[latencytop/f16] print the error message only after cleaning up curses

[Michal Schmidt]

commit 228c18b00566ab35fb1b5d772b7a0c062fbc9bd7
Author: Michal Schmidt <mschmidt at redhat.com>
Date:   Sun Feb 19 22:19:40 2012 +0100

    print the error message only after cleaning up curses
    
    (cherry picked from commit 498804be9fff0c2f9c58c04ae8672d1cfd234b7e)

 ...p-better-error-message-if-run-as-non-root.patch |   36 -----------
 latencytop-better-error-message.patch              |   64 ++++++++++++++++++++
 latencytop.spec                                    |    7 ++-
 3 files changed, 69 insertions(+), 38 deletions(-)
---
diff --git a/latencytop-better-error-message.patch b/latencytop-better-error-message.patch
new file mode 100644
index 0000000..d432de4
--- /dev/null
+++ b/latencytop-better-error-message.patch
@@ -0,0 +1,64 @@
+From b608ddda22ac33195ba57311d42ac83facbd8695 Mon Sep 17 00:00:00 2001
+From: Michal Schmidt <mschmidt at redhat.com>
+Date: Thu, 16 Feb 2012 00:04:00 +0100
+Subject: [PATCH 2/2] better error message
+
+Only suggest CONFIG_LATENCYTOP on ENOENT.
+Print the message after curses is cleaned up to make it visible.
+---
+ src/latencytop.c |   18 +++++++++++++++---
+ 1 files changed, 15 insertions(+), 3 deletions(-)
+
+diff --git a/src/latencytop.c b/src/latencytop.c
+index 0ffb7f3..3b62c5d 100644
+--- a/src/latencytop.c
++++ b/src/latencytop.c
+@@ -24,6 +24,7 @@
+ 
+ #define _GNU_SOURCE
+ 
++#include <errno.h>
+ #include <stdio.h>
+ #include <stdlib.h>
+ #include <unistd.h>
+@@ -113,6 +114,17 @@ static void fixup_reason(struct latency_line *line, char *c)
+ 		strncpy(line->reason, c2, 1024);
+ }
+ 
++static int die_errno;
++
++static void print_error_msg(void) {
++	if (!die_errno)
++		return;
++
++	fprintf(stderr, "Failed to open /proc/latency_stats: %s\n", strerror(die_errno));
++	if (die_errno == ENOENT)
++		fprintf(stderr, "Please enable the CONFIG_LATENCYTOP configuration in your kernel.\n");
++}
++
+ void parse_global_list(void)
+ {
+ 	FILE *file;
+@@ -120,8 +132,7 @@ void parse_global_list(void)
+ 	size_t dummy;
+ 	file = fopen("/proc/latency_stats","r+");
+ 	if (!file) {
+-		fprintf(stderr, "Please enable the CONFIG_LATENCYTOP configuration in your kernel.\n");
+-		fprintf(stderr, "Exiting...\n");
++		die_errno = errno;
+ 		exit(EXIT_FAILURE);
+ 	}
+ 	/* wipe first line */
+@@ -540,7 +551,8 @@ int main(int argc, char **argv)
+ 
+ 	enable_sysctl();
+ 	atexit(cleanup_sysctl);
+-
++	/* needs to run after curses is gone */
++	atexit(print_error_msg);
+ #ifdef HAS_GTK_GUI
+ 	if (preinitialize_gtk_ui(&argc, &argv))
+ 		use_gtk = 1;
+-- 
+1.7.7.6
+
diff --git a/latencytop.spec b/latencytop.spec
index f3a10ab..f30fddf 100644
--- a/latencytop.spec
+++ b/latencytop.spec
@@ -1,6 +1,6 @@
 Name:           latencytop
 Version:        0.5
-Release:        7%{?dist}
+Release:        8%{?dist}
 Summary:        System latency monitor (with GUI)
 
 Group:          Applications/System
@@ -10,7 +10,7 @@ Source0:        http://www.latencytop.org/download/%{name}-%{version}.tar.gz
 Patch0:         latencytop-Makefile-fixes.patch
 Patch1:         latencytop-Makefile-default-to-no-gtk.patch
 Patch2:         latencytop-remove-the-fsync-view.patch
-Patch3:         latencytop-better-error-message-if-run-as-non-root.patch
+Patch3:         latencytop-better-error-message.patch
 BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 
 BuildRequires:  ncurses-devel glib2-devel gtk2-devel pkgconfig
@@ -86,6 +86,9 @@ rm -rf %{buildroot}
 
 
 %changelog
+* Sun Feb 19 2012 Michal Schmidt <mschmidt at redhat.com> - 0.5-8
+- Print the error message only after cleaning up curses.
+
 * Thu Feb 16 2012 Michal Schmidt <mschmidt at redhat.com> - 0.5-7
 - Remove the broken fsync view, stop using the obsolete 'tracing_enabled'.
 - Better error message when run as non-root.