Attachment 123607 Details for Bug 95191 – On Windows make access to member 'refcount' of struct DBusBabysitter thread save.

[patch] On Windows make access to member 'refcount' of struct DBusBabysitter thread save.

0002-On-Windows-make-access-to-member-refcount-of-struct-DB.txt (text/plain), 3.79 KB, created by Ralf Habacker on 2016-05-10 15:06:14 UTC

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Creator: Ralf Habacker

Created: 2016-05-10 15:06:14 UTC

Size: 3.79 KB

patch

obsolete

>From 5bd460ecf027bb36ffd21d325739bb51df94521f Mon Sep 17 00:00:00 2001
>From: Ralf Habacker <ralf.habacker@freenet.de>
>Date: Tue, 10 May 2016 16:53:57 +0200
>Subject: [PATCH 2/2] On Windows make access to member 'refcount' of struct
> DBusBabysitter thread save.
>
>Bug: https://bugs.freedesktop.org/show_bug.cgi?id=95191
>---
> dbus/dbus-internals.h |  1 +
> dbus/dbus-spawn-win.c | 42 +++++++++++++++++++++++++++++++++++-------
> dbus/dbus-sysdeps.h   |  3 +++
> 3 files changed, 39 insertions(+), 7 deletions(-)
>
>diff --git a/dbus/dbus-internals.h b/dbus/dbus-internals.h
>index 82950a0..7ec77e5 100644
>--- a/dbus/dbus-internals.h
>+++ b/dbus/dbus-internals.h
>@@ -124,6 +124,7 @@ static void _dbus_verbose(const char * x,...) {;}
> #  define _dbus_is_verbose() FALSE 
> #endif /* !DBUS_ENABLE_VERBOSE_MODE */
> 
>+DBUS_PRIVATE_EXPORT
> void _dbus_trace_ref (const char *obj_name,
>                       void       *obj,
>                       int         old_refcount,
>diff --git a/dbus/dbus-spawn-win.c b/dbus/dbus-spawn-win.c
>index 964888f..516cc9d 100644
>--- a/dbus/dbus-spawn-win.c
>+++ b/dbus/dbus-spawn-win.c
>@@ -60,7 +60,7 @@
>  */
> struct DBusBabysitter
>   {
>-    int refcount;
>+    DBusAtomic refcount;
> 
>     HANDLE start_sync_event;
> #ifdef DBUS_ENABLE_EMBEDDED_TESTS
>@@ -89,16 +89,40 @@ struct DBusBabysitter
>     int child_status;
>   };
> 
>+static void
>+_dbus_babysitter_trace_ref (DBusBabysitter *sitter,
>+                            int old_refcount,
>+                            int new_refcount,
>+                            const char *why);
>+
>+void
>+_dbus_babysitter_trace_ref (DBusBabysitter *sitter,
>+    int old_refcount,
>+    int new_refcount,
>+    const char *why)
>+{
>+#ifdef DBUS_ENABLE_VERBOSE_MODE
>+  static int enabled = -1;
>+
>+  _dbus_trace_ref ("DBusBabysitter", sitter, old_refcount, new_refcount, why,
>+      "DBUS_BABYSITTER_TRACE", &enabled);
>+#endif
>+}
>+
> static DBusBabysitter*
> _dbus_babysitter_new (void)
> {
>   DBusBabysitter *sitter;
>+  static int enabled = -1;
>+  dbus_int32_t old_refcount;
> 
>   sitter = dbus_new0 (DBusBabysitter, 1);
>   if (sitter == NULL)
>     return NULL;
> 
>-  sitter->refcount = 1;
>+  old_refcount = _dbus_atomic_inc (&sitter->refcount);
>+
>+  _dbus_babysitter_trace_ref (sitter, old_refcount, old_refcount+1, __FUNCTION__);
> 
>   sitter->start_sync_event = CreateEvent (NULL, FALSE, FALSE, NULL);
>   if (sitter->start_sync_event == NULL)
>@@ -146,11 +170,13 @@ _dbus_babysitter_new (void)
> DBusBabysitter *
> _dbus_babysitter_ref (DBusBabysitter *sitter)
> {
>+  dbus_int32_t old_refcount;
>   PING();
>   _dbus_assert (sitter != NULL);
>-  _dbus_assert (sitter->refcount > 0);
>+  _dbus_assert (_dbus_atomic_get (&sitter->refcount) > 0);
> 
>-  sitter->refcount += 1;
>+  old_refcount = _dbus_atomic_inc (&sitter->refcount);
>+  _dbus_babysitter_trace_ref (sitter, old_refcount, old_refcount+1, __FUNCTION__);
> 
>   return sitter;
> }
>@@ -185,14 +211,16 @@ void
> _dbus_babysitter_unref (DBusBabysitter *sitter)
> {
>   int i;
>+  dbus_int32_t old_refcount;
> 
>   PING();
>   _dbus_assert (sitter != NULL);
>-  _dbus_assert (sitter->refcount > 0);
>+  _dbus_assert (_dbus_atomic_get (&sitter->refcount) > 0);
> 
>-  sitter->refcount -= 1;
>+  old_refcount = _dbus_atomic_dec (&sitter->refcount);
>+  _dbus_babysitter_trace_ref (sitter, old_refcount, old_refcount-1, __FUNCTION__);
> 
>-  if (sitter->refcount == 0)
>+  if (old_refcount == 1)
>     {
>       close_socket_to_babysitter (sitter);
> 
>diff --git a/dbus/dbus-sysdeps.h b/dbus/dbus-sysdeps.h
>index 29356e1..00967dd 100644
>--- a/dbus/dbus-sysdeps.h
>+++ b/dbus/dbus-sysdeps.h
>@@ -296,8 +296,11 @@ struct DBusAtomic
> #   undef DBUS_HAVE_ATOMIC_INT
> #endif
> 
>+DBUS_PRIVATE_EXPORT
> dbus_int32_t _dbus_atomic_inc (DBusAtomic *atomic);
>+DBUS_PRIVATE_EXPORT
> dbus_int32_t _dbus_atomic_dec (DBusAtomic *atomic);
>+DBUS_PRIVATE_EXPORT
> dbus_int32_t _dbus_atomic_get (DBusAtomic *atomic);
> 
> #ifdef DBUS_WIN
>-- 
>1.8.4.5
>

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Attachments on bug 95191: 123326 | 123585 | 123606 | 123607 | 123615 | 123616 | 123655 | 123656 | 123657 | 123660 | 123661 | 123662 | 123682 | 123695 | 123738 | 123739 | 123740 | 123741 | 123742 | 123754 | 123779 | 123782 | 123783 | 123830 | 123913 | 123936 | 125072 | 125075

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