[go-nuts] about "hybrid barrier"
Hi, I came across two questions regarding the hybrid barrier that I am hoping someone can help with. 1. Chang https://go-review.googlesource.com/c/go/+/31765 says: *"It's unconditional for now because barriers on channel operations require checking both the source and destination stacks and we don't have a way to funnel this information into the write barrier at the moment."* Can anyone help in understanding the statement, say with a sample? Isn't "channel operations involving both stacks" already covered by runtime.sendDirect? 2. comments in mbarrier.go says // The insertion part of the barrier // is necessary while the calling goroutine's stack is grey. In // pseudocode, the barrier is: // // writePointer(slot, ptr): // shade(*slot) // if current stack is grey: // shade(ptr) // *slot = ptr What does "grey stack" mean? Is a stack considered 'grey' right after its goroutine gets suspended, scanned and resumed to execution? Thanks a lot. -- 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/a36d3b5f-144b-446d-83a6-746394d2d99an%40googlegroups.com.
[go-nuts] about "hybrid barrier"
Hi, I came across two questions regarding the hybrid barrier that I am hoping someone can help with. 1. Chang https://go-review.googlesource.com/c/go/+/31765 says: "It's unconditional for now because barriers on channel operations require checking both the source and destination stacks and we don't have a way to funnel this information into the write barrier at the moment." Can anyone help in understanding the statement, say with a sample? Isn't "channel operations involving both stacks" already covered by runtime. sendDirect? 2. comments in mbarrier.go says // The insertion part of the barrier // is necessary while the calling goroutine's stack is grey. In // pseudocode, the barrier is: // // writePointer(slot, ptr): // shade(*slot) // if current stack is grey: // shade(ptr) // *slot = ptr What does "grey stack" mean? Is a stack considered 'grey' right after its goroutine gets suspended, scanned and resumed to execution? Thanks a lot. -- 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/797952e5-bd27-423f-91cc-e5b5ac46f4d1n%40googlegroups.com.
