2 * Copyright (C) 2006-2009 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file stdin.c Functions that deal with reading from stdin. */
9 #include <dirent.h> /* readdir() */
20 #include "buffer_tree.h"
24 * The pre_select function of the stdin task.
26 * \param s The scheduler this task was registered to.
27 * \param t The task structure of the stdin task.
29 * This function is always successful. If there is space left in the
30 * buffer of the stdin task, it adds \p STDIN_FILENO to the read fd set
33 static void stdin_pre_select(struct sched *s, struct task *t)
35 struct stdin_task *sit = container_of(t, struct stdin_task, task);
37 if (sit->output_error && *sit->output_error < 0) {
38 t->error = *sit->output_error;
43 if (sit->loaded >= sit->bufsize)
46 para_fd_set(STDIN_FILENO, &s->rfds, &s->max_fileno);
49 #define STDIN_MAX_PENDING (1024 * 1024)
51 static void stdin_pre_select_btr(struct sched *s, struct task *t)
53 struct stdin_task *sit = container_of(t, struct stdin_task, task);
55 if (btr_no_children(sit->btrn)) {
56 t->error = -E_STDIN_NO_CHILD;
57 btr_del_node(sit->btrn);
62 if (btr_bytes_pending(sit->btrn) > STDIN_MAX_PENDING)
66 para_fd_set(STDIN_FILENO, &s->rfds, &s->max_fileno);
71 * The post select function of the stdin task.
73 * \param s The scheduler this task was registered to.
74 * \param t The task structure of the stdin task.
76 * This function checks if \p STDIN_FILENO was included by in the read fd set
77 * of \a s during the previous pre_select call. If yes, and \p STDIN_FILENO
78 * appears to be readable, data is read from stdin into the buffer of the
81 static void stdin_post_select(struct sched *s, struct task *t)
83 struct stdin_task *sit = container_of(t, struct stdin_task, task);
86 if (sit->output_error && *sit->output_error < 0) {
87 t->error = *sit->output_error;
93 if (!FD_ISSET(STDIN_FILENO, &s->rfds))
95 ret = read(STDIN_FILENO, sit->buf + sit->loaded, sit->bufsize - sit->loaded);
97 t->error = ERRNO_TO_PARA_ERROR(errno);
101 t->error = -E_STDIN_EOF;
104 #define STDIN_INPUT_BUFFER_SIZE 4000
105 static void stdin_post_select_btr(struct sched *s, struct task *t)
107 struct stdin_task *sit = container_of(t, struct stdin_task, task);
111 t->error = -E_STDIN_NO_CHILD;
112 if (btr_no_children(sit->btrn))
118 if (!FD_ISSET(STDIN_FILENO, &s->rfds))
121 buf = para_malloc(STDIN_INPUT_BUFFER_SIZE);
122 ret = read(STDIN_FILENO, buf, STDIN_INPUT_BUFFER_SIZE);
124 t->error = -ERRNO_TO_PARA_ERROR(errno);
126 t->error = -E_STDIN_EOF;
129 btr_add_output(buf, ret, sit->btrn);
133 btr_del_node(sit->btrn);
138 * Initialize a stdin task structure with default values.
140 * \param sit The stdin task structure.
142 * This fills in the pre/post select function pointers of the task structure
143 * given by \a sit. Moreover, the stdin file desctiptor is set to nonblocking
144 * mode and \a bufsize is initialized to 16 KB (but no buffer is allocated).
146 void stdin_set_defaults(struct stdin_task *sit)
150 sit->bufsize = 32 * 1024;
152 sit->task.pre_select = stdin_pre_select_btr;
153 sit->task.post_select = stdin_post_select_btr;
155 sit->task.pre_select = stdin_pre_select;
156 sit->task.post_select = stdin_post_select;
158 sprintf(sit->task.status, "stdin reader");
159 ret = mark_fd_nonblocking(STDIN_FILENO);
162 sit->output_error = NULL;
163 PARA_EMERG_LOG("%s\n", para_strerror(-ret));