106 lines
2.3 KiB
C
106 lines
2.3 KiB
C
#include <linux/console.h>
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#include <linux/types.h>
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#include <linux/wait.h>
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#include "speakup.h"
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#include "spk_priv.h"
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#define SYNTH_BUF_SIZE 8192 /* currently 8K bytes */
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static u_char synth_buffer[SYNTH_BUF_SIZE]; /* guess what this is for! */
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static u_char *buff_in = synth_buffer;
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static u_char *buff_out = synth_buffer;
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static u_char *buffer_end = synth_buffer + SYNTH_BUF_SIZE - 1;
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/* These try to throttle applications by stopping the TTYs
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* Note: we need to make sure that we will restart them eventually, which is
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* usually not possible to do from the notifiers. TODO: it should be possible
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* starting from linux 2.6.26.
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*
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* So we only stop when we know alive == 1 (else we discard the data anyway),
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* and the alive synth will eventually call start_ttys from the thread context.
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*/
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void speakup_start_ttys(void)
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{
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int i;
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for (i = 0; i < MAX_NR_CONSOLES; i++) {
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if (speakup_console[i] && speakup_console[i]->tty_stopped)
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continue;
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if ((vc_cons[i].d != NULL) && (vc_cons[i].d->port.tty != NULL))
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start_tty(vc_cons[i].d->port.tty);
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}
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}
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EXPORT_SYMBOL_GPL(speakup_start_ttys);
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static void speakup_stop_ttys(void)
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{
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int i;
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for (i = 0; i < MAX_NR_CONSOLES; i++)
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if ((vc_cons[i].d != NULL) && (vc_cons[i].d->port.tty != NULL))
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stop_tty(vc_cons[i].d->port.tty);
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}
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static int synth_buffer_free(void)
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{
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int bytes_free;
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if (buff_in >= buff_out)
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bytes_free = SYNTH_BUF_SIZE - (buff_in - buff_out);
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else
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bytes_free = buff_out - buff_in;
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return bytes_free;
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}
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int synth_buffer_empty(void)
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{
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return (buff_in == buff_out);
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}
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EXPORT_SYMBOL_GPL(synth_buffer_empty);
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void synth_buffer_add(char ch)
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{
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if (!synth->alive) {
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/* This makes sure that we won't stop TTYs if there is no synth
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* to restart them */
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return;
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}
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if (synth_buffer_free() <= 100) {
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synth_start();
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speakup_stop_ttys();
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}
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if (synth_buffer_free() <= 1)
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return;
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*buff_in++ = ch;
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if (buff_in > buffer_end)
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buff_in = synth_buffer;
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}
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char synth_buffer_getc(void)
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{
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char ch;
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if (buff_out == buff_in)
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return 0;
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ch = *buff_out++;
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if (buff_out > buffer_end)
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buff_out = synth_buffer;
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return ch;
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}
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EXPORT_SYMBOL_GPL(synth_buffer_getc);
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char synth_buffer_peek(void)
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{
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if (buff_out == buff_in)
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return 0;
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return *buff_out;
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}
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EXPORT_SYMBOL_GPL(synth_buffer_peek);
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void synth_buffer_clear(void)
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{
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buff_in = buff_out = synth_buffer;
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}
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EXPORT_SYMBOL_GPL(synth_buffer_clear);
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