add poll_event*()

@@ -47,4 +47,81 @@ static inline void ssleep(unsigned int s
 	msleep(seconds * 1000);
 }
 
+/*
+ * poll_event* check if an @condition is true every @interval milliseconds,
+ * up to a @timeout maximum, if specified, else forever.
+ * The *_interruptible versions will sleep in TASK_INTERRUPTIBLE
+ * (instead of TASK_UNINTERRUPTIBLE) and will return early on signals
+ * Note that these interfaces are distinctly different than
+ * wait_event*() in two ways:
+ * 	1) No wait-queues
+ * 	2) Specify the time you want to sleep, not when you want to
+ * 	wake-up. Thus, callers should not add the current time to
+ * 	@timeout before calling, as it will be done by the macro.
+ */
+
+/* no return value */
+#define poll_event(condition, interval)				\
+do {								\
+	while (!(condition))					\
+		msleep(interval);				\
+} while(0)
+
+/* return 0 if condition caused return, -ETIME if timeout */
+#define poll_event_timeout(condition, interval, timeout)		\
+({									\
+	int __ret = 0;							\
+	unsigned long stop = jiffies + msecs_to_jiffies(timeout);	\
+ 									\
+	for (;;) {							\
+		if (condition)						\
+			break;						\
+		msleep(interval);					\
+		if (time_after(jiffies, stop)) {			\
+			__ret = -ETIME;					\
+ 			break;						\
+		}							\
+	}								\
+	__ret;								\
+})
+
+/* return 0 if condition caused return, -EINTR if signal */
+#define poll_event_interruptible(condition, interval)	\
+({							\
+	int __ret = 0;					\
+							\
+	for (;;) {					\
+		if (condition)				\
+			break;				\
+		msleep_interruptible(interval);		\
+		if (signal_pending(current)) {		\
+			__ret = -EINTR;			\
+ 			break;				\
+		}					\
+	}						\
+	__ret;
+})
+
+/* return 0 if condition caused return, -EINTR if signal, -ETIME if
+ * timeout */
+#define poll_event_interruptible_timeout(conditition, interval, timeout)	\
+({										\
+	int __ret = 0;								\
+	unsigned long stop = jiffies + msecs_to_jiffies(timeout);		\
+										\
+	for (;;) {								\
+		if (condition)							\
+			break;							\
+		msleep_interruptible(interval);					\
+		if (signal_pending(current)) {					\
+			__ret = -EINTR;						\
+			break;							\
+		}								\
+		if (time_after(jiffies, stop)) {				\
+			__ret = -ETIME;						\
+			break;							\
+		}								\
+	}									\
+})
+
 #endif /* defined(_LINUX_DELAY_H) */

@@ -47,4 +47,106 @@ static inline void ssleep(unsigned int s
 	msleep(seconds * 1000);
 }
 
+/*
+ * poll_event* check if an @condition is true every @interval milliseconds,
+ * up to a @timeout maximum, if specified, else forever.
+ * The *_interruptible versions will sleep in TASK_INTERRUPTIBLE
+ * (instead of TASK_UNINTERRUPTIBLE) and will return early on signals
+ * Note that these interfaces are distinctly different than
+ * wait_event*() in two ways:
+ * 	1) No wait-queues
+ * 	2) Specify the time you want to sleep, not when you want to
+ * 	wake-up. Thus, callers should not add the current time to
+ * 	@timeout before calling, as it will be done by the macro.
+ */
+
+/**
+ * poll_event - check a condition at regular intervals
+ * @condition: Condition to check
+ * @interval: Number of milliseconds between checks
+ */
+#define poll_event(condition, interval)				\
+do {								\
+	while (!(condition))					\
+		msleep(interval);				\
+} while(0)
+
+/**
+ * poll_event_timeout - check a condition at regular intervals with a timeout
+ * @condition: Condition to check
+ * @interval: Number of milliseconds between checks
+ * @timeout: Maximum total number of milliseconds to take
+ * returns: 0, if condition caused return
+ * 	    -ETIME, if timeout
+ */
+#define poll_event_timeout(condition, interval, timeout)		\
+({									\
+	int __ret = 0;							\
+	unsigned long stop = jiffies + msecs_to_jiffies(timeout);	\
+ 									\
+	for (;;) {							\
+		if (condition)						\
+			break;						\
+		msleep(interval);					\
+		if (time_after(jiffies, stop)) {			\
+			__ret = -ETIME;					\
+ 			break;						\
+		}							\
+	}								\
+	__ret;								\
+})
+
+/**
+ * poll_event_interruptible - check a condition at regular intervals, returning early on signals
+ * @condition: Condition to check
+ * @interval: Number of milliseconds between checks
+ * returns: 0, if condition caused return
+ * 	    -EINTR, if a signal
+ */
+#define poll_event_interruptible(condition, interval)	\
+({							\
+	int __ret = 0;					\
+							\
+	for (;;) {					\
+		if (condition)				\
+			break;				\
+		msleep_interruptible(interval);		\
+		if (signal_pending(current)) {		\
+			__ret = -EINTR;			\
+ 			break;				\
+		}					\
+	}						\
+	__ret;
+})
+
+/**
+ * poll_event_interruptible_timeout - check a condition at regular intervals with a timeout, returning early on signals
+ * @condition: Condition to check
+ * @interval: Number of milliseconds between checks
+ * @timeout: Maximum total number of milliseconds to take
+ * returns 0, if condition caused return
+ * 	   -EINTR, if a signal
+ * 	   -ETIME, if timeout
+ */
+#define poll_event_interruptible_timeout(conditition, interval, timeout)	\
+({										\
+	int __ret = 0;								\
+	unsigned long stop = jiffies + msecs_to_jiffies(timeout);		\
+										\
+	for (;;) {								\
+		if (condition)							\
+			break;							\
+		msleep_interruptible(interval);					\
+		if (signal_pending(current)) {					\
+			__ret = -EINTR;						\
+			break;							\
+		}								\
+		if (time_after(jiffies, stop)) {				\
+			__ret = -ETIME;						\
+			break;							\
+		}								\
+	}									\
+	__ret;									\
+})
+
 #endif /* defined(_LINUX_DELAY_H) */