#include <stdlib.h>
#include <pthread.h>
-#include <assert.h>
#include <limits.h>
#include <unistd.h>
#include <stdint.h>
#include <urcu/list.h>
#include <urcu/futex.h>
#include <urcu/tls-compat.h>
+#include <urcu/debug.h>
#ifdef __cplusplus
extern "C" {
-#endif
+#endif
/*
* This code section can only be included in LGPL 2.1 compatible source code.
* This is required to permit relinking with newer versions of the library.
*/
-#ifdef DEBUG_RCU
-#define rcu_assert(args...) assert(args)
-#else
-#define rcu_assert(args...)
-#endif
-
enum rcu_state {
RCU_READER_ACTIVE_CURRENT,
RCU_READER_ACTIVE_OLD,
RCU_READER_INACTIVE,
};
-#ifdef DEBUG_YIELD
-#include <sched.h>
-#include <time.h>
-#include <pthread.h>
-#include <unistd.h>
-
-#define RCU_YIELD_READ (1 << 0)
-#define RCU_YIELD_WRITE (1 << 1)
-
-/* maximum sleep delay, in us */
-#define MAX_SLEEP 50
-
-extern unsigned int rcu_yield_active;
-extern DECLARE_URCU_TLS(unsigned int, rcu_rand_yield);
-
-static inline void rcu_debug_yield_read(void)
-{
- if (rcu_yield_active & RCU_YIELD_READ)
- if (rand_r(&URCU_TLS(rcu_rand_yield)) & 0x1)
- usleep(rand_r(&URCU_TLS(rcu_rand_yield)) % MAX_SLEEP);
-}
-
-static inline void rcu_debug_yield_write(void)
-{
- if (rcu_yield_active & RCU_YIELD_WRITE)
- if (rand_r(&URCU_TLS(rcu_rand_yield)) & 0x1)
- usleep(rand_r(&URCU_TLS(rcu_rand_yield)) % MAX_SLEEP);
-}
-
-static inline void rcu_debug_yield_init(void)
-{
- URCU_TLS(rcu_rand_yield) = time(NULL) ^ (unsigned long) pthread_self();
-}
-#else
-static inline void rcu_debug_yield_read(void)
-{
-}
-
-static inline void rcu_debug_yield_write(void)
-{
-}
-
-static inline void rcu_debug_yield_init(void)
-{
-
-}
-#endif
-
#define RCU_GP_ONLINE (1UL << 0)
#define RCU_GP_CTR (1UL << 1)
-/*
- * Global quiescent period counter with low-order bits unused.
- * Using a int rather than a char to eliminate false register dependencies
- * causing stalls on some architectures.
- */
-extern unsigned long rcu_gp_ctr;
+struct rcu_gp {
+ /*
+ * Global quiescent period counter with low-order bits unused.
+ * Using a int rather than a char to eliminate false register
+ * dependencies causing stalls on some architectures.
+ */
+ unsigned long ctr;
+
+ int32_t futex;
+} __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
+
+extern struct rcu_gp rcu_gp;
struct rcu_reader {
/* Data used by both reader and synchronize_rcu() */
struct cds_list_head node __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
int waiting;
pthread_t tid;
+ /* Reader registered flag, for internal checks. */
+ unsigned int registered:1;
};
extern DECLARE_URCU_TLS(struct rcu_reader, rcu_reader);
-extern int32_t rcu_gp_futex;
-
/*
* Wake-up waiting synchronize_rcu(). Called from many concurrent threads.
*/
if (caa_unlikely(_CMM_LOAD_SHARED(URCU_TLS(rcu_reader).waiting))) {
_CMM_STORE_SHARED(URCU_TLS(rcu_reader).waiting, 0);
cmm_smp_mb();
- if (uatomic_read(&rcu_gp_futex) != -1)
+ if (uatomic_read(&rcu_gp.futex) != -1)
return;
- uatomic_set(&rcu_gp_futex, 0);
- futex_noasync(&rcu_gp_futex, FUTEX_WAKE, 1,
- NULL, NULL, 0);
+ uatomic_set(&rcu_gp.futex, 0);
+ /*
+ * Ignoring return value until we can make this function
+ * return something (because urcu_die() is not publicly
+ * exposed).
+ */
+ (void) futex_noasync(&rcu_gp.futex, FUTEX_WAKE, 1,
+ NULL, NULL, 0);
}
}
v = CMM_LOAD_SHARED(*ctr);
if (!v)
return RCU_READER_INACTIVE;
- if (v == rcu_gp_ctr)
+ if (v == rcu_gp.ctr)
return RCU_READER_ACTIVE_CURRENT;
return RCU_READER_ACTIVE_OLD;
}
*/
static inline void _rcu_read_lock(void)
{
- rcu_assert(URCU_TLS(rcu_reader).ctr);
+ urcu_assert(URCU_TLS(rcu_reader).ctr);
}
/*
*/
static inline void _rcu_read_unlock(void)
{
+ urcu_assert(URCU_TLS(rcu_reader).ctr);
}
/*
* to be invoked directly from non-LGPL code.
*
* We skip the memory barriers and gp store if our local ctr already
- * matches the global rcu_gp_ctr value: this is OK because a prior
+ * matches the global rcu_gp.ctr value: this is OK because a prior
* _rcu_quiescent_state() or _rcu_thread_online() already updated it
* within our thread, so we have no quiescent state to report.
*/
{
unsigned long gp_ctr;
- if ((gp_ctr = CMM_LOAD_SHARED(rcu_gp_ctr)) == URCU_TLS(rcu_reader).ctr)
+ urcu_assert(URCU_TLS(rcu_reader).registered);
+ if ((gp_ctr = CMM_LOAD_SHARED(rcu_gp.ctr)) == URCU_TLS(rcu_reader).ctr)
return;
_rcu_quiescent_state_update_and_wakeup(gp_ctr);
}
*/
static inline void _rcu_thread_offline(void)
{
+ urcu_assert(URCU_TLS(rcu_reader).registered);
cmm_smp_mb();
CMM_STORE_SHARED(URCU_TLS(rcu_reader).ctr, 0);
cmm_smp_mb(); /* write URCU_TLS(rcu_reader).ctr before read futex */
*/
static inline void _rcu_thread_online(void)
{
+ urcu_assert(URCU_TLS(rcu_reader).registered);
cmm_barrier(); /* Ensure the compiler does not reorder us with mutex */
- _CMM_STORE_SHARED(URCU_TLS(rcu_reader).ctr, CMM_LOAD_SHARED(rcu_gp_ctr));
+ _CMM_STORE_SHARED(URCU_TLS(rcu_reader).ctr, CMM_LOAD_SHARED(rcu_gp.ctr));
cmm_smp_mb();
}
-#ifdef __cplusplus
+#ifdef __cplusplus
}
#endif
projects / urcu.git / blobdiff