configure.ac: do not check for malloc.h
[paraslash.git] / stdout.c
1 /*
2 * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
17 */
18
19 /** \file stdout.c functions that deal with writing to stdout */
20
21 #include "para.h"
22 #include "string.h"
23 #include "list.h"
24 #include "sched.h"
25 #include "fd.h"
26 #include "error.h"
27 #include "stdout.h"
28
29 /**
30 * the pre_select function of the stdout task
31 *
32 * \param s the scheduler this task was registered to
33 * \param t the task structure of the stdout task
34 *
35 * This function is always successful. If there is data available in the input
36 * buffer, it adds \p STDOUT_FILENO to the write fd set of \a s.
37 */
38 void stdout_pre_select(struct sched *s, struct task *t)
39 {
40 struct stdout_task *sot = t->private_data;
41
42 t->ret = 1;
43 sot->check_fd = 0;
44 if (!*sot->loaded) {
45 if (*sot->input_eof) {
46 t->ret = -E_STDOUT_EOF;
47 s->timeout.tv_sec = 0;
48 s->timeout.tv_usec = 1;
49 }
50 return;
51 }
52 sot->check_fd = 1;
53 para_fd_set(STDOUT_FILENO, &s->wfds, &s->max_fileno);
54 }
55
56 /**
57 * the post select function of the stdout task
58 *
59 * \param s the scheduler this task was registered to
60 * \param t the task structure of the stdout task
61 *
62 * This function checks if \p STDOUT_FILENO was included by in the write fd set
63 * of \a s during the previous pre_select call. If yes, and \p STDOUT_FILENO
64 * appeears to be writable, the data loaded in the input buffer is written to
65 * stdout.
66 */
67 void stdout_post_select(struct sched *s, struct task *t)
68 {
69 struct stdout_task *sot = t->private_data;
70 ssize_t ret;
71
72 t->ret = 1;
73 if (!sot->check_fd) {
74 if (*sot->input_eof)
75 t->ret = -E_STDOUT_EOF;
76 return;
77 }
78 if (!FD_ISSET(STDOUT_FILENO, &s->wfds))
79 return;
80 t->ret = -E_STDOUT_WRITE;
81 ret = write(STDOUT_FILENO, sot->buf, *sot->loaded);
82 if (ret <= 0)
83 return;
84 *sot->loaded -= ret;
85 if (*sot->loaded)
86 memmove(sot->buf, sot->buf + ret, *sot->loaded);
87 t->ret = 1;
88 }
89
90 static void stdout_default_event_handler(struct task *t)
91 {
92 PARA_NOTICE_LOG("%p: %s\n", t, PARA_STRERROR(-t->ret));
93 unregister_task(t);
94 }
95
96 /**
97 * initialize a stdout task structure with default values
98 *
99 * \param sot the stdout task structure
100 *
101 * This fills in the pre/post select function poinzters of the task structure
102 * given by \a sot. It also sets up a default error handler which unregisters
103 * the task on errors and clears the eof flag of \a sot.
104 */
105 void stdout_set_defaults(struct stdout_task *sot)
106 {
107 sot->task.private_data = sot;
108 sot->task.pre_select = stdout_pre_select;
109 sot->task.post_select = stdout_post_select;
110 sot->task.event_handler = stdout_default_event_handler;
111 sot->eof = 0;
112 mark_fd_nonblock(STDOUT_FILENO);
113 sprintf(sot->task.status, "stdout writer");
114 }