| 1 | /* |
| 2 | * Copyright (C) 2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #define _LGPL_SOURCE |
| 9 | #include <urcu/uatomic.h> |
| 10 | #include <sys/time.h> |
| 11 | #include <sys/resource.h> |
| 12 | #include <errno.h> |
| 13 | #include <stdio.h> |
| 14 | #include "fd-limit.h" |
| 15 | #include <common/error.h> |
| 16 | |
| 17 | /* total count of fd. */ |
| 18 | static long fd_count; |
| 19 | |
| 20 | /* |
| 21 | * threshold in % of number of fd allowed. |
| 22 | */ |
| 23 | static long fd_threshold[LTTNG_FD_NR_TYPES] = { |
| 24 | [LTTNG_FD_APPS] = 75, |
| 25 | }; |
| 26 | |
| 27 | static rlim_t max_nr_fd; |
| 28 | |
| 29 | int lttng_fd_get(enum lttng_fd_type type, unsigned int nr) |
| 30 | { |
| 31 | long newval; |
| 32 | |
| 33 | if (type >= LTTNG_FD_NR_TYPES) { |
| 34 | return -EINVAL; |
| 35 | } |
| 36 | |
| 37 | newval = uatomic_add_return(&fd_count, (long) nr); |
| 38 | if ((long) (newval * 100) |
| 39 | - (long) (max_nr_fd * fd_threshold[type]) > 0) { |
| 40 | uatomic_sub(&fd_count, (long) nr); |
| 41 | return -EPERM; |
| 42 | } |
| 43 | return 0; |
| 44 | } |
| 45 | |
| 46 | void lttng_fd_put(enum lttng_fd_type type, unsigned int nr) |
| 47 | { |
| 48 | uatomic_sub(&fd_count, (long) nr); |
| 49 | } |
| 50 | |
| 51 | void lttng_fd_init(void) |
| 52 | { |
| 53 | struct rlimit rlim; |
| 54 | int ret; |
| 55 | |
| 56 | ret = getrlimit(RLIMIT_NOFILE, &rlim); |
| 57 | if (ret < 0) { |
| 58 | PERROR("getrlimit"); |
| 59 | } |
| 60 | max_nr_fd = rlim.rlim_cur; |
| 61 | } |