cmd/compile: prevent duplicated works in WriteRuntimeTypes

While processing signatset, the entry is deleted immediately after being
pushed to signatslice. Then calling writeType may add the same type
to signatset again. That would add more works, though not a big impact
to the performace, since when writeType is guarded by s.Siggen() check.

Instead, we should keep the entry in signatset, so written type will
never be added again.

This change does not affect compiler performace, but help debugging
issue like one in #46386 easier.

Change-Id: Iddafe773885fa21cb7003ba27ddf9554fc3f297d
Reviewed-on: https://go-review.googlesource.com/c/go/+/326029
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This commit is contained in:
Cuong Manh Le 2021-06-08 19:28:45 +07:00
parent 9871726c72
commit 91e2e3b903

View file

@ -39,8 +39,11 @@ func CountPTabs() int {
// runtime interface and reflection data structures
var (
signatmu sync.Mutex // protects signatset and signatslice
signatset = make(map[*types.Type]struct{})
// protects signatset and signatslice
signatmu sync.Mutex
// Tracking which types need runtime type descriptor
signatset = make(map[*types.Type]struct{})
// Queue of types wait to be generated runtime type descriptor
signatslice []*types.Type
gcsymmu sync.Mutex // protects gcsymset and gcsymslice
@ -1248,7 +1251,6 @@ func WriteRuntimeTypes() {
// Transfer entries to a slice and sort, for reproducible builds.
for _, t := range signatslice {
signats = append(signats, typeAndStr{t: t, short: types.TypeSymName(t), regular: t.String()})
delete(signatset, t)
}
signatslice = signatslice[:0]
sort.Sort(typesByString(signats))