X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=include%2Furcu%2Ftls-compat.h;h=431319d608518af222045f9467dfb8081dfaaa8c;hp=8ac1ea0615ddc2eb91ee51e9e15b89bd094d4c81;hb=HEAD;hpb=6893800a4d1cc14dff0395ddcd660a5138db183d

diff --git a/include/urcu/tls-compat.h b/include/urcu/tls-compat.h
index 8ac1ea0..1f3ef0f 100644
--- a/include/urcu/tls-compat.h
+++ b/include/urcu/tls-compat.h
@@ -1,26 +1,12 @@
+// SPDX-FileCopyrightText: 2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
 #ifndef _URCU_TLS_COMPAT_H
 #define _URCU_TLS_COMPAT_H
 
 /*
- * urcu/tls-compat.h
- *
  * Userspace RCU library - Thread-Local Storage Compatibility Header
- *
- * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <stdlib.h>
@@ -32,7 +18,21 @@
 extern "C" {
 #endif
 
-#ifdef CONFIG_RCU_TLS	/* Based on ax_tls.m4 */
+#ifdef CONFIG_RCU_TLS
+
+/*
+ * Default to '__thread' on all C and C++ compilers except MSVC. While C11 has
+ * '_Thread_local' and C++11 has 'thread_local', only '__thread' seems to have
+ * a compatible implementation when linking public extern symbols across
+ * language boundaries.
+ *
+ * For more details, see 'https://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html'.
+ */
+#if defined(_MSC_VER)
+# define URCU_TLS_STORAGE_CLASS	__declspec(thread)
+#else
+# define URCU_TLS_STORAGE_CLASS	__thread
+#endif
 
 /*
  * Hint: How to define/declare TLS variables of compound types
@@ -65,10 +65,13 @@ extern "C" {
  */
 
 # define DECLARE_URCU_TLS(type, name)	\
-	CONFIG_RCU_TLS type name
+	URCU_TLS_STORAGE_CLASS type name
 
 # define DEFINE_URCU_TLS(type, name)	\
-	CONFIG_RCU_TLS type name
+	URCU_TLS_STORAGE_CLASS type name
+
+# define DEFINE_URCU_TLS_INIT(type, name, init)	\
+	URCU_TLS_STORAGE_CLASS type name = (init)
 
 # define URCU_TLS(name)		(name)
 
@@ -95,14 +98,15 @@ struct urcu_tls {
  * Note: we don't free memory at process exit, since it will be dealt
  * with by the OS.
  */
-# define DEFINE_URCU_TLS_1(type, name)				\
+# define DEFINE_URCU_TLS_INIT_1(type, name, do_init)		\
 	type *__tls_access_ ## name(void)			\
 	{							\
 		static struct urcu_tls __tls_ ## name = {	\
+			.key = 0,				\
 			.init_mutex = PTHREAD_MUTEX_INITIALIZER,\
 			.init_done = 0,				\
 		};						\
-		void *__tls_p;					\
+		__typeof__(type) *__tls_p;			\
 		if (!__tls_ ## name.init_done) {		\
 			/* Mutex to protect concurrent init */	\
 			pthread_mutex_lock(&__tls_ ## name.init_mutex); \
@@ -115,17 +119,24 @@ struct urcu_tls {
 			pthread_mutex_unlock(&__tls_ ## name.init_mutex); \
 		}						\
 		cmm_smp_rmb();	/* read init_done before getting key */ \
-		__tls_p = pthread_getspecific(__tls_ ## name.key); \
+		__tls_p = (__typeof__(type) *) pthread_getspecific(__tls_ ## name.key); \
 		if (caa_unlikely(__tls_p == NULL)) {		\
-			__tls_p = calloc(1, sizeof(type));	\
+			__tls_p = (__typeof__(type) *) calloc(1, sizeof(type));	\
+			do_init					\
 			(void) pthread_setspecific(__tls_ ## name.key,	\
 				__tls_p);			\
 		}						\
 		return __tls_p;					\
 	}
 
+# define _URCU_TLS_INIT(init)					\
+	*__tls_p = (init);
+
+# define DEFINE_URCU_TLS_INIT(type, name, init)			\
+	DEFINE_URCU_TLS_INIT_1(type, name, _URCU_TLS_INIT(init))
+
 # define DEFINE_URCU_TLS(type, name)				\
-	DEFINE_URCU_TLS_1(type, name)
+	DEFINE_URCU_TLS_INIT_1(type, name, /* empty */)
 
 # define URCU_TLS_1(name)	(*__tls_access_ ## name())