1 #include <linux/console.h> 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 */ speakup_start_ttys(void)23void 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; 30 if ((vc_cons[i].d != NULL) && (vc_cons[i].d->port.tty != NULL)) 31 start_tty(vc_cons[i].d->port.tty); 32 } 33 } 34 EXPORT_SYMBOL_GPL(speakup_start_ttys); 35 speakup_stop_ttys(void)36static void speakup_stop_ttys(void) 37 { 38 int i; 39 40 for (i = 0; i < MAX_NR_CONSOLES; i++) 41 if ((vc_cons[i].d != NULL) && (vc_cons[i].d->port.tty != NULL)) 42 stop_tty(vc_cons[i].d->port.tty); 43 } 44 synth_buffer_free(void)45static 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 synth_buffer_empty(void)56int synth_buffer_empty(void) 57 { 58 return (buff_in == buff_out); 59 } 60 EXPORT_SYMBOL_GPL(synth_buffer_empty); 61 synth_buffer_add(char ch)62void 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 synth_buffer_getc(void)80char 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 synth_buffer_peek(void)93char 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 synth_buffer_clear(void)101void synth_buffer_clear(void) 102 { 103 buff_in = buff_out = synth_buffer; 104 return; 105 } 106 EXPORT_SYMBOL_GPL(synth_buffer_clear); 107