Fix two gcc warnings on 64 bit archs.
[paraslash.git] / stdin.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 stdin.c Functions that deal with reading from stdin. */
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 "stdin.h"
18
19 /**
20 * The pre_select function of the stdin task.
21 *
22 * \param s The scheduler this task was registered to.
23 * \param t The task structure of the stdin task.
24 *
25 * This function is always successful. If there is space left in the
26 * buffer of the stdin task, it adds \p STDIN_FILENO to the read fd set
27 * of \a s.
28 */
29 static void stdin_pre_select(struct sched *s, struct task *t)
30 {
31 struct stdin_task *sit = container_of(t, struct stdin_task, task);
32
33 if (sit->output_error && *sit->output_error < 0) {
34 t->error = *sit->output_error;
35 return;
36 }
37 t->error = 0;
38 sit->check_fd = 0;
39 if (sit->loaded >= sit->bufsize)
40 return;
41 sit->check_fd = 1;
42 para_fd_set(STDIN_FILENO, &s->rfds, &s->max_fileno);
43 }
44
45 /**
46 * The post select function of the stdin task.
47 *
48 * \param s The scheduler this task was registered to.
49 * \param t The task structure of the stdin task.
50 *
51 * This function checks if \p STDIN_FILENO was included by in the read fd set
52 * of \a s during the previous pre_select call. If yes, and \p STDIN_FILENO
53 * appears to be readable, data is read from stdin into the buffer of the
54 * stdin task.
55 */
56 static void stdin_post_select(struct sched *s, struct task *t)
57 {
58 struct stdin_task *sit = container_of(t, struct stdin_task, task);
59 ssize_t ret;
60
61 if (sit->output_error && *sit->output_error < 0) {
62 t->error = *sit->output_error;
63 return;
64 }
65 t->error = 0;
66 if (!sit->check_fd)
67 return;
68 if (!FD_ISSET(STDIN_FILENO, &s->rfds))
69 return;
70 ret = read(STDIN_FILENO, sit->buf + sit->loaded, sit->bufsize - sit->loaded);
71 if (ret < 0)
72 t->error = ERRNO_TO_PARA_ERROR(errno);
73 else if (ret > 0)
74 sit->loaded += ret;
75 else
76 t->error = -E_STDIN_EOF;
77 }
78
79 /**
80 * Initialize a stdin task structure with default values.
81 *
82 * \param sit The stdin task structure.
83 *
84 * This fills in the pre/post select function pointers of the task structure
85 * given by \a sit. Moreover, the stdin file desctiptor is set to nonblocking
86 * mode and \a bufsize is initialized to 16 KB (but no buffer is allocated).
87 */
88 void stdin_set_defaults(struct stdin_task *sit)
89 {
90 int ret;
91
92 sit->bufsize = 32 * 1024,
93 sit->task.pre_select = stdin_pre_select;
94 sit->task.post_select = stdin_post_select;
95 sprintf(sit->task.status, "stdin reader");
96 ret = mark_fd_nonblocking(STDIN_FILENO);
97 if (ret >= 0)
98 return;
99 sit->output_error = NULL;
100 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
101 exit(EXIT_FAILURE);
102 }