From 573316e3c2ddd91fd0f36d2251f9660b4f98bebc Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@lukeshu.com>
Date: Sun, 8 Jan 2023 23:48:37 -0700
Subject: binstruct: Make the cache thread-safe

---
 Makefile                 |  2 +-
 go.mod                   |  2 +-
 lib/binstruct/structs.go | 27 +++++++++++++--------------
 3 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/Makefile b/Makefile
index b3bcdd8..c16dfd7 100644
--- a/Makefile
+++ b/Makefile
@@ -54,7 +54,7 @@ go-mod-tidy:
 go-mod-tidy: go-mod-tidy/main
 go-mod-tidy/main:
 	rm -f go.sum
-	go mod tidy -go $(goversion) -compat $(goversion)
+	go mod tidy -go 1.20 -compat $(goversion)
 .PHONY: go-mod-tidy/main
 
 go-mod-tidy: $(patsubst tools/src/%/go.mod,go-mod-tidy/tools/%,$(wildcard tools/src/*/go.mod))
diff --git a/go.mod b/go.mod
index 2bd05ff..f2e26e7 100644
--- a/go.mod
+++ b/go.mod
@@ -4,7 +4,7 @@
 
 module git.lukeshu.com/btrfs-progs-ng
 
-go 1.19
+go 1.20
 
 require (
 	git.lukeshu.com/go/lowmemjson v0.3.4
diff --git a/lib/binstruct/structs.go b/lib/binstruct/structs.go
index 7eea600..52e5406 100644
--- a/lib/binstruct/structs.go
+++ b/lib/binstruct/structs.go
@@ -10,6 +10,8 @@ import (
 	"strconv"
 	"strings"
 
+	"git.lukeshu.com/go/typedsync"
+
 	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct/binutil"
 )
 
@@ -178,21 +180,18 @@ func genStructHandler(structInfo reflect.Type) (structHandler, error) {
 	return ret, nil
 }
 
-var structCache = make(map[reflect.Type]structHandler)
+var structCache typedsync.CacheMap[reflect.Type, structHandler]
 
 func getStructHandler(typ reflect.Type) structHandler {
-	h, ok := structCache[typ]
-	if ok {
+	ret, _ := structCache.LoadOrCompute(typ, func(typ reflect.Type) structHandler {
+		h, err := genStructHandler(typ)
+		if err != nil {
+			panic(&InvalidTypeError{
+				Type: typ,
+				Err:  err,
+			})
+		}
 		return h
-	}
-
-	h, err := genStructHandler(typ)
-	if err != nil {
-		panic(&InvalidTypeError{
-			Type: typ,
-			Err:  err,
-		})
-	}
-	structCache[typ] = h
-	return h
+	})
+	return ret
 }
-- 
cgit v1.2.3-2-g168b