From 1fc08f5e9ef733ef1ce6f363fecedc2260e78974 Mon Sep 17 00:00:00 2001
From: dim <dim@FreeBSD.org>
Date: Sat, 14 Apr 2012 13:54:10 +0000
Subject: Vendor import of llvm trunk r154661:
http://llvm.org/svn/llvm-project/llvm/trunk@r154661
---
include/llvm/Support/LockFileManager.h | 74 ++++++++++++++++++++++++++++++++++
1 file changed, 74 insertions(+)
create mode 100644 include/llvm/Support/LockFileManager.h
(limited to 'include/llvm/Support/LockFileManager.h')
diff --git a/include/llvm/Support/LockFileManager.h b/include/llvm/Support/LockFileManager.h
new file mode 100644
index 0000000..e2fa8eb
--- /dev/null
+++ b/include/llvm/Support/LockFileManager.h
@@ -0,0 +1,74 @@
+//===--- LockFileManager.h - File-level locking utility ---------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_SUPPORT_LOCKFILEMANAGER_H
+#define LLVM_SUPPORT_LOCKFILEMANAGER_H
+
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/system_error.h"
+#include <utility> // for std::pair
+
+namespace llvm {
+
+/// \brief Class that manages the creation of a lock file to aid
+/// implicit coordination between different processes.
+///
+/// The implicit coordination works by creating a ".lock" file alongside
+/// the file that we're coordinating for, using the atomicity of the file
+/// system to ensure that only a single process can create that ".lock" file.
+/// When the lock file is removed, the owning process has finished the
+/// operation.
+class LockFileManager {
+public:
+ /// \brief Describes the state of a lock file.
+ enum LockFileState {
+ /// \brief The lock file has been created and is owned by this instance
+ /// of the object.
+ LFS_Owned,
+ /// \brief The lock file already exists and is owned by some other
+ /// instance.
+ LFS_Shared,
+ /// \brief An error occurred while trying to create or find the lock
+ /// file.
+ LFS_Error
+ };
+
+private:
+ SmallString<128> LockFileName;
+ SmallString<128> UniqueLockFileName;
+
+ Optional<std::pair<std::string, int> > Owner;
+ Optional<error_code> Error;
+
+ LockFileManager(const LockFileManager &);
+ LockFileManager &operator=(const LockFileManager &);
+
+ static Optional<std::pair<std::string, int> >
+ readLockFile(StringRef LockFileName);
+
+ static bool processStillExecuting(StringRef Hostname, int PID);
+
+public:
+
+ LockFileManager(StringRef FileName);
+ ~LockFileManager();
+
+ /// \brief Determine the state of the lock file.
+ LockFileState getState() const;
+
+ operator LockFileState() const { return getState(); }
+
+ /// \brief For a shared lock, wait until the owner releases the lock.
+ void waitForUnlock();
+};
+
+} // end namespace llvm
+
+#endif // LLVM_SUPPORT_LOCKFILEMANAGER_H
--
cgit v1.1