1 files changed, 61 insertions, 0 deletions
diff --git a/src/port/pqsignal.c b/src/port/pqsignal.c
new file mode 100644
index 0000000..a373b48
--- /dev/null
+++ b/src/port/pqsignal.c
@@ -0,0 +1,61 @@
+/*-------------------------------------------------------------------------
+ *
+ * pqsignal.c
+ *	  reliable BSD-style signal(2) routine stolen from RWW who stole it
+ *	  from Stevens...
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/port/pqsignal.c
+ *
+ *	We now assume that all Unix-oid systems have POSIX sigaction(2)
+ *	with support for restartable signals (SA_RESTART).  We used to also
+ *	support BSD-style signal(2), but there really shouldn't be anything
+ *	out there anymore that doesn't have the POSIX API.
+ *
+ *	Windows, of course, is resolutely in a class by itself.  In the backend,
+ *	we don't use this file at all; src/backend/port/win32/signal.c provides
+ *	pqsignal() for the backend environment.  Frontend programs can use
+ *	this version of pqsignal() if they wish, but beware that this does
+ *	not provide restartable signals on Windows.
+ *
+ * ------------------------------------------------------------------------
+ */
+
+#include "c.h"
+
+#include <signal.h>
+
+#if !defined(WIN32) || defined(FRONTEND)
+
+/*
+ * Set up a signal handler, with SA_RESTART, for signal "signo"
+ *
+ * Returns the previous handler.
+ */
+pqsigfunc
+pqsignal(int signo, pqsigfunc func)
+{
+#ifndef WIN32
+	struct sigaction act,
+				oact;
+
+	act.sa_handler = func;
+	sigemptyset(&act.sa_mask);
+	act.sa_flags = SA_RESTART;
+#ifdef SA_NOCLDSTOP
+	if (signo == SIGCHLD)
+		act.sa_flags |= SA_NOCLDSTOP;
+#endif
+	if (sigaction(signo, &act, &oact) < 0)
+		return SIG_ERR;
+	return oact.sa_handler;
+#else							/* WIN32 */
+	return signal(signo, func);
+#endif
+}
+
+#endif							/* !defined(WIN32) || defined(FRONTEND) */