From 6ff7b50a7de5ad329b185bfaf5b44fa54ed6c91b Mon Sep 17 00:00:00 2001
From: Kelvin Sherlock <ksherlock@gmail.com>
Date: Mon, 22 Feb 2016 12:03:58 -0500
Subject: [PATCH] use atomic variable for the control-c flag.

---
 command.cpp   | 3 ++-
 mpw-shell.cpp | 7 ++++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/command.cpp b/command.cpp
index 1357a3f..64d120b 100644
--- a/command.cpp
+++ b/command.cpp
@@ -18,8 +18,9 @@
 #include <unistd.h>
 #include <sys/wait.h>
 #include <sysexits.h>
+#include <atomic>
 
-extern volatile int control_c;
+extern std::atomic<int> control_c;
 
 namespace fs = filesystem;
 extern fs::path mpw_path();
diff --git a/mpw-shell.cpp b/mpw-shell.cpp
index 1ffe24b..574db95 100644
--- a/mpw-shell.cpp
+++ b/mpw-shell.cpp
@@ -29,6 +29,7 @@
 #include <pwd.h>
 #include <sysexits.h>
 #include <paths.h>
+#include <atomic>
 
 namespace fs = filesystem;
 
@@ -168,13 +169,13 @@ int read_make(phase1 &p1, phase2 &p2, Environment &env, const std::vector<std::s
 	return env.status();
 }
 
-volatile int control_c = 0;
+std::atomic<int> control_c{0};
 void control_c_handler(int signal, siginfo_t *sinfo, void *context) {
 
 	// libedit gobbles up the first control-C and doesn't return until the second.
-	// GNU's readline may return no the first.
+	// GNU's readline may return on the first.
 	if (control_c > 3) abort();
-	control_c++;
+	++control_c;
 	//fprintf(stderr, "interrupt!\n");
 }