Handle SIGINT etc. via a sigwait() signal handler thread

This allows other threads to install callbacks that run in a regular,
non-signal context. In particular, we can use this to signal the
downloader thread to quit.

Closes #1183.

1 files changed, 3 insertions, 17 deletions

diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc
index 0c6e3fb76d64..44579a236774 100644
--- a/src/libmain/shared.cc
+++ b/src/libmain/shared.cc
@@ -24,12 +24,6 @@
 namespace nix {
 
 
-static void sigintHandler(int signo)
-{
-    _isInterrupted = 1;
-}
-
-
 static bool gcWarning = true;
 
 void printGCWarning()
@@ -120,19 +114,11 @@ void initNix()
     settings.processEnvironment();
     settings.loadConfFile();
 
-    /* Catch SIGINT. */
-    struct sigaction act;
-    act.sa_handler = sigintHandler;
-    sigemptyset(&act.sa_mask);
-    act.sa_flags = 0;
-    if (sigaction(SIGINT, &act, 0))
-        throw SysError("installing handler for SIGINT");
-    if (sigaction(SIGTERM, &act, 0))
-        throw SysError("installing handler for SIGTERM");
-    if (sigaction(SIGHUP, &act, 0))
-        throw SysError("installing handler for SIGHUP");
+    startSignalHandlerThread();
 
     /* Ignore SIGPIPE. */
+    struct sigaction act;
+    sigemptyset(&act.sa_mask);
     act.sa_handler = SIG_IGN;
     act.sa_flags = 0;
     if (sigaction(SIGPIPE, &act, 0))