x86: allocate membarrier system call number

[urcu.git] / urcu.c

diff --git a/urcu.c b/urcu.c
index 5ffeb79553b6374f0fb1a607b3862ed78dda63e2..a620b762b4796712bd05efb862de8cb6c53c41fd 100644 (file)
--- a/urcu.c
+++ b/urcu.c
@@ -37,6 +37,7 @@
 #include <errno.h>
 #include <poll.h>
 
+#include "urcu/arch.h"
 #include "urcu/wfcqueue.h"
 #include "urcu/map/urcu.h"
 #include "urcu/static/urcu.h"
@@ -63,16 +64,9 @@
  */
 #define RCU_QS_ACTIVE_ATTEMPTS 100
 
-/*
- * RCU_MEMBARRIER is only possibly available on Linux.
- */
-#if defined(RCU_MEMBARRIER) && defined(__linux__)
-#include <urcu/syscall-compat.h>
-#endif
-
-/* If the headers do not support SYS_membarrier, fall back on RCU_MB */
-#ifdef SYS_membarrier
-# define membarrier(...)               syscall(SYS_membarrier, __VA_ARGS__)
+/* If the headers do not support membarrier system call, fall back on RCU_MB */
+#ifdef __NR_membarrier
+# define membarrier(...)               syscall(__NR_membarrier, __VA_ARGS__)
 #else
 # define membarrier(...)               -ENOSYS
 #endif
@@ -165,7 +159,7 @@ static void mutex_unlock(pthread_mutex_t *mutex)
 }
 
 #ifdef RCU_MEMBARRIER
-static void smp_mb_master(int group)
+static void smp_mb_master(void)
 {
        if (caa_likely(rcu_has_sys_membarrier))
                (void) membarrier(MEMBARRIER_CMD_SHARED, 0);
@@ -175,7 +169,7 @@ static void smp_mb_master(int group)
 #endif
 
 #ifdef RCU_MB
-static void smp_mb_master(int group)
+static void smp_mb_master(void)
 {
        cmm_smp_mb();
 }
@@ -224,7 +218,7 @@ static void force_mb_all_readers(void)
        cmm_smp_mb();   /* read ->need_mb before ending the barrier */
 }
 
-static void smp_mb_master(int group)
+static void smp_mb_master(void)
 {
        force_mb_all_readers();
 }
@@ -236,7 +230,7 @@ static void smp_mb_master(int group)
 static void wait_gp(void)
 {
        /* Read reader_gp before read futex */
-       smp_mb_master(RCU_MB_GROUP);
+       smp_mb_master();
        if (uatomic_read(&rcu_gp.futex) != -1)
                return;
        while (futex_async(&rcu_gp.futex, FUTEX_WAIT, -1,
@@ -280,7 +274,7 @@ static void wait_for_readers(struct cds_list_head *input_readers,
                if (wait_loops >= RCU_QS_ACTIVE_ATTEMPTS) {
                        uatomic_dec(&rcu_gp.futex);
                        /* Write futex before read reader_gp */
-                       smp_mb_master(RCU_MB_GROUP);
+                       smp_mb_master();
                }
 
                cds_list_for_each_entry_safe(index, tmp, input_readers, node) {
@@ -310,7 +304,7 @@ static void wait_for_readers(struct cds_list_head *input_readers,
                if (cds_list_empty(input_readers)) {
                        if (wait_loops >= RCU_QS_ACTIVE_ATTEMPTS) {
                                /* Read reader_gp before write futex */
-                               smp_mb_master(RCU_MB_GROUP);
+                               smp_mb_master();
                                uatomic_set(&rcu_gp.futex, 0);
                        }
                        break;
@@ -333,13 +327,13 @@ static void wait_for_readers(struct cds_list_head *input_readers,
                if (cds_list_empty(input_readers)) {
                        if (wait_loops >= RCU_QS_ACTIVE_ATTEMPTS) {
                                /* Read reader_gp before write futex */
-                               smp_mb_master(RCU_MB_GROUP);
+                               smp_mb_master();
                                uatomic_set(&rcu_gp.futex, 0);
                        }
                        break;
                } else {
                        if (wait_gp_loops == KICK_READER_LOOPS) {
-                               smp_mb_master(RCU_MB_GROUP);
+                               smp_mb_master();
                                wait_gp_loops = 0;
                        }
                        /* Temporarily unlock the registry lock. */
@@ -400,7 +394,7 @@ void synchronize_rcu(void)
         * because it iterates on reader threads.
         */
        /* Write new ptr before changing the qparity */
-       smp_mb_master(RCU_MB_GROUP);
+       smp_mb_master();
 
        /*
         * Wait for readers to observe original parity or be quiescent.
@@ -461,7 +455,7 @@ void synchronize_rcu(void)
         * being freed. Must be done within rcu_registry_lock because it
         * iterates on reader threads.
         */
-       smp_mb_master(RCU_MB_GROUP);
+       smp_mb_master();
 out:
        mutex_unlock(&rcu_registry_lock);
        mutex_unlock(&rcu_gp_lock);
@@ -500,6 +494,8 @@ void rcu_register_thread(void)
        assert(!(URCU_TLS(rcu_reader).ctr & RCU_GP_CTR_NEST_MASK));
 
        mutex_lock(&rcu_registry_lock);
+       assert(!URCU_TLS(rcu_reader).registered);
+       URCU_TLS(rcu_reader).registered = 1;
        rcu_init();     /* In case gcc does not support constructor attribute */
        cds_list_add(&URCU_TLS(rcu_reader).node, &registry);
        mutex_unlock(&rcu_registry_lock);
@@ -508,6 +504,8 @@ void rcu_register_thread(void)
 void rcu_unregister_thread(void)
 {
        mutex_lock(&rcu_registry_lock);
+       assert(URCU_TLS(rcu_reader).registered);
+       URCU_TLS(rcu_reader).registered = 0;
        cds_list_del(&URCU_TLS(rcu_reader).node);
        mutex_unlock(&rcu_registry_lock);
 }