Changes in kernel/generic/src/ipc/kbox.c [07d4271:fafb8e5] in mainline

File:

• kernel/generic/src/ipc/kbox.c (modified) (7 diffs)

kernel/generic/src/ipc/kbox.c

@@ -90 +90 @@
                 LOG("Join kb.thread.");
                 thread_join(TASK->kb.thread);
+                thread_detach(TASK->kb.thread);
                 LOG("...join done.");
                 TASK->kb.thread = NULL;
@@ -135 +136 @@
                 /* Only detach kbox thread unless already terminating. */
                 if (TASK->kb.finished == false) {
-                        /* Release kbox thread so it gets freed from memory. */
-                        thread_put(TASK->kb.thread);
+                        /* Detach kbox thread so it gets freed from memory. */
+                        thread_detach(TASK->kb.thread);
                         TASK->kb.thread = NULL;
                 }
@@ -200 +201 @@
 /** Connect phone to a task kernel-box specified by id.
  *
+ * Note that this is not completely atomic. For optimisation reasons, the task
+ * might start cleaning up kbox after the phone has been connected and before
+ * a kbox thread has been created. This must be taken into account in the
+ * cleanup code.
+ *
  * @param[out] out_phone  Phone capability handle on success.
  * @return Error code.
@@ -206 +212 @@
 errno_t ipc_connect_kbox(task_id_t taskid, cap_phone_handle_t *out_phone)
 {
+        irq_spinlock_lock(&tasks_lock, true);
+
         task_t *task = task_find_by_id(taskid);
-        if (!task)
+        if (task == NULL) {
+                irq_spinlock_unlock(&tasks_lock, true);
                 return ENOENT;
+        }
+
+        atomic_inc(&task->refcount);
+
+        irq_spinlock_unlock(&tasks_lock, true);
 
         mutex_lock(&task->kb.cleanup_lock);
+
+        if (atomic_predec(&task->refcount) == 0) {
+                mutex_unlock(&task->kb.cleanup_lock);
+                task_destroy(task);
+                return ENOENT;
+        }
 
         if (task->kb.finished) {
                 mutex_unlock(&task->kb.cleanup_lock);
-                task_release(task);
                 return EINVAL;
         }
@@ -225 +244 @@
                 if (!kb_thread) {
                         mutex_unlock(&task->kb.cleanup_lock);
-                        task_release(task);
                         return ENOMEM;
                 }
 
                 task->kb.thread = kb_thread;
-                thread_start(kb_thread);
+                thread_ready(kb_thread);
         }
 
@@ -238 +256 @@
         if (rc != EOK) {
                 mutex_unlock(&task->kb.cleanup_lock);
-                task_release(task);
                 return rc;
         }
@@ -249 +266 @@
 
         mutex_unlock(&task->kb.cleanup_lock);
-        task_release(task);
         *out_phone = phone_handle;
         return EOK;