From 7f1f9e14afe5170faba0c19c0732f54bd7982184 Mon Sep 17 00:00:00 2001
From: Kai Koehne <kai.koehne@nokia.com>
Date: Fri, 28 May 2010 13:45:53 +0200
Subject: [PATCH] Fix crashes when loading large .qmlproject's (Mac OS X)
There is a hard limit on the number of file handles that can be open at one point per process on Mac OS X (e.g. it's 2560 on Mac OS X Snow Leopard Server, as shown by ulimit -a). Opening one or several .qmlproject's with a large number of directories to watch easily exceeds this. The results are crashes later on, e.g. when threads cannot be created any more.
This patch implements a heuristic that the file system watcher used for .qmlproject files never uses more than half the number of available file handles. It also increases the number from rlim_cur to rlim_max - the old code in main.cpp failed, see last section in
http://developer.apple.com/maac/library/documentation/Darwin/Reference/ManPages/man2/setrlimit.2.html
for details.
Reviewed-by: ckamm
Task-number: QTCREATORBUG-1487
Task-number: QTCREATORBUG-1486
---
src/app/main.cpp | 3 +-
.../fileformat/filesystemwatcher.cpp | 35 +++++++++++++++++++
2 files changed, 37 insertions(+), 1 deletion(-)
diff --git a/src/app/main.cpp b/src/app/main.cpp
index af205c30fbd..efbbd311deb 100644
--- a/src/app/main.cpp
+++ b/src/app/main.cpp
@@ -173,7 +173,8 @@ int main(int argc, char **argv)
// increase the number of file that can be opened in Qt Creator.
struct rlimit rl;
getrlimit(RLIMIT_NOFILE, &rl);
- rl.rlim_cur = rl.rlim_max;
+
+ rl.rlim_cur = qMin((rlim_t)OPEN_MAX, rl.rlim_max);
setrlimit(RLIMIT_NOFILE, &rl);
#endif
diff --git a/src/plugins/qmlprojectmanager/fileformat/filesystemwatcher.cpp b/src/plugins/qmlprojectmanager/fileformat/filesystemwatcher.cpp
index 1f898ff48f5..eb4b79f1a83 100644
--- a/src/plugins/qmlprojectmanager/fileformat/filesystemwatcher.cpp
+++ b/src/plugins/qmlprojectmanager/fileformat/filesystemwatcher.cpp
@@ -72,6 +72,19 @@ void FileSystemWatcher::addFile(const QString &file)
addFiles(QStringList(file));
}
+
+#ifdef Q_OS_MAC
+
+// Returns upper limit of file handles that can be opened by this process at once. Exceeding it will probably result in crashes!
+static rlim_t getFileLimit()
+{
+ struct rlimit rl;
+ getrlimit(RLIMIT_NOFILE, &rl);
+ return rl.rlim_cur;
+}
+
+#endif
+
void FileSystemWatcher::addFiles(const QStringList &files)
{
QStringList toAdd;
@@ -84,6 +97,17 @@ void FileSystemWatcher::addFiles(const QStringList &files)
qWarning() << "FileSystemWatcher: File" << file << "is already being watched";
continue;
}
+
+#ifdef Q_OS_MAC
+ static rlim_t maxFileOpen = getFileLimit();
+ // We're potentially watching a _lot_ of directories. This might crash qtcreator when we hit the upper limit.
+ // Heuristic is therefore: Don't use more than half of the file handles available in this watcher
+ if ((rlim_t)m_directories.size() + (rlim_t)m_files.size() > maxFileOpen / 2) {
+ qWarning() << "File" << file << "is not watched: Too many file handles are already open (max is" << maxFileOpen;
+ break;
+ }
+#endif
+
m_files.append(file);
const int count = ++m_fileCount[file];
@@ -149,6 +173,17 @@ void FileSystemWatcher::addDirectories(const QStringList &directories)
qWarning() << "Directory" << directory << "is already being watched";
continue;
}
+
+#ifdef Q_OS_MAC
+ static rlim_t maxFileOpen = getFileLimit();
+ // We're potentially watching a _lot_ of directories. This might crash qtcreator when we hit the upper limit.
+ // Heuristic is therefore: Don't use more than half of the file handles available in this watcher
+ if ((rlim_t)m_directories.size() + (rlim_t)m_files.size() > maxFileOpen / 2) {
+ qWarning() << "Directory" << directory << "is not watched: Too many file handles are already open (max is" << maxFileOpen;
+ break;
+ }
+#endif
+
m_directories.append(directory);
const int count = ++m_directoryCount[directory];
--
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