class LockFileManager

Declaration

class LockFileManager { /* full declaration omitted */ };

Description

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.

Declared at: llvm/include/llvm/Support/LockFileManager.h:27

Member Variables

private SmallString<128> FileName

private SmallString<128> LockFileName

private SmallString<128> UniqueLockFileName

private Optional<std::pair<std::string, int>> Owner

private std::error_code ErrorCode

private std::string ErrorDiagMsg

Method Overview

• private LockFileManager(const llvm::LockFileManager &)
• public LockFileManager(llvm::StringRef FileName)
• public std::string getErrorMessage() const
• public llvm::LockFileManager::LockFileState getState() const
• public llvm::LockFileManager::LockFileState operator llvm::LockFileManager::LockFileState() const
• private static bool processStillExecuting(llvm::StringRef Hostname, int PID)
• private static Optional<std::pair<std::string, int>> readLockFile(llvm::StringRef LockFileName)
• public void setError(const std::error_code & EC, llvm::StringRef ErrorMsg = "")
• public std::error_code unsafeRemoveLockFile()
• public llvm::LockFileManager::WaitForUnlockResult waitForUnlock(const unsigned int MaxSeconds = 90)
• public ~LockFileManager()

Methods

¶LockFileManager(const llvm::LockFileManager&)

Declared at: llvm/include/llvm/Support/LockFileManager.h:61

Parameters

const llvm::LockFileManager&

¶LockFileManager(llvm::StringRef FileName)

Declared at: llvm/include/llvm/Support/LockFileManager.h:71

Parameters

llvm::StringRef FileName

¶std::string getErrorMessage() const

Description

Get error message, or "" if there is no error.

Declared at: llvm/include/llvm/Support/LockFileManager.h:89

¶llvm::LockFileManager::LockFileState getState()
    const

Description

Determine the state of the lock file.

Declared at: llvm/include/llvm/Support/LockFileManager.h:75

¶llvm::LockFileManager::LockFileState
operator llvm::LockFileManager::LockFileState()
    const

Declared at: llvm/include/llvm/Support/LockFileManager.h:77

¶static bool processStillExecuting(
    llvm::StringRef Hostname,
    int PID)

Declared at: llvm/include/llvm/Support/LockFileManager.h:67

Parameters

llvm::StringRef Hostname

int PID

¶static Optional<std::pair<std::string, int>>
readLockFile(llvm::StringRef LockFileName)

Description

Attempt to read the lock file with the given name, if it exists.

Declared at: llvm/include/llvm/Support/LockFileManager.h:65

Parameters

llvm::StringRef LockFileName

The name of the lock file to read.

Returns

The process ID of the process that owns this lock file

¶void setError(const std::error_code& EC,
              llvm::StringRef ErrorMsg = "")

Description

Set error and error message

Declared at: llvm/include/llvm/Support/LockFileManager.h:92

Parameters

const std::error_code& EC

llvm::StringRef ErrorMsg = ""

¶std::error_code unsafeRemoveLockFile()

Description

Remove the lock file. This may delete a different lock file than the one previously read if there is a race.

Declared at: llvm/include/llvm/Support/LockFileManager.h:86

¶llvm::LockFileManager::WaitForUnlockResult
waitForUnlock(const unsigned int MaxSeconds = 90)

Description

For a shared lock, wait until the owner releases the lock. Total timeout for the file to appear is ~1.5 minutes.

Declared at: llvm/include/llvm/Support/LockFileManager.h:82

Parameters

const unsigned int MaxSeconds = 90

the maximum total wait time in seconds.

¶~LockFileManager()

Declared at: llvm/include/llvm/Support/LockFileManager.h:72