[ovs-dev] [PATCH] compiler: Add OVS_ACQ_BEFORE, OVS_ACQ_AFTER macros.
Ben Pfaff
blp at nicira.com
Fri Aug 9 19:34:33 UTC 2013
An upcoming patch will add the first uses.
Signed-off-by: Ben Pfaff <blp at nicira.com>
---
This will be used by a revision of the netdev patch 27/27
that I am about to send out.
lib/compiler.h | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/lib/compiler.h b/lib/compiler.h
index 94a2218..2ca81bd 100644
--- a/lib/compiler.h
+++ b/lib/compiler.h
@@ -65,6 +65,16 @@
* while the specific MUTEX is held.
*
*
+ * On a variable A of mutex type:
+ *
+ * - OVS_ACQ_BEFORE(B), where B is a mutex or a comma-separated list of
+ * mutexes, declare that if both A and B are acquired at the same time,
+ * then A must be acquired before B. That is, B nests inside A.
+ *
+ * - OVS_ACQ_AFTER(B) is the opposite of OVS_ACQ_BEFORE(B), that is, it
+ * declares that A nests inside B.
+ *
+ *
* On a function, the following attributes apply to mutexes:
*
* - OVS_ACQUIRES(MUTEX) indicate that the function must be called without
@@ -84,6 +94,7 @@
* - OVS_LOCKS_EXCLUDED(MUTEX) indicates that the function may only be
* called when MUTEX is not held.
*
+ *
* The following variants, with the same syntax, apply to reader-writer locks:
*
* mutex rwlock, for reading rwlock, for writing
@@ -115,6 +126,8 @@
#define OVS_GUARDED_BY(...) __attribute__((guarded_by(__VA_ARGS__)))
#define OVS_RELEASES(...) __attribute__((unlock_function(__VA_ARGS__)))
#define OVS_EXCLUDED(...) __attribute__((locks_excluded(__VA_ARGS__)))
+#define OVS_ACQ_BEFORE(...) __attribute__((acquired_before(__VA_ARGS__)))
+#define OVS_ACQ_AFTER(...) __attribute__((acquired_after(__VA_ARGS__)))
#elif __CHECKER__
/* "sparse" annotations for mutexes and mutex-like constructs.
*
@@ -136,6 +149,8 @@
#define OVS_GUARDED_BY(...)
#define OVS_EXCLUDED(...)
#define OVS_RELEASES(...) __attribute__((context(MUTEX, 1, 0)))
+#define OVS_ACQ_BEFORE(...)
+#define OVS_ACQ_AFTER(...)
#define OVS_MACRO_LOCK(...) __context__(MUTEX, 0, 1)
#define OVS_MACRO_RELEASE(...) __context__(MUTEX, 1, 0)
#else
@@ -153,6 +168,8 @@
#define OVS_GUARDED_BY(...)
#define OVS_EXCLUDED(...)
#define OVS_RELEASES(...)
+#define OVS_ACQ_BEFORE(...)
+#define OVS_ACQ_AFTER(...)
#define OVS_MACRO_LOCK(...)
#define OVS_MACRO_RELEASE(...)
#endif
--
1.7.10.4
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