From 33f46be98b6364ebc0b8036d3ef830aa9ede80a8 Mon Sep 17 00:00:00 2001
From: Jeff Carr <jcarr@wit.com>
Date: Thu, 23 Feb 2023 21:18:19 -0600
Subject: [PATCH] trying in vain to figure out which goroutine I'm in

Signed-off-by: Jeff Carr <jcarr@wit.com>
---
 example-pprof-simple/Makefile | 11 ++++------
 example-pprof-simple/foo.go   | 38 +++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 7 deletions(-)
 create mode 100644 example-pprof-simple/foo.go

diff --git a/example-pprof-simple/Makefile b/example-pprof-simple/Makefile
index fa67bcf..b0c8dbc 100644
--- a/example-pprof-simple/Makefile
+++ b/example-pprof-simple/Makefile
@@ -1,9 +1,6 @@
 run:
 	GO111MODULE="off" go run -v -x main.go
-
-prep:
-	GO111MODULE="off" go get -v .
-
-build:
-	GO111MODULE="off" go build -v -x
-	# go build
+	@echo
+	@echo "Run foo.go:"
+	@echo
+	GO111MODULE="off" go run foo.go
diff --git a/example-pprof-simple/foo.go b/example-pprof-simple/foo.go
new file mode 100644
index 0000000..4fd371e
--- /dev/null
+++ b/example-pprof-simple/foo.go
@@ -0,0 +1,38 @@
+package main
+
+import (
+	"runtime/pprof"
+	"context"
+	"fmt"
+	"time"
+)
+
+func main() {
+	type favContextKey string
+
+	f := func(ctx context.Context, k string) {
+		ctx2 := context.WithValue(context.Background(), "language", "Go2")
+		if v := ctx2.Value(k); v != nil {
+			fmt.Println("found value:", v)
+		} else {
+			fmt.Println("key not found:", k)
+		}
+		pprof.SetGoroutineLabels(ctx)
+
+		if v := ctx.Value(k); v != nil {
+			fmt.Println("found value:", v)
+		} else {
+			fmt.Println("key not found:", k)
+		}
+	}
+
+	ctx := context.WithValue(context.Background(), "language", "Go")
+
+	f(ctx, "language")
+	f(ctx, "color")
+
+	go f(ctx, "language")
+	go f(ctx, "color")
+
+	time.Sleep(time.Duration(1) * time.Second)
+}