Changeset 80649a91 in mainline for libc/generic/psthread.c

Timestamp:

2006-05-21T19:28:37Z (19 years ago)

Author:

Ondrej Palkovsky <ondrap@…>

Branches:

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

Children:

a410beb

Parents:

1ee11f4

Message:

Merged libadt into libc.
Made lot of psthread and thread stuff thread-safe.
Added new driver framework for easy C connection programming.
Changed FB code to use new API.

File:

• libc/generic/psthread.c (modified) (9 diffs)

libc/generic/psthread.c

@@ -34 +34 @@
 #include <stdio.h>
 #include <kernel/arch/faddr.h>
-
+#include <futex.h>
+#include <assert.h>
 
 #ifndef PSTHREAD_INITIAL_STACK_PAGES_NO
@@ -41 +42 @@
 
 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 *pt;
+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;
         }
@@ -63 +73 @@
 void psthread_teardown(psthread_data_t *pt)
 {
+        __free_tls(pt->tcb);
         free(pt);
 }
@@ -73 +84 @@
         psthread_data_t *pt;
 
-        if (list_empty(&ready_list)) {
-                /* Wait on IPC queue etc... */
-                printf("Cannot exit!!!\n");
+        futex_down(&psthread_futex);
+
+        if (!list_empty(&ready_list))
+                pt = list_get_instance(ready_list.next, psthread_data_t, link);
+        else if (!list_empty(&manager_list)) 
+                pt = list_get_instance(manager_list.next, psthread_data_t, link);
+        else {
+                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 */
 }
 
@@ -99 +117 @@
 /** 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)
-{
-        psthread_data_t *pt;
-
-        if (list_empty(&ready_list))
-                return 0;
+int psthread_schedule_next_adv(pschange_type ctype)
+{
+        psthread_data_t *pt;
+        int retval = 0;
+        
+        futex_down(&psthread_futex);
+
+        if (ctype == PS_PREEMPT && list_empty(&ready_list))
+                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;
+        if (!context_save(&pt->ctx)) 
+                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);
         
-        list_append(&pt->link, &ready_list);
-        pt = list_get_instance(ready_list.next, psthread_data_t, link);
+        if (ctype == PS_TO_MANAGER)
+                pt = list_get_instance(manager_list.next,psthread_data_t, link);
+        else
+                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;
 }
 
@@ -143 +184 @@
 
         free(pt->stack);
-        __free_tls(pt->tcb);
         psthread_teardown((void *)pt);
 
@@ -150 +190 @@
 
 /**
- * Create a userspace thread and append it to ready list.
+ * Create a userspace thread
  *
  * @param func Pseudo thread function.
@@ -160 +200 @@
 {
         psthread_data_t *pt;
-        tcb_t *tcb;
-
-        tcb = __make_tls();
-        if (!tcb)
+
+        pt = psthread_setup();
+        if (!pt) 
                 return 0;
-
-        pt = psthread_setup(tcb);
-        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;
@@ -186 +218 @@
         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);
-
-        return (pstid_t )pt;
-}
+        futex_up(&psthread_futex);
+}
+
+/** Add a thread to manager list */
+void psthread_add_manager(pstid_t psthrid)
+{
+        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);
+}