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-rw-r--r--sys/kern/kern_sx.c46
-rw-r--r--sys/sys/sx.h56
2 files changed, 75 insertions, 27 deletions
diff --git a/sys/kern/kern_sx.c b/sys/kern/kern_sx.c
index 2619f4b..124ebff 100644
--- a/sys/kern/kern_sx.c
+++ b/sys/kern/kern_sx.c
@@ -95,8 +95,8 @@ _sx_slock(struct sx *sx, const char *file, int line)
mtx_lock(&sx->sx_lock);
KASSERT(sx->sx_xholder != curproc,
- ("%s (%s): trying to get slock while xlock is held\n", __FUNCTION__,
- sx->sx_object.lo_name));
+ ("%s (%s): slock while xlock is held @ %s:%d\n", __FUNCTION__,
+ sx->sx_object.lo_name, file, line));
/*
* Loop in case we lose the race for lock acquisition.
@@ -116,6 +116,24 @@ _sx_slock(struct sx *sx, const char *file, int line)
mtx_unlock(&sx->sx_lock);
}
+int
+_sx_try_slock(struct sx *sx, const char *file, int line)
+{
+
+ mtx_lock(&sx->sx_lock);
+ if (sx->sx_cnt >= 0) {
+ sx->sx_cnt++;
+ LOCK_LOG_TRY("SLOCK", &sx->sx_object, 0, 1, file, line);
+ WITNESS_LOCK(&sx->sx_object, LOP_TRYLOCK, file, line);
+ mtx_unlock(&sx->sx_lock);
+ return (1);
+ } else {
+ LOCK_LOG_TRY("SLOCK", &sx->sx_object, 0, 0, file, line);
+ mtx_unlock(&sx->sx_lock);
+ return (0);
+ }
+}
+
void
_sx_xlock(struct sx *sx, const char *file, int line)
{
@@ -152,12 +170,32 @@ _sx_xlock(struct sx *sx, const char *file, int line)
mtx_unlock(&sx->sx_lock);
}
+int
+_sx_try_xlock(struct sx *sx, const char *file, int line)
+{
+
+ mtx_lock(&sx->sx_lock);
+ if (sx->sx_cnt == 0) {
+ sx->sx_cnt--;
+ sx->sx_xholder = curproc;
+ LOCK_LOG_TRY("XLOCK", &sx->sx_object, 0, 1, file, line);
+ WITNESS_LOCK(&sx->sx_object, LOP_EXCLUSIVE | LOP_TRYLOCK, file,
+ line);
+ mtx_unlock(&sx->sx_lock);
+ return (1);
+ } else {
+ LOCK_LOG_TRY("XLOCK", &sx->sx_object, 0, 0, file, line);
+ mtx_unlock(&sx->sx_lock);
+ return (0);
+ }
+}
+
void
_sx_sunlock(struct sx *sx, const char *file, int line)
{
mtx_lock(&sx->sx_lock);
- _SX_ASSERT_SLOCKED(sx);
+ _SX_ASSERT_SLOCKED(sx, file, line);
WITNESS_UNLOCK(&sx->sx_object, 0, file, line);
@@ -186,7 +224,7 @@ _sx_xunlock(struct sx *sx, const char *file, int line)
{
mtx_lock(&sx->sx_lock);
- _SX_ASSERT_XLOCKED(sx);
+ _SX_ASSERT_XLOCKED(sx, file, line);
MPASS(sx->sx_cnt == -1);
WITNESS_UNLOCK(&sx->sx_object, LOP_EXCLUSIVE, file, line);
diff --git a/sys/sys/sx.h b/sys/sys/sx.h
index c3c62b3..f123a3f8 100644
--- a/sys/sys/sx.h
+++ b/sys/sys/sx.h
@@ -50,48 +50,58 @@ void sx_init(struct sx *sx, const char *description);
void sx_destroy(struct sx *sx);
void _sx_slock(struct sx *sx, const char *file, int line);
void _sx_xlock(struct sx *sx, const char *file, int line);
+int _sx_try_slock(struct sx *sx, const char *file, int line);
+int _sx_try_xlock(struct sx *sx, const char *file, int line);
void _sx_sunlock(struct sx *sx, const char *file, int line);
void _sx_xunlock(struct sx *sx, const char *file, int line);
-#define sx_slock(sx) _sx_slock((sx), __FILE__, __LINE__)
-#define sx_xlock(sx) _sx_xlock((sx), __FILE__, __LINE__)
-#define sx_sunlock(sx) _sx_sunlock((sx), __FILE__, __LINE__)
-#define sx_xunlock(sx) _sx_xunlock((sx), __FILE__, __LINE__)
+#define sx_slock(sx) _sx_slock((sx), __FILE__, __LINE__)
+#define sx_xlock(sx) _sx_xlock((sx), __FILE__, __LINE__)
+#define sx_try_slock(sx) _sx_try_slock((sx), __FILE__, __LINE__)
+#define sx_try_xlock(sx) _sx_try_xlock((sx), __FILE__, __LINE__)
+#define sx_sunlock(sx) _sx_sunlock((sx), __FILE__, __LINE__)
+#define sx_xunlock(sx) _sx_xunlock((sx), __FILE__, __LINE__)
#ifdef INVARIANTS
/*
- * SX_ASSERT_SLOCKED() can only detect that at least *some* thread owns an
- * slock, but it cannot guarantee that *this* thread owns an slock.
+ * In the non-WITNESS case, SX_ASSERT_LOCKED() and SX_ASSERT_SLOCKED()
+ * can only detect that at least *some* thread owns an slock, but it cannot
+ * guarantee that *this* thread owns an slock.
*/
-#define SX_ASSERT_SLOCKED(sx) do { \
- mtx_lock(&(sx)->sx_lock); \
- _SX_ASSERT_SLOCKED((sx)); \
- mtx_unlock(&(sx)->sx_lock); \
+#ifdef WITNESS
+#define _SX_ASSERT_LOCKED(sx, file, line) \
+ witness_assert(&(sx)->sx_object, LA_LOCKED, file, line)
+#define _SX_ASSERT_SLOCKED(sx, file, line) \
+ witness_assert(&(sx)->sx_object, LA_SLOCKED, file, line)
+#else
+#define _SX_ASSERT_LOCKED(sx, file, line) do { \
+ KASSERT(((sx)->sx_cnt > 0 || (sx)->sx_xholder == curproc), \
+ ("Lock %s not locked @ %s:%d", (sx)->sx_object.lo_name, \
+ file, line)); \
} while (0)
-#define _SX_ASSERT_SLOCKED(sx) do { \
- KASSERT(((sx)->sx_cnt > 0), ("%s: lacking slock %s\n", \
- __FUNCTION__, (sx)->sx_object.lo_name)); \
+#define _SX_ASSERT_SLOCKED(sx, file, line) do { \
+ KASSERT(((sx)->sx_cnt > 0), ("Lock %s not share locked @ %s:%d",\
+ (sx)->sx_object.lo_name, file, line)); \
} while (0)
+#endif
+#define SX_ASSERT_LOCKED(sx) _SX_ASSERT_LOCKED((sx), __FILE__, __LINE__)
+#define SX_ASSERT_SLOCKED(sx) _SX_ASSERT_SLOCKED((sx), __FILE__, __LINE__)
/*
* SX_ASSERT_XLOCKED() detects and guarantees that *we* own the xlock.
*/
-#define SX_ASSERT_XLOCKED(sx) do { \
- mtx_lock(&(sx)->sx_lock); \
- _SX_ASSERT_XLOCKED((sx)); \
- mtx_unlock(&(sx)->sx_lock); \
-} while (0)
-#define _SX_ASSERT_XLOCKED(sx) do { \
+#define _SX_ASSERT_XLOCKED(sx, file, line) do { \
KASSERT(((sx)->sx_xholder == curproc), \
- ("%s: thread %p lacking xlock %s\n", __FUNCTION__, \
- curproc, (sx)->sx_object.lo_name)); \
+ ("Lock %s not exclusively locked @ %s:%d", \
+ (sx)->sx_object.lo_name, file, line)); \
} while (0)
+#define SX_ASSERT_XLOCKED(sx) _SX_ASSERT_XLOCKED((sx), __FILE__, __LINE__)
#else /* INVARIANTS */
#define SX_ASSERT_SLOCKED(sx)
#define SX_ASSERT_XLOCKED(sx)
-#define _SX_ASSERT_SLOCKED(sx)
-#define _SX_ASSERT_XLOCKED(sx)
+#define _SX_ASSERT_SLOCKED(sx, file, line)
+#define _SX_ASSERT_XLOCKED(sx, file, line)
#endif /* INVARIANTS */
#endif /* _KERNEL */
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