From 0f31431b38936983c803c10b241f55299818baad Mon Sep 17 00:00:00 2001
From: David Chisnall <dchisnall@pathscale.com>
Date: Thu, 24 Nov 2011 17:02:08 +0000
Subject: Add fake TLS support so that we work for single-threaded programs
 when not linked to pthread.

---
 src/exception.cc | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

(limited to 'src')

diff --git a/src/exception.cc b/src/exception.cc
index abf6a10..0896354 100644
--- a/src/exception.cc
+++ b/src/exception.cc
@@ -288,12 +288,25 @@ static void thread_cleanup(void* thread_info)
  */
 static pthread_once_t once_control = PTHREAD_ONCE_INIT;
 
+/**
+ * We may not be linked against a full pthread implementation.  If we're not,
+ * then we need to fake the thread-local storage by storing 'thread-local'
+ * things in a global.
+ */
+static bool fakeTLS;
+/**
+ * Thread-local storage for a single-threaded program.
+ */
+static __cxa_thread_info singleThreadInfo;
 /**
  * Initialise eh_key.
  */
 static void init_key(void)
 {
 	pthread_key_create(&eh_key, thread_cleanup);
+	pthread_setspecific(eh_key, (void*)0x42);
+	fakeTLS = (pthread_getspecific(eh_key) != (void*)0x42);
+	pthread_setspecific(eh_key, 0);
 }
 
 /**
@@ -301,7 +314,11 @@ static void init_key(void)
  */
 static __cxa_thread_info *thread_info()
 {
-	pthread_once(&once_control, init_key);
+	if (pthread_once(&once_control, init_key))
+	{
+		fakeTLS = true;
+	}
+	if (fakeTLS) { return &singleThreadInfo; }
 	__cxa_thread_info *info = (__cxa_thread_info*)pthread_getspecific(eh_key);
 	if (0 == info)
 	{
@@ -316,6 +333,7 @@ static __cxa_thread_info *thread_info()
  */
 static __cxa_thread_info *thread_info_fast()
 {
+	if (fakeTLS) { return &singleThreadInfo; }
 	return (__cxa_thread_info*)pthread_getspecific(eh_key);
 }
 /**
-- 
cgit v1.2.3