ISO C11 requires operations on the same stream (or whatever a FILE struct handles) _not_ to interleave with each other. This should include outputting each character using puts() or printf() functions, since they both manipulate the `stdout` stream.
It should be noted that mingw-w64 has never claimed C11 compatibility. On the other hand, GCC has enabled -std=gnu11 since GCC 5. Such interleaving behavior would conflict with GCC's new default expectation. --- WG14 N1570 (a.k.a. draft for ISO C11) 7.21.2 Streams 7 Each stream has an associated lock that is used to prevent data races when multiple threads of execution access a stream, and to restrict the interleaving of stream operations performed by multiple threads. Only one thread may hold this lock at a time. The lock is reentrant: a single thread may hold the lock multiple times at a given time. 8 All functions that read, write, position, or query the position of a stream lock the stream before accessing it. They release the lock associated with the stream when the access is complete. ------------------ Best regards, lh_mouse 2015-08-03 ------------------------------------------------------------- 发件人：Dongsheng Song <dongsheng.s...@gmail.com> 发送日期：2015-08-03 10:58 收件人：mingw64 抄送： 主题：Re: [Mingw-w64-public] Patch for locking printf On Sat, Aug 1, 2015 at 6:56 AM, JonY <jo...@users.sourceforge.net> wrote: > > On 7/23/2015 06:24, JonY wrote: > > Hi, > > > > Patch introduces a new macro __MINGW_PRINTF_LOCKING for fprintf and > > vfprintf so when called on the same FILE stream, the operations are not > > overlapped. __USE_MINGW_ANSI_STDIO must also be set for the new macro to > > take effect. > > > > The reason why it is done in such a way is so programs that already > > doing their own locking will not be affected. > > > > Idea from user Mateusz of Sourceforge. Patch OK? > > > > Ping? I like the idea. But AFAIK, this code is not portable since it's neither a standard extension nor the standards of practice. ------------------------------------------------------------------------------ _______________________________________________ Mingw-w64-public mailing list Mingw-w64-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mingw-w64-public ------------------------------------------------------------------------------ _______________________________________________ Mingw-w64-public mailing list Mingw-w64-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
