2 * Copyright (C) 2006-2012 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. */
18 #include "buffer_tree.h"
22 * The pre_select function of the stdin task.
24 * \param s The scheduler this task was registered to.
25 * \param t The task structure of the stdin task.
27 * This function is always successful. If there is space left in the
28 * buffer of the stdin task, it adds \p STDIN_FILENO to the read fd set
31 static void stdin_pre_select(struct sched
*s
, struct task
*t
)
33 struct stdin_task
*sit
= container_of(t
, struct stdin_task
, task
);
37 ret
= btr_node_status(sit
->btrn
, 0, BTR_NT_ROOT
);
42 if (btr_pool_unused(sit
->btrp
) > 0)
43 return para_fd_set(STDIN_FILENO
, &s
->rfds
, &s
->max_fileno
);
44 sched_request_timeout_ms(100, s
);
48 * The post select function of the stdin task.
50 * \param s The scheduler this task was registered to.
51 * \param t The task structure of the stdin task.
53 * This function checks if \p STDIN_FILENO was included by in the read fd set
54 * of \a s during the previous pre_select call. If yes, and \p STDIN_FILENO
55 * appears to be readable, data is read from stdin and fed into the buffer
58 static void stdin_post_select(struct sched
*s
, struct task
*t
)
60 struct stdin_task
*sit
= container_of(t
, struct stdin_task
, task
);
66 ret
= btr_node_status(sit
->btrn
, 0, BTR_NT_ROOT
);
71 sz
= btr_pool_get_buffer(sit
->btrp
, &buf
);
75 * Do not use the maximal size to avoid having only a single buffer
76 * reference for the whole pool. This is bad because if that single
77 * reference can not be freed, we're stuck.
79 sz
= PARA_MIN(sz
, btr_pool_size(sit
->btrp
) / 2);
80 ret
= read_nonblock(STDIN_FILENO
, buf
, sz
, &s
->rfds
, &n
);
82 btr_add_output_pool(sit
->btrp
, n
, sit
->btrn
);
86 btr_remove_node(sit
->btrn
);
87 //btr_pool_free(sit->btrp);
92 * Initialize a stdin task structure with default values.
94 * \param sit The stdin task structure.
96 * This fills in the pre/post select function pointers of the task structure
97 * given by \a sit. Moreover, the stdin file desctiptor is set to nonblocking
98 * mode, and a buffer tree is created.
100 void stdin_set_defaults(struct stdin_task
*sit
)
104 sit
->task
.pre_select
= stdin_pre_select
;
105 sit
->task
.post_select
= stdin_post_select
;
106 sit
->btrp
= btr_pool_new("stdin", 128 * 1024);
107 sprintf(sit
->task
.status
, "stdin reader");
108 ret
= mark_fd_nonblocking(STDIN_FILENO
);
111 PARA_EMERG_LOG("%s\n", para_strerror(-ret
));