pps-sntp.cpp File Reference

The pps-sntp.cpp file contains functions and structures for accessing time updates via SNTP. More...

#include "../client/pps-client.h"

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Data Structures
struct	sntpLocalVars

Macros
#define	ADDR_LEN   17

Functions
int	allocNTPServerList (timeCheckParams *tcp)
void	copyToLog (char *logbuf, const char *msg)
time_t	getServerTime (const char *server, int id, char *strbuf, char *logbuf)
void	doTimeCheck (timeCheckParams *tcp)
int	getTimeConsensusAndCount (void)
void	updateLog (char *buf, int numServers)
void	makeSNTPTimeQuery (timeCheckParams *tcp)
int	allocInitializeSNTPThreads (timeCheckParams *tcp)
void	freeSNTPThreads (timeCheckParams *tcp)

Variables
struct G	g
	Declares the global variables defined in pps-client.h. More...
const char *	srv0 = "0.debian.pool.ntp.org"
const char *	srv1 = "1.debian.pool.ntp.org"
const char *	srv2 = "2.debian.pool.ntp.org"
const char *	srv3 = "3.debian.pool.ntp.org"

Detailed Description

The pps-sntp.cpp file contains functions and structures for accessing time updates via SNTP.

Copyright (C) 2016-2018 Raymond S. Connell

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

Definition in file pps-sntp.cpp.

Macro Definition Documentation

ADDR_LEN

#define ADDR_LEN   17

Definition at line 23 of file pps-sntp.cpp.

Function Documentation

allocInitializeSNTPThreads()

int allocInitializeSNTPThreads

(

timeCheckParams *

tcp

)

Allocates memory and initializes threads that will be used by makeSNTPTimeQuery() to query SNTP time servers. Thread must be released and memory deleted by calling freeSNTPThreads().

Parameters

[out]

tcp

Struct pointer for passing data.

Returns

0 on success or -1 on error.

Definition at line 416 of file pps-sntp.cpp.

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allocNTPServerList()

int allocNTPServerList

(

timeCheckParams *

tcp

)

Allocates memory, reads the list of NTP servers above and partitions the memory into an array of server addresses that are returned by tcp->ntp_server[].

The memory MUST be released by the caller by calling "delete" on the tcp->buf param. That automatically frees the tcp->ntp_server[] array memory.

Parameters

[out]

tcp

Struct pointer for passing data to a thread.

Returns

The number of server addresses or -1 on error.

Definition at line 58 of file pps-sntp.cpp.

copyToLog()

void copyToLog	(	char *	logbuf,
		const char *	msg
	)

Definition at line 98 of file pps-sntp.cpp.

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doTimeCheck()

void doTimeCheck

(

timeCheckParams *

tcp

)

Requests a date/time from an SNTP time server in a detached thread that exits after filling the timeCheckParams struct, tcp, with the requested information and any error info.

Parameters

[in,out]

tcp

struct pointer for passing data.

Definition at line 233 of file pps-sntp.cpp.

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freeSNTPThreads()

void freeSNTPThreads

(

timeCheckParams *

tcp

)

Releases threads and deletes memory used by makeSNTPTimeQuery();

Parameters

[in]

tcp

The struct pointer that was used for passing data.

Definition at line 456 of file pps-sntp.cpp.

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getServerTime()

time_t getServerTime	(	const char *	server,
		int	id,
		char *	strbuf,
		char *	logbuf
	)

Gets the time correction in whole seconds determined by an SNTP server.

Parameters

[in]	server	The server URL.
[in]	id	An identifer for constructing a filename for server messages.
[in]	strbuf	A buffer to hold server messages.
[in]	logbuf	A buffer to hold messages for the error log.

Returns

The time correction to be made or -1 on error.

Definition at line 119 of file pps-sntp.cpp.

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getTimeConsensusAndCount()

int getTimeConsensusAndCount

(

void

)

Takes a consensus of the time error between local time and the time reported by SNTP servers and reports the error as g.consensusTimeError.

Returns

The number of SNTP servers reporting.

Definition at line 263 of file pps-sntp.cpp.

makeSNTPTimeQuery()

void makeSNTPTimeQuery

(

timeCheckParams *

tcp

)

At an interval defined by CHECK_TIME, queries a list of SNTP servers for date/time using detached threads so that delays in server responses do not affect the operation of the waitForPPS() loop.

Parameters

[in,out]

tcp

Struct pointer for passing data.

Definition at line 341 of file pps-sntp.cpp.

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updateLog()

void updateLog	(	char *	buf,
		int	numServers
	)

Updates the PPS-Client log with any errors reported by threads querying SNTP time servers.

Parameters

[out]	buf	The message buffer shared by the threads.
[in]	numServers	The number of SNTP servers.

Definition at line 321 of file pps-sntp.cpp.

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Variable Documentation

g

struct G g

Declares the global variables defined in pps-client.h.

Definition at line 53 of file pps-client.cpp.

srv0

const char* srv0 = "0.debian.pool.ntp.org"

Definition at line 40 of file pps-sntp.cpp.

srv1

const char* srv1 = "1.debian.pool.ntp.org"

Definition at line 41 of file pps-sntp.cpp.

srv2

const char* srv2 = "2.debian.pool.ntp.org"

Definition at line 42 of file pps-sntp.cpp.

srv3

const char* srv3 = "3.debian.pool.ntp.org"

Definition at line 43 of file pps-sntp.cpp.