (item == &devices_list) {
+                fibril_mutex_unlock(&devices_list_mutex);
                 return NULL;
+        }
         
         device = list_get_instance(item, devmap_device_t, devices);
+        
+        fibril_mutex_unlock(&devices_list_mutex);
         
         return device;
@@ -236 +258 @@
         driver->name[name_size] = 0;
         
+        /* Initialize mutex for list of devices owned by this driver */
+        fibril_mutex_initialize(&driver->devices_mutex);
+        
         /*
          * Initialize list of asociated devices
          */
-        list_initialize(&(driver->devices));
+        list_initialize(&driver->devices);
         
         /*
@@ -262 +287 @@
         list_initialize(&(driver->drivers));
         
+        fibril_mutex_lock(&drivers_list_mutex);
+        
         /* TODO:
          * check that no driver with name equal to driver->name is registered
@@ -270 +297 @@
          */
         list_append(&(driver->drivers), &drivers_list);
+        fibril_mutex_unlock(&drivers_list_mutex);
         
         ipc_answer_0(iid, EOK);
@@ -286 +314 @@
                 return EEXISTS;
         
+        fibril_mutex_lock(&drivers_list_mutex);
+        
         if (driver->phone != 0)
                 ipc_hangup(driver->phone);
@@ -291 +321 @@
         /* Remove it from list of drivers */
         list_remove(&(driver->drivers));
+        
+        /* Unregister all its devices */
+        fibril_mutex_lock(&devices_list_mutex);
+        fibril_mutex_lock(&driver->devices_mutex);
         
         while (!list_empty(&(driver->devices))) {
@@ -298 +332 @@
         }
         
+        fibril_mutex_unlock(&driver->devices_mutex);
+        fibril_mutex_unlock(&devices_list_mutex);
+        fibril_mutex_unlock(&drivers_list_mutex);
+        
         /* free name and driver */
         if (driver->name != NULL)
@@ -311 +349 @@
 static void process_pending_lookup(void)
 {
-        async_serialize_start();
-        
         link_t *cur;
         
@@ -331 +367 @@
                 goto loop;
         }
-        
-        async_serialize_end();
 }
 
@@ -386 +420 @@
         list_initialize(&(device->driver_devices));
         
+        fibril_mutex_lock(&devices_list_mutex);
+        
         /* Check that device with such name is not already registered */
         if (NULL != devmap_device_find_name(device->name)) {
                 printf(NAME ": Device '%s' already registered\n", device->name);
+                fibril_mutex_unlock(&devices_list_mutex);
                 free(device->name);
                 free(device);
@@ -403 +440 @@
         list_append(&device->devices, &devices_list);
         
+        /* Insert device into list of devices that belog to one driver */
+        fibril_mutex_lock(&device->driver->devices_mutex);
+        
         list_append(&device->driver_devices, &device->driver->devices);
+        
+        fibril_mutex_unlock(&device->driver->devices_mutex);
+        fibril_mutex_unlock(&devices_list_mutex);
         
         ipc_answer_1(iid, EOK, device->handle);
@@ -556 +599 @@
 static void devmap_get_count(ipc_callid_t iid, ipc_call_t *icall)
 {
+        fibril_mutex_lock(&devices_list_mutex);
         ipc_answer_1(iid, EOK, list_count(&devices_list));
+        fibril_mutex_unlock(&devices_list_mutex);
 }
 
 static void devmap_get_devices(ipc_callid_t iid, ipc_call_t *icall)
 {
+        fibril_mutex_lock(&devices_list_mutex);
+        
         ipc_callid_t callid;
         size_t size;
@@ -604 +651 @@
         free(desc);
         
+        fibril_mutex_unlock(&devices_list_mutex);
+        
         ipc_answer_1(iid, EOK, pos);
 }
@@ -627 +676 @@
         list_initialize(&(device->driver_devices));
         
+        fibril_mutex_lock(&devices_list_mutex);
+        
         /* Get unique device handle */
         device->handle = devmap_create_handle();
@@ -633 +684 @@
         /* Insert device into list of all devices  */
         list_append(&device->devices, &devices_list);
+        
+        fibril_mutex_unlock(&devices_list_mutex);
         
         return true;
@@ -656 +709 @@
                 ipc_callid_t callid = async_get_call(&call);
                 
-                async_serialize_start();
-                
                 switch (IPC_GET_METHOD(call)) {
                 case IPC_M_PHONE_HUNGUP:
                         cont = false;
-                        async_serialize_end();
                         continue;
                 case DEVMAP_DRIVER_UNREGISTER:
@@ -687 +737 @@
                                 ipc_answer_0(callid, ENOENT);
                 }
-                
-                async_serialize_end();
         }
         
@@ -695 +743 @@
                  * Unregister the device driver and all its devices.
                  */
-                
-                async_serialize_start();
-                
                 devmap_driver_unregister(driver);
                 driver = NULL;
-                
-                async_serialize_end();
         }
 }
@@ -718 +761 @@
                 ipc_callid_t callid = async_get_call(&call);
                 
-                async_serialize_start();
-                
                 switch (IPC_GET_METHOD(call)) {
                 case IPC_M_PHONE_HUNGUP:
                         cont = false;
-                        async_serialize_end();
                         continue;
                 case DEVMAP_DEVICE_GET_HANDLE:
@@ -741 +781 @@
                                 ipc_answer_0(callid, ENOENT);
                 }
-                
-                async_serialize_end();
         }
 }