kernel/timeout: Add absolute timeout APIs
Add support for "absolute" timeouts, which are expressed relative to
system uptime instead of deltas from current time. These allow for
more race-resistant code to be written by allowing application code to
do a single timeout computation, once, and then reuse the timeout
value even if the thread wakes up and needs to suspend again later.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
diff --git a/include/kernel.h b/include/kernel.h
index 94bf673..def4de8 100644
--- a/include/kernel.h
+++ b/include/kernel.h
@@ -1607,6 +1607,32 @@
#define K_FOREVER Z_FOREVER
/**
+ * @brief Generates an absolute/uptime timeout value in ticks
+ *
+ * This macro generates a timeout delay that represents an expiration
+ * at the absolute uptime value specified, in ticks. That is, the
+ * timeout will expire immediately after the system uptime reaches the
+ * specified tick count.
+ *
+ * @param t Tick uptime value
+ * @return Timeout delay value
+ */
+#define K_TIMEOUT_ABS_TICKS(t) Z_TIMEOUT_TICKS(Z_TICK_ABS(MAX(t, 0)))
+
+/**
+ * @brief Generates an absolute/uptime timeout value in ms
+ *
+ * This macro generates a timeout delay that represents an expiration
+ * at the absolute uptime value specified, in milliseconds. That is,
+ * the timeout will expire immediately after the system uptime reaches
+ * the specified tick count.
+ *
+ * @param t Millisecond uptime value
+ * @return Timeout delay value
+ */
+#define K_TIMEOUT_ABS_MS(t) K_TIMEOUT_ABS_TICKS(k_ms_to_ticks_ceil64(t))
+
+/**
* @}
*/
