| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | #ifndef NETDATA_FILE_LOCK_H |
| 4 | #define NETDATA_FILE_LOCK_H |
| 5 | |
| 6 | #include "libnetdata/libnetdata-platform-fwd.h" |
| 7 | |
| 8 | #if defined(OS_WINDOWS) |
| 9 | #include <windows.h> |
| 10 | #endif |
| 11 | |
| 12 | typedef struct file_lock { |
| 13 | #if defined(OS_LINUX) || defined(OS_FREEBSD) || defined(OS_MACOS) |
| 14 | int fd; |
| 15 | #elif defined(OS_WINDOWS) |
| 16 | HANDLE handle; |
| 17 | #else |
| 18 | #error "Unsupported operating system" |
| 19 | #endif |
| 20 | } FILE_LOCK; |
| 21 | |
| 22 | // Initialize to invalid values |
| 23 | #if defined(OS_LINUX) || defined(OS_FREEBSD) || defined(OS_MACOS) |
| 24 | #define FILE_LOCK_INVALID ((FILE_LOCK){ .fd = -1 }) |
| 25 | #define FILE_LOCK_OK(lock) ((lock).fd != -1) |
| 26 | #elif defined(OS_WINDOWS) |
| 27 | #define FILE_LOCK_INVALID ((FILE_LOCK){ .handle = INVALID_HANDLE_VALUE }) |
| 28 | #define FILE_LOCK_OK(lock) ((lock).handle != INVALID_HANDLE_VALUE) |
| 29 | #endif |
| 30 | |
| 31 | /** |
| 32 | * Get a file lock |
| 33 | * |
| 34 | * Attempts to acquire an exclusive lock on a file. The lock is automatically released |
| 35 | * when the process exits or if the process crashes. Only one process can hold the lock |
| 36 | * at a time. |
| 37 | * |
| 38 | * @param filename UTF-8 encoded filename (MSYS2/Cygwin path format or native Windows path on Windows) |
| 39 | * @return FILE_LOCK The lock handle. Use FILE_LOCK_OK() to check if lock was acquired |
| 40 | */ |
| 41 | FILE_LOCK file_lock_get(const char *filename); |
| 42 | |
| 43 | /** |
| 44 | * Release a file lock |
| 45 | * |
| 46 | * Releases a previously acquired file lock. After calling this function, |
| 47 | * another process may acquire the lock. |
| 48 | * |
| 49 | * @param lock The lock to release |
| 50 | */ |
| 51 | void file_lock_release(FILE_LOCK lock); |
| 52 | |
| 53 | #endif //NETDATA_FILE_LOCK_H |