Implemented handling for constant TIME_ZERO for timeout specifications.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@811 35acf78f-673a-0410-8e92-d51de3d6d3f4

2 files changed, 11 insertions, 3 deletions

diff --git a/src/chschd.c b/src/chschd.c
index aad060ac9..3c17c3831 100644
--- a/src/chschd.c
+++ b/src/chschd.c
@@ -122,8 +122,10 @@ static void wakeup(void *p) {
  * to sleep is awakened after the specified time has elapsed.
  *
  * @param newstate the new thread state
- * @param time the number of ticks before the operation timeouts. The value
- *             zero (@p TIME_INFINITE) is allowed.
+ * @param time the number of ticks before the operation timeouts. The
+ *             following special values are allowed:
+ *             - @p TIME_ZERO immediate timeout.
+ *             - @p TIME_INFINITE no timeout.
  * @return The wakeup message.
  * @retval RDY_TIMEOUT if a timeout occurs.
  * @note The function must be called in the system mutex zone.
@@ -131,6 +133,8 @@ static void wakeup(void *p) {
  */
 msg_t chSchGoSleepTimeoutS(tstate_t newstate, systime_t time) {
 
+  if (TIME_ZERO == time)
+    return RDY_OK;
   if (TIME_INFINITE != time) {
     VirtualTimer vt;
 
diff --git a/src/include/scheduler.h b/src/include/scheduler.h
index 9b16dccc9..c79f061f7 100644
--- a/src/include/scheduler.h
+++ b/src/include/scheduler.h
@@ -41,9 +41,13 @@
 #define HIGHPRIO        127             /**< Highest user priority.*/
 #define ABSPRIO         255             /**< Greatest possible priority.*/
 
+/** Zero time specification for all the syscalls with a timeout
+    specification.*/
+#define TIME_ZERO   ((systime_t)0)
+
 /** Infinite time specification for all the syscalls with a timeout
     specification.*/
-#define TIME_INFINITE   0
+#define TIME_INFINITE   ((systime_t)-1)
 
 /** The priority of the first thread on the given ready list. */
 #define firstprio(rlp)  ((rlp)->p_next->p_prio)