Changeset a66e2993 in mainline for uspace/lib/c/generic/fibril_synch.c

Timestamp:

2010-11-05T16:16:57Z (14 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

0485135, 60898b6

Parents:

f4057f5 (diff), 55bd76c (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge from lp:~jakub/helenos/deadlock-detection.

File:

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

uspace/lib/c/generic/fibril_synch.c

@@ -58 +58 @@
 }
 
-static bool check_for_deadlock(fibril_owner_info_t *oi)
-{
-        while (oi && oi->owned_by) {
-                if (oi->owned_by == (fibril_t *) fibril_get_id())
-                        return true;
-                oi = oi->owned_by->waits_for;
-        }
-
-        return false;
-}
-
 static void print_deadlock(fibril_owner_info_t *oi)
 {
@@ -89 +78 @@
                 oi = oi->owned_by->waits_for;
         }
-
-        abort();
-}
+}
+
+
+static void check_for_deadlock(fibril_owner_info_t *oi)
+{
+        while (oi && oi->owned_by) {
+                if (oi->owned_by == (fibril_t *) fibril_get_id()) {
+                        print_deadlock(oi);
+                        abort();
+                }
+                oi = oi->owned_by->waits_for;
+        }
+}
+
 
 void fibril_mutex_initialize(fibril_mutex_t *fm)
@@ -113 +113 @@
                 link_initialize(&wdata.wu_event.link);
                 list_append(&wdata.wu_event.link, &fm->waiters);
-
-                if (check_for_deadlock(&fm->oi))
-                        print_deadlock(&fm->oi);
+                check_for_deadlock(&fm->oi);
                 f->waits_for = &fm->oi;
-
                 fibril_switch(FIBRIL_TO_MANAGER);
         } else {
@@ -194 +191 @@
                 f->flags &= ~FIBRIL_WRITER;
                 list_append(&wdata.wu_event.link, &frw->waiters);
+                check_for_deadlock(&frw->oi);
+                f->waits_for = &frw->oi;
                 fibril_switch(FIBRIL_TO_MANAGER);
         } else {
@@ -203 +202 @@
 void fibril_rwlock_write_lock(fibril_rwlock_t *frw)
 {
+        fibril_t *f = (fibril_t *) fibril_get_id();
+        
         futex_down(&async_futex);
         if (frw->writers || frw->readers) {
-                fibril_t *f = (fibril_t *) fibril_get_id();
                 awaiter_t wdata;
 
@@ -214 +214 @@
                 f->flags |= FIBRIL_WRITER;
                 list_append(&wdata.wu_event.link, &frw->waiters);
+                check_for_deadlock(&frw->oi);
+                f->waits_for = &frw->oi;
                 fibril_switch(FIBRIL_TO_MANAGER);
         } else {
+                frw->oi.owned_by = f;
                 frw->writers++;
                 futex_up(&async_futex);
@@ -233 +236 @@
         
         assert(!frw->readers && !frw->writers);
+        
+        frw->oi.owned_by = NULL;
         
         while (!list_empty(&frw->waiters)) {
@@ -241 +246 @@
                 wdp = list_get_instance(tmp, awaiter_t, wu_event.link);
                 f = (fibril_t *) wdp->fid;
+                
+                f->waits_for = NULL;
                 
                 if (f->flags & FIBRIL_WRITER) {
@@ -250 +257 @@
                         fibril_add_ready(wdp->fid);
                         frw->writers++;
+                        frw->oi.owned_by = f;
                         optimize_execution_power();
                         break;