| 1 | /* |
| 2 | * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: LGPL-2.1-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include <unistd.h> |
| 9 | #include <urcu/ref.h> |
| 10 | |
| 11 | #include "fd-handle.h" |
| 12 | #include <common/error.h> |
| 13 | |
| 14 | struct fd_handle { |
| 15 | struct urcu_ref ref; |
| 16 | int fd; |
| 17 | }; |
| 18 | |
| 19 | static void fd_handle_release(struct urcu_ref *ref) |
| 20 | { |
| 21 | int ret; |
| 22 | struct fd_handle *handle = container_of(ref, struct fd_handle, ref); |
| 23 | |
| 24 | LTTNG_ASSERT(handle->fd >= 0); |
| 25 | ret = close(handle->fd); |
| 26 | if (ret == -1) { |
| 27 | PERROR("Failed to close file descriptor of fd_handle upon release: fd = %d", |
| 28 | handle->fd); |
| 29 | } |
| 30 | |
| 31 | free(handle); |
| 32 | } |
| 33 | |
| 34 | struct fd_handle *fd_handle_create(int fd) |
| 35 | { |
| 36 | struct fd_handle *handle = NULL; |
| 37 | |
| 38 | if (fd < 0) { |
| 39 | ERR("Attempted to create an fd_handle from an invalid file descriptor: fd = %d", |
| 40 | fd); |
| 41 | goto end; |
| 42 | } |
| 43 | |
| 44 | handle = (fd_handle *) zmalloc(sizeof(*handle)); |
| 45 | if (!handle) { |
| 46 | PERROR("Failed to allocate fd_handle"); |
| 47 | goto end; |
| 48 | } |
| 49 | |
| 50 | urcu_ref_init(&handle->ref); |
| 51 | handle->fd = fd; |
| 52 | |
| 53 | end: |
| 54 | return handle; |
| 55 | } |
| 56 | |
| 57 | void fd_handle_get(struct fd_handle *handle) |
| 58 | { |
| 59 | if (!handle) { |
| 60 | return; |
| 61 | } |
| 62 | |
| 63 | urcu_ref_get(&handle->ref); |
| 64 | } |
| 65 | |
| 66 | void fd_handle_put(struct fd_handle *handle) |
| 67 | { |
| 68 | if (!handle) { |
| 69 | return; |
| 70 | } |
| 71 | |
| 72 | urcu_ref_put(&handle->ref, fd_handle_release); |
| 73 | } |
| 74 | |
| 75 | int fd_handle_get_fd(struct fd_handle *handle) |
| 76 | { |
| 77 | LTTNG_ASSERT(handle); |
| 78 | return handle->fd; |
| 79 | } |
| 80 | |
| 81 | struct fd_handle *fd_handle_copy(const struct fd_handle *handle) |
| 82 | { |
| 83 | struct fd_handle *new_handle = NULL; |
| 84 | const int new_fd = dup(handle->fd); |
| 85 | |
| 86 | if (new_fd < 0) { |
| 87 | PERROR("Failed to duplicate file descriptor while copying fd_handle: fd = %d", handle->fd); |
| 88 | goto end; |
| 89 | } |
| 90 | |
| 91 | new_handle = fd_handle_create(new_fd); |
| 92 | end: |
| 93 | return new_handle; |
| 94 | } |