WebSVN – HelenOS-historic – Diff – /uspace/trunk/libc/generic/psthread.c

 /*
  * Copyright (C) 2006 Ondrej Palkovsky
  * 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.
  */
 #include <libadt/list.h>
 #include <psthread.h>
 #include <malloc.h>
 #include <unistd.h>
 #include <thread.h>
 #include <stdio.h>
 #include <kernel/arch/faddr.h>
+#include <futex.h>
+#include <assert.h>
 #ifndef PSTHREAD_INITIAL_STACK_PAGES_NO
 #define PSTHREAD_INITIAL_STACK_PAGES_NO 1
 #endif
 static LIST_INITIALIZE(ready_list);
+static LIST_INITIALIZE(manager_list);
 static void psthread_exit(void) __attribute__ ((noinline));
 static void psthread_main(void);
+static atomic_t psthread_futex = FUTEX_INITIALIZER;
 /** Setup PSthread information into TCB structure */
-psthread_data_t * psthread_setup(tcb_t *tcb)
+psthread_data_t * psthread_setup()
+{
     psthread_data_t *pt;
+    tcb_t *tcb;
+    tcb = __make_tls();
+    if (!tcb)
+        return NULL;
     pt = malloc(sizeof(*pt));
     if (!pt) {
+        __free_tls(tcb);
         return NULL;
+    }
     tcb->pst_data = pt;
     pt->tcb = tcb;
     return pt;
+}
 void psthread_teardown(psthread_data_t *pt)
+{
+    __free_tls(pt->tcb);
     free(pt);
+}
 /** Function to preempt to other pseudo thread without adding
  * currently running pseudo thread to ready_list.
  */
 void psthread_exit(void)
+{
     psthread_data_t *pt;
+    futex_down(&psthread_futex);
-    if (list_empty(&ready_list)) {
+    if (!list_empty(&ready_list))
+        pt = list_get_instance(ready_list.next, psthread_data_t, link);
-        /* Wait on IPC queue etc... */
+    else if (!list_empty(&manager_list))
+        pt = list_get_instance(manager_list.next, psthread_data_t, link);
+    else {
-        printf("Cannot exit!!!\n");
+        printf("Cannot find suitable psthread to run.\n");
         _exit(0);
+    }
-    pt = list_get_instance(ready_list.next, psthread_data_t, link);
     list_remove(&pt->link);
+    futex_up(&psthread_futex);
     context_restore(&pt->ctx);
+    /* Never reached */
+}
 /** Function that is called on entry to new uspace thread */
 void psthread_main(void)
+{
     psthread_data_t *pt = __tcb_get()->pst_data;
     pt->retval = pt->func(pt->arg);
     pt->finished = 1;
     if (pt->waiter)
         list_append(&pt->waiter->link, &ready_list);
     psthread_exit();
+}
 /** Schedule next userspace pseudo thread.
+ *
+ * @param tomanager If true, we are switching to next ready manager thread
+ *                  (if none is found, thread is exited)
+ * @param frommanager If true, we are switching from manager thread
  * @return 0 if there is no ready pseudo thread, 1 otherwise.
  */
-int psthread_schedule_next(void)
+int psthread_schedule_next_adv(pschange_type ctype)
+{
     psthread_data_t *pt;
+    int retval = 0;
+    futex_down(&psthread_futex);
-    if (list_empty(&ready_list))
+    if (ctype == PS_PREEMPT && list_empty(&ready_list))
-        return 0;
+        goto ret_0;
+    if (ctype == PS_FROM_MANAGER && list_empty(&ready_list)) {
+        goto ret_0;
+    }
+    assert(!(ctype == PS_TO_MANAGER && list_empty(&manager_list)));
     pt = __tcb_get()->pst_data;
     if (!context_save(&pt->ctx))
-        return 1;
+        return 1; // futex_up already done here
+    if (ctype == PS_PREEMPT)
+        list_append(&pt->link, &ready_list);
+    else if (ctype == PS_FROM_MANAGER)
+        list_append(&pt->link, &manager_list);
+    if (ctype == PS_TO_MANAGER)
-    list_append(&pt->link, &ready_list);
+        pt = list_get_instance(manager_list.next,psthread_data_t, link);
+    else
-    pt = list_get_instance(ready_list.next, psthread_data_t, link);
+        pt = list_get_instance(ready_list.next, psthread_data_t, link);
     list_remove(&pt->link);
+    futex_up(&psthread_futex);
     context_restore(&pt->ctx);
+ret_0:
+    futex_up(&psthread_futex);
+    return retval;
+}
 /** Wait for uspace pseudo thread to finish.
+ *
  * @param psthrid Pseudo thread to wait for.
+ *
  * @return Value returned by the finished thread.
  */
 int psthread_join(pstid_t psthrid)
+{
     volatile psthread_data_t *pt, *mypt;
     volatile int retval;
     /* Handle psthrid = Kernel address -> it is wait for call */
     pt = (psthread_data_t *) psthrid;
     if (!pt->finished) {
         mypt = __tcb_get()->pst_data;
         if (context_save(&((psthread_data_t *) mypt)->ctx)) {
             pt->waiter = (psthread_data_t *) mypt;
             psthread_exit();
+        }
+    }
     retval = pt->retval;
     free(pt->stack);
-    __free_tls(pt->tcb);
     psthread_teardown((void *)pt);
     return retval;
+}
 /**
- * Create a userspace thread and append it to ready list.
+ * Create a userspace thread
+ *
  * @param func Pseudo thread function.
  * @param arg Argument to pass to func.
+ *
  * @return 0 on failure, TLS of the new pseudo thread.
  */
 pstid_t psthread_create(int (*func)(void *), void *arg)
+{
     psthread_data_t *pt;
-    tcb_t *tcb;
-    tcb = __make_tls();
-    if (!tcb)
-        return 0;
-    pt = psthread_setup(tcb);
+    pt = psthread_setup();
-    if (!pt) {
+    if (!pt)
-        __free_tls(tcb);
         return 0;
-    }
     pt->stack = (char *) malloc(PSTHREAD_INITIAL_STACK_PAGES_NO*getpagesize());
     if (!pt->stack) {
-        __free_tls(tcb);
         psthread_teardown(pt);
         return 0;
+    }
     pt->arg= arg;
     pt->func = func;
     pt->finished = 0;
     pt->waiter = NULL;
     context_save(&pt->ctx);
     context_set(&pt->ctx, FADDR(psthread_main), pt->stack, PSTHREAD_INITIAL_STACK_PAGES_NO*getpagesize(),
-            tcb);
+            pt->tcb);
+    return (pstid_t )pt;
+}
+/** Add a thread to ready list */
+void psthread_add_ready(pstid_t psthrid)
+{
+    psthread_data_t *pt;
+    pt = (psthread_data_t *) psthrid;
+    futex_down(&psthread_futex);
     list_append(&pt->link, &ready_list);
+    futex_up(&psthread_futex);
+}
+/** Add a thread to manager list */
+void psthread_add_manager(pstid_t psthrid)
+{
-    return (pstid_t )pt;
+    psthread_data_t *pt;
+    pt = (psthread_data_t *) psthrid;
+    futex_down(&psthread_futex);
+    list_append(&pt->link, &manager_list);
+    futex_up(&psthread_futex);
+}
+/** Remove one manager from manager list */
+void psthread_remove_manager()
+{
+    futex_down(&psthread_futex);
+    if (list_empty(&manager_list)) {
+        printf("No manager found!.\n");
+        futex_up(&psthread_futex);
+        return;
+    }
+    list_remove(manager_list.next);
+    futex_up(&psthread_futex);
+}

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/libc/generic/psthread.c @ 1653 – Rev 1155 → 1392