web/license.html: make it clear that paraslash is licensed under the GPL V2
[paraslash.git] / stdout.c
1 /*
2 * Copyright (C) 2006 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 "para.h"
10 #include "string.h"
11 #include "list.h"
12 #include "sched.h"
13 #include "fd.h"
14 #include "error.h"
15 #include "stdout.h"
16
17 /**
18 * the pre_select function of the stdout task
19 *
20 * \param s the scheduler this task was registered to
21 * \param t the task structure of the stdout task
22 *
23 * This function is always successful. If there is data available in the input
24 * buffer, it adds \p STDOUT_FILENO to the write fd set of \a s.
25 */
26 void stdout_pre_select(struct sched *s, struct task *t)
27 {
28 struct stdout_task *sot = t->private_data;
29
30 t->ret = 1;
31 sot->check_fd = 0;
32 if (!*sot->loaded) {
33 if (*sot->input_eof) {
34 t->ret = -E_STDOUT_EOF;
35 s->timeout.tv_sec = 0;
36 s->timeout.tv_usec = 1;
37 }
38 return;
39 }
40 sot->check_fd = 1;
41 para_fd_set(STDOUT_FILENO, &s->wfds, &s->max_fileno);
42 }
43
44 /**
45 * the post select function of the stdout task
46 *
47 * \param s the scheduler this task was registered to
48 * \param t the task structure of the stdout task
49 *
50 * This function checks if \p STDOUT_FILENO was included by in the write fd set
51 * of \a s during the previous pre_select call. If yes, and \p STDOUT_FILENO
52 * appeears to be writable, the data loaded in the input buffer is written to
53 * stdout.
54 */
55 void stdout_post_select(struct sched *s, struct task *t)
56 {
57 struct stdout_task *sot = t->private_data;
58 ssize_t ret;
59
60 t->ret = 1;
61 if (!sot->check_fd) {
62 if (*sot->input_eof)
63 t->ret = -E_STDOUT_EOF;
64 return;
65 }
66 if (!FD_ISSET(STDOUT_FILENO, &s->wfds))
67 return;
68 t->ret = -E_STDOUT_WRITE;
69 ret = write(STDOUT_FILENO, sot->buf, *sot->loaded);
70 if (ret <= 0)
71 return;
72 *sot->loaded -= ret;
73 if (*sot->loaded)
74 memmove(sot->buf, sot->buf + ret, *sot->loaded);
75 t->ret = 1;
76 }
77
78 static void stdout_default_event_handler(struct task *t)
79 {
80 PARA_NOTICE_LOG("%p: %s\n", t, PARA_STRERROR(-t->ret));
81 unregister_task(t);
82 }
83
84 /**
85 * initialize a stdout task structure with default values
86 *
87 * \param sot the stdout task structure
88 *
89 * This fills in the pre/post select function poinzters of the task structure
90 * given by \a sot. It also sets up a default error handler which unregisters
91 * the task on errors and clears the eof flag of \a sot.
92 */
93 void stdout_set_defaults(struct stdout_task *sot)
94 {
95 sot->task.private_data = sot;
96 sot->task.pre_select = stdout_pre_select;
97 sot->task.post_select = stdout_post_select;
98 sot->task.event_handler = stdout_default_event_handler;
99 sot->eof = 0;
100 mark_fd_nonblock(STDOUT_FILENO);
101 sprintf(sot->task.status, "stdout writer");
102 }