[glib] Add g_system_thread_set_name() implementation for W32 threads

[Руслан Ижбулатов <ruslanizhb src gnome org>]

commit e118856430a798bbc529691ad235fd0b0684439d
Author: Руслан Ижбулатов <lrn1986 gmail com>
Date:   Tue Apr 7 20:05:45 2015 +0000

    Add g_system_thread_set_name() implementation for W32 threads
    
    This works by using semi-documented[1] exception to tell the debugger
    that a thread needs to have its name changed.
    
    If this exception is not caught and handled by something, it will crash
    the process, so we need to set up our own handler in case there's no
    debugger attached or the debugger can't handle this type of exception.
    
    Since SEH is not supported by gcc on i686 (at the moment), we need to use VEH
    instead. For completeness the MSVC-oriented code still uses SEH, although
    there is no reason why it shouldn't work with the VEH variant used by MinGW.
    
    VEH handler has to be set up somewhere (g_thread_win32_init () works nicely)
    and removed once it's not needed (g_thread_win32_process_detach () is added
    expressly for that purpose). Note that g_thread_win32_process_detach() is
    only called when glib is unloaded by FreeLibrary(), not when glib-using
    process is terminating.
    
    This exception is known to work with WinDbg, and adding support for it into
    GDB proved to be feasible (GDB patch will be sent upstream, eventually).
    
    [1] https://msdn.microsoft.com/en-us/library/xcb2z8hs%28v=vs.71%29.aspx
    
    https://bugzilla.gnome.org/show_bug.cgi?id=747478

 glib/glib-init.c     |    7 ++++
 glib/glib-init.h     |    1 +
 glib/gthread-win32.c |   79 +++++++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 86 insertions(+), 1 deletions(-)
---
diff --git a/glib/glib-init.c b/glib/glib-init.c
index 33dd4bf..5a5c215 100644
--- a/glib/glib-init.c
+++ b/glib/glib-init.c
@@ -273,6 +273,13 @@ DllMain (HINSTANCE hinstDLL,
 #endif
       break;
 
+    case DLL_PROCESS_DETACH:
+#ifdef THREADS_WIN32
+      if (lpvReserved == NULL)
+        g_thread_win32_process_detach ();
+#endif
+      break;
+
     default:
       /* do nothing */
       ;
diff --git a/glib/glib-init.h b/glib/glib-init.h
index e893d55..0cab67f 100644
--- a/glib/glib-init.h
+++ b/glib/glib-init.h
@@ -31,6 +31,7 @@ void g_quark_init (void);
 #ifdef G_OS_WIN32
 #include <windows.h>
 
+void g_thread_win32_process_detach (void);
 void g_thread_win32_thread_detach (void);
 void g_thread_win32_init (void);
 void g_clock_win32_init (void);
diff --git a/glib/gthread-win32.c b/glib/gthread-win32.c
index 275ecc6..8395acd 100644
--- a/glib/gthread-win32.c
+++ b/glib/gthread-win32.c
@@ -496,10 +496,67 @@ g_system_thread_wait (GRealThread *thread)
   win32_check_for_error (WAIT_FAILED != WaitForSingleObject (wt->handle, INFINITE));
 }
 
+#define EXCEPTION_SET_THREAD_NAME ((DWORD) 0x406D1388)
+
+#ifndef _MSC_VER
+static void *SetThreadName_VEH_handle = NULL;
+
+static LONG __stdcall
+SetThreadName_VEH (PEXCEPTION_POINTERS ExceptionInfo)
+{
+  if (ExceptionInfo->ExceptionRecord != NULL &&
+      ExceptionInfo->ExceptionRecord->ExceptionCode == EXCEPTION_SET_THREAD_NAME)
+    return EXCEPTION_CONTINUE_EXECUTION;
+
+  return EXCEPTION_CONTINUE_SEARCH;
+}
+#endif
+
+typedef struct _THREADNAME_INFO
+{
+  DWORD  dwType;       /* must be 0x1000 */
+  LPCSTR szName;       /* pointer to name (in user addr space) */
+  DWORD  dwThreadID;   /* thread ID (-1=caller thread) */
+  DWORD  dwFlags;      /* reserved for future use, must be zero */
+} THREADNAME_INFO;
+
+static void
+SetThreadName (DWORD  dwThreadID,
+               LPCSTR szThreadName)
+{
+   THREADNAME_INFO info;
+   DWORD infosize;
+
+   info.dwType = 0x1000;
+   info.szName = szThreadName;
+   info.dwThreadID = dwThreadID;
+   info.dwFlags = 0;
+
+   infosize = sizeof (info) / sizeof (DWORD);
+
+#ifdef _MSC_VER
+   __try
+     {
+       RaiseException (EXCEPTION_SET_THREAD_NAME, 0, infosize, (DWORD *) &info);
+     }
+   __except (EXCEPTION_EXECUTE_HANDLER)
+     {
+     }
+#else
+   /* Without a debugger we *must* have an exception handler,
+    * otherwise raising an exception will crash the process.
+    */
+   if ((!IsDebuggerPresent ()) && (SetThreadName_VEH_handle == NULL))
+     return;
+
+   RaiseException (EXCEPTION_SET_THREAD_NAME, 0, infosize, (DWORD *) &info);
+#endif
+}
+
 void
 g_system_thread_set_name (const gchar *name)
 {
-  /* FIXME: implement */
+  SetThreadName ((DWORD) -1, name);
 }
 
 /* {{{1 SRWLock and CONDITION_VARIABLE emulation (for Windows XP) */
@@ -988,6 +1045,14 @@ g_thread_win32_init (void)
     g_thread_xp_init ();
 
   InitializeCriticalSection (&g_private_lock);
+
+#ifndef _MSC_VER
+  SetThreadName_VEH_handle = AddVectoredExceptionHandler (1, &SetThreadName_VEH);
+  if (SetThreadName_VEH_handle == NULL)
+    {
+      /* This is bad, but what can we do? */
+    }
+#endif
 }
 
 void
@@ -1028,4 +1093,16 @@ g_thread_win32_thread_detach (void)
     g_thread_impl_vtable.CallThisOnThreadExit ();
 }
 
+void
+g_thread_win32_process_detach (void)
+{
+#ifndef _MSC_VER
+  if (SetThreadName_VEH_handle != NULL)
+    {
+      RemoveVectoredExceptionHandler (SetThreadName_VEH_handle);
+      SetThreadName_VEH_handle = NULL;
+    }
+#endif
+}
+
 /* vim:set foldmethod=marker: */