X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu-bp.c;h=3b2062d6590034ad33619ab1372b137237a9fd1e;hp=136f97d3cf6746eef6d39a9f2a22ca1139a342fc;hb=541d828d3101283ccdb1e25fa5a885e1d1743c1a;hpb=16aa9ee87cf4364921c36025359be01390338d87

diff --git a/urcu-bp.c b/urcu-bp.c
index 136f97d..3b2062d 100644
--- a/urcu-bp.c
+++ b/urcu-bp.c
@@ -24,6 +24,7 @@
  */
 
 #define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <stdio.h>
 #include <pthread.h>
 #include <signal.h>
@@ -35,14 +36,58 @@
 #include <unistd.h>
 #include <sys/mman.h>
 
-#include "urcu-bp-static.h"
+#include "urcu/wfqueue.h"
+#include "urcu/map/urcu-bp.h"
+#include "urcu/static/urcu-bp.h"
+#include "urcu-pointer.h"
+
 /* Do not #define _LGPL_SOURCE to ensure we can emit the wrapper symbols */
+#undef _LGPL_SOURCE
 #include "urcu-bp.h"
+#define _LGPL_SOURCE
+
+#ifndef MAP_ANONYMOUS
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+
+#ifndef __linux__
+
+#define MREMAP_MAYMOVE	1
+#define MREMAP_FIXED	2
+
+/*
+ * mremap wrapper for non-Linux systems. Maps a RW, anonymous private mapping.
+ * This is not generic.
+*/
+void *mremap(void *old_address, size_t old_size, size_t new_size, int flags)
+{
+	void *new_address;
+
+	assert(flags & MREMAP_MAYMOVE);
+	assert(!(flags & MREMAP_FIXED));
+	new_address = mmap(old_address, new_size,
+			   PROT_READ | PROT_WRITE,
+			   MAP_ANONYMOUS | MAP_PRIVATE,
+			   -1, 0);
+	if (new_address == MAP_FAILED)
+		return MAP_FAILED;
+	if (old_address) {
+		memcpy(new_address, old_address, old_size);
+		munmap(old_address, old_size);
+	}
+	return new_address;
+}
+#endif
 
 /* Sleep delay in us */
 #define RCU_SLEEP_DELAY		1000
 #define ARENA_INIT_ALLOC	16
 
+/*
+ * Active attempts to check for reader Q.S. before calling sleep().
+ */
+#define RCU_QS_ACTIVE_ATTEMPTS 100
+
 void __attribute__((destructor)) rcu_bp_exit(void);
 
 static pthread_mutex_t rcu_gp_lock = PTHREAD_MUTEX_INITIALIZER;
@@ -76,6 +121,9 @@ struct registry_arena {
 
 static struct registry_arena registry_arena;
 
+/* Saved fork signal mask, protected by rcu_gp_lock */
+static sigset_t saved_fork_signal_mask;
+
 static void rcu_gc_registry(void);
 
 static void mutex_lock(pthread_mutex_t *mutex)
@@ -95,11 +143,6 @@ static void mutex_lock(pthread_mutex_t *mutex)
 			perror("Error in pthread mutex lock");
 			exit(-1);
 		}
-		if (rcu_reader.need_mb) {
-			cmm_smp_mb();
-			rcu_reader.need_mb = 0;
-			cmm_smp_mb();
-		}
 		poll(NULL,0,10);
 	}
 #endif /* #else #ifndef DISTRUST_SIGNALS_EXTREME */
@@ -123,13 +166,13 @@ void update_counter_and_wait(void)
 	struct rcu_reader *index, *tmp;
 
 	/* Switch parity: 0 -> 1, 1 -> 0 */
-	CAA_STORE_SHARED(rcu_gp_ctr, rcu_gp_ctr ^ RCU_GP_CTR_PHASE);
+	CMM_STORE_SHARED(rcu_gp_ctr, rcu_gp_ctr ^ RCU_GP_CTR_PHASE);
 
 	/*
 	 * Must commit qparity update to memory before waiting for other parity
 	 * quiescent state. Failure to do so could result in the writer waiting
 	 * forever while new readers are always accessing data (no progress).
-	 * Ensured by CAA_STORE_SHARED and CAA_LOAD_SHARED.
+	 * Ensured by CMM_STORE_SHARED and CMM_LOAD_SHARED.
 	 */
 
 	/*
@@ -250,7 +293,6 @@ static void resize_arena(struct registry_arena *arena, size_t len)
 	if (new_arena == arena->p)
 		return;
 
-	memcpy(new_arena, arena->p, arena->len);
 	bzero(new_arena + arena->len, len - arena->len);
 	arena->p = new_arena;
 }
@@ -263,7 +305,7 @@ static void add_thread(void)
 	if (registry_arena.len
 	    < registry_arena.used + sizeof(struct rcu_reader))
 		resize_arena(&registry_arena,
-		max(registry_arena.len << 1, ARENA_INIT_ALLOC));
+		caa_max(registry_arena.len << 1, ARENA_INIT_ALLOC));
 	/*
 	 * Find a free spot.
 	 */
@@ -332,7 +374,54 @@ end:
 	assert(!ret);
 }
 
-void rcu_bp_exit()
+void rcu_bp_exit(void)
+{
+	if (registry_arena.p)
+		munmap(registry_arena.p, registry_arena.len);
+}
+
+/*
+ * Holding the rcu_gp_lock across fork will make sure we fork() don't race with
+ * a concurrent thread executing with this same lock held. This ensures that the
+ * registry is in a coherent state in the child.
+ */
+void rcu_bp_before_fork(void)
+{
+	sigset_t newmask, oldmask;
+	int ret;
+
+	ret = sigemptyset(&newmask);
+	assert(!ret);
+	ret = pthread_sigmask(SIG_SETMASK, &newmask, &oldmask);
+	assert(!ret);
+	mutex_lock(&rcu_gp_lock);
+	saved_fork_signal_mask = oldmask;
+}
+
+void rcu_bp_after_fork_parent(void)
+{
+	sigset_t oldmask;
+	int ret;
+
+	oldmask = saved_fork_signal_mask;
+	mutex_unlock(&rcu_gp_lock);
+	ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
+	assert(!ret);
+}
+
+void rcu_bp_after_fork_child(void)
 {
-	munmap(registry_arena.p, registry_arena.len);
+	sigset_t oldmask;
+	int ret;
+
+	rcu_gc_registry();
+	oldmask = saved_fork_signal_mask;
+	mutex_unlock(&rcu_gp_lock);
+	ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
+	assert(!ret);
 }
+
+DEFINE_RCU_FLAVOR()
+
+#include "urcu-call-rcu-impl.h"
+#include "urcu-defer-impl.h"