FSEvents file system watcher: Do not watch whole parent hierarchies.

Unfortunately the FSEvents implementation for watching parent
hierarchies has the major flaw, that watching a path will then
create watches for the whole parent hierarchy even if that
hierarchy is already watched. Watching /A/B/C and /A/B/D will
create two watches each for /A and /A/B. This leads to an explosion
of open file handles.
Luckily we do not need to watch the parent hierarchy since this
is not a supported usecase of QFileSystemWatcher anyhow, so just don't
do it.

Task-number: QTCREATORBUG-13531
Change-Id: I9ecb5f08e4be35e4fbd58a7ca3155867fcb1589f
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
This commit is contained in:
Eike Ziller 2014-12-01 09:10:43 +01:00 committed by Jani Heikkinen
parent a2da88712f
commit 03b5ecce4a

View File

@ -518,7 +518,6 @@ bool QFseventsFileSystemWatcherEngine::startStream()
NULL
};
const CFAbsoluteTime latency = .5; // in seconds
FSEventStreamCreateFlags flags = kFSEventStreamCreateFlagWatchRoot;
// Never start with kFSEventStreamEventIdSinceNow, because this will generate an invalid
// soft-assert in FSEventStreamFlushSync in CarbonCore when no event occurred.
@ -530,7 +529,7 @@ bool QFseventsFileSystemWatcherEngine::startStream()
reinterpret_cast<CFArrayRef>(pathsToWatch),
lastReceivedEvent,
latency,
flags);
FSEventStreamCreateFlags(0));
if (!stream) {
DEBUG() << "Failed to create stream!";