1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 | #include <linux/console.h> #include <linux/types.h> #include <linux/wait.h> #include "speakup.h" #include "spk_priv.h" #define SYNTH_BUF_SIZE 8192 /* currently 8K bytes */ static u_char synth_buffer[SYNTH_BUF_SIZE]; /* guess what this is for! */ static u_char *buff_in = synth_buffer; static u_char *buff_out = synth_buffer; static u_char *buffer_end = synth_buffer + SYNTH_BUF_SIZE - 1; /* These try to throttle applications by stopping the TTYs * Note: we need to make sure that we will restart them eventually, which is * usually not possible to do from the notifiers. TODO: it should be possible * starting from linux 2.6.26. * * So we only stop when we know alive == 1 (else we discard the data anyway), * and the alive synth will eventually call start_ttys from the thread context. */ void speakup_start_ttys(void) { int i; for (i = 0; i < MAX_NR_CONSOLES; i++) { if (speakup_console[i] && speakup_console[i]->tty_stopped) continue; if ((vc_cons[i].d) && (vc_cons[i].d->port.tty)) start_tty(vc_cons[i].d->port.tty); } } EXPORT_SYMBOL_GPL(speakup_start_ttys); static void speakup_stop_ttys(void) { int i; for (i = 0; i < MAX_NR_CONSOLES; i++) if ((vc_cons[i].d && (vc_cons[i].d->port.tty))) stop_tty(vc_cons[i].d->port.tty); } static int synth_buffer_free(void) { int bytes_free; if (buff_in >= buff_out) bytes_free = SYNTH_BUF_SIZE - (buff_in - buff_out); else bytes_free = buff_out - buff_in; return bytes_free; } int synth_buffer_empty(void) { return (buff_in == buff_out); } EXPORT_SYMBOL_GPL(synth_buffer_empty); void synth_buffer_add(char ch) { if (!synth->alive) { /* This makes sure that we won't stop TTYs if there is no synth * to restart them */ return; } if (synth_buffer_free() <= 100) { synth_start(); speakup_stop_ttys(); } if (synth_buffer_free() <= 1) return; *buff_in++ = ch; if (buff_in > buffer_end) buff_in = synth_buffer; } char synth_buffer_getc(void) { char ch; if (buff_out == buff_in) return 0; ch = *buff_out++; if (buff_out > buffer_end) buff_out = synth_buffer; return ch; } EXPORT_SYMBOL_GPL(synth_buffer_getc); char synth_buffer_peek(void) { if (buff_out == buff_in) return 0; return *buff_out; } EXPORT_SYMBOL_GPL(synth_buffer_peek); void synth_buffer_clear(void) { buff_in = synth_buffer; buff_out = synth_buffer; } EXPORT_SYMBOL_GPL(synth_buffer_clear); |