From: Ivan Maidanski <ivmai@mail.ru>
Date: Tue, 17 Nov 2015 08:39:29 +0000 (+0300)
Subject: Allow specific TLS attributes for GC_thread_key
X-Git-Tag: gc7_6_0~110
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=02528757f439dfc5750e28fb3e5794303ccd21f9;p=gc

Allow specific TLS attributes for GC_thread_key

* doc/README.macros (GC_ATTR_TLS_FAST): Document.
* include/private/thread_local_alloc.h (GC_ATTR_TLS_FAST): New macro
(empty by default).
* include/private/thread_local_alloc.h (GC_thread_key): Use
GC_ATTR_TLS_FAST.
* thread_local_alloc.c (GC_thread_key): Likewise.
---

diff --git a/doc/README.macros b/doc/README.macros
index 09dedcf8..c3d27437 100644
--- a/doc/README.macros
+++ b/doc/README.macros
@@ -394,6 +394,9 @@ USE_COMPILER_TLS        Causes thread local allocation to use
   default in HP/UX.  It may help performance on recent Linux installations.
   (It failed for me on RedHat 8, but appears to work on RedHat 9.)
 
+GC_ATTR_TLS_FAST        Use specific attributes for GC_thread_key like
+  __attribute__((tls_model("local-exec"))).
+
 PARALLEL_MARK   Allows the marker to run in multiple threads.  Recommended
   for multiprocessors.
 
diff --git a/include/private/thread_local_alloc.h b/include/private/thread_local_alloc.h
index d5c5d580..9205bd83 100644
--- a/include/private/thread_local_alloc.h
+++ b/include/private/thread_local_alloc.h
@@ -162,13 +162,17 @@ GC_INNER void GC_mark_thread_local_fls_for(GC_tlfs p);
   GC_EXTERN ptr_t * GC_finalized_objfreelist;
 #endif
 
+#ifndef GC_ATTR_TLS_FAST
+# define GC_ATTR_TLS_FAST /* empty */
+#endif
+
 extern
 #if defined(USE_COMPILER_TLS)
-  __thread
+  __thread GC_ATTR_TLS_FAST
 #elif defined(USE_WIN32_COMPILER_TLS)
-  __declspec(thread)
+  __declspec(thread) GC_ATTR_TLS_FAST
 #endif
-GC_key_t GC_thread_key;
+  GC_key_t GC_thread_key;
 /* This is set up by the thread_local_alloc implementation.  No need    */
 /* for cleanup on thread exit.  But the thread support layer makes sure */
 /* that GC_thread_key is traced, if necessary.                          */
diff --git a/thread_local_alloc.c b/thread_local_alloc.c
index 29a337b2..9db324eb 100644
--- a/thread_local_alloc.c
+++ b/thread_local_alloc.c
@@ -24,9 +24,9 @@
 #include <stdlib.h>
 
 #if defined(USE_COMPILER_TLS)
-  __thread
+  __thread GC_ATTR_TLS_FAST
 #elif defined(USE_WIN32_COMPILER_TLS)
-  __declspec(thread)
+  __declspec(thread) GC_ATTR_TLS_FAST
 #endif
 GC_key_t GC_thread_key;