WebSVN – HelenOS – Diff – /trunk/kernel/generic/src/ipc/kbox.c

 /*
  * Copyright (c) 2008 Jiri Svoboda
  * All rights reserved.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
+ *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  * - Redistributions in binary form must reproduce the above copyright
  *   notice, this list of conditions and the following disclaimer in the
  *   documentation and/or other materials provided with the distribution.
  * - The name of the author may not be used to endorse or promote products
  *   derived from this software without specific prior written permission.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 /** @addtogroup genericipc
  * @{
  */
 /** @file
  */
 #include <synch/synch.h>
 #include <synch/spinlock.h>
 #include <synch/mutex.h>
 #include <ipc/ipc.h>
 #include <ipc/ipcrsc.h>
 #include <arch.h>
 #include <errno.h>
 #include <debug.h>
 #include <udebug/udebug_ipc.h>
 #include <ipc/kbox.h>
 void ipc_kbox_cleanup(void)
+{
     ipl_t ipl;
     bool have_kb_thread;
     /* Only hold kb_cleanup_lock while setting kb_finished - this is enough */
     mutex_lock(&TASK->kb_cleanup_lock);
     TASK->kb_finished = true;
     mutex_unlock(&TASK->kb_cleanup_lock);
     have_kb_thread = (TASK->kb_thread != NULL);
     /* From now on nobody will try to connect phones or attach kbox threads */
     /*
      * Disconnect all phones connected to our kbox. Passing true for
      * notify_box causes a HANGUP message to be inserted for each
      * disconnected phone. This ensures the kbox thread is going to
      * wake up and terminate.
      */
     ipc_answerbox_slam_phones(&TASK->kernel_box, have_kb_thread);
     /*
      * If the task was being debugged, clean up debugging session.
      * This is necessarry as slamming the phones won't force
      * kbox thread to clean it up since sender != debugger.
      */
     ipl = interrupts_disable();
     spinlock_lock(&TASK->lock);
     udebug_task_cleanup(TASK);
     spinlock_unlock(&TASK->lock);
     interrupts_restore(ipl);
     if (have_kb_thread) {
         LOG("join kb_thread..\n");
         thread_join(TASK->kb_thread);
         thread_detach(TASK->kb_thread);
         LOG("join done\n");
         TASK->kb_thread = NULL;
+    }
     /* Answer all messages in 'calls' and 'dispatched_calls' queues */
     spinlock_lock(&TASK->kernel_box.lock);
     ipc_cleanup_call_list(&TASK->kernel_box.dispatched_calls);
     ipc_cleanup_call_list(&TASK->kernel_box.calls);
     spinlock_unlock(&TASK->kernel_box.lock);
+}
+/** Handle hangup message in kbox.
+ *
+ * @param call  The IPC_M_PHONE_HUNGUP call structure.
+ * @param last  Output, the function stores @c true here if
+ *      this was the last phone, @c false otherwise.
+ **/
+static void kbox_proc_phone_hungup(call_t *call, bool *last)
+{
+    ipl_t ipl;
+    LOG("kbox_proc_phone_hungup()\n");
+    /* Was it our debugger, who hung up? */
+    if (call->sender == TASK->udebug.debugger) {
+        /* Terminate debugging session (if any) */
+        LOG("kbox: terminate debug session\n");
+        ipl = interrupts_disable();
+        spinlock_lock(&TASK->lock);
+        udebug_task_cleanup(TASK);
+        spinlock_unlock(&TASK->lock);
+        interrupts_restore(ipl);
+    } else {
+        LOG("kbox: was not debugger\n");
+    }
+    LOG("kbox: continue with hangup message\n");
+    IPC_SET_RETVAL(call->data, 0);
+    ipc_answer(&TASK->kernel_box, call);
+    ipl = interrupts_disable();
+    spinlock_lock(&TASK->lock);
+    spinlock_lock(&TASK->answerbox.lock);
+    if (list_empty(&TASK->answerbox.connected_phones)) {
+        /*
+         * Last phone has been disconnected. Detach this thread so it
+         * gets freed and signal to the caller.
+         */
+        /* Only detach kbox thread unless already terminating. */
+        mutex_lock(&TASK->kb_cleanup_lock);
+        if (&TASK->kb_finished == false) {
+            /* Detach kbox thread so it gets freed from memory. */
+            thread_detach(TASK->kb_thread);
+            TASK->kb_thread = NULL;
+        }
+        mutex_unlock(&TASK->kb_cleanup_lock);
+        LOG("phone list is empty\n");
+        *last = true;
+    } else {
+        *last = false;
+    }
+    spinlock_unlock(&TASK->answerbox.lock);
+    spinlock_unlock(&TASK->lock);
+    interrupts_restore(ipl);
+}
+/** Implementing function for the kbox thread.
+ *
+ * This function listens for debug requests. It terminates
+ * when all phones are disconnected from the kbox.
+ *
+ * @param arg   Ignored.
+ */
 static void kbox_thread_proc(void *arg)
+{
     call_t *call;
-    int method;
     bool done;
-    ipl_t ipl;
     (void)arg;
     LOG("kbox_thread_proc()\n");
     done = false;
     while (!done) {
         call = ipc_wait_for_call(&TASK->kernel_box, SYNCH_NO_TIMEOUT,
             SYNCH_FLAGS_NONE);
-        if (call != NULL) {
+        if (call == NULL)
+            continue;   /* Try again. */
-            method = IPC_GET_METHOD(call->data);
+        switch (IPC_GET_METHOD(call->data)) {
-            if (method == IPC_M_DEBUG_ALL) {
+        case IPC_M_DEBUG_ALL:
+            /* Handle debug call. */
-                udebug_call_receive(call);
+            udebug_call_receive(call);
-            }
+            break;
-            if (method == IPC_M_PHONE_HUNGUP) {
+        case IPC_M_PHONE_HUNGUP:
-                LOG("kbox: handle hangup message\n");
-                /* Was it our debugger, who hung up? */
-                if (call->sender == TASK->udebug.debugger) {
-                    /* Terminate debugging session (if any) */
-                    LOG("kbox: terminate debug session\n");
-                    ipl = interrupts_disable();
-                    spinlock_lock(&TASK->lock);
-                    udebug_task_cleanup(TASK);
-                    spinlock_unlock(&TASK->lock);
-                    interrupts_restore(ipl);
-                } else {
-                    LOG("kbox: was not debugger\n");
-                }
+            /*
-                LOG("kbox: continue with hangup message\n");
+             * Process the hangup call. If this was the last
-                IPC_SET_RETVAL(call->data, 0);
-                ipc_answer(&TASK->kernel_box, call);
+             * phone, done will be set to true and the
-                ipl = interrupts_disable();
+             * while loop will terminate.
-                spinlock_lock(&TASK->lock);
-                spinlock_lock(&TASK->answerbox.lock);
-                if (list_empty(&TASK->answerbox.connected_phones)) {
-                    /*
+             */
-                     * Last phone has been disconnected.
+            kbox_proc_phone_hungup(call, &done);
-                     * Detach this thread so it gets
-                     * freed and terminate.
-                     */
+            break;
-                    /* Only need to detach thread unless already terminating. */
-                    mutex_lock(&TASK->kb_cleanup_lock);
-                    if (&TASK->kb_finished == false) {
-                        /* Detach thread so it gets freed. */
-                        thread_detach(TASK->kb_thread);
-                        TASK->kb_thread = NULL;
-                    }
+        default:
-                    mutex_unlock(&TASK->kb_cleanup_lock);
-                    done = true;
+            /* Ignore */
-                    LOG("phone list is empty\n");
-                }
+            break;
-                spinlock_unlock(&TASK->answerbox.lock);
-                spinlock_unlock(&TASK->lock);
-                interrupts_restore(ipl);
-            }
+        }
+    }
     LOG("kbox: finished\n");
+}
 /**
  * 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.
+ *
  * @return      Phone id on success, or negative error code.
  */
 int ipc_connect_kbox(task_id_t taskid)
+{
     int newphid;
     task_t *ta;
     thread_t *kb_thread;
     ipl_t ipl;
     ipl = interrupts_disable();
     spinlock_lock(&tasks_lock);
     ta = task_find_by_id(taskid);
     if (ta == NULL) {
         spinlock_unlock(&tasks_lock);
         interrupts_restore(ipl);
         return ENOENT;
+    }
     atomic_inc(&ta->refcount);
     spinlock_unlock(&tasks_lock);
     interrupts_restore(ipl);
     mutex_lock(&ta->kb_cleanup_lock);
     if (atomic_predec(&ta->refcount) == 0) {
         mutex_unlock(&ta->kb_cleanup_lock);
         task_destroy(ta);
         return ENOENT;
+    }
     if (ta->kb_finished != false) {
         mutex_unlock(&ta->kb_cleanup_lock);
         return EINVAL;
+    }
     newphid = phone_alloc();
     if (newphid < 0) {
         mutex_unlock(&ta->kb_cleanup_lock);
         return ELIMIT;
+    }
     /* Connect the newly allocated phone to the kbox */
     ipc_phone_connect(&TASK->phones[newphid], &ta->kernel_box);
     if (ta->kb_thread != NULL) {
         mutex_unlock(&ta->kb_cleanup_lock);
         return newphid;
+    }
     /* Create a kbox thread */
     kb_thread = thread_create(kbox_thread_proc, NULL, ta, 0, "kbox", false);
     if (!kb_thread) {
         mutex_unlock(&ta->kb_cleanup_lock);
         return ENOMEM;
+    }
     ta->kb_thread = kb_thread;
     thread_ready(kb_thread);
     mutex_unlock(&ta->kb_cleanup_lock);
     return newphid;
+}
 /** @}
  */

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/ipc/kbox.c @ 3870 – Rev 3495 → 3496