projects / lttng-tools.git / blame
| Commit | Line | Data |
|---|---|---|
| f5ea0241 | 1 | /* |
| ab5be9fa | 2 | * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| f5ea0241 | 3 | * |
| ab5be9fa | 4 | * SPDX-License-Identifier: LGPL-2.1-only |
| f5ea0241 | 5 | * |
| f5ea0241 JG |
6 | */ |
| 7 | ||
| 8 | #ifndef FS_HANDLE_H | |
| 9 | #define FS_HANDLE_H | |
| 10 | ||
| 11 | #include <common/macros.h> | |
| 8bb66c3c | 12 | #include <stdio.h> |
| f5ea0241 JG |
13 | |
| 14 | struct fs_handle; | |
| 15 | ||
| 16 | /* | |
| 17 | * Marks the handle as the most recently used and marks the 'fd' as | |
| 18 | * "in-use". This prevents the tracker from recycling the underlying | |
| 19 | * file descriptor while it is actively being used by a thread. | |
| 20 | * | |
| 21 | * Don't forget that the tracker may be initiating an fd 'suspension' | |
| 22 | * from another thread as the need to free an fd slot may arise from any | |
| 23 | * thread within the daemon. | |
| 24 | * | |
| 25 | * Note that a restorable fd should never be held for longer than | |
| 26 | * strictly necessary (e.g. the duration of a syscall()). | |
| 27 | * | |
| 28 | * Returns the fd on success, otherwise a negative value may be returned | |
| 29 | * if the restoration of the fd failed. | |
| 30 | */ | |
| 31 | LTTNG_HIDDEN | |
| 32 | int fs_handle_get_fd(struct fs_handle *handle); | |
| 33 | ||
| 34 | /* | |
| 35 | * Used by the caller to signal that it is no longer using the underlying fd and | |
| 36 | * that it may be safely suspended. | |
| 37 | */ | |
| 38 | LTTNG_HIDDEN | |
| 39 | void fs_handle_put_fd(struct fs_handle *handle); | |
| 40 | ||
| 41 | /* | |
| 42 | * Unlink the file associated to an fs_handle. Note that the unlink | |
| 43 | * operation will not be performed immediately. It will only be performed | |
| 44 | * once all references to the underlying file (through other fs_handle objects) | |
| 45 | * have been released. | |
| 46 | * | |
| 47 | * However, note that the file will be renamed so as to provide the observable | |
| 48 | * effect of an unlink(), that is removing a name from the filesystem. | |
| 49 | * | |
| 50 | * Returns 0 on success, otherwise a negative value will be returned | |
| 51 | * if the operation failed. | |
| 52 | */ | |
| 53 | LTTNG_HIDDEN | |
| 54 | int fs_handle_unlink(struct fs_handle *handle); | |
| 55 | ||
| 56 | /* | |
| 57 | * Frees the handle and discards the underlying fd. | |
| 58 | */ | |
| 59 | LTTNG_HIDDEN | |
| 60 | int fs_handle_close(struct fs_handle *handle); | |
| 61 | ||
| 8bb66c3c JG |
62 | LTTNG_HIDDEN |
| 63 | ssize_t fs_handle_read(struct fs_handle *handle, void *buf, size_t count); | |
| 64 | ||
| 65 | LTTNG_HIDDEN | |
| 66 | ssize_t fs_handle_write(struct fs_handle *handle, const void *buf, size_t count); | |
| 67 | ||
| 68 | LTTNG_HIDDEN | |
| 69 | int fs_handle_truncate(struct fs_handle *handle, off_t offset); | |
| 70 | ||
| 71 | LTTNG_HIDDEN | |
| 3e778ab0 | 72 | off_t fs_handle_seek(struct fs_handle *handle, off_t offset, int whence); |
| 8bb66c3c | 73 | |
| f5ea0241 | 74 | #endif /* FS_HANDLE_H */ |