//
// Cforall Version 1.0.0 Copyright (C) 2018 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// clock --
//
// Author           : Peter A. Buhr
// Created On       : Thu Apr 12 14:36:06 2018
// Last Modified By : Peter A. Buhr
// Last Modified On : Wed Apr 14 17:48:25 2021
// Update Count     : 20
//

#include <time.hfa>

//######################### C time #########################

static inline char * ctime( time_t tp ) { char * buf = ctime( &tp ); buf[24] = '\0'; return buf; }
static inline char * ctime_r( time_t tp, char * buf ) { ctime_r( &tp, buf ); buf[24] = '\0'; return buf; }
static inline tm * gmtime( time_t tp ) { return gmtime( &tp ); }
static inline tm * gmtime_r( time_t tp, tm * result ) { return gmtime_r( &tp, result ); }
static inline tm * localtime( time_t tp ) { return localtime( &tp ); }
static inline tm * localtime_r( time_t tp, tm * result ) { return localtime_r( &tp, result ); }

//######################### Clock #########################

struct Clock {											// private
	Duration offset;									// for virtual clock: contains offset from real-time
};

static inline {
	void reset( Clock & clk, Duration adj ) with( clk ) {
		offset = adj + __timezone`s;					// timezone (global) is (UTC - local time) in seconds
	} // reset

	void ?{}( Clock & clk ) { reset( clk, (Duration){ 0 } ); }
	void ?{}( Clock & clk, Duration adj ) { reset( clk, adj ); }

	// System-wide clock that measures real, i.e., wall-clock) time. This clock is affected by discontinuous jumps in
	// the system time. For example, manual changes of the clock, and incremental adjustments performed by adjtime(3)
	// and NTP (daylight saving (Fall back).
	Duration resolutionNsec() {
		struct timespec res;
		clock_getres( CLOCK_REALTIME, &res );
		return ((int64_t)res.tv_sec * TIMEGRAN + res.tv_nsec)`ns;
	} // resolutionNsec

	Duration resolution() {
		struct timespec res;
		clock_getres( CLOCK_REALTIME_COARSE, &res );
		return ((int64_t)res.tv_sec * TIMEGRAN + res.tv_nsec)`ns;
	} // resolution

	Time timeNsec() {									// with nanoseconds
		timespec curr;
		clock_gettime( CLOCK_REALTIME, &curr );
		return (Time){ curr };
	} // timeNsec

	Time time() {										// without nanoseconds
		timespec curr;
		clock_gettime( CLOCK_REALTIME_COARSE, &curr );
		curr.tv_nsec = 0;
		return (Time){ curr };
	} // time

	Time time( Clock & clk ) with( clk ) {
		return time() + offset;
	} // time

	Time ?()( Clock & clk ) with( clk ) {				// alternative syntax
		return time() + offset;
	} // ?()

	timeval time( Clock & clk ) {
		return (timeval){ clk() };
	} // time

	tm time( Clock & clk ) with( clk ) {
		tm ret;
		localtime_r( time( clk ).tv_sec, &ret );
		return ret;
	} // time

	// CFA processor CPU-time watch that ticks when the processor (kernel thread) is running. This watch is affected by
	// discontinuous jumps when the OS is not running the kernal thread. A duration is returned because the value is
	// relative and cannot be converted to real-time (wall-clock) time.
	Duration processor() {
		timespec ts;
		clock_gettime( CLOCK_THREAD_CPUTIME_ID, &ts );
		return (Duration){ ts };
	} // processor

	// Program CPU-time watch measures CPU time consumed by all processors (kernel threads) in the UNIX process.  This
	// watch is affected by discontinuous jumps when the OS is not running the kernel threads. A duration is returned
	// because the value is relative and cannot be converted to real-time (wall-clock) time.
	Duration program() {
		timespec ts;
		clock_gettime( CLOCK_PROCESS_CPUTIME_ID, &ts );
		return (Duration){ ts };
	} // program

	// Monotonic stopwatch starting at machine boot and includes system suspension. This watch is unaffected by
	// discontinuous jumps resulting from manual changes of the clock, and incremental adjustments performed by
	// adjtime(3) and NTP (Fall back). A duration is returned because the value is relative and cannot be converted to
	// real-time (wall-clock) time.
	Duration boot() {
		timespec ts;
		clock_gettime( CLOCK_BOOTTIME, &ts );
		return (Duration){ ts };
	} // boot
} // distribution

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