Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/include/llvm/Support/LockFileManager.h b/linux-x64/clang/include/llvm/Support/LockFileManager.h
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+//===--- 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/Support/FileSystem.h"
+#include <system_error>
+#include <utility> // for std::pair
+
+namespace llvm {
+class StringRef;
+
+/// \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
+ };
+
+ /// \brief Describes the result of waiting for the owner to release the lock.
+ enum WaitForUnlockResult {
+ /// \brief The lock was released successfully.
+ Res_Success,
+ /// \brief Owner died while holding the lock.
+ Res_OwnerDied,
+ /// \brief Reached timeout while waiting for the owner to release the lock.
+ Res_Timeout
+ };
+
+private:
+ SmallString<128> FileName;
+ SmallString<128> LockFileName;
+ Optional<sys::fs::TempFile> UniqueLockFile;
+
+ Optional<std::pair<std::string, int> > Owner;
+ std::error_code ErrorCode;
+ std::string ErrorDiagMsg;
+
+ LockFileManager(const LockFileManager &) = delete;
+ LockFileManager &operator=(const LockFileManager &) = delete;
+
+ 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.
+ WaitForUnlockResult waitForUnlock();
+
+ /// \brief Remove the lock file. This may delete a different lock file than
+ /// the one previously read if there is a race.
+ std::error_code unsafeRemoveLockFile();
+
+ /// \brief Get error message, or "" if there is no error.
+ std::string getErrorMessage() const;
+
+ /// \brief Set error and error message
+ void setError(const std::error_code &EC, StringRef ErrorMsg = "") {
+ ErrorCode = EC;
+ ErrorDiagMsg = ErrorMsg.str();
+ }
+};
+
+} // end namespace llvm
+
+#endif // LLVM_SUPPORT_LOCKFILEMANAGER_H