Fix a race condition in the lock-file manager: once the lock file is

gone, check for the actual file we care about.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172033 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Douglas Gregor 2013-01-10 02:01:35 +00:00
parent 06c7008e30
commit 69a2d6f55a
2 changed files with 14 additions and 3 deletions

View File

@ -41,6 +41,7 @@ public:
};
private:
SmallString<128> FileName;
SmallString<128> LockFileName;
SmallString<128> UniqueLockFileName;

View File

@ -64,6 +64,7 @@ bool LockFileManager::processStillExecuting(StringRef Hostname, int PID) {
LockFileManager::LockFileManager(StringRef FileName)
{
this->FileName = FileName;
LockFileName = FileName;
LockFileName += ".lock";
@ -175,6 +176,7 @@ void LockFileManager::waitForUnlock() {
#endif
// Don't wait more than an hour for the file to appear.
const unsigned MaxSeconds = 3600;
bool LockFileGone = false;
do {
// Sleep for the designated interval, to allow the owning process time to
// finish up and remove the lock file.
@ -185,10 +187,18 @@ void LockFileManager::waitForUnlock() {
#else
nanosleep(&Interval, NULL);
#endif
// If the file no longer exists, we're done.
// If the lock file no longer exists, wait for the actual file.
bool Exists = false;
if (!sys::fs::exists(LockFileName.str(), Exists) && !Exists)
return;
if (!LockFileGone) {
if (!sys::fs::exists(LockFileName.str(), Exists) && !Exists) {
LockFileGone = true;
Exists = false;
}
}
if (LockFileGone) {
if (!sys::fs::exists(FileName.str(), Exists) && Exists)
return;
}
if (!processStillExecuting((*Owner).first, (*Owner).second))
return;