From 3d1699ea787f38be6088f9a098d6e08dafca9387 Mon Sep 17 00:00:00 2001 From: Keith Randall Date: Wed, 31 May 2017 08:45:10 -0700 Subject: runtime: new itab lookup table Keep itabs in a growable hash table. Use a simple open-addressable hash table, quadratic probing, power of two sized. Synchronization gets a bit more tricky. The common read path now has two atomic reads, one to get the table pointer and one to read the entry out of the table. I set the max load factor to 75%, kind of arbitrarily. There's a space-speed tradeoff here, and I'm not sure where we should land. Because we use open addressing the itab.link field is no longer needed. I'll remove it in a separate CL. Fixes #20505 Change-Id: Ifb3d9a337512d6cf968c1fceb1eeaf89559afebf Reviewed-on: https://go-review.googlesource.com/44472 Run-TryBot: Keith Randall TryBot-Result: Gobot Gobot Reviewed-by: Josh Bleecher Snyder --- src/runtime/runtime2.go | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'src/runtime/runtime2.go') diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go index adfdec6eac..456b650f5c 100644 --- a/src/runtime/runtime2.go +++ b/src/runtime/runtime2.go @@ -624,14 +624,13 @@ type _func struct { // Needs to be in sync with // ../cmd/compile/internal/gc/reflect.go:/^func.dumptypestructs. type itab struct { - inter *interfacetype - _type *_type - link *itab - hash uint32 // copy of _type.hash. Used for type switches. - bad bool // type does not implement interface - inhash bool // has this itab been added to hash? - unused [2]byte - fun [1]uintptr // variable sized + inter *interfacetype + _type *_type + _ uintptr + hash uint32 // copy of _type.hash. Used for type switches. + bad bool // type does not implement interface + _ [3]byte + fun [1]uintptr // variable sized } // Lock-free stack node. -- cgit v1.3-5-g9baa