Legal problem with win32/thread_primitives.hpp

[pdimov]

A third-party legal review has identified a problem as reported here:

https://lists.boost.org/Archives/boost/2018/02/241435.php

regarding

thread/include/boost/thread/win32/thread_primitives.hpp

Lines 89 to 110 in 526c72c

	// Borrowed from https://stackoverflow.com/questions/8211820/userland-interrupt-timer-access-such-as-via-kequeryinterrupttime-or-similar
	inline ticks_type __stdcall GetTickCount64emulation()
	{
	static long count = -1l;
	unsigned long previous_count, current_tick32, previous_count_zone, current_tick32_zone;
	ticks_type current_tick64;
	previous_count = (unsigned long) boost::detail::interlocked_read_acquire(&count);
	current_tick32 = ::boost::winapi::GetTickCount();
	if(previous_count == (unsigned long)-1l)
	{
	// count has never been written
	unsigned long initial_count;
	initial_count = current_tick32 >> 28;
	previous_count = (unsigned long) _InterlockedCompareExchange(&count, (long)initial_count, -1l);
	current_tick64 = initial_count;
	current_tick64 <<= 28;
	current_tick64 += current_tick32 & 0x0FFFFFFF;
	return current_tick64;
	}

introduced by

04c5341

The easiest way to fix that is to rewrite GetTickCount64emulation in terms of boost::atomic_uint64_t. As pointed out in

https://lists.boost.org/Archives/boost/2018/02/241453.php

an implementation already exists in Boost.Log:

https://github.com/boostorg/log/blob/1cc577cbf5fae8f55c71c4493a7ef89027bd85dc/src/timestamp.cpp#L66-L86

[viboes]

I missed the comment on this commit.

could someone provide a PR?

[pdimov]

@Lastique perhaps?

[Lastique]

I will make a PR shortly.

[viboes]

Thank you very much.