Timer Library Complete

include/timerlib.h

@@ -0,0 +1,174 @@
+#ifndef __TIMER_WRAP__
+#define __TIMER_WRAP__
+
+//To use POSIX TIMER library
+#define __USE_POSIX199309 1
+
+#include <signal.h>
+#include <time.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+
+/*
+* Timer Data Structure, with attributes 
+* for controlling timer.
+*/
+
+typedef enum {
+
+	TIMER_INIT,
+	TIMER_RUNNING,
+	TIMER_CANCELLED,
+	TIMER_DELETED,
+	TIMER_PAUSED,
+	TIMER_RESUMED
+
+} TIMER_STATE_T;
+
+
+
+typedef struct Timer_ {
+	
+	/* Timer config */
+	timer_t* posix_timer;				//Handle to Posix timer
+	void* user_arg;						//Arg to passed to timer callback fun.
+	unsigned long exp_time;				//expiration or fire time after timer start
+	unsigned long sec_exp_time;			//expiration or fire time after first timer exp., used in periodic timer
+	uint32_t threshold;					//No. of times to invoke the timer callback
+	void (*cb)(struct Timer_*, void*);	//Function-pointer to timer callback
+	bool exponential_backoff;			//If the timer is exponential type
+
+	/*
+	* Dynamic Attributes of timer data structure:
+	* 
+	* Attributes which change dynamically with exec. of
+	* program.
+	* 
+	*/
+
+	unsigned long time_remaining;		//Time left for paused timer for next expiration/launch
+	uint32_t invocation_counter;		//No. of times callback is invoked( Useful in periodic/exponential type)
+	struct itimerspec ts;
+	unsigned long exp_back_off_time;
+	TIMER_STATE_T timer_state;			//State of the Timer object
+
+}Timer_t;
+
+
+
+/*
+* Assignment-1 functions.
+*/
+
+unsigned long
+timespec_to_millisec(struct timespec* time);
+
+void
+timer_fill_itimerspec(struct timespec* ts,
+	unsigned long msec);
+
+/*
+* Assignment-1 functions.
+*/
+
+
+
+/*
+* Assignment-2 functions
+*/
+
+static inline void
+timer_delete_user_data(Timer_t* timer) {
+
+	if (timer->user_arg) {
+		free(timer->user_arg);
+		timer->user_arg = NULL;
+	}
+}
+
+static inline TIMER_STATE_T
+timer_get_current_state(Timer_t* timer) {
+
+	return timer->timer_state;
+}
+
+static inline void
+timer_set_state(Timer_t* timer, TIMER_STATE_T timer_state) {
+
+	timer->timer_state = timer_state;
+
+}
+
+/*
+* Assignment-2 functions
+*/
+
+
+
+/*Return NULL in timer creation fails, else
+return a pointer to Timer object*/
+
+Timer_t*
+setup_timer(
+	/* Timer Callback with user data and user size */
+	void (*)(Timer_t*, void*),
+	/* First expiration timer interval in msec*/
+	unsigned long,
+	/*Subsequent expiration time interval in msec*/
+	unsigned long,
+	/*Max no of expiration, 0 for infinite */
+	uint32_t,
+	/* Arg to timer callback */
+	void*,
+	/* Is timer Exp back off */
+	bool
+);
+
+/*****APIs' to control timer******/
+
+void
+resurrect_timer(Timer_t* timer);
+
+void
+start_timer(Timer_t* timer);
+
+unsigned long
+timer_get_time_remaining_in_milli_sec(Timer_t* timer);
+
+void
+pause_timer(Timer_t* timer);
+
+
+void
+resume_timer(Timer_t* timer);
+
+int
+execute_timer(Timer_t* timer, TIMER_STATE_T action);
+
+void
+delete_timer(Timer_t* timer);
+
+void
+cancel_timer(Timer_t* timer);
+
+void
+restart_timer(Timer_t* timer);
+
+void
+reschedule_timer(Timer_t* timer,
+	unsigned long exp_ti,
+	unsigned long sec_exp_ti);
+
+void
+print_timer(Timer_t* timer);
+
+bool
+is_timer_running(Timer_t* timer);
+
+
+/*****APIs' to control timer******/
+
+#endif