[tor-commits] [meek/master] Update server shutdown procedure.

[dcf at torproject.org]

commit 502001aed9e40f79807b913b02ea82f7c381e47d
Author: David Fifield <david at bamsoftware.com>
Date:   Tue Mar 20 23:24:10 2018 -0700

    Update server shutdown procedure.
    
    Ignore SIGINT, honor TOR_PT_EXIT_ON_STDIN_CLOSE.
---
 meek-server/meek-server.go | 33 ++++++++++++++++-----------------
 1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/meek-server/meek-server.go b/meek-server/meek-server.go
index 79dd80c..fe4c263 100644
--- a/meek-server/meek-server.go
+++ b/meek-server/meek-server.go
@@ -24,6 +24,7 @@ import (
 	"flag"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"log"
 	"net"
 	"net/http"
@@ -496,9 +497,19 @@ func main() {
 	var numHandlers int = 0
 	var sig os.Signal
 	sigChan := make(chan os.Signal, 1)
-	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
+	signal.Notify(sigChan, syscall.SIGTERM)
+
+	if os.Getenv("TOR_PT_EXIT_ON_STDIN_CLOSE") == "1" {
+		// This environment variable means we should treat EOF on stdin
+		// just like SIGTERM: https://bugs.torproject.org/15435.
+		go func() {
+			io.Copy(ioutil.Discard, os.Stdin)
+			log.Printf("synthesizing SIGTERM because of stdin close")
+			sigChan <- syscall.SIGTERM
+		}()
+	}
 
-	// Wait for first signal.
+	// Keep track of handlers and wait for a signal.
 	sig = nil
 	for sig == nil {
 		select {
@@ -508,27 +519,15 @@ func main() {
 			log.Printf("got signal %s", sig)
 		}
 	}
+
 	/*
 		// Not supported until go1.8.
 		for _, server := range servers {
 			server.Close()
 		}
 	*/
-
-	if sig == syscall.SIGTERM {
-		log.Printf("done")
-		return
-	}
-
-	// Wait for second signal or no more handlers.
-	sig = nil
-	for sig == nil && numHandlers != 0 {
-		select {
-		case n := <-handlerChan:
-			numHandlers += n
-		case sig = <-sigChan:
-			log.Printf("got second signal %s", sig)
-		}
+	for numHandlers > 0 {
+		numHandlers += <-handlerChan
 	}
 
 	log.Printf("done")