[gnome-keyring/wip/fork-fixes] daemon: Since stdout is open, just print evironment directly

[Stefan Walter <stefw src gnome org>]

commit 134e754b27031edb864b2e02e308e76f69368a4c
Author: Stef Walter <stefw gnome org>
Date:   Fri Oct 16 21:35:19 2015 +0200

    daemon: Since stdout is open, just print evironment directly

 daemon/gkd-main.c |   88 ++++++++++++-----------------------------------------
 1 files changed, 20 insertions(+), 68 deletions(-)
---
diff --git a/daemon/gkd-main.c b/daemon/gkd-main.c
index eb58dab..ab16299 100644
--- a/daemon/gkd-main.c
+++ b/daemon/gkd-main.c
@@ -504,67 +504,6 @@ print_environment (void)
        fflush (stdout);
 }
 
-static void
-print_environment_from_fd (int fd)
-{
-       char *output;
-       gsize output_size;
-       GInputStream *stream;
-       gboolean res;
-
-       stream = g_unix_input_stream_new (fd, TRUE);
-       res = g_input_stream_read_all (stream,
-                                      &output_size, sizeof (output_size),
-                                      NULL, NULL, NULL);
-       if (!res)
-               exit (1);
-
-       output = g_malloc0 (output_size);
-       res = g_input_stream_read_all (stream,
-                                      output, output_size,
-                                      NULL, NULL, NULL);
-       if (!res)
-               exit (1);
-
-       printf ("%s\n", output);
-       fflush (stdout);
-       g_free (output);
-       g_object_unref (stream);
-}
-
-static void
-send_environment_and_finish_parent (int fd)
-{
-       char *output;
-       gsize output_size;
-       GOutputStream *stream;
-       gboolean res;
-
-       if (fd < 0) {
-               print_environment ();
-               return;
-       }
-
-       output = g_strjoinv ("\n", (gchar **) gkd_util_get_environment ());
-       output_size = strlen (output) + 1;
-
-       stream = g_unix_output_stream_new (fd, TRUE);
-       res = g_output_stream_write_all (stream,
-                                        &output_size, sizeof (output_size),
-                                        NULL, NULL, NULL);
-       if (!res)
-               exit (1);
-
-       res = g_output_stream_write_all (stream,
-                                        output, output_size,
-                                        NULL, NULL, NULL);
-       if (!res)
-               exit (1);
-
-       g_free (output);
-       g_object_unref (stream);
-}
-
 static gboolean
 initialize_daemon_at (const gchar *directory)
 {
@@ -680,6 +619,13 @@ redirect_fds_after_fork (void)
        }
 }
 
+static void
+block_on_fd (int fd)
+{
+       unsigned char dummy;
+       read (fd, &dummy, 1);
+}
+
 static int
 fork_and_print_environment (void)
 {
@@ -698,6 +644,7 @@ fork_and_print_environment (void)
 
        if (pid != 0) {
                /* Here we are in the initial process */
+               close (wakeup_fds[1]);
 
                if (run_daemonized) {
 
@@ -710,8 +657,8 @@ fork_and_print_environment (void)
                                exit (WEXITSTATUS (status));
 
                } else {
-                       /* Not double forking */
-                       print_environment_from_fd (wakeup_fds[0]);
+                       /* Not double forking, wait for child */
+                       block_on_fd (wakeup_fds[0]);
                }
 
                /* The initial process exits successfully */
@@ -731,6 +678,7 @@ fork_and_print_environment (void)
                pid = fork ();
 
                if (pid != 0) {
+                       close (wakeup_fds[1]);
 
                        /* Here we are in the intermediate child process */
 
@@ -742,7 +690,7 @@ fork_and_print_environment (void)
                                exit (1);
 
                        /* We've done two forks. */
-                       print_environment_from_fd (wakeup_fds[0]);
+                       block_on_fd (wakeup_fds[0]);
 
                        /* The intermediate child exits */
                        exit (0);
@@ -963,10 +911,11 @@ main (int argc, char *argv[])
        if (run_for_start) {
                if (discover_other_daemon (initialize_daemon_at, TRUE)) {
                        /*
-                        * Another daemon was initialized, print out environment
-                        * for any callers, and quit or go comatose.
+                        * Another daemon was initialized, print out environment,
+                        * tell parent we're done, and quit or go comatose.
                         */
-                       send_environment_and_finish_parent (parent_wakeup_fd);
+                       print_environment ();
+                       close (parent_wakeup_fd);
                        if (run_foreground) {
                                connection = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, &error);
                                if (error) {
@@ -1013,9 +962,12 @@ main (int argc, char *argv[])
 
        signal (SIGPIPE, SIG_IGN);
 
+       /* Print the environment and tell the parent we're done */
+       print_environment ();
+       close (parent_wakeup_fd);
+
        if (!run_foreground)
                redirect_fds_after_fork ();
-       send_environment_and_finish_parent (parent_wakeup_fd);
 
        g_unix_signal_add (SIGTERM, on_signal_term, loop);
        g_unix_signal_add (SIGHUP, on_signal_term, loop);