gthr-win32.h: Wrap all functions in extern "C".

	* gthr-win32.h: Wrap all functions in extern "C".
	(__gthread_key_t): Typedef as unsigned long,
	not win32 DWORD.
	(__GTHREAD_ONCE_INIT): Use 0, not win32 FALSE.
	(__gthread_mutex_t): Typedef as void*, not win32 HANDLE.
	(__gthr_win32_once, __gthr_win32_key_create,
	__gthr_win32_key_delete, __gthr_win32_getspecific,
	__gthr_win32_setspecific, __gthr_win32_mutex_init_function,
	__gthr_win32_mutex_lock,__gthr_win32_mutex_trylock,
	__gthr_win32_mutex_unlock): Declare.
	(__gthread_once,__gthread_key_create,
	__gthread_key_delete, __gthread_getspecific,
	__gthread_setspecific, __gthread_mutex_init_function,
	__gthread_mutex_lock,__gthread_mutex_trylock,
	__gthread_mutex_unlock): Call corresponding
	__gthr_win32_* extern implementations if #defined
	__GTHREAD_HIDE_WIN32API.
	* config/i386/t-mingw32 (LIB2FUNCS_EXTRA): Set to
	$(srcdir)/config/i386/gthr-win32.c
	* config/i386/gthr-win32.c: New implementation file.
	(__gthr_win32_once, __gthr_win32_key_create,
	__gthr_win32_key_delete, __gthr_win32_getspecific,
	__gthr_win32_setspecific, __gthr_win32_mutex_init_function,
	__gthr_win32_mutex_lock,__gthr_win32_mutex_trylock,
	__gthr_win32_mutex_unlock): New functions, based on
	static inlines in gthr-win32.h.

From-SVN: r54484

1 files changed, 174 insertions, 0 deletions

diff --git a/gcc/config/i386/gthr-win32.c b/gcc/config/i386/gthr-win32.c
new file mode 100644
index 00000000000..06dc2045d24
--- /dev/null
+++ b/gcc/config/i386/gthr-win32.c
@@ -0,0 +1,174 @@
+/* Implementation of W32-specific threads compatibility routines for
+   libgcc2.   */ 
+
+/* Copyright (C) 1999, 2000, 2002 Free Software Foundation, Inc.
+   Contributed by Mumit Khan <khan@xraylith.wisc.edu>.
+   Modified and moved to separate file by Danny Smith
+   <dannysmith@users.sourceforge.net>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+02111-1307, USA.  */
+
+/* As a special exception, if you link this library with other files,
+   some of which are compiled with GCC, to produce an executable,
+   this library does not by itself cause the resulting executable
+   to be covered by the GNU General Public License.
+   This exception does not however invalidate any other reasons why
+   the executable file might be covered by the GNU General Public License.  */
+
+
+#ifndef __GTHREAD_HIDE_WIN32API
+# define __GTHREAD_HIDE_WIN32API
+#endif
+#include <gthr-win32.h>
+#include <windows.h>
+
+/* Windows32 threads specific definitions. The windows32 threading model
+   does not map well into pthread-inspired gcc's threading model, and so 
+   there are caveats one needs to be aware of.
+
+   1. The destructor supplied to __gthread_key_create is ignored for
+      generic x86-win32 ports. This will certainly cause memory leaks 
+      due to unreclaimed eh contexts (sizeof (eh_context) is at least 
+      24 bytes for x86 currently).
+
+      This memory leak may be significant for long-running applications
+      that make heavy use of C++ EH.
+
+      However, Mingw runtime (version 0.3 or newer) provides a mechanism
+      to emulate pthreads key dtors; the runtime provides a special DLL,
+      linked in if -mthreads option is specified, that runs the dtors in
+      the reverse order of registration when each thread exits. If
+      -mthreads option is not given, a stub is linked in instead of the
+      DLL, which results in memory leak. Other x86-win32 ports can use 
+      the same technique of course to avoid the leak.
+
+   2. The error codes returned are non-POSIX like, and cast into ints.
+      This may cause incorrect error return due to truncation values on 
+      hw where sizeof (DWORD) > sizeof (int).
+   
+   3. We might consider using Critical Sections instead of Windows32 
+      mutexes for better performance, but emulating __gthread_mutex_trylock 
+      interface becomes more complicated (Win9x does not support
+      TryEnterCriticalSectioni, while NT does).
+  
+   The basic framework should work well enough. In the long term, GCC
+   needs to use Structured Exception Handling on Windows32.  */
+
+int
+__gthr_win32_once (__gthread_once_t *once, void (*func) (void))
+{
+  if (once == NULL || func == NULL)
+    return EINVAL;
+
+  if (! once->done)
+    {
+      if (InterlockedIncrement (&(once->started)) == 0)
+        {
+	  (*func) ();
+	  once->done = TRUE;
+	}
+      else
+	{
+	  /* Another thread is currently executing the code, so wait for it 
+	     to finish; yield the CPU in the meantime.  If performance 
+	     does become an issue, the solution is to use an Event that 
+	     we wait on here (and set above), but that implies a place to 
+	     create the event before this routine is called.  */ 
+	  while (! once->done)
+	    Sleep (0);
+	}
+    }
+  return 0;
+}
+
+/* Windows32 thread local keys don't support destructors; this leads to
+   leaks, especially in threaded applications making extensive use of 
+   C++ EH. Mingw uses a thread-support DLL to work-around this problem.  */
+
+int
+__gthr_win32_key_create (__gthread_key_t *key, void (*dtor) (void *))
+{
+  int status = 0;
+  DWORD tls_index = TlsAlloc ();
+  if (tls_index != 0xFFFFFFFF)
+    {
+      *key = tls_index;
+#ifdef MINGW32_SUPPORTS_MT_EH
+      /* Mingw runtime will run the dtors in reverse order for each thread
+         when the thread exits.  */
+      status = __mingwthr_key_dtor (*key, dtor);
+#endif
+    }
+  else
+    status = (int) GetLastError ();
+  return status;
+}
+
+int
+__gthr_win32_key_delete (__gthread_key_t key)
+{
+  return (TlsFree (key) != 0) ? 0 : (int) GetLastError ();
+}
+
+void *
+__gthr_win32_getspecific (__gthread_key_t key)
+{
+  DWORD lasterror;
+  void *ptr;
+  lasterror = GetLastError();
+  ptr = TlsGetValue(key);
+  SetLastError( lasterror );
+  return ptr;
+}
+
+int
+__gthr_win32_setspecific (__gthread_key_t key, const void *ptr)
+{
+  return (TlsSetValue (key, (void*) ptr) != 0) ? 0 : (int) GetLastError ();
+}
+
+void
+__gthr_win32_mutex_init_function (__gthread_mutex_t *mutex)
+{
+  /* Create unnamed mutex with default security attr and no initial owner.  */ 
+  *mutex = CreateMutex (NULL, 0, NULL);
+}
+
+int
+__gthr_win32_mutex_lock (__gthread_mutex_t *mutex)
+{
+  if (WaitForSingleObject (*mutex, INFINITE) == WAIT_OBJECT_0)
+    return 0;
+  else
+    return 1;
+}
+
+int
+__gthr_win32_mutex_trylock (__gthread_mutex_t *mutex)
+{
+  if (WaitForSingleObject (*mutex, 0) == WAIT_OBJECT_0)
+    return 0;
+  else
+    return 1;
+}
+
+int
+__gthr_win32_mutex_unlock (__gthread_mutex_t *mutex)
+{
+    return (ReleaseMutex (*mutex) != 0) ? 0 : 1;
+}