LLVM: llvm::LockFileManager Class Reference (original) (raw)

Class that manages the creation of a lock file to aid implicit coordination between different processes. More...

#include "[llvm/Support/LockFileManager.h](LockFileManager%5F8h%5Fsource.html)"

Public Types
enum LockFileState { LFS_Owned, LFS_Shared, LFS_Error }
Describes the state of a lock file. More...
enum WaitForUnlockResult { Res_Success, Res_OwnerDied, Res_Timeout }
Describes the result of waiting for the owner to release the lock. More...
Public Member Functions
LockFileManager (StringRef FileName)
~LockFileManager ()
LockFileState getState () const
Determine the state of the lock file.
operator LockFileState () const
WaitForUnlockResult waitForUnlock (const unsigned MaxSeconds=90)
For a shared lock, wait until the owner releases the lock.
std::error_code unsafeRemoveLockFile ()
Remove the lock file.
std::string getErrorMessage () const
Get error message, or "" if there is no error.
void setError (const std::error_code &EC, StringRef ErrorMsg="")
Set error and error message.

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.

Definition at line 27 of file LockFileManager.h.

◆ LockFileState

Describes the state of a lock file.

Enumerator
LFS_Owned The lock file has been created and is owned by this instance of the object.
LFS_Shared The lock file already exists and is owned by some other instance.
LFS_Error An error occurred while trying to create or find the lock file.

Definition at line 30 of file LockFileManager.h.

◆ WaitForUnlockResult

Describes the result of waiting for the owner to release the lock.

Enumerator
Res_Success The lock was released successfully.
Res_OwnerDied Owner died while holding the lock.
Res_Timeout Reached timeout while waiting for the owner to release the lock.

Definition at line 43 of file LockFileManager.h.

LockFileManager::LockFileManager ( StringRef FileName )

Definition at line 160 of file LockFileManager.cpp.

References llvm::raw_fd_ostream::clear_error(), llvm::raw_fd_ostream::close(), llvm::sys::fs::create_link(), llvm::sys::fs::createUniqueFile(), llvm::raw_fd_ostream::error(), llvm::sys::fs::exists(), llvm::file_exists, getHostID(), llvm::sys::Process::getProcessId(), llvm::raw_fd_ostream::has_error(), llvm::sys::fs::make_absolute(), llvm::sys::fs::remove(), setError(), and llvm::SmallString< InternalLen >::str().

◆ ~LockFileManager()

LockFileManager::~LockFileManager ( )

◆ getErrorMessage()

std::string LockFileManager::getErrorMessage ( ) const

◆ getState()

◆ operator LockFileState()

◆ setError()

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

◆ unsafeRemoveLockFile()

std::error_code LockFileManager::unsafeRemoveLockFile ( )

◆ waitForUnlock()

For a shared lock, wait until the owner releases the lock.

Total timeout for the file to appear is ~1.5 minutes.

Parameters

MaxSeconds the maximum total wait time in seconds.

Definition at line 295 of file LockFileManager.cpp.

References llvm::sys::fs::access(), llvm::SmallString< InternalLen >::c_str(), llvm::sys::fs::Exist, llvm::sys::fs::exists(), getState(), LFS_Shared, llvm::no_such_file_or_directory, Res_OwnerDied, Res_Success, Res_Timeout, and llvm::ExponentialBackoff::waitForNextAttempt().

Referenced by llvm::AMDGPUSplitModulePass::run().

The documentation for this class was generated from the following files: