[waffle] [PATCH 3/4] core: Support systems without thread-local storage

[Chad Versace]

XCode 3.1 ships with an old version of clang that does not support TLS.
There are Waffle users that require support for Mac OS 10.5, for which
XCode 3.1 is the last supported version.

Signed-off-by: Chad Versace <chad.versace at linux.intel.com>
---
 src/waffle/core/wcore_tinfo.c | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/waffle/core/wcore_tinfo.c b/src/waffle/core/wcore_tinfo.c
index da57b82..4184b52 100644
--- a/src/waffle/core/wcore_tinfo.c
+++ b/src/waffle/core/wcore_tinfo.c
@@ -1,4 +1,4 @@
-// Copyright 2012 Intel Corporation
+// Copyright 2012-2013 Intel Corporation
 //
 // All rights reserved.
 //
@@ -41,6 +41,7 @@
 static pthread_once_t wcore_tinfo_once = PTHREAD_ONCE_INIT;
 static pthread_key_t wcore_tinfo_key;
 
+#ifdef WAFFLE_HAS_TLS
 /// @brief Thread-local storage for all of Waffle.
 ///
 /// For documentation on the tls_model, see the GCC manual [1] and
@@ -51,12 +52,12 @@ static pthread_key_t wcore_tinfo_key;
 ///
 /// [2] Ulrich Drepper. "Elf Handling For Thread Local Storage".
 ///     http://people.redhat.com/drepper/tls.pdf
-
 static __thread struct wcore_tinfo wcore_tinfo
 #ifdef WAFFLE_HAS_TLS_MODEL_INITIAL_EXEC
     __attribute__((tls_model("initial-exec")))
 #endif
     ;
+#endif // WAFFLE_HAS_TLS
 
 static void __attribute__((noreturn))
 wcore_tinfo_abort_init(void)
@@ -73,6 +74,10 @@ wcore_tinfo_key_dtor(void *args)
         return;
 
     wcore_error_tinfo_destroy(tinfo->error);
+
+#ifndef WAFFLE_HAS_TLS
+    free(tinfo);
+#endif
 }
 
 static void
@@ -99,6 +104,7 @@ wcore_tinfo_init(struct wcore_tinfo *tinfo)
 
     tinfo->is_init = true;
 
+#ifdef WAFFLE_HAS_TLS
     // Register tinfo with the key's destructor to prevent memory leaks at
     // thread exit. The destructor must be registered once per process, but
     // each instance of tinfo must be registered individually. The key's data
@@ -107,6 +113,7 @@ wcore_tinfo_init(struct wcore_tinfo *tinfo)
     err = pthread_once(&wcore_tinfo_once, wcore_tinfo_key_create);
     if (err)
         wcore_tinfo_abort_init();
+#endif
 
     err = pthread_setspecific(wcore_tinfo_key, tinfo);
     if (err)
@@ -116,8 +123,28 @@ wcore_tinfo_init(struct wcore_tinfo *tinfo)
 struct wcore_tinfo*
 wcore_tinfo_get(void)
 {
+#ifdef WAFFLE_HAS_TLS
     wcore_tinfo_init(&wcore_tinfo);
     return &wcore_tinfo;
+#else
+    int err;
+    struct wcore_tinfo *tinfo;
+
+    err = pthread_once(&wcore_tinfo_once, wcore_tinfo_key_create);
+    if (err)
+        wcore_tinfo_abort_init();
+
+    tinfo = pthread_getspecific(wcore_tinfo_key);
+    if (tinfo)
+        return tinfo;
+
+    tinfo = malloc(sizeof(*tinfo));
+    if (!tinfo)
+        wcore_tinfo_abort_init();
+
+    wcore_tinfo_init(tinfo);
+    return tinfo;
+#endif
 }
 
 /// @}
-- 
1.8.3.1