From 6cd025ed002278ae21d9aad59978e8081e2b29e5 Mon Sep 17 00:00:00 2001
From: Marcos Vives Del Sol <socram8888@gmail.com>
Date: Sat, 20 Jun 2015 16:59:09 +0200
Subject: [PATCH] Added special case for timeouts that don't expire

---
 libnfc/timing.c | 17 ++++++++++++++---
 libnfc/timing.h |  6 ++++++
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/libnfc/timing.c b/libnfc/timing.c
index 8b17d71..e937a39 100644
--- a/libnfc/timing.c
+++ b/libnfc/timing.c
@@ -22,6 +22,9 @@
 #define MICROS_PER_SEC 1000000
 #define NANOS_PER_SEC 1000000000
 
+#define MAGIC_EXPIRED	((uint64_t) -1)
+#define MAGIC_NEVER	((uint64_t) -2)
+
 // Use Windows' API directly if Win32 for highest possible resolution
 #if defined(CYGWIN) || defined(_WIN32)
 #	include <windows.h>
@@ -61,14 +64,22 @@ void timeout_init(timeout_t * to, unsigned int millis) {
 	*to = time_millis() + millis;
 }
 
+void timeout_never(timeout_t * to) {
+	*to = MAGIC_NEVER;
+}
+
 bool timeout_check(timeout_t * to) {
-	if (*to == 0) {
-		return false;
+	switch (*to) {
+		case MAGIC_EXPIRED:
+			return false;
+		case MAGIC_NEVER:
+			return true;
 	}
 
 	ms_t now = time_millis();
 	if (now >= *to) {
-		*to = 0;
+		// Mark as expired and fail in next check
+		*to = MAGIC_EXPIRED;
 	}
 
 	return true;
diff --git a/libnfc/timing.h b/libnfc/timing.h
index beb9e47..5ee7bab 100644
--- a/libnfc/timing.h
+++ b/libnfc/timing.h
@@ -38,6 +38,12 @@ typedef ms_t timeout_t;
  */
 void timeout_init(timeout_t * to, unsigned int millis);
 
+/**
+ * @brief Initializes a timeout which never expires
+ * @param to Timeout handle
+ */
+void timeout_never(timeout_t * to);
+
 /**
  * @brief Checks if the timeout has NOT expired
  * @param to Timeout handle