From 3e34124e68734fc1d51a47665f3455f21f2906d1 Mon Sep 17 00:00:00 2001
From: Maarten ter Huurne <maarten@treewalker.org>
Date: Thu, 7 Aug 2014 16:48:30 +0200
Subject: [PATCH] Added Launcher class

Currently the launched application is exec-ed from deep within the menu
code. This means a lot of destructors are never run and as a result
for example file descriptors from the menu remain open in the launched
process.

This is a first step to move the launch invocation from a deep call
stack to the top level.
---
 src/Makefile.am  |  2 +-
 src/gmenu2x.cpp  |  5 ++++-
 src/launcher.cpp | 33 +++++++++++++++++++++++++++++++++
 src/launcher.h   | 20 ++++++++++++++++++++
 src/linkapp.cpp  | 16 +++++++++++-----
 5 files changed, 69 insertions(+), 7 deletions(-)
 create mode 100644 src/launcher.cpp
 create mode 100644 src/launcher.h

diff --git a/src/Makefile.am b/src/Makefile.am
index c5ad333..f5cc34c 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -2,7 +2,7 @@ bin_PROGRAMS = gmenu2x
 
 gmenu2x_SOURCES = font.cpp cpu.cpp dirdialog.cpp filedialog.cpp \
 	filelister.cpp gmenu2x.cpp iconbutton.cpp imagedialog.cpp inputdialog.cpp \
-	inputmanager.cpp linkapp.cpp link.cpp \
+	inputmanager.cpp linkapp.cpp link.cpp launcher.cpp \
 	menu.cpp menusettingbool.cpp menusetting.cpp menusettingdir.cpp \
 	menusettingfile.cpp menusettingimage.cpp menusettingint.cpp \
 	menusettingmultistring.cpp menusettingrgba.cpp menusettingstring.cpp \
diff --git a/src/gmenu2x.cpp b/src/gmenu2x.cpp
index df186bb..da7f8d3 100644
--- a/src/gmenu2x.cpp
+++ b/src/gmenu2x.cpp
@@ -30,6 +30,7 @@
 #include "helppopup.h"
 #include "iconbutton.h"
 #include "inputdialog.h"
+#include "launcher.h"
 #include "linkapp.h"
 #include "mediamonitor.h"
 #include "menu.h"
@@ -648,7 +649,9 @@ void GMenu2X::explorer() {
 #ifdef ENABLE_CPUFREQ
 		setClock(cpuFreqAppDefault);
 #endif
-		execlp("/bin/sh","/bin/sh","-c",command.c_str(),NULL);
+
+		Launcher launcher(vector<string> { "/bin/sh", "-c", command });
+		launcher.exec();
 
 		//if execution continues then something went wrong and as we already called SDL_Quit we cannot continue
 		//try relaunching gmenu2x
diff --git a/src/launcher.cpp b/src/launcher.cpp
new file mode 100644
index 0000000..85ebe9c
--- /dev/null
+++ b/src/launcher.cpp
@@ -0,0 +1,33 @@
+#include "launcher.h"
+
+#include "debug.h"
+
+#include <cerrno>
+#include <cstring>
+#include <unistd.h>
+
+using namespace std;
+
+
+Launcher::Launcher(vector<string> const& commandLine)
+	: commandLine(commandLine)
+{
+}
+
+Launcher::Launcher(vector<string> && commandLine)
+	: commandLine(commandLine)
+{
+}
+
+void Launcher::exec()
+{
+	vector<const char *> args;
+	args.reserve(commandLine.size() + 1);
+	for (auto arg : commandLine) {
+		args.push_back(arg.c_str());
+	}
+	args.push_back(nullptr);
+	execvp(commandLine[0].c_str(), (char* const*)&args[0]);
+	WARNING("Failed to exec '%s': %s\n",
+			commandLine[0].c_str(), strerror(errno));
+}
diff --git a/src/launcher.h b/src/launcher.h
new file mode 100644
index 0000000..0c99b28
--- /dev/null
+++ b/src/launcher.h
@@ -0,0 +1,20 @@
+#ifndef LAUNCHER_H
+#define LAUNCHER_H
+
+#include <string>
+#include <vector>
+
+
+class Launcher
+{
+public:
+	Launcher(std::vector<std::string> const& commandLine);
+	Launcher(std::vector<std::string> && commandLine);
+
+	void exec();
+
+private:
+	std::vector<std::string> commandLine;
+};
+
+#endif // LAUNCHER_H
diff --git a/src/linkapp.cpp b/src/linkapp.cpp
index 43e5ba3..9498007 100644
--- a/src/linkapp.cpp
+++ b/src/linkapp.cpp
@@ -23,6 +23,7 @@
 #include "debug.h"
 #include "delegate.h"
 #include "gmenu2x.h"
+#include "launcher.h"
 #include "menu.h"
 #include "selector.h"
 #include "surface.h"
@@ -40,6 +41,7 @@
 #include <array>
 #include <fstream>
 #include <sstream>
+#include <utility>
 
 #if defined(PLATFORM_A320) || defined(PLATFORM_GCW0)
 #include <linux/vt.h>
@@ -608,17 +610,21 @@ void LinkApp::launch(const string &selectedFile) {
 	}
 #endif
 
+	vector<string> commandLine;
 	if (isOpk()) {
 #ifdef HAVE_LIBOPK
-		execlp("opkrun", "opkrun", "-m", metadata.c_str(), opkFile.c_str(),
-					!params.empty() ? params.c_str() : NULL,
-					NULL);
+		commandLine = { "opkrun", "-m", metadata, opkFile };
+		if (!params.empty()) {
+			commandLine.push_back(params);
+		}
 #endif
 	} else {
-		std::string command = exec + " " + params;
-		execlp("/bin/sh", "/bin/sh", "-c", command.c_str(), NULL);
+		commandLine = { "/bin/sh", "-c", exec + " " + params };
 	}
 
+	Launcher launcher(move(commandLine));
+	launcher.exec();
+
 	//if execution continues then something went wrong and as we already called SDL_Quit we cannot continue
 	//try relaunching gmenu2x
 	gmenu2x->main();