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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> | |
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 */ |