#include <iostream>

uint64_t ptp_time_ns = 883612965570493000; // 2262
        //  922337203685477000
        //  883612800000000000 - 1998
        // 1609459200000000000 - 2021
        // 8835955200000000000 - 2250
        //16725225600000000000 - 2500

uint64_t cst_us = 18446744073709550;
// CST
// min:                 0 (UINT64 MIN)
// max: 18446744073709551 (UINT64 MAX / 1000) // 2554

                     //= 
uint64_t ptp_offset_ns = ptp_time_ns - (cst_us * 1000ULL);//-725846400000000000;//883612800000000000;//

// PTP_OFFSET
// min:                    0 (UINT64 MIN)
// max: 18446744073709551615 (UINT64 MAX)

uint64_t ReadClockTime()
{
  return (cst_us * 1000ULL) + ptp_offset_ns;
}

uint64_t ReadClockOffset()
{
  return ptp_offset_ns;
}

bool GetSystemTimeAndOffsetMicros(uint64_t& rSystemTime, uint64_t& rSystemTimeOffset)
{
    std::cout << "==GetSystemTimeAndOffsetMicros==" << std::endl;
    std::cout << "CST [us]: " <<  cst_us            << std::endl;
    std::cout << "CST [ns]: " << (cst_us * 1000ULL) << std::endl;

    bool m_pTimeSyncClock = true;

    if (m_pTimeSyncClock)
    {
        int64_t ullCurrentTimeNsecs   = ReadClockTime();
        int64_t ullCurrentOffsetNsecs = ReadClockOffset();

        std::cout << "ullCurrentTimeNsecs   [ns]: " << (uint64_t)ullCurrentTimeNsecs   << " (" << (int64_t)(ullCurrentTimeNsecs)   << ")" << std::endl;
        std::cout << "ullCurrentOffsetNsecs [ns]: " << (uint64_t)ullCurrentOffsetNsecs << " (" << (int64_t)(ullCurrentOffsetNsecs) << ")" << std::endl;

        int64_t ullLeapNsecs = 37000000000;

        rSystemTime =       (ullCurrentTimeNsecs   - ullLeapNsecs) / 1000LL;
        rSystemTimeOffset = (ullCurrentOffsetNsecs - ullLeapNsecs) / 1000LL;

        std::cout << "rSystemTime       [ns]: " << rSystemTime       << " (" << (int64_t)(rSystemTime)       << ")" << std::endl;
        std::cout << "rSystemTimeOffset [ns]: " << rSystemTimeOffset << " (" << (int64_t)(rSystemTimeOffset) << ")" << std::endl;

        return true;
    }
    return false;
}

int main() 
{
    uint64_t ullSystemTimeValue;
    uint64_t ullSystemTimeOffset;
    
    GetSystemTimeAndOffsetMicros(ullSystemTimeValue, ullSystemTimeOffset);
    
    uint64_t ullCSTTimeValue = ullSystemTimeValue - ullSystemTimeOffset;
    
    std::cout << std::endl << "==RESULTS==" << std::endl;
    std::cout << "ullSystemTimeValue  : " << ullSystemTimeValue << " (" << (int64_t)ullSystemTimeValue << ")" << std::endl;
    std::cout << "ullSystemTimeOffset : " << ullSystemTimeOffset << " (" << (int64_t)ullSystemTimeOffset << ")" << std::endl;
    std::cout << "ullCSTTimeValue     : " << ullCSTTimeValue << " (" << (int64_t)ullCSTTimeValue << ")" << std::endl;
    std::cout << "ullCSTTimeValue orig: " << cst_us << " (" << (int64_t)cst_us << ")" << std::endl;
    return 0;
}

C++ Online Compiler

Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++ and start coding!

Read inputs from stdin

OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

#include <iostream>
#include <string>
using namespace std;

int main() 
{
    string name;
    cout << "Enter name:";
    getline (cin, name);
    cout << "Hello " << name;
    return 0;
}

About C++

C++ is a widely used middle-level programming language.

  • Supports different platforms like Windows, various Linux flavours, MacOS etc
  • C++ supports OOPS concepts like Inheritance, Polymorphism, Encapsulation and Abstraction.
  • Case-sensitive
  • C++ is a compiler based language
  • C++ supports structured programming language
  • C++ provides alot of inbuilt functions and also supports dynamic memory allocation.
  • Like C, C++ also allows you to play with memory using Pointers.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition If-Else is used.

if(conditional-expression) {
   //code
}
else {
   //code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression){    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
......    
    
default:     
 code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  //code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while (condition) {  
// code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {  
 // code 
} while (condition);

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.

How to declare a Function:

return_type function_name(parameters);

How to call a Function:

function_name (parameters)

How to define a Function:

return_type function_name(parameters) {  
 // code
}