openNativeFileForRead(const Twine &Name, OpenFlags Flags = OF_None,
SmallVectorImpl<char> *RealPath = nullptr);
-/// Try to locks the file during the specified time.
-///
-/// This function implements advisory locking on entire file. If it returns
-/// <em>errc::success</em>, the file is locked by the calling process. Until the
-/// process unlocks the file by calling \a unlockFile, all attempts to lock the
-/// same file will fail/block. The process that locked the file may assume that
-/// none of other processes read or write this file, provided that all processes
-/// lock the file prior to accessing its content.
-///
-/// @param File The descriptor representing the file to lock.
-/// @param Timeout Time in milliseconds that the process should wait before
-/// reporting lock failure. Zero value means try to get lock only
-/// once.
-/// @returns errc::success if lock is successfully obtained,
-/// errc::no_lock_available if the file cannot be locked, or platform-specific
-/// error_code otherwise.
-std::error_code
-tryLockFile(int FD,
- std::chrono::milliseconds Timeout = std::chrono::milliseconds(0));
-
-/// Lock the file.
-///
-/// This function acts as @ref tryLockFile(int,std::chrono::milliseconds) but it
-/// waits infinitely.
-std::error_code lockFile(int FD);
-
-/// Unlock the file.
-///
-/// @param File The descriptor representing the file to unlock.
-/// @returns errc::success if lock is successfully released or platform-specific
-/// error_code otherwise.
-std::error_code unlockFile(int FD);
-
/// @brief Close the file object. This should be used instead of ::close for
/// portability. On error, the caller should assume the file is closed, as is
/// the case for Process::SafelyCloseFileDescriptor
#include <dirent.h>
#include <pwd.h>
-#include <sys/file.h>
#ifdef __APPLE__
#include <mach-o/dyld.h>
return NumRead;
}
-std::error_code tryLockFile(int FD, std::chrono::milliseconds Timeout) {
- auto Start = std::chrono::steady_clock::now();
- auto End = Start + Timeout;
- do {
- if (::flock(FD, LOCK_EX | LOCK_NB) == 0)
- return std::error_code();
- int Error = errno;
- if (Error == EWOULDBLOCK) {
- usleep(1000);
- continue;
- }
- return std::error_code(Error, std::generic_category());
- } while (std::chrono::steady_clock::now() < End);
- return make_error_code(errc::no_lock_available);
-}
-
-std::error_code lockFile(int FD) {
- if (::flock(FD, LOCK_EX) == 0)
- return std::error_code();
- return std::error_code(errno, std::generic_category());
-}
-
-std::error_code unlockFile(int FD) {
- if (::flock(FD, LOCK_UN) == -1)
- return std::error_code(errno, std::generic_category());
- return std::error_code();
-}
-
std::error_code closeFile(file_t &F) {
file_t TmpF = F;
F = kInvalidFile;
return readNativeFileImpl(FileHandle, Buf, &Overlapped);
}
-std::error_code tryLockFile(int FD, std::chrono::milliseconds Timeout) {
- DWORD Flags = LOCKFILE_EXCLUSIVE_LOCK | LOCKFILE_FAIL_IMMEDIATELY;
- OVERLAPPED OV = {0};
- file_t File = convertFDToNativeFile(FD);
- auto Start = std::chrono::steady_clock::now();
- auto End = Start + Timeout;
- do {
- if (::LockFileEx(File, Flags, 0, MAXDWORD, MAXDWORD, &OV))
- return std::error_code();
- DWORD Error = ::GetLastError();
- if (Error == ERROR_LOCK_VIOLATION) {
- ::Sleep(1);
- continue;
- }
- return mapWindowsError(Error);
- } while (std::chrono::steady_clock::now() < End);
- return mapWindowsError(ERROR_LOCK_VIOLATION);
-}
-
-std::error_code lockFile(int FD) {
- DWORD Flags = LOCKFILE_EXCLUSIVE_LOCK;
- OVERLAPPED OV = {0};
- file_t File = convertFDToNativeFile(FD);
- if (::LockFileEx(File, Flags, 0, MAXDWORD, MAXDWORD, &OV))
- return std::error_code();
- DWORD Error = ::GetLastError();
- return mapWindowsError(Error);
-}
-
-std::error_code unlockFile(int FD) {
- OVERLAPPED OV = {0};
- file_t File = convertFDToNativeFile(FD);
- if (::UnlockFileEx(File, 0, MAXDWORD, MAXDWORD, &OV))
- return std::error_code();
- return mapWindowsError(::GetLastError());
-}
-
std::error_code closeFile(file_t &F) {
file_t TmpF = F;
F = kInvalidFile;
#include <sys/stat.h>
#endif
-#include <future>
-
using namespace llvm;
using namespace llvm::sys;
}
#endif
-TEST_F(FileSystemTest, lockFile) {
- int FD1, FD2;
- SmallString<64> TempPath;
- ASSERT_NO_ERROR(fs::createTemporaryFile("test", "temp", FD1, TempPath));
- FileRemover Cleanup(TempPath);
- ASSERT_NO_ERROR(fs::openFileForReadWrite(TempPath, FD2, fs::CD_OpenExisting,
- fs::OF_Append));
- ASSERT_NO_ERROR(fs::tryLockFile(FD1));
-
- ASSERT_EQ(errc::no_lock_available,
- fs::tryLockFile(FD2, std::chrono::milliseconds(5)));
- ASSERT_NO_ERROR(fs::unlockFile(FD1));
- ASSERT_NO_ERROR(fs::tryLockFile(FD2));
- ASSERT_NO_ERROR(fs::unlockFile(FD2));
-}
-
-TEST_F(FileSystemTest, lockFileThread) {
-#if LLVM_ENABLE_THREADS
- int FD1, FD2;
- SmallString<64> TempPath;
- ASSERT_NO_ERROR(fs::createTemporaryFile("test", "temp", FD1, TempPath));
- FileRemover Cleanup(TempPath);
- ASSERT_NO_ERROR(fs::openFileForReadWrite(TempPath, FD2, fs::CD_OpenExisting,
- fs::OF_Append));
-
- ASSERT_NO_ERROR(fs::tryLockFile(FD1));
- ASSERT_ERROR(fs::tryLockFile(FD2));
- std::future<std::error_code> Future = std::async(std::launch::async, [&] {
- return fs::tryLockFile(FD2, std::chrono::seconds(5));
- });
- ASSERT_NO_ERROR(fs::unlockFile(FD1));
- ASSERT_NO_ERROR(Future.get());
- fs::unlockFile(FD2);
-
- ASSERT_NO_ERROR(fs::tryLockFile(FD1));
- ASSERT_ERROR(fs::tryLockFile(FD2));
- Future = std::async(std::launch::async, [&] { return fs::lockFile(FD2); });
- ASSERT_NO_ERROR(fs::unlockFile(FD1));
- ASSERT_NO_ERROR(Future.get());
- fs::unlockFile(FD2);
-#endif
-}
-
} // anonymous namespace