From 9bb732d9816a0de6f7e5d1a8de50406b0d23f7fe Mon Sep 17 00:00:00 2001
From: Frank Mueller <mue@tideland.biz>
Date: Fri, 23 Mar 2018 14:58:40 +0100
Subject: [PATCH] Add profiling with pprof (#754)

---
 cmd/statusd/main.go   |  9 +++++++++
 profiling/profiler.go | 40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)
 create mode 100644 profiling/profiler.go

diff --git a/cmd/statusd/main.go b/cmd/statusd/main.go
index f1fcae9dc..9b639bb5e 100644
--- a/cmd/statusd/main.go
+++ b/cmd/statusd/main.go
@@ -18,6 +18,7 @@ import (
 	"github.com/status-im/status-go/geth/params"
 	"github.com/status-im/status-go/metrics"
 	nodemetrics "github.com/status-im/status-go/metrics/node"
+	"github.com/status-im/status-go/profiling"
 )
 
 var (
@@ -41,6 +42,8 @@ var (
 	ipcEnabled        = flag.Bool("ipc", false, "Enable IPC RPC endpoint")
 	cliEnabled        = flag.Bool("cli", false, "Enable debugging CLI server")
 	cliPort           = flag.String("cliport", debug.CLIPort, "CLI server's listening port")
+	pprofEnabled      = flag.Bool("pprof", false, "Enable runtime profiling via pprof")
+	pprofPort         = flag.Int("pprofport", 52525, "Port for runtime profiling via pprof")
 	logLevel          = flag.String("log", "INFO", `Log level, one of: "ERROR", "WARN", "INFO", "DEBUG", and "TRACE"`)
 	logFile           = flag.String("logfile", "", "Path to the log file")
 	version           = flag.Bool("version", false, "Print version")
@@ -127,6 +130,7 @@ func main() {
 
 	// handle interrupt signals
 	interruptCh := haltOnInterruptSignal(backend.NodeManager())
+
 	// Check if debugging CLI connection shall be enabled.
 	if *cliEnabled {
 		err := startDebug(backend)
@@ -136,6 +140,11 @@ func main() {
 		}
 	}
 
+	// Check if profiling shall be enabled.
+	if *pprofEnabled {
+		profiling.NewProfiler(*pprofPort).Go()
+	}
+
 	// Run stats server.
 	if *statsEnabled {
 		go startCollectingStats(interruptCh, backend.NodeManager())
diff --git a/profiling/profiler.go b/profiling/profiler.go
new file mode 100644
index 000000000..8f7be0dc4
--- /dev/null
+++ b/profiling/profiler.go
@@ -0,0 +1,40 @@
+package profiling
+
+import (
+	"fmt"
+	"net/http"
+	hpprof "net/http/pprof"
+
+	"github.com/ethereum/go-ethereum/log"
+)
+
+// Profiler runs and controls a HTTP pprof interface.
+type Profiler struct {
+	server *http.Server
+}
+
+// NewProfiler creates an instance of the profiler with
+// the given port.
+func NewProfiler(port int) *Profiler {
+	mux := http.NewServeMux()
+	mux.HandleFunc("/debug/pprof/", hpprof.Index)
+	mux.HandleFunc("/debug/pprof/cmdline", hpprof.Cmdline)
+	mux.HandleFunc("/debug/pprof/profile", hpprof.Profile)
+	mux.HandleFunc("/debug/pprof/symbol", hpprof.Symbol)
+	mux.HandleFunc("/debug/pprof/trace", hpprof.Trace)
+	p := Profiler{
+		server: &http.Server{
+			Addr:    fmt.Sprintf(":%d", port),
+			Handler: mux,
+		},
+	}
+	return &p
+}
+
+// Go starts the HTTP pprof in the background.
+func (p *Profiler) Go() {
+	go func() {
+		log.Info("debug server stopped", "err", p.server.ListenAndServe())
+	}()
+	log.Info("debug server started")
+}