Move pthread-locking stuff to "internal.h".

(_U_dyn_info_list_lock): Rename from "registration_lock" and change from r/w-lock
	to a simple mutex (spin) lock.
(_U_dyn_register): Insert into doubly-linked list.

(Logical change 1.30)

src/dyn-register.c

@@ -1,52 +1,19 @@
-#include <libunwind.h>
+#include "internal.h"
 
-#ifndef HAVE_CMP8XCHG16
+pthread_mutex_t _U_dyn_info_list_lock = PTHREAD_MUTEX_INITIALIZER;
 
-#include <pthread.h>
+void
-
-/* Make it easy to write thread-safe code which may or may not be
-   linked against libpthread.  The macros below can be used
-   unconditionally and if -lpthread is around, they'll call the
-   corresponding routines otherwise, they do nothing.  */
-
-#pragma weak pthread_rwlock_rdlock
-#pragma weak pthread_rwlock_wrlock
-#pragma weak pthread_rwlock_unlock
-
-#define rw_rdlock(l)    (pthread_rwlock_rdlock ? pthread_rwlock_rdlock (l) : 0)
-#define rw_wrlock(l)    (pthread_rwlock_wrlock ? pthread_rwlock_wrlock (l) : 0)
-#define rw_unlock(l)    (pthread_rwlock_unlock ? pthread_rwlock_unlock (l) : 0)
-
-static pthread_rwlock_t registration_lock = PTHREAD_RWLOCK_INITIALIZER;
-
-#endif
-
-extern unw_dyn_info_list_t _U_dyn_info_list;
-
-int
 _U_dyn_register (unw_dyn_info_t *di)
 {
-#ifdef HAVE_CMP8XCHG16
+  mutex_lock (&_U_dyn_info_list_lock);
-  unw_dyn_info_t *old_list_head, *new_list_head;
-  unsigned long old_gen, new_gen;
-
-  do
-    {
-      old_gen = _U_dyn_info_list.generation;
-      old_list_head = _U_dyn_info_list.first;
-
-      new_gen = old_gen + 1;
-      new_list_head = di;
-      di->next = old_list_head;
-    }
-  while (cmp8xchg16 (&_U_dyn_info_list, new_gen, new_list_head) != old_gen);
-#else
-  rw_wrlock (&registration_lock);
   {
     ++_U_dyn_info_list.generation;
+
     di->next = _U_dyn_info_list.first;
+    di->prev = NULL;
+    if (di->next)
+	    di->next->prev = di;
     _U_dyn_info_list.first = di;
   }
-  rw_unlock (&registration_lock);
+  mutex_unlock (&_U_dyn_info_list_lock);
-#endif
 }