projects / lttng-tools.git / blame
| Commit | Line | Data |
|---|---|---|
| 9fd92637 DG |
1 | /* |
| 2 | * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com> | |
| 3 | * | |
| 4 | * This program is free software; you can redistribute it and/or modify it | |
| 5 | * under the terms of the GNU General Public License, version 2 only, as | |
| 6 | * published by the Free Software Foundation. | |
| 7 | * | |
| 8 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
| 11 | * more details. | |
| 12 | * | |
| 13 | * You should have received a copy of the GNU General Public License along with | |
| 14 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
| 15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 16 | */ | |
| 17 | ||
| 18 | #ifndef LTTNG_PIPE_H | |
| 19 | #define LTTNG_PIPE_H | |
| 20 | ||
| 21 | #include <pthread.h> | |
| 22 | ||
| 23 | enum lttng_pipe_state { | |
| 24 | LTTNG_PIPE_STATE_OPENED = 1, | |
| 25 | LTTNG_PIPE_STATE_CLOSED = 2, | |
| 26 | }; | |
| 27 | ||
| 28 | struct lttng_pipe { | |
| 29 | /* Read: 0, Write: 1. */ | |
| 30 | int fd[2]; | |
| 31 | /* | |
| 32 | * Flags of the pipe once opened. pipe(2) specifies either O_NONBLOCK or | |
| 33 | * O_CLOEXEC can be used. Flags are set using fcntl(2) call. | |
| 34 | */ | |
| 35 | int flags; | |
| 36 | ||
| 37 | /* | |
| 38 | * These states are protected by the operation mutex below. | |
| 39 | */ | |
| 40 | enum lttng_pipe_state r_state; | |
| 41 | enum lttng_pipe_state w_state; | |
| 42 | ||
| 43 | /* Held for each read(2) operation. */ | |
| 44 | pthread_mutex_t read_mutex; | |
| 45 | /* Held for each write(2) operation. */ | |
| 46 | pthread_mutex_t write_mutex; | |
| 47 | }; | |
| 48 | ||
| 49 | /* | |
| 50 | * Return 1 if read side is open else 0. | |
| 51 | */ | |
| 52 | static inline int lttng_pipe_is_read_open(struct lttng_pipe *pipe) | |
| 53 | { | |
| 54 | return pipe->r_state == LTTNG_PIPE_STATE_OPENED ? 1 : 0; | |
| 55 | } | |
| 56 | ||
| 57 | /* | |
| 58 | * Return 1 if write side is open else 0. | |
| 59 | */ | |
| 60 | static inline int lttng_pipe_is_write_open(struct lttng_pipe *pipe) | |
| 61 | { | |
| 62 | return pipe->w_state == LTTNG_PIPE_STATE_OPENED ? 1 : 0; | |
| 63 | } | |
| 64 | ||
| 65 | static inline int lttng_pipe_get_readfd(struct lttng_pipe *pipe) | |
| 66 | { | |
| 67 | return pipe->fd[0]; | |
| 68 | } | |
| 69 | ||
| 70 | static inline int lttng_pipe_get_writefd(struct lttng_pipe *pipe) | |
| 71 | { | |
| 72 | return pipe->fd[1]; | |
| 73 | } | |
| 74 | ||
| 75 | struct lttng_pipe *lttng_pipe_open(int flags); | |
| 76 | int lttng_pipe_write_close(struct lttng_pipe *pipe); | |
| 77 | int lttng_pipe_read_close(struct lttng_pipe *pipe); | |
| 78 | /* Close both side of pipe. */ | |
| 79 | int lttng_pipe_close(struct lttng_pipe *pipe); | |
| 80 | void lttng_pipe_destroy(struct lttng_pipe *pipe); | |
| 81 | ||
| 82 | ssize_t lttng_pipe_read(struct lttng_pipe *pipe, void *buf, size_t count); | |
| 83 | ssize_t lttng_pipe_write(struct lttng_pipe *pipe, const void *buf, | |
| 84 | size_t count); | |
| 85 | ||
| 86 | #endif /* LTTNG_PIPE_H */ |