15976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org//===--- LockFileManager.h - File-level locking utility ---------*- C++ -*-===// 25976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org// 35976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org// The LLVM Compiler Infrastructure 45976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org// 55976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org// This file is distributed under the University of Illinois Open Source 65976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org// License. See LICENSE.TXT for details. 75976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org// 85976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org//===----------------------------------------------------------------------===// 95976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org#ifndef LLVM_SUPPORT_LOCKFILEMANAGER_H 105976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org#define LLVM_SUPPORT_LOCKFILEMANAGER_H 115976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 125976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org#include "llvm/ADT/Optional.h" 135976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org#include "llvm/ADT/SmallString.h" 145976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org#include "llvm/ADT/StringRef.h" 155976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org#include <system_error> 165976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org#include <utility> // for std::pair 175976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 185976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.orgnamespace llvm { 195976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org/// \brief Class that manages the creation of a lock file to aid 205976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org/// implicit coordination between different processes. 215976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org/// 225976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org/// The implicit coordination works by creating a ".lock" file alongside 235976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org/// the file that we're coordinating for, using the atomicity of the file 245976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org/// system to ensure that only a single process can create that ".lock" file. 255976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org/// When the lock file is removed, the owning process has finished the 265976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org/// operation. 275976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.orgclass LockFileManager { 285976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.orgpublic: 295976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org /// \brief Describes the state of a lock file. 305976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org enum LockFileState { 315976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org /// \brief The lock file has been created and is owned by this instance 325976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org /// of the object. 335976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org LFS_Owned, 345976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org /// \brief The lock file already exists and is owned by some other 355976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org /// instance. 365976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org LFS_Shared, 375976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org /// \brief An error occurred while trying to create or find the lock 385976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org /// file. 395976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org LFS_Error 405976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org }; 415976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 425976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org /// \brief Describes the result of waiting for the owner to release the lock. 435976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org enum WaitForUnlockResult { 445976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org /// \brief The lock was released successfully. 455976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org Res_Success, 465976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org /// \brief Owner died while holding the lock. 475976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org Res_OwnerDied, 485976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org /// \brief Reached timeout while waiting for the owner to release the lock. 495976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org Res_Timeout 505976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org }; 515976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 525976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.orgprivate: 535976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org SmallString<128> FileName; 54582fe818e571fa2571267f5e369715188472f352wu@webrtc.org SmallString<128> LockFileName; 55582fe818e571fa2571267f5e369715188472f352wu@webrtc.org SmallString<128> UniqueLockFileName; 565976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 575976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org Optional<std::pair<std::string, int> > Owner; 585976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org Optional<std::error_code> Error; 595976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 605976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org LockFileManager(const LockFileManager &) LLVM_DELETED_FUNCTION; 615976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org LockFileManager &operator=(const LockFileManager &) LLVM_DELETED_FUNCTION; 625976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 635976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org static Optional<std::pair<std::string, int> > 645976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org readLockFile(StringRef LockFileName); 65582fe818e571fa2571267f5e369715188472f352wu@webrtc.org 665976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org static bool processStillExecuting(StringRef Hostname, int PID); 675976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 685976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.orgpublic: 695976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 705976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org LockFileManager(StringRef FileName); 715976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org ~LockFileManager(); 725976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 735976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org /// \brief Determine the state of the lock file. 745976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org LockFileState getState() const; 755976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 765976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org operator LockFileState() const { return getState(); } 775976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 785976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org /// \brief For a shared lock, wait until the owner releases the lock. 795976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org WaitForUnlockResult waitForUnlock(); 805976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org}; 815976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 825976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org} // end namespace llvm 835976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org 845976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org#endif // LLVM_SUPPORT_LOCKFILEMANAGER_H 855976650443d68ccfadf1dea24999ee459dd2819mflodman@webrtc.org