From 71a15024894b876bc75dd34485535379d3ca434f Mon Sep 17 00:00:00 2001
From: Stefan Lankes <lankes@lfbs.rwth-aachen.de>
Date: Tue, 24 Apr 2012 20:47:36 +0200
Subject: [PATCH] add support of pid caching

---
 newlib/src/libgloss/metalsvm/config.h |  3 +++
 newlib/src/libgloss/metalsvm/fork.c   |  4 +++-
 newlib/src/libgloss/metalsvm/getpid.c | 17 ++++++++++-------
 3 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/newlib/src/libgloss/metalsvm/config.h b/newlib/src/libgloss/metalsvm/config.h
index 21f199e5..32a0f6fe 100644
--- a/newlib/src/libgloss/metalsvm/config.h
+++ b/newlib/src/libgloss/metalsvm/config.h
@@ -22,5 +22,8 @@
 /* support for section attributes */
 #define HAVE_SECTION_ATTRIBUTES		1
 
+/* definition of an invalid pid */
+#define INVALID_PID			0
+
 /* symbol prefix */
 #define __SYMBOL_PREFIX			""
diff --git a/newlib/src/libgloss/metalsvm/fork.c b/newlib/src/libgloss/metalsvm/fork.c
index d4fcacde..b27c3b4a 100644
--- a/newlib/src/libgloss/metalsvm/fork.c
+++ b/newlib/src/libgloss/metalsvm/fork.c
@@ -40,6 +40,8 @@
 #include "warning.h"
 #include "syscall.h"
 
+extern int __private_pid;
+
 int
 _DEFUN (_fork, (),
         _NOARGS)
@@ -51,7 +53,7 @@ _DEFUN (_fork, (),
 	if (ret < 0) {
 		errno = -ret;
 		ret = -1;
-	}
+	} else __private_pid = INVALID_PID;
 
 	return ret;
 }
diff --git a/newlib/src/libgloss/metalsvm/getpid.c b/newlib/src/libgloss/metalsvm/getpid.c
index 9c2f2f26..c822722f 100644
--- a/newlib/src/libgloss/metalsvm/getpid.c
+++ b/newlib/src/libgloss/metalsvm/getpid.c
@@ -40,17 +40,20 @@
 #include "warning.h"
 #include "syscall.h"
 
+int __private_pid = INVALID_PID;
+
 int
 _DEFUN (_getpid, (),
         _NOARGS)
 {
-	int ret;
-
-        ret = SYSCALL0(__NR_getpid);
-	if (ret < 0) {
-		errno = -ret;
-		ret = -1;
+	if (__private_pid == INVALID_PID) {
+		__private_pid = SYSCALL0(__NR_getpid);
+		if (__private_pid < 0) {
+			errno = -__private_pid;
+			__private_pid = INVALID_PID;
+			return -1;
+		}
 	}
 
-        return ret;
+	return __private_pid;
 }