On Sun, Jan 22, 2023 at 5:49 PM Ian Lance Taylor <i...@golang.org> wrote:
> On Sat, Jan 21, 2023, 11:12 PM Peter Rabbitson (ribasushi) < > ribasu...@gmail.com> wrote: > >> This question is focused exclusively on the writer side. > > > Perhaps I misunderstand, but it doesn't make sense to ask a question about > the memory model only about one side or the other. The memory model is > about communication between two goroutines. It has very little to say > about the behavior of a single goroutine. > I might be using the wrong term then, although a lot of text in https://go.dev/ref/mem is relevant, it just does not answer my very specific question. Let me try from a different angle: I want to write a single-threaded program in go which once compiled has a certain behavior from the point of view of the OS, . More specifically this program, from the Linux OS point of view should in very strict order: 1. grab a memory region 2. write an arbitrary amount of data to the region's end 3. write some more data to the region start By definition 1) will happen first ( you got to grab in order to write ), but it is also critical that the program does all of 2), before it starts doing 3). Modern compilers are wicked smart, and often do emit assembly that would have some of 3) interleaved with 2). Moreover, due to kernel thread preemption 2) and 3) could execute simultaneously on different physical CPUs, requiring a NUMA-global synchronization signal to prevent this ( I believe it is LOCK on x86 ). I am trying to understand how to induce all of this ordering from within a go program in the most lightweight manner possible ( refer to the problem statement and attempts starting on line 38 at https://go.dev/play/p/ZXMg_Qq3ygF ) If I were in C-land I believe would use something like: #include <asm/system.h> void wmb(void); The question is - what is the go equivalent. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/CAMrvTSL%2B5XO%3Dz6815RN6sNxLJsce%2BJsyRYm3zq85NiA6L9O_cA%40mail.gmail.com.
