r1=0 and r2=0 That is my result with Cygwin on windows. It’s false. When I compiled with gcc. The result is correct but when I use lasted Cygwin gcc in windows 10. The result is false. Get Outlook for iOS ________________________________ From: Lavrentiev, Anton (NIH/NLM/NCBI) [C] Sent: Thursday, June 8, 2023 5:37:31 PM To: Mümin A. ; cygwin@cygwin.com Subject: RE: [EXTERNAL] Memory Barriers at pthread using CYGWIN > result should be > > r1 = 1, r2 = 1 > And what was the result you saw? Anton Lavrentiev Contractor NIH/NLM/NCBI