Version 0.9.5

[userspace-rcu.git] / urcu-bp.c

diff --git a/urcu-bp.c b/urcu-bp.c
index 6b78af8bd8dfc77545a8a11adcfec997434e57bd..9c7da3d8d235355246de95dfb5de87c8dcc1fec8 100644 (file)
--- a/urcu-bp.c
+++ b/urcu-bp.c
@@ -36,6 +36,7 @@
 #include <unistd.h>
 #include <sys/mman.h>
 
+#include "urcu/arch.h"
 #include "urcu/wfcqueue.h"
 #include "urcu/map/urcu-bp.h"
 #include "urcu/static/urcu-bp.h"
@@ -94,16 +95,9 @@ void *mremap_wrapper(void *old_address, size_t old_size,
 static
 int rcu_bp_refcount;
 
-/*
- * RCU_MEMBARRIER is only possibly available on Linux.
- */
-#ifdef __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 smp_mb. */
+#ifdef __NR_membarrier
+# define membarrier(...)               syscall(__NR_membarrier, __VA_ARGS__)
 #else
 # define membarrier(...)               -ENOSYS
 #endif
@@ -379,13 +373,14 @@ void expand_arena(struct registry_arena *arena)
                        sizeof(struct registry_chunk)
                        + sizeof(struct rcu_reader));
                new_chunk_len = ARENA_INIT_ALLOC;
-               new_chunk = mmap(NULL, new_chunk_len,
+               new_chunk = (struct registry_chunk *) mmap(NULL,
+                       new_chunk_len,
                        PROT_READ | PROT_WRITE,
                        MAP_ANONYMOUS | MAP_PRIVATE,
                        -1, 0);
                if (new_chunk == MAP_FAILED)
                        abort();
-               bzero(new_chunk, new_chunk_len);
+               memset(new_chunk, 0, new_chunk_len);
                new_chunk->data_len =
                        new_chunk_len - sizeof(struct registry_chunk);
                cds_list_add_tail(&new_chunk->node, &arena->chunk_list);
@@ -405,7 +400,7 @@ void expand_arena(struct registry_arena *arena)
        if (new_chunk != MAP_FAILED) {
                /* Should not have moved. */
                assert(new_chunk == last_chunk);
-               bzero((char *) last_chunk + old_chunk_len,
+               memset((char *) last_chunk + old_chunk_len, 0,
                        new_chunk_len - old_chunk_len);
                last_chunk->data_len =
                        new_chunk_len - sizeof(struct registry_chunk);
@@ -413,13 +408,14 @@ void expand_arena(struct registry_arena *arena)
        }
 
        /* Remap did not succeed, we need to add a new chunk. */
-       new_chunk = mmap(NULL, new_chunk_len,
+       new_chunk = (struct registry_chunk *) mmap(NULL,
+               new_chunk_len,
                PROT_READ | PROT_WRITE,
                MAP_ANONYMOUS | MAP_PRIVATE,
                -1, 0);
        if (new_chunk == MAP_FAILED)
                abort();
-       bzero(new_chunk, new_chunk_len);
+       memset(new_chunk, 0, new_chunk_len);
        new_chunk->data_len =
                new_chunk_len - sizeof(struct registry_chunk);
        cds_list_add_tail(&new_chunk->node, &arena->chunk_list);
@@ -585,6 +581,17 @@ void urcu_bp_thread_exit_notifier(void *rcu_key)
        rcu_bp_unregister(rcu_key);
 }
 
+static
+void rcu_sys_membarrier_status(int available)
+{
+       /*
+        * membarrier has blocking behavior, which changes the
+        * application behavior too much compared to using barriers when
+        * synchronize_rcu is used repeatedly (without using call_rcu).
+        * Don't use membarrier for now.
+        */
+}
+
 static
 void rcu_bp_init(void)
 {
@@ -597,9 +604,8 @@ void rcu_bp_init(void)
                if (ret)
                        abort();
                ret = membarrier(MEMBARRIER_CMD_QUERY, 0);
-               if (ret >= 0 && (ret & MEMBARRIER_CMD_SHARED)) {
-                       urcu_bp_has_sys_membarrier = 1;
-               }
+               rcu_sys_membarrier_status(ret >= 0
+                               && (ret & MEMBARRIER_CMD_SHARED));
                initialized = 1;
        }
        mutex_unlock(&init_lock);
@@ -615,9 +621,10 @@ void rcu_bp_exit(void)
 
                cds_list_for_each_entry_safe(chunk, tmp,
                                &registry_arena.chunk_list, node) {
-                       munmap(chunk, chunk->data_len
+                       munmap((void *) chunk, chunk->data_len
                                        + sizeof(struct registry_chunk));
                }
+               CDS_INIT_LIST_HEAD(&registry_arena.chunk_list);
                ret = pthread_key_delete(urcu_bp_key);
                if (ret)
                        abort();