Move functions only needed by audiod from stat.c to audiod_command.c.
[paraslash.git] / stdout.c
1 /*
2 * Copyright (C) 2006-2009 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file stdout.c Functions that deal with writing to stdout. */
8
9 #include <dirent.h> /* readdir() */
10 #include <assert.h>
11
12 #include "para.h"
13 #include "list.h"
14 #include "sched.h"
15 #include "fd.h"
16 #include "error.h"
17 #include "stdout.h"
18
19 /**
20 * The pre_select function of the stdout task.
21 *
22 * \param s The scheduler this task was registered to.
23 * \param t The task structure of the stdout task.
24 *
25 * This function is always successful. If there is data available in the input
26 * buffer, it adds \p STDOUT_FILENO to the write fd set of \a s.
27 */
28 static void stdout_pre_select(struct sched *s, struct task *t)
29 {
30 struct stdout_task *sot = container_of(t, struct stdout_task, task);
31
32 t->error = 0;
33 sot->check_fd = 0;
34 if (!*sot->loaded) {
35 if (*sot->input_error < 0) {
36 t->error = *sot->input_error;
37 s->timeout.tv_sec = 0;
38 s->timeout.tv_usec = 1;
39 }
40 return;
41 }
42 sot->check_fd = 1;
43 para_fd_set(STDOUT_FILENO, &s->wfds, &s->max_fileno);
44 }
45
46 /**
47 * The post select function of the stdout task.
48 *
49 * \param s The scheduler this task was registered to.
50 * \param t The task structure of the stdout task.
51 *
52 * This function checks if \p STDOUT_FILENO was included by in the write fd set
53 * of \a s during the previous pre_select call. If yes, and \p STDOUT_FILENO
54 * appeears to be writable, the data loaded in the input buffer is written to
55 * stdout.
56 */
57 static void stdout_post_select(struct sched *s, struct task *t)
58 {
59 struct stdout_task *sot = container_of(t, struct stdout_task, task);
60 ssize_t ret;
61
62 t->error = 0;
63 if (!sot->check_fd) {
64 if (!*sot->loaded && *sot->input_error < 0)
65 t->error = *sot->input_error;
66 return;
67 }
68 if (!FD_ISSET(STDOUT_FILENO, &s->wfds))
69 return;
70 ret = write(STDOUT_FILENO, *sot->bufp, *sot->loaded);
71 if (ret < 0) {
72 t->error = -ERRNO_TO_PARA_ERROR(errno);
73 return;
74 }
75 *sot->loaded -= ret;
76 if (*sot->loaded)
77 memmove(*sot->bufp, *sot->bufp + ret, *sot->loaded);
78 }
79
80 /**
81 * Initialize a stdout task structure with default values.
82 *
83 * \param sot The stdout task structure.
84 *
85 * This fills in the pre/post select function poinzters of the task structure
86 * given by \a sot.
87 */
88 void stdout_set_defaults(struct stdout_task *sot)
89 {
90 int ret;
91
92 sot->task.pre_select = stdout_pre_select;
93 sot->task.post_select = stdout_post_select;
94 sprintf(sot->task.status, "stdout writer");
95 ret = mark_fd_nonblocking(STDOUT_FILENO);
96 if (ret >= 0)
97 return;
98 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
99 exit(EXIT_FAILURE);
100 }