r18332: added back in our shared mmap test code

(This used to be commit 6ff100b26698a50ba79b587a687cc0d440f73b55)

2 files changed, 77 insertions, 1 deletions

diff --git a/source4/lib/replace/libreplace.m4 b/source4/lib/replace/libreplace.m4
index 6c8c01d687..cd9d171662 100644
--- a/source4/lib/replace/libreplace.m4
+++ b/source4/lib/replace/libreplace.m4
@@ -42,7 +42,6 @@ AC_HEADER_STDC
 AC_CHECK_SIZEOF(off_t,cross)
 AC_CHECK_SIZEOF(size_t,cross)
 AC_CHECK_SIZEOF(ssize_t,cross)
-AC_FUNC_MMAP
 
 AC_CHECK_HEADERS([stdint.h inttypes.h])
 AC_CHECK_TYPE(uint_t, unsigned int)
@@ -83,9 +82,18 @@ AC_INCLUDES_DEFAULT
 )
 
 
+AC_CACHE_CHECK([for working mmap],samba_cv_HAVE_MMAP,[
+AC_TRY_RUN([#include "$libreplacedir/test/shared_mmap.c"],
+           samba_cv_HAVE_MMAP=yes,samba_cv_HAVE_MMAP=no,samba_cv_HAVE_MMAP=cross)])
+if test x"$samba_cv_HAVE_MMAP" = x"yes"; then
+    AC_DEFINE(HAVE_MMAP,1,[Whether mmap works])
+fi
+
+
 AC_CACHE_CHECK([for broken inet_ntoa],samba_cv_REPLACE_INET_NTOA,[
 AC_TRY_RUN([
 #include <stdio.h>
+#include <unistd.h>
 #include <sys/types.h>
 #include <netinet/in.h>
 #ifdef HAVE_ARPA_INET_H
diff --git a/source4/lib/replace/test/shared_mmap.c b/source4/lib/replace/test/shared_mmap.c
new file mode 100644
index 0000000000..50dad8d696
--- /dev/null
+++ b/source4/lib/replace/test/shared_mmap.c
@@ -0,0 +1,68 @@
+/* this tests whether we can use a shared writeable mmap on a file -
+   as needed for the mmap variant of FAST_SHARE_MODES */
+
+#if defined(HAVE_UNISTD_H)
+#include <unistd.h>
+#endif
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#define DATA "conftest.mmap"
+
+#ifndef MAP_FILE
+#define MAP_FILE 0
+#endif
+
+main()
+{
+	int *buf;
+	int i; 
+	int fd = open(DATA,O_RDWR|O_CREAT|O_TRUNC,0666);
+	int count=7;
+
+	if (fd == -1) exit(1);
+
+	for (i=0;i<10000;i++) {
+		write(fd,&i,sizeof(i));
+	}
+
+	close(fd);
+
+	if (fork() == 0) {
+		fd = open(DATA,O_RDWR);
+		if (fd == -1) exit(1);
+
+		buf = (int *)mmap(NULL, 10000*sizeof(int), 
+				   (PROT_READ | PROT_WRITE), 
+				   MAP_FILE | MAP_SHARED, 
+				   fd, 0);
+
+		while (count-- && buf[9124] != 55732) sleep(1);
+
+		if (count <= 0) exit(1);
+
+		buf[1763] = 7268;
+		exit(0);
+	}
+
+	fd = open(DATA,O_RDWR);
+	if (fd == -1) exit(1);
+
+	buf = (int *)mmap(NULL, 10000*sizeof(int), 
+			   (PROT_READ | PROT_WRITE), 
+			   MAP_FILE | MAP_SHARED, 
+			   fd, 0);
+
+	if (buf == (int *)-1) exit(1);
+
+	buf[9124] = 55732;
+
+	while (count-- && buf[1763] != 7268) sleep(1);
+
+	unlink(DATA);
+		
+	if (count > 0) exit(0);
+	exit(1);
+}