Merge topic branch t/openssl-3 into master
[paraslash.git] / stdin.c
1 /* Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
2
3 /** \file stdin.c Functions that deal with reading from stdin. */
4
5 #include <regex.h>
6
7 #include "para.h"
8 #include "list.h"
9 #include "sched.h"
10 #include "fd.h"
11 #include "error.h"
12 #include "stdin.h"
13 #include "buffer_tree.h"
14 #include "string.h"
15
16 /*
17 * If there is space left in the buffer of the stdin task, ask the scheduler to
18 * monitor STDIN_FILENO.
19 */
20 static void stdin_pre_monitor(struct sched *s, void *context)
21 {
22 struct stdin_task *sit = context;
23 int ret;
24
25 ret = btr_node_status(sit->btrn, 0, BTR_NT_ROOT);
26 if (ret < 0)
27 sched_min_delay(s);
28 if (ret <= 0)
29 return;
30 if (btr_pool_unused(sit->btrp) > 0)
31 return sched_monitor_readfd(STDIN_FILENO, s);
32 sched_request_timeout_ms(100, s);
33 }
34
35 /*
36 * Feed data from stdin into the buffer tree if STDIN_FILENO is ready for
37 * reading.
38 */
39 static int stdin_post_monitor(__a_unused struct sched *s, void *context)
40 {
41 struct stdin_task *sit = context;
42 ssize_t ret;
43 size_t sz, n;
44 char *buf = NULL;
45
46 ret = btr_node_status(sit->btrn, 0, BTR_NT_ROOT);
47 if (ret < 0)
48 goto err;
49 if (ret == 0)
50 return 0;
51 sz = btr_pool_get_buffer(sit->btrp, &buf);
52 if (sz == 0)
53 return 0;
54 if (sit->must_set_nonblock_flag) {
55 ret = mark_fd_nonblocking(STDIN_FILENO);
56 if (ret < 0)
57 goto err;
58 sit->must_set_nonblock_flag = false;
59 }
60 /*
61 * Do not use the maximal size to avoid having only a single buffer
62 * reference for the whole pool. This is bad because if that single
63 * reference can not be freed, we're stuck.
64 */
65 sz = PARA_MIN(sz, btr_pool_size(sit->btrp) / 2);
66 ret = read_nonblock(STDIN_FILENO, buf, sz, &n);
67 if (n > 0)
68 btr_add_output_pool(sit->btrp, n, sit->btrn);
69 if (ret >= 0)
70 return 0;
71 err:
72 btr_remove_node(&sit->btrn);
73 /* Revert to blocking mode if necessary. */
74 fcntl(STDIN_FILENO, F_SETFL, sit->fd_flags);
75 //btr_pool_free(sit->btrp);
76 return ret;
77 }
78
79 /**
80 * Register a stdin task structure.
81 *
82 * \param sit The stdin task structure to register.
83 * \param s The task will be added to this scheduler's task list.
84 *
85 * This allocates a buffer tree pool for I/O, sets up \a sit and registers a
86 * task with \a sit as context pointer.
87 */
88 void stdin_task_register(struct stdin_task *sit, struct sched *s)
89 {
90 int ret;
91 struct task_info ti = {
92 .name = "stdin",
93 .pre_monitor = stdin_pre_monitor,
94 .post_monitor = stdin_post_monitor,
95 .context = sit,
96 };
97
98 sit->btrp = btr_pool_new("stdin", 128 * 1024);
99 /*
100 * Both STDIN_FILENO and STDOUT_FILENO may refer to the same open file
101 * description (the terminal), and thus share the same file status
102 * flags. In order to not interfere with the stdout task, we only get
103 * the file status flags for STDIN here and save a copy. The nonblock
104 * flag is set later on the first read.
105 */
106 ret = fcntl(STDIN_FILENO, F_GETFL);
107 if (ret < 0) {
108 PARA_EMERG_LOG("F_GETFL: %s\n", strerror(errno));
109 exit(EXIT_FAILURE);
110 }
111 sit->fd_flags = ret;
112 sit->must_set_nonblock_flag = (sit->fd_flags & O_NONBLOCK) == 0
113 && !isatty(STDIN_FILENO);
114 sit->task = task_register(&ti, s);
115 }