Merge pull request #8 from dtrudg/issue7

Disable Go runtime GC for starter process

Author: dtrudg

LICENSE.md

@@ -1,7 +1,7 @@
 Copyright (c) 2015-2017, Gregory M. Kurtzer. All rights reserved.
 Copyright (c) 2016-2017, The Regents of the University of California. All right reserved.
 Copyright (c) 2017, SingularityWare, LLC. All rights reserved.
-Copyright (c) 2018-2019, Sylabs, Inc. All rights reserved.
+Copyright (c) 2018-2021, Sylabs, Inc. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:

cmd/starter/c/starter.c

@@ -1,5 +1,5 @@
 /*
-  Copyright (c) 2018-2020, Sylabs, Inc. All rights reserved.
+  Copyright (c) 2018-2021, Sylabs, Inc. All rights reserved.
 
   This software is licensed under a 3-clause BSD license.  Please
   consult LICENSE.md file distributed with the sources of this project regarding
@@ -986,6 +986,7 @@ static void cleanup_fd(fdlist_t *master, struct starter *starter) {
             if ( starter->fds[i] == fd ) {
                 found = true;
                 /* set force close on exec */
+                debugf("Setting FD_CLOEXEC on starter fd %d\n", starter->fds[i]);
                 if ( fcntl(starter->fds[i], F_SETFD, FD_CLOEXEC) < 0 ) {
                     debugf("Can't set FD_CLOEXEC on file descriptor %d: %s\n", starter->fds[i], strerror(errno));
                 }
@@ -1139,9 +1140,17 @@ static void cleanenv(void) {
     /*
      * keep only SINGULARITY_MESSAGELEVEL for GO runtime, set others to empty
      * string and not NULL (see issue #3703 for why)
+     *
+     * DCT - also keep any GOGC and GODEBUG vars for go runtime
+     * debugging purposes.
      */
     for (e = environ; *e != NULL; e++) {
-        if ( strncmp(MSGLVL_ENV "=", *e, sizeof(MSGLVL_ENV)) != 0 ) {
+        if ( strncmp(MSGLVL_ENV "=", *e, strlen(MSGLVL_ENV "=")) == 0 ||
+             strncmp("GOGC" "=", *e, strlen("GOGC" "=")) == 0 ||
+             strncmp("GODEBUG" "=", *e, strlen("GODEBUG" "=")) == 0 ) {
+            debugf("Keeping env var %s\n", *e);
+        } else {
+            debugf("Clearing env var %s\n", *e);
             *e = "";
         }
     }

internal/pkg/util/starter/starter.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2019-2020, Sylabs Inc. All rights reserved.
+// Copyright (c) 2019-2021, Sylabs Inc. All rights reserved.
 // This software is licensed under a 3-clause BSD license. Please consult the
 // LICENSE.md file distributed with the sources of this project regarding your
 // rights to use or distribute this software.
@@ -89,6 +89,8 @@ func Exec(name string, config *config.Common, ops ...CommandOp) error {
 	if err := c.init(config, ops...); err != nil {
 		return fmt.Errorf("while initializing starter command: %s", err)
 	}
+	sylog.Debugf("Setting GOGC=off for starter")
+	c.env = append(c.env, "GOGC=off")
 	err := unix.Exec(c.path, []string{name}, c.env)
 	return fmt.Errorf("while executing %s: %s", c.path, err)
 }