Changeset b0a76d5 in mainline

Timestamp:

2010-12-21T15:23:31Z (14 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

c81b6f2

Parents:

be942bc

Message:

Add interfaces for partial enforcement of locking protocols in userspace:

• fibril_mutex_is_locked()
• fibril_rwlock_is_read_locked()
• fibril_rwlock_is_write_locked()

Location:

uspace/lib/c

Files:

• generic/fibril_synch.c (modified) (6 diffs)
• include/fibril_synch.h (modified) (2 diffs)

uspace/lib/c/generic/fibril_synch.c

@@ -139 +139 @@
 static void _fibril_mutex_unlock_unsafe(fibril_mutex_t *fm)
 {
-        assert(fm->counter <= 0);
         if (fm->counter++ < 0) {
                 link_t *tmp;
@@ -165 +164 @@
 void fibril_mutex_unlock(fibril_mutex_t *fm)
 {
+        assert(fibril_mutex_is_locked(fm));
         futex_down(&async_futex);
         _fibril_mutex_unlock_unsafe(fm);
         futex_up(&async_futex);
+}
+
+bool fibril_mutex_is_locked(fibril_mutex_t *fm)
+{
+        bool locked = false;
+        
+        futex_down(&async_futex);
+        if (fm->counter <= 0) 
+                locked = true;
+        futex_up(&async_futex);
+        
+        return locked;
 }
 
@@ -230 +242 @@
 {
         futex_down(&async_futex);
-        assert(frw->readers || (frw->writers == 1));
         if (frw->readers) {
                 if (--frw->readers) {
@@ -296 +307 @@
 void fibril_rwlock_read_unlock(fibril_rwlock_t *frw)
 {
+        assert(fibril_rwlock_is_read_locked(frw));
         _fibril_rwlock_common_unlock(frw);
 }
@@ -301 +313 @@
 void fibril_rwlock_write_unlock(fibril_rwlock_t *frw)
 {
+        assert(fibril_rwlock_is_write_locked(frw));
         _fibril_rwlock_common_unlock(frw);
+}
+
+bool fibril_rwlock_is_read_locked(fibril_rwlock_t *frw)
+{
+        bool locked = false;
+
+        futex_down(&async_futex);
+        if (frw->readers)
+                locked = true;
+        futex_up(&async_futex);
+
+        return locked;
+}
+
+bool fibril_rwlock_is_write_locked(fibril_rwlock_t *frw)
+{
+        bool locked = false;
+
+        futex_down(&async_futex);
+        if (frw->writers) {
+                assert(frw->writers == 1);
+                locked = true;
+        }
+        futex_up(&async_futex);
+
+        return locked;
 }
 
@@ -314 +353 @@
 {
         awaiter_t wdata;
+
+        assert(fibril_mutex_is_locked(fm));
 
         if (timeout < 0)

uspace/lib/c/include/fibril_synch.h

@@ -105 +105 @@
 extern bool fibril_mutex_trylock(fibril_mutex_t *);
 extern void fibril_mutex_unlock(fibril_mutex_t *);
+extern bool fibril_mutex_is_locked(fibril_mutex_t *);
 
 extern void fibril_rwlock_initialize(fibril_rwlock_t *);
@@ -111 +112 @@
 extern void fibril_rwlock_read_unlock(fibril_rwlock_t *);
 extern void fibril_rwlock_write_unlock(fibril_rwlock_t *);
+extern bool fibril_rwlock_is_read_locked(fibril_rwlock_t *);
+extern bool fibril_rwlock_is_write_locked(fibril_rwlock_t *);
 
 extern void fibril_condvar_initialize(fibril_condvar_t *);