From: Keith Packard <keithp@keithp.com>
Date: Tue, 23 Apr 2013 01:27:52 +0000 (-0500)
Subject: altos: Eliminate stdio looping when system has a single stdio source
X-Git-Tag: 1.2.1~37
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=8d0f4bc23eae4f1e085bfb853c995f1fb6b8b594

altos: Eliminate stdio looping when system has a single stdio source

No need to loop if there's only one

Signed-off-by: Keith Packard <keithp@keithp.com>
---

diff --git a/src/avr/ao_avr_stdio.c b/src/avr/ao_avr_stdio.c
index 2765853a..f9c0f88c 100644
--- a/src/avr/ao_avr_stdio.c
+++ b/src/avr/ao_avr_stdio.c
@@ -20,16 +20,7 @@
 int
 stdio_put(char c, FILE *stream)
 {
-	if (ao_cur_task && ao_num_stdios)
-		putchar(c);
-	else
-	{
-		if (c == '\n')
-			stdio_put('\r', stream);
-		loop_until_bit_is_set(UCSR1A, UDRE1);
-		UDR1 = c;
-	}
-
+	putchar(c);
 	return 0;
 }
 
diff --git a/src/core/ao_stdio.c b/src/core/ao_stdio.c
index 977d74b1..cd144d6b 100644
--- a/src/core/ao_stdio.c
+++ b/src/core/ao_stdio.c
@@ -66,8 +66,15 @@
 #define AO_NUM_STDIOS	(HAS_USB + PACKET_HAS_SLAVE + USE_SERIAL_STDIN)
 
 __xdata struct ao_stdio ao_stdios[AO_NUM_STDIOS];
+
+#if AO_NUM_STDIOS > 1
 __pdata int8_t ao_cur_stdio;
 __pdata int8_t ao_num_stdios;
+#else
+__pdata int8_t ao_cur_stdio;
+#define ao_cur_stdio	0
+#define ao_num_stdios	0
+#endif
 
 void
 putchar(char c)
@@ -107,12 +114,16 @@ getchar(void) __reentrant
 		c = ao_stdios[stdio]._pollchar();
 		if (c != AO_READ_AGAIN)
 			break;
+#if AO_NUM_STDIOS > 1
 		if (++stdio == ao_num_stdios)
 			stdio = 0;
 		if (stdio == ao_cur_stdio)
+#endif
 			ao_sleep(&ao_stdin_ready);
 	}
+#if AO_NUM_STDIOS > 1
 	ao_cur_stdio = stdio;
+#endif
 	ao_arch_release_interrupts();
 	return c;
 }
@@ -128,11 +139,17 @@ ao_add_stdio(int (*_pollchar)(void),
 	     void (*putchar)(char),
 	     void (*flush)(void)) __reentrant
 {
+#if AO_NUM_STDIOS > 1
 	if (ao_num_stdios == AO_NUM_STDIOS)
 		ao_panic(AO_PANIC_STDIO);
+#endif
 	ao_stdios[ao_num_stdios]._pollchar = _pollchar;
 	ao_stdios[ao_num_stdios].putchar = putchar;
 	ao_stdios[ao_num_stdios].flush = flush;
 	ao_stdios[ao_num_stdios].echo = 1;
+#if AO_NUM_STDIOS > 1
 	return ao_num_stdios++;
+#else
+	return 0;
+#endif
 }