restart functionality

R=rsc
DELTA=21  (19 added, 0 deleted, 2 changed)
OCL=28938
CL=28941

diff --git a/usr/gri/pretty/godoc.go b/usr/gri/pretty/godoc.go
index fab13b61da09d35fd0eb6a2803749ae0a55d9814..1848b58a22945f2110fc8ea75114cfc668cc5f63 100644 (file)
--- a/usr/gri/pretty/godoc.go
+++ b/usr/gri/pretty/godoc.go
@@ -601,7 +601,7 @@ func servePkg(c *http.Conn, r *http.Request) {
 // ----------------------------------------------------------------------------
 // Server
 
-func LoggingHandler(h http.Handler) http.Handler {
+func loggingHandler(h http.Handler) http.Handler {
        return http.HandlerFunc(func(c *http.Conn, req *http.Request) {
                log.Stderrf("%s\t%s", req.Host, req.Url.Path);
                h.ServeHTTP(c, req);
@@ -609,6 +609,18 @@ func LoggingHandler(h http.Handler) http.Handler {
 }
 
 
+func restartGodoc(c *http.Conn, r *http.Request) {
+       binary := os.Args[0];  // TODO currently requires absolute paths because of chdir in the beginning
+       pid, err := os.ForkExec(binary, os.Args, os.Environ(), "", []*os.File{os.Stdin, os.Stdout, os.Stderr});
+       if err != nil {
+               log.Stderrf("os.ForkExec(%s): %v", binary, err);
+               return;  // do not terminate
+       }
+       log.Stderrf("restarted %s, pid = %d\n", binary, pid);
+       os.Exit(0);
+}
+
+
 func usage() {
        fmt.Fprintf(os.Stderr,
                "usage: godoc package [name ...]\n"
@@ -648,12 +660,19 @@ func main() {
                        log.Stderrf("goroot = %s\n", goroot);
                        log.Stderrf("pkgroot = %s\n", *pkgroot);
                        log.Stderrf("tmplroot = %s\n", *tmplroot);
-                       handler = LoggingHandler(handler);
+                       handler = loggingHandler(handler);
                }
 
                http.Handle(Pkg, http.HandlerFunc(servePkg));
+               http.Handle("/debug/restart", http.HandlerFunc(restartGodoc));
                http.Handle("/", http.HandlerFunc(serveFile));
 
+               // The server may have been restarted; always wait 1sec to
+               // give the forking server a chance to shut down and release
+               // the http port. (This is necessary because under OS X Exec
+               // won't work if there are more than one thread running.)
+               time.Sleep(1e9);
+
                if err := http.ListenAndServe(*httpaddr, handler); err != nil {
                        log.Exitf("ListenAndServe %s: %v", *httpaddr, err)
                }