Use initial-exec TLS model

Use initial-exec TLS model for TLS variables. Those are faster, and
signal-handler-safe.

Link: https://docs.oracle.com/cd/E23824_01/html/819-0690/chapter8-20.html
Link: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#Common-Variable-Attributes
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/configure.ac b/configure.ac
index e2acfa9057bbd20a0cefcb104c047021ab5bd10d..08ca3b6587438405864385dcfaf96e78b0a69237 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -225,26 +225,22 @@ AM_CONDITIONAL([HAVE_DLINFO], [test "x${ac_cv_have_decl_RTLD_DI_LINKMAP}" = "xye
 AC_CHECK_HEADERS([urcu-bp.h], [], [AC_MSG_ERROR([Cannot find [URCU] headers (urcu-bp.h). Use [CPPFLAGS]=-Idir to specify their location.
 This error can also occur when the liburcu package's configure script has not been run.])])
 
+# URCU library version needed or newer
+m4_define([WRONG_LIBURCU_MSG], [Userspace RCU (liburcu) >= 0.11.0 is needed])
+
+#Macro added in urcu 0.6.6
+AC_CHECK_DECL([caa_likely], [],
+       [AC_MSG_ERROR([WRONG_LIBURCU_MSG])], [[#include <urcu.h>]])
+#Macro added in urcu 0.11.0
+AC_CHECK_DECL([DEFINE_URCU_TLS_IE], [],
+       [AC_MSG_ERROR([WRONG_LIBURCU_MSG])], [[#include <urcu/tls-compat.h>]]
+)
+
 # urcu-cds - check that URCU Concurrent Data Structure lib is available to compilation
 # Part of Userspace RCU library 0.7.2 or better.
 AC_CHECK_LIB([urcu-cds], [_cds_lfht_new], [], [AC_MSG_ERROR([Cannot find
 liburcu-cds lib, part of Userspace RCU 0.7 or better. Use [LDFLAGS]=-Ldir to specify its location.])])
 
-AC_MSG_CHECKING([caa_likely()])
-AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
-       #include <urcu/compiler.h>
-       void fct(void)
-       {
-               if (caa_likely(1)) {
-               }
-       }
-]])], [
-       AC_MSG_RESULT([yes])
-], [
-       AC_MSG_RESULT([no])
-       AC_MSG_ERROR([Please upgrade your version of liburcu to 0.6.6 or better])
-])
-
 # urcu - check that URCU lib is available to compilation
 AC_CHECK_LIB([urcu-bp], [synchronize_rcu_bp], [], [AC_MSG_ERROR([Cannot find liburcu-bp lib. Use [LDFLAGS]=-Ldir to specify its location.])])
 

diff --git a/liblttng-ust-comm/lttng-ust-fd-tracker.c b/liblttng-ust-comm/lttng-ust-fd-tracker.c
index 5a763ff2960550c094306d9d7d90de3d2bf9d037..04ae2391f034f7f8a23e92aef97d3e4ace8518a0 100644 (file)
--- a/liblttng-ust-comm/lttng-ust-fd-tracker.c
+++ b/liblttng-ust-comm/lttng-ust-fd-tracker.c
@@ -65,7 +65,7 @@ static pthread_mutex_t ust_safe_guard_fd_mutex = PTHREAD_MUTEX_INITIALIZER;
  * Track whether we are within lttng-ust or application, for close
  * system call override by LD_PRELOAD library.
  */
-static DEFINE_URCU_TLS(int, thread_fd_tracking);
+static DEFINE_URCU_TLS_IE(int, thread_fd_tracking);
 
 /* fd_set used to book keep fd being used by lttng-ust. */
 static fd_set *lttng_fd_set;

diff --git a/liblttng-ust-java-agent/jni/common/lttng_ust_context.c b/liblttng-ust-java-agent/jni/common/lttng_ust_context.c
index 3bed11ec8ff435768259a460d9dffbfb0636efc0..e9b6da282db3bfbc5ec075a8ea64178c6f9ef851 100644 (file)
--- a/liblttng-ust-java-agent/jni/common/lttng_ust_context.c
+++ b/liblttng-ust-java-agent/jni/common/lttng_ust_context.c
@@ -24,6 +24,7 @@
 #include <lttng/ust-events.h>
 #include <lttng/ringbuffer-config.h>
 #include <lttng/ust-context-provider.h>
+#include <urcu/tls-compat.h>
 
 #include "helper.h"
 #include "lttng_ust_context.h"
@@ -56,7 +57,7 @@ struct lttng_ust_jni_ctx_entry {
 } __attribute__((packed));
 
 /* TLS passing context info from JNI to callbacks. */
-__thread struct lttng_ust_jni_tls lttng_ust_context_info_tls;
+DECLARE_URCU_TLS_IE(struct lttng_ust_jni_tls, lttng_ust_context_info_tls);
 
 static const char *get_ctx_string_at_offset(int32_t offset)
 {

diff --git a/liblttng-ust-java-agent/jni/common/lttng_ust_context.h b/liblttng-ust-java-agent/jni/common/lttng_ust_context.h
index 415f7de228fa9bcbc500dc28929a978272ef0b76..8ea43e1ae362d471279c7b77c18c5bee9e2abf3f 100644 (file)
--- a/liblttng-ust-java-agent/jni/common/lttng_ust_context.h
+++ b/liblttng-ust-java-agent/jni/common/lttng_ust_context.h
@@ -19,6 +19,8 @@
 #ifndef LIBLTTNG_UST_JAVA_AGENT_JNI_COMMON_LTTNG_UST_CONTEXT_H_
 #define LIBLTTNG_UST_JAVA_AGENT_JNI_COMMON_LTTNG_UST_CONTEXT_H_
 
+#include <urcu/tls-compat.h>
+
 struct lttng_ust_jni_ctx_entry;
 
 struct lttng_ust_jni_tls {
@@ -28,6 +30,6 @@ struct lttng_ust_jni_tls {
        int32_t ctx_strings_len;
 };
 
-extern __thread struct lttng_ust_jni_tls lttng_ust_context_info_tls;
+extern DECLARE_URCU_TLS(struct lttng_ust_jni_tls, lttng_ust_context_info_tls);
 
 #endif /* LIBLTTNG_UST_JAVA_AGENT_JNI_COMMON_LTTNG_UST_CONTEXT_H_ */

diff --git a/liblttng-ust-libc-wrapper/lttng-ust-malloc.c b/liblttng-ust-libc-wrapper/lttng-ust-malloc.c
index f3e1e19e28e52d8d5fe07d399f6c4741d0d87282..f30a2c694372970c7f68581364075a67534dbeb4 100644 (file)
--- a/liblttng-ust-libc-wrapper/lttng-ust-malloc.c
+++ b/liblttng-ust-libc-wrapper/lttng-ust-malloc.c
@@ -95,7 +95,7 @@ void ust_malloc_spin_unlock(pthread_mutex_t *lock)
 #define calloc static_calloc
 #define pthread_mutex_lock ust_malloc_spin_lock
 #define pthread_mutex_unlock ust_malloc_spin_unlock
-static DEFINE_URCU_TLS(int, malloc_nesting);
+static DEFINE_URCU_TLS_IE(int, malloc_nesting);
 #undef ust_malloc_spin_unlock
 #undef ust_malloc_spin_lock
 #undef calloc

diff --git a/liblttng-ust-libc-wrapper/lttng-ust-pthread.c b/liblttng-ust-libc-wrapper/lttng-ust-pthread.c
index 7836ffa02175d7599e4472403964b1b1069f4c33..6554a47afe7057f3b8c2c21147574c2f77d5ad09 100644 (file)
--- a/liblttng-ust-libc-wrapper/lttng-ust-pthread.c
+++ b/liblttng-ust-libc-wrapper/lttng-ust-pthread.c
@@ -23,6 +23,7 @@
  * libc.
  */
 #include <lttng/ust-dlfcn.h>
+#include <urcu/tls-compat.h>
 #include <helper.h>
 #include <pthread.h>
 
@@ -31,7 +32,7 @@
 #define TP_IP_PARAM ip
 #include "ust_pthread.h"
 
-static __thread int thread_in_trace;
+static DEFINE_URCU_TLS_IE(int, thread_in_trace);
 
 int pthread_mutex_lock(pthread_mutex_t *mutex)
 {

diff --git a/liblttng-ust/lttng-context-procname.c b/liblttng-ust/lttng-context-procname.c
index b6e69501d81c08bc79c5f82d9ff5b85d1d22230a..4b8da28f255aa56d74fe87c67f12cdd214680782 100644 (file)
--- a/liblttng-ust/lttng-context-procname.c
+++ b/liblttng-ust/lttng-context-procname.c
@@ -38,7 +38,7 @@
  * thread.
  */
 typedef char procname_array[17];
-static DEFINE_URCU_TLS(procname_array, cached_procname);
+static DEFINE_URCU_TLS_IE(procname_array, cached_procname);
 
 static inline
 char *wrapper_getprocname(void)

diff --git a/liblttng-ust/lttng-context-vtid.c b/liblttng-ust/lttng-context-vtid.c
index f28e470a38c91be3e88c7b1d1fcd42c591d73c67..8c9bbec56e67324bdaeeca71893197a58b571f38 100644 (file)
--- a/liblttng-ust/lttng-context-vtid.c
+++ b/liblttng-ust/lttng-context-vtid.c
@@ -34,7 +34,7 @@
  * We cache the result to ensure we don't trigger a system call for
  * each event.
  */
-static DEFINE_URCU_TLS(pid_t, cached_vtid);
+static DEFINE_URCU_TLS_IE(pid_t, cached_vtid);
 
 /*
  * Upon fork or clone, the TID assigned to our thread is not the same as

diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index 511b9cf4a88214c0225ff8a7e15a63cbca32145e..eec049b31fb2a09de4add833adac706e2e4168ce 100644 (file)
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -86,7 +86,7 @@ static int initialized;
 static pthread_mutex_t ust_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 /* Allow nesting the ust_mutex within the same thread. */
-static DEFINE_URCU_TLS(int, ust_mutex_nest);
+static DEFINE_URCU_TLS_IE(int, ust_mutex_nest);
 
 /*
  * ust_exit_mutex protects thread_active variable wrt thread exit. It

diff --git a/libringbuffer/ring_buffer_frontend.c b/libringbuffer/ring_buffer_frontend.c
index 331639f1e86826b2c67d186dfa8d0907df70f0d8..396b0064b5b13dd59cc4488008c9df9e2f75c9fb 100644 (file)
--- a/libringbuffer/ring_buffer_frontend.c
+++ b/libringbuffer/ring_buffer_frontend.c
@@ -118,7 +118,7 @@ struct switch_offsets {
                     switch_old_end:1;
 };
 
-DEFINE_URCU_TLS(unsigned int, lib_ring_buffer_nesting);
+DEFINE_URCU_TLS_IE(unsigned int, lib_ring_buffer_nesting);
 
 /*
  * wakeup_fd_mutex protects wakeup fd use by timer from concurrent

diff --git a/tests/test-app-ctx/hello.c b/tests/test-app-ctx/hello.c
index 197df21e1ada8bbc1d9e1cdadfc992ae522abd0c..f2859a7a13612318650abc313cafddd7c3b25e06 100644 (file)
--- a/tests/test-app-ctx/hello.c
+++ b/tests/test-app-ctx/hello.c
@@ -26,6 +26,7 @@
 #include <fcntl.h>
 #include <signal.h>
 #include <string.h>
+#include <urcu/tls-compat.h>
 /*
  * Work-around inet.h missing struct mmsghdr forward declaration, with
  * triggers a warning when system files warnings are enabled.
@@ -43,7 +44,7 @@ struct mmsghdr;
 #include <lttng/ringbuffer-config.h>
 #include <lttng/ust-context-provider.h>
 
-static __thread unsigned int test_count;
+static DEFINE_URCU_TLS_IE(unsigned int, test_count);
 
 void test_inc_count(void)
 {