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-rwxr-xr-xcores/arduino/Arduino.h2
-rw-r--r--cores/arduino/hooks.c31
-rw-r--r--cores/arduino/wiring.c1
3 files changed, 34 insertions, 0 deletions
diff --git a/cores/arduino/Arduino.h b/cores/arduino/Arduino.h
index b265825..02c2a8f 100755
--- a/cores/arduino/Arduino.h
+++ b/cores/arduino/Arduino.h
@@ -15,6 +15,8 @@
extern "C"{
#endif
+void yield(void);
+
#define HIGH 0x1
#define LOW 0x0
diff --git a/cores/arduino/hooks.c b/cores/arduino/hooks.c
new file mode 100644
index 0000000..641eabc
--- /dev/null
+++ b/cores/arduino/hooks.c
@@ -0,0 +1,31 @@
+/*
+ Copyright (c) 2012 Arduino. All right reserved.
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ See the GNU Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+*/
+
+/**
+ * Empty yield() hook.
+ *
+ * This function is intended to be used by library writers to build
+ * libraries or sketches that supports cooperative threads.
+ *
+ * Its defined as a weak symbol and it can be redefined to implement a
+ * real cooperative scheduler.
+ */
+static void __empty() {
+ // Empty
+}
+void yield(void) __attribute__ ((weak, alias("__empty")));
diff --git a/cores/arduino/wiring.c b/cores/arduino/wiring.c
index ac8bb6f..ec5b888 100644
--- a/cores/arduino/wiring.c
+++ b/cores/arduino/wiring.c
@@ -111,6 +111,7 @@ void delay(unsigned long ms)
uint16_t start = (uint16_t)micros();
while (ms > 0) {
+ yield();
if (((uint16_t)micros() - start) >= 1000) {
ms--;
start += 1000;