From 40aac94801f86355bd86cf5b340481ee2f501d3c Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Fri, 27 Aug 2004 22:33:54 -0400
Subject: re PR c++/13684 (local static object variable constructed once but
 ctors and dtors called multiple times on same memory when called in multiple
 threads)

        PR c++/13684
        * cp/decl.c (expand_static_init): Use thread-safety API.
        (register_dtor_fn): Return the call, don't expand it.
        * cp/tree.c (add_stmt_to_compound): New fn.
        (stabilize_call): Use it.
        * gimplify.c (gimplify_cleanup_point_expr): Handle CLEANUP_EH_ONLY.
        (gimple_push_cleanup): Add eh_only parm.
        (gimplify_target_expr): Pass it.
        * c.opt (-fno-threadsafe-statics): New option.
        * c-opts.c (c_common_handle_option): Handle it.
        * c-common.h (flag_threadsafe_statics): Declare it.
        * c-common.c (flag_threadsafe_statics): Record it.
        * doc/invoke.texi: Document it.
        * tsystem.h (_GNU_SOURCE): Define.
        * gthr-posix.h (__gthread_recursive_mutex_t): New typedef.
        (__GTHREAD_RECURSIVE_MUTEX_INIT): New macro.
        (__GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION): New macro.
        (__gthread_recursive_mutex_init_function): New fn.
        (__gthread_recursive_mutex_lock): New fn.
        (__gthread_recursive_mutex_trylock): New fn.
        (__gthread_recursive_mutex_unlock): New fn.
        * gthr-solaris.h, gthr-single.h, gthr-dce.h: Likewise.
        * gthr-win32.h, gthr-vxworks.h: Likewise.
        * gthr.h: Document.

        * libsupc++/guard.cc (static_mutex): Internal class implementing a
        recursive mutex which controls initialization of local statics.
        (__gnu_cxx::recursive_init): New exception class.
        (__cxa_guard_acquire): Deal with locking and recursion detection.
        (acquire_1, __cxa_guard_abort, __cxa_guard_release): Likewise.

From-SVN: r86687
---
 gcc/config/i386/gthr-win32.c | 70 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

(limited to 'gcc/config/i386/gthr-win32.c')

diff --git a/gcc/config/i386/gthr-win32.c b/gcc/config/i386/gthr-win32.c
index c53369b..6fb3cf8 100644
--- a/gcc/config/i386/gthr-win32.c
+++ b/gcc/config/i386/gthr-win32.c
@@ -182,3 +182,73 @@ __gthr_win32_mutex_unlock (__gthread_mutex_t *mutex)
   else
     return 0;
 }
+
+void
+__gthr_win32_recursive_mutex_init_function (__gthread_recursive_mutex_t *mutex)
+{
+  mutex->counter = -1;
+  mutex->depth = 0;
+  mutex->owner = 0;
+  mutex->sema = CreateSemaphore (NULL, 0, 65535, NULL);
+}
+
+int
+__gthr_win32_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex)
+{
+  DWORD me = GetCurrentThreadId();
+  if (InterlockedIncrement (&mutex->counter) == 0)
+    {
+      mutex->depth = 1;
+      mutex->owner = me;
+    }
+  else if (mutex->owner == me)
+    {
+      InterlockedDecrement (&mx->lock_idx);
+      ++(mutex->depth);
+    }
+  else if (WaitForSingleObject (mutex->sema, INFINITE) == WAIT_OBJECT_0)
+    {
+      mutex->depth = 1;
+      mutex->owner = me;
+    }
+  else
+    {
+      /* WaitForSingleObject returns WAIT_FAILED, and we can only do
+         some best-effort cleanup here.  */
+      InterlockedDecrement (&mutex->counter);
+      return 1;
+    }
+  return 0;
+}
+
+int
+__gthr_win32_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex)
+{
+  DWORD me = GetCurrentThreadId();
+  if (__GTHR_W32_InterlockedCompareExchange (&mutex->counter, 0, -1) < 0)
+    {
+      mutex->depth = 1;
+      mutex->owner = me;
+    }
+  else if (mutex->owner == me)
+    ++(mutex->depth);
+  else
+    return 1;
+
+  return 0;
+}
+
+int
+__gthr_win32_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex)
+{
+  --(mutex->depth);
+  if (mutex->depth == 0)
+    {
+      mutex->owner = 0;
+
+      if (InterlockedDecrement (&mutex->counter) >= 0)
+	return ReleaseSemaphore (mutex->sema, 1, NULL) ? 0 : 1;
+    }
+
+  return 0;
+}
-- 
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