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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> | |
a247c6e0 | 22 | #include <common/macros.h> |
9fd92637 DG |
23 | |
24 | enum lttng_pipe_state { | |
25 | LTTNG_PIPE_STATE_OPENED = 1, | |
26 | LTTNG_PIPE_STATE_CLOSED = 2, | |
27 | }; | |
28 | ||
29 | struct lttng_pipe { | |
30 | /* Read: 0, Write: 1. */ | |
31 | int fd[2]; | |
32 | /* | |
33 | * Flags of the pipe once opened. pipe(2) specifies either O_NONBLOCK or | |
34 | * O_CLOEXEC can be used. Flags are set using fcntl(2) call. | |
35 | */ | |
36 | int flags; | |
37 | ||
38 | /* | |
39 | * These states are protected by the operation mutex below. | |
40 | */ | |
41 | enum lttng_pipe_state r_state; | |
42 | enum lttng_pipe_state w_state; | |
43 | ||
44 | /* Held for each read(2) operation. */ | |
45 | pthread_mutex_t read_mutex; | |
46 | /* Held for each write(2) operation. */ | |
47 | pthread_mutex_t write_mutex; | |
48 | }; | |
49 | ||
50 | /* | |
51 | * Return 1 if read side is open else 0. | |
52 | */ | |
53 | static inline int lttng_pipe_is_read_open(struct lttng_pipe *pipe) | |
54 | { | |
55 | return pipe->r_state == LTTNG_PIPE_STATE_OPENED ? 1 : 0; | |
56 | } | |
57 | ||
58 | /* | |
59 | * Return 1 if write side is open else 0. | |
60 | */ | |
61 | static inline int lttng_pipe_is_write_open(struct lttng_pipe *pipe) | |
62 | { | |
63 | return pipe->w_state == LTTNG_PIPE_STATE_OPENED ? 1 : 0; | |
64 | } | |
65 | ||
66 | static inline int lttng_pipe_get_readfd(struct lttng_pipe *pipe) | |
67 | { | |
68 | return pipe->fd[0]; | |
69 | } | |
70 | ||
71 | static inline int lttng_pipe_get_writefd(struct lttng_pipe *pipe) | |
72 | { | |
73 | return pipe->fd[1]; | |
74 | } | |
75 | ||
a247c6e0 | 76 | LTTNG_HIDDEN |
9fd92637 | 77 | struct lttng_pipe *lttng_pipe_open(int flags); |
a247c6e0 | 78 | LTTNG_HIDDEN |
9c2bd8db JG |
79 | struct lttng_pipe *lttng_pipe_named_open(const char *path, mode_t mode, |
80 | int flags); | |
81 | LTTNG_HIDDEN | |
9fd92637 | 82 | int lttng_pipe_write_close(struct lttng_pipe *pipe); |
a247c6e0 | 83 | LTTNG_HIDDEN |
9fd92637 DG |
84 | int lttng_pipe_read_close(struct lttng_pipe *pipe); |
85 | /* Close both side of pipe. */ | |
a247c6e0 | 86 | LTTNG_HIDDEN |
9fd92637 | 87 | int lttng_pipe_close(struct lttng_pipe *pipe); |
a247c6e0 | 88 | LTTNG_HIDDEN |
9fd92637 DG |
89 | void lttng_pipe_destroy(struct lttng_pipe *pipe); |
90 | ||
a247c6e0 | 91 | LTTNG_HIDDEN |
9fd92637 | 92 | ssize_t lttng_pipe_read(struct lttng_pipe *pipe, void *buf, size_t count); |
a247c6e0 | 93 | LTTNG_HIDDEN |
9fd92637 DG |
94 | ssize_t lttng_pipe_write(struct lttng_pipe *pipe, const void *buf, |
95 | size_t count); | |
55dfb029 JG |
96 | /* Returns and releases the read end of the pipe. */ |
97 | LTTNG_HIDDEN | |
98 | int lttng_pipe_release_readfd(struct lttng_pipe *pipe); | |
99 | /* Returns and releases the write end of the pipe. */ | |
100 | LTTNG_HIDDEN | |
101 | int lttng_pipe_release_writefd(struct lttng_pipe *pipe); | |
9fd92637 DG |
102 | |
103 | #endif /* LTTNG_PIPE_H */ |