Opened 5 years ago

Closed 5 years ago

#13251 closed Bugs (duplicate)

Sine / cosine is not thread safe

Reported by: lessig@… Owned by: John Maddock
Milestone: To Be Determined Component: multiprecision
Version: Boost 1.63.0 Severity: Showstopper
Keywords: Cc:

Description

For boost::multiprecision::cpp_dec_float_* the sine / cosine functions are not thread safe. System is:

Apple LLVM version 9.0.0 (clang-900.0.37) Target: x86_64-apple-darwin16.7.0 Thread model: posix

Change History (3)

comment:1 by John Maddock, 5 years ago

I'm not seeing this: please explain?

comment:2 by martin@…, 5 years ago

Hi,

I can reproduce the error - protecting sin/cos asin/acos with mutexes for testing makes the functions 'work' again.

This problem seems to be compiler-specific, does not happen with clang-5.0.0 (linux), but gcc 6.3.0, 6.4.0, 7.2.0 (linux) and MSVC 14.0 (2015) are affected, using boost 1.65.1. The problem does not occur in boost 1.64.0 in my setup. (boost release builds)

I have not done much testing, but the functions only fail seldomly, and if they do they seem to be correct in the first digits. (using cpp_dec_float with 50 bits precision)

Thanks for looking into this

comment:3 by John Maddock, 5 years ago

Resolution: → duplicate
Status: new → closed

Closing as duplicate of ​https://github.com/boostorg/multiprecision/issues/40

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