From: Laszlo Ersek <lersek@redhat.com>
To: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
Cc: "libaiqing@huawei.com" <libaiqing@huawei.com>,
"mdroth@linux.vnet.ibm.com" <mdroth@linux.vnet.ibm.com>,
"stefanha@gmail.com" <stefanha@gmail.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
"lcapitulino@redhat.com" <lcapitulino@redhat.com>,
"vrozenfe@redhat.com" <vrozenfe@redhat.com>,
"pbonzini@redhat.com" <pbonzini@redhat.com>,
Seiji Aguchi <seiji.aguchi@hds.com>,
"areis@redhat.com" <areis@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v4 06/10] qemu-ga: Add Windows VSS provider to quiesce applications on fsfreeze
Date: Fri, 28 Jun 2013 12:44:36 +0200 [thread overview]
Message-ID: <51CD6914.5060601@redhat.com> (raw)
In-Reply-To: <CDF1DFE4.30A0%Tomoki.Sekiyama@hds.com>
>>>>> +STDAPI DllCanUnloadNow()
>>>>> +{
>>>>> + return g_nComObjsInUse == 0 ? S_OK : S_FALSE;
>>>>> +}
>>
>> Don't you need some kind of atomic or locked read here? We could read a
>> stale value here. Granted, most stale values would err on the safe side
>> (ie. read >0 instead of ==0), but in theory the other mistake is
>> possible, no?
>
> MSDN says "Simple reads and writes to properly-aligned 32bit variables
> are atomic", and I couldn't find a function to atomic read provided.
> (Maybe InterlockedCompareExchange(&g_nComObjsInUse, 0, 0)...?)
Alright then. Thanks!
Laszlo
next prev parent reply other threads:[~2013-06-28 10:42 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-06 15:06 [Qemu-devel] [PATCH v4 00/10] qemu-ga: fsfreeze on Windows using VSS Tomoki Sekiyama
2013-06-06 15:06 ` [Qemu-devel] [PATCH v4 01/10] configure: Support configuring c++ compiler Tomoki Sekiyama
2013-06-18 10:17 ` Paolo Bonzini
2013-06-25 8:15 ` Laszlo Ersek
2013-06-06 15:06 ` [Qemu-devel] [PATCH v4 02/10] Add c++ keywords to QAPI helper script Tomoki Sekiyama
2013-06-25 8:16 ` Laszlo Ersek
2013-06-06 15:06 ` [Qemu-devel] [PATCH v4 03/10] checkpatch.pl: check .cpp files Tomoki Sekiyama
2013-06-25 8:17 ` Laszlo Ersek
2013-06-06 15:06 ` [Qemu-devel] [PATCH v4 04/10] Add a script to extract VSS SDK headers on POSIX system Tomoki Sekiyama
2013-06-25 8:30 ` Laszlo Ersek
2013-06-25 15:01 ` Laszlo Ersek
2013-06-25 15:01 ` Paolo Bonzini
2013-06-26 10:52 ` Laszlo Ersek
2013-06-06 15:06 ` [Qemu-devel] [PATCH v4 05/10] qemu-ga: Add configure options to specify path to Windows/VSS SDK Tomoki Sekiyama
2013-06-25 11:16 ` Laszlo Ersek
2013-06-28 10:43 ` Daniel P. Berrange
2013-06-28 10:54 ` Paolo Bonzini
2013-06-28 11:01 ` Daniel P. Berrange
2013-06-28 11:18 ` Paolo Bonzini
2013-06-28 11:30 ` Daniel P. Berrange
2013-06-28 12:18 ` Paolo Bonzini
2013-06-28 11:05 ` Laszlo Ersek
2013-06-06 15:06 ` [Qemu-devel] [PATCH v4 06/10] qemu-ga: Add Windows VSS provider to quiesce applications on fsfreeze Tomoki Sekiyama
2013-06-25 16:03 ` Laszlo Ersek
2013-06-25 16:19 ` Paolo Bonzini
2013-06-25 18:23 ` Tomoki Sekiyama
2013-06-25 18:59 ` Paolo Bonzini
2013-06-25 19:28 ` Tomoki Sekiyama
2013-06-25 19:52 ` Laszlo Ersek
2013-06-26 14:32 ` Laszlo Ersek
2013-06-26 21:27 ` Paolo Bonzini
2013-06-26 22:09 ` Tomoki Sekiyama
2013-06-27 15:01 ` Laszlo Ersek
2013-06-27 22:25 ` Tomoki Sekiyama
2013-06-28 7:05 ` Paolo Bonzini
2013-06-28 10:40 ` Laszlo Ersek
2013-06-28 10:40 ` Paolo Bonzini
2013-06-28 17:18 ` Tomoki Sekiyama
2013-06-28 10:44 ` Laszlo Ersek [this message]
2013-06-25 21:15 ` Paolo Bonzini
2013-06-25 22:31 ` Tomoki Sekiyama
2013-06-26 5:59 ` Paolo Bonzini
2013-06-26 14:13 ` Tomoki Sekiyama
2013-06-30 13:16 ` Gal Hammer
2013-07-01 18:57 ` Tomoki Sekiyama
2013-07-02 12:36 ` Gal Hammer
2013-06-06 15:06 ` [Qemu-devel] [PATCH v4 07/10] qemu-ga: Add Windows VSS requester to quiesce applications and filesystems Tomoki Sekiyama
2013-06-28 18:01 ` Laszlo Ersek
2013-06-28 18:34 ` Laszlo Ersek
2013-06-30 1:21 ` Tomoki Sekiyama
2013-07-01 8:31 ` Laszlo Ersek
2013-06-06 15:06 ` [Qemu-devel] [PATCH v4 08/10] qemu-ga: call Windows VSS requester in fsfreeze command handler Tomoki Sekiyama
2013-07-01 13:29 ` Laszlo Ersek
2013-07-01 17:48 ` Eric Blake
2013-07-01 17:59 ` Tomoki Sekiyama
2013-07-02 6:36 ` Laszlo Ersek
2013-07-02 14:09 ` Luiz Capitulino
2013-07-02 14:44 ` Laszlo Ersek
2013-07-02 15:16 ` Luiz Capitulino
2013-07-02 15:28 ` Laszlo Ersek
2013-07-02 14:58 ` Michael Roth
2013-06-06 15:06 ` [Qemu-devel] [PATCH v4 09/10] qemu-ga: install Windows VSS provider on `qemu-ga -s install' Tomoki Sekiyama
2013-07-01 14:50 ` Laszlo Ersek
2013-07-01 17:59 ` Tomoki Sekiyama
2013-06-06 15:07 ` [Qemu-devel] [PATCH v4 10/10] QMP/qemu-ga-client: make timeout longer for guest-fsfreeze-freeze command Tomoki Sekiyama
2013-06-18 10:17 ` Paolo Bonzini
2013-07-01 15:02 ` Laszlo Ersek
2013-06-10 9:26 ` [Qemu-devel] [PATCH v4 00/10] qemu-ga: fsfreeze on Windows using VSS Stefan Hajnoczi
2013-06-24 19:30 ` Tomoki Sekiyama
2013-06-24 21:13 ` Laszlo Ersek
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