This has a whiff of the double-checked locking anti-pattern. I can't see a way where it would really bite us in this case, but that anti- pattern has several subtleties. So, I just wanted to prompt people to double-check it (pun acknowledged).
Cheers, Ken
On Mar 18, 2008, at 7:44 AM, Alexandre Julliard wrote:
Module: wine Branch: master Commit: 15907b5035ea7f03b369a0463ab1f6ac2b24704e URL: http://source.winehq.org/git/wine.git/?a=commit;h=15907b5035ea7f03b369a0463a...
Author: Maarten Lankhorst m.b.lankhorst@gmail.com Date: Mon Mar 17 13:15:42 2008 -0700
winmm: Fix midi deadlock by not holding lock on release.
dlls/winmm/mci.c | 22 ++++++++++++++-------- 1 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/dlls/winmm/mci.c b/dlls/winmm/mci.c index b7b5ac2..c792d18 100644 --- a/dlls/winmm/mci.c +++ b/dlls/winmm/mci.c @@ -1767,19 +1767,25 @@ static DWORD MCI_Close(UINT16 wDevID, DWORD dwParam, LPMCI_GENERIC_PARMS lpParms TRACE("(%04x, %08X, %p)\n", wDevID, dwParam, lpParms);
if (wDevID == MCI_ALL_DEVICE_ID) {
- LPWINE_MCIDRIVER next;
- EnterCriticalSection(&WINMM_cs); /* FIXME: shall I notify once after all is done, or for
*/
- each of the open drivers ? if the latest, which notif
- to return when only one fails ?
- for (wmd = MciDrivers; wmd; ) {
next = wmd->lpNext;MCI_Close(wmd->wDeviceID, dwParam, lpParms);wmd = next;
- while (MciDrivers) {
/* Retrieve the device ID under lock, but send themessage without,
* the driver might be calling some winmm functionsfrom another
* thread before being fully stopped.*/EnterCriticalSection(&WINMM_cs);if (!MciDrivers){LeaveCriticalSection(&WINMM_cs);break;}wDevID = MciDrivers->wDeviceID;LeaveCriticalSection(&WINMM_cs);MCI_Close(wDevID, dwParam, lpParms);
- LeaveCriticalSection(&WINMM_cs); return 0; }