Changeset 116d3f6f in mainline for uspace/lib/libc/generic/fibril.c

Timestamp:

2007-10-03T06:55:56Z (18 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

18525c5

Parents:

5b5d25f

Message:

Rename fibril_schedule_next_adv() to fibril_switch(). Rename
fibril_schedule_next() to fibril_yield(). Some fibril structures could be
uninitialized, set them to zero in fibril_setup(). For some fibrils, the stack
member can be NULL (e.g. every thread's first/main fibril); don't do free on
these stacks when cleaning up after a dead fibril.

File:

• uspace/lib/libc/generic/fibril.c (modified) (9 diffs)

uspace/lib/libc/generic/fibril.c

@@ -76 +76 @@
                 return NULL;
 
-        f = malloc(sizeof(*f));
+        f = malloc(sizeof(fibril_t));
         if (!f) {
                 __free_tls(tcb);
@@ -85 +85 @@
         f->tcb = tcb;
 
+        f->func = NULL;
+        f->arg = NULL;
+        f->stack = NULL;
+        f->clean_after_me = NULL;
+        f->retval = 0;
+        f->flags = 0;
+
         return f;
 }
@@ -107 +114 @@
         f->retval = f->func(f->arg);
 
-        fibril_schedule_next_adv(FIBRIL_FROM_DEAD);
+        fibril_switch(FIBRIL_FROM_DEAD);
         /* not reached */
 }
 
-/** Schedule next fibril.
+/** Switch from the current fibril.
  *
  * If calling with FIBRIL_TO_MANAGER parameter, the async_futex should be
@@ -122 +129 @@
  *                      return 1 otherwise.
  */
-int fibril_schedule_next_adv(fibril_switch_type_t stype)
+int fibril_switch(fibril_switch_type_t stype)
 {
         fibril_t *srcf, *dstf;
@@ -139 +146 @@
                  * managers.
                  */
-                if (list_empty(&serialized_list) && fibrils_in_manager <=
-                    serialized_fibrils) {
+                if (list_empty(&serialized_list) &&
+                    fibrils_in_manager <= serialized_fibrils) {
                         goto ret_0;
                 }
@@ -164 +171 @@
                                  * restored context here.
                                  */
-                                free(srcf->clean_after_me->stack);
+                                void *stack = srcf->clean_after_me->stack; 
+                                if (stack) {
+                                        /*
+                                         * This check is necessary because a
+                                         * thread could have exited like a
+                                         * normal fibril using the
+                                         * FIBRIL_FROM_DEAD switch type. In that
+                                         * case, its fibril will not have the
+                                         * stack member filled.
+                                         */
+                                        free(stack);
+                                }
                                 fibril_teardown(srcf->clean_after_me);
                                 srcf->clean_after_me = NULL;
@@ -185 +203 @@
                 }
         }
-
+        
         /* Choose a new fibril to run */
         if (stype == FIBRIL_TO_MANAGER || stype == FIBRIL_FROM_DEAD) {
@@ -195 +213 @@
                 fibrils_in_manager++;
 
-                if (stype == FIBRIL_FROM_DEAD)
+                if (stype == FIBRIL_FROM_DEAD) 
                         dstf->clean_after_me = srcf;
         } else {
@@ -234 +252 @@
         f->stack = (char *) malloc(FIBRIL_INITIAL_STACK_PAGES_NO *
             getpagesize());
-
         if (!f->stack) {
                 fibril_teardown(f);
                 return 0;
         }
-
+        
+        f->func = func;
         f->arg = arg;
-        f->func = func;
-        f->clean_after_me = NULL;
-        f->retval = 0;
-        f->flags = 0;
 
         context_save(&f->ctx);