sparse: Remove support for thread-safety annotations.

The Clang support for thread-safety annotations is much more effective
than "sparse" support.  I found that I was unable to make the annotations
warning-free under sparse.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>

include/sparse/pthread.h

@@ -21,18 +21,6 @@
 /* Get actual <pthread.h> definitions for us to annotate and build on. */
 #include_next <pthread.h>
 
-#include "compiler.h"
-
-int pthread_mutex_lock(pthread_mutex_t *mutex) OVS_ACQUIRES(mutex);
-int pthread_mutex_unlock(pthread_mutex_t *mutex) OVS_RELEASES(mutex);
-
-int pthread_rwlock_rdlock(pthread_rwlock_t *rwlock) OVS_ACQ_RDLOCK(rwlock);
-int pthread_rwlock_wrlock(pthread_rwlock_t *rwlock) OVS_ACQ_WRLOCK(rwlock);
-int pthread_rwlock_unlock(pthread_rwlock_t *rwlock) OVS_RELEASES(rwlock);
-
-int pthread_cond_wait(pthread_cond_t *, pthread_mutex_t *mutex)
-    OVS_REQUIRES(mutex);
-
 /* Sparse complains about the proper PTHREAD_*_INITIALIZER definitions.
  * Luckily, it's not a real compiler so we can overwrite it with something
  * simple. */
@@ -47,29 +35,3 @@ int pthread_cond_wait(pthread_cond_t *, pthread_mutex_t *mutex)
 
 #undef PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP
 #define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP {}
-
-#define pthread_mutex_trylock(MUTEX)                    \
-    ({                                                  \
-        int retval = pthread_mutex_trylock(mutex);      \
-        if (!retval) {                                  \
-            OVS_MACRO_LOCK(MUTEX);                      \
-        }                                               \
-        retval;                                         \
-    })
-
-#define pthread_rwlock_tryrdlock(RWLOCK)                \
-    ({                                                  \
-        int retval = pthread_rwlock_tryrdlock(rwlock);  \
-        if (!retval) {                                  \
-            OVS_MACRO_LOCK(RWLOCK);                     \
-        }                                               \
-        retval;                                         \
-    })
-#define pthread_rwlock_trywrlock(RWLOCK)                \
-    ({                                                  \
-        int retval = pthread_rwlock_trywrlock(rwlock);  \
-        if (!retval) {                                  \
-            OVS_MACRO_LOCK(RWLOCK);                     \
-        }                                               \
-        retval;                                         \
-    })

lib/compiler.h

@@ -128,32 +128,7 @@
 #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.
- *
- * Change the thread-safety check annotations to use "context" attribute.
- *
- * OVS_MACRO_LOCK and OVS_MACRO_RELEASE are suitable for use within macros,
- * where there is no function prototype to annotate. */
-#define OVS_LOCKABLE
-#define OVS_REQ_RDLOCK(...) __attribute__((context(MUTEX, 1, 1)))
-#define OVS_ACQ_RDLOCK(...) __attribute__((context(MUTEX, 0, 1)))
-#define OVS_REQ_WRLOCK(...) __attribute__((context(MUTEX, 1, 1)))
-#define OVS_ACQ_WRLOCK(...) __attribute__((context(MUTEX, 0, 1)))
-#define OVS_REQUIRES(...)   __attribute__((context(MUTEX, 1, 1)))
-#define OVS_ACQUIRES(...)   __attribute__((context(MUTEX, 0, 1)))
-#define OVS_TRY_WRLOCK(RETVAL, ...)
-#define OVS_TRY_RDLOCK(RETVAL, ...)
-#define OVS_TRY_LOCK(REVAL, ...)
-#define OVS_GUARDED
-#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
+#else  /* not Clang */
 #define OVS_LOCKABLE
 #define OVS_REQ_RDLOCK(...)
 #define OVS_ACQ_RDLOCK(...)
@@ -170,8 +145,6 @@
 #define OVS_RELEASES(...)
 #define OVS_ACQ_BEFORE(...)
 #define OVS_ACQ_AFTER(...)
-#define OVS_MACRO_LOCK(...)
-#define OVS_MACRO_RELEASE(...)
 #endif
 
 /* ISO C says that a C implementation may choose any integer type for an enum

lib/ovs-thread.h

@@ -496,11 +496,6 @@ ovsthread_once_start(struct ovsthread_once *once)
     return OVS_UNLIKELY(!ovsthread_once_is_done__(once)
                         && !ovsthread_once_start__(once));
 }
-
-#ifdef __CHECKER__
-#define ovsthread_once_start(ONCE) \
-    ((ONCE)->done ? false : ({ OVS_MACRO_LOCK((&ONCE->mutex)); true; }))
-#endif
 
 /* Thread ID.
  *

ofproto/ofproto-dpif.c

@@ -4756,6 +4756,7 @@ bool
 rule_dpif_lookup_in_table(struct ofproto_dpif *ofproto,
                           const struct flow *flow, struct flow_wildcards *wc,
                           uint8_t table_id, struct rule_dpif **rule)
+    OVS_ACQ_RDLOCK((*rule)->up.evict)
 {
     struct cls_rule *cls_rule;
     struct classifier *cls;

ofproto/ofproto.c

@@ -5459,7 +5459,8 @@ oftable_enable_eviction(struct oftable *table,
 /* Removes 'rule' from the oftable that contains it. */
 static void
 oftable_remove_rule__(struct ofproto *ofproto, struct classifier *cls,
-                      struct rule *rule) OVS_REQ_WRLOCK(cls->rwlock)
+                      struct rule *rule)
+    OVS_REQ_WRLOCK(cls->rwlock) OVS_RELEASES(rule->evict)
 {
     classifier_remove(cls, &rule->cr);
     if (rule->meter_id) {