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c6e3fd22 | 1 | #include <linux/console.h> |
c6e3fd22 WH |
2 | #include <linux/types.h> |
3 | #include <linux/wait.h> | |
4 | ||
5 | #include "speakup.h" | |
6 | #include "spk_priv.h" | |
7 | ||
8 | #define synthBufferSize 8192 /* currently 8K bytes */ | |
9 | ||
10 | static u_char synth_buffer[synthBufferSize]; /* guess what this is for! */ | |
11 | static u_char *buff_in = synth_buffer; | |
12 | static u_char *buff_out = synth_buffer; | |
13 | static u_char *buffer_end = synth_buffer+synthBufferSize-1; | |
14 | ||
15 | /* These try to throttle applications by stopping the TTYs | |
16 | * Note: we need to make sure that we will restart them eventually, which is | |
17 | * usually not possible to do from the notifiers. TODO: it should be possible | |
18 | * starting from linux 2.6.26. | |
19 | * | |
20 | * So we only stop when we know alive == 1 (else we discard the data anyway), | |
21 | * and the alive synth will eventually call start_ttys from the thread context. | |
22 | */ | |
23 | void speakup_start_ttys(void) | |
24 | { | |
25 | int i; | |
26 | ||
27 | for (i = 0; i < MAX_NR_CONSOLES; i++) { | |
28 | if (speakup_console[i] && speakup_console[i]->tty_stopped) | |
29 | continue; | |
5b19208a GKH |
30 | if ((vc_cons[i].d != NULL) && (vc_cons[i].d->port.tty != NULL)) |
31 | start_tty(vc_cons[i].d->port.tty); | |
c6e3fd22 WH |
32 | } |
33 | } | |
34 | EXPORT_SYMBOL_GPL(speakup_start_ttys); | |
35 | ||
36 | static void speakup_stop_ttys(void) | |
37 | { | |
38 | int i; | |
39 | ||
40 | for (i = 0; i < MAX_NR_CONSOLES; i++) | |
5b19208a GKH |
41 | if ((vc_cons[i].d != NULL) && (vc_cons[i].d->port.tty != NULL)) |
42 | stop_tty(vc_cons[i].d->port.tty); | |
c6e3fd22 WH |
43 | } |
44 | ||
45 | static int synth_buffer_free(void) | |
46 | { | |
47 | int bytesFree; | |
48 | ||
49 | if (buff_in >= buff_out) | |
50 | bytesFree = synthBufferSize - (buff_in - buff_out); | |
51 | else | |
52 | bytesFree = buff_out - buff_in; | |
53 | return bytesFree; | |
54 | } | |
55 | ||
56 | int synth_buffer_empty(void) | |
57 | { | |
58 | return (buff_in == buff_out); | |
59 | } | |
60 | EXPORT_SYMBOL_GPL(synth_buffer_empty); | |
61 | ||
62 | void synth_buffer_add(char ch) | |
63 | { | |
64 | if (!synth->alive) { | |
65 | /* This makes sure that we won't stop TTYs if there is no synth | |
66 | * to restart them */ | |
67 | return; | |
68 | } | |
69 | if (synth_buffer_free() <= 100) { | |
70 | synth_start(); | |
71 | speakup_stop_ttys(); | |
72 | } | |
73 | if (synth_buffer_free() <= 1) | |
74 | return; | |
75 | *buff_in++ = ch; | |
76 | if (buff_in > buffer_end) | |
77 | buff_in = synth_buffer; | |
78 | } | |
79 | ||
80 | char synth_buffer_getc(void) | |
81 | { | |
82 | char ch; | |
83 | ||
84 | if (buff_out == buff_in) | |
85 | return 0; | |
86 | ch = *buff_out++; | |
87 | if (buff_out > buffer_end) | |
88 | buff_out = synth_buffer; | |
89 | return ch; | |
90 | } | |
91 | EXPORT_SYMBOL_GPL(synth_buffer_getc); | |
92 | ||
93 | char synth_buffer_peek(void) | |
94 | { | |
95 | if (buff_out == buff_in) | |
96 | return 0; | |
97 | return *buff_out; | |
98 | } | |
99 | EXPORT_SYMBOL_GPL(synth_buffer_peek); | |
100 | ||
101 | void synth_buffer_clear(void) | |
102 | { | |
103 | buff_in = buff_out = synth_buffer; | |
104 | return; | |
105 | } | |
106 | EXPORT_SYMBOL_GPL(synth_buffer_clear); |