Issue #11277: mmap calls fcntl(fd, F_FULLFSYNC) on Mac OS X to get around a
mmap bug with sparse files. Patch written by Steffen Daode Nurpmeso.
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index f484a7a..88da4a0 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -23,6 +23,9 @@
#ifndef MS_WINDOWS
#define UNIX
+# ifdef __APPLE__
+# include <fcntl.h>
+# endif
#endif
#ifdef MS_WINDOWS
@@ -1091,6 +1094,12 @@
"mmap invalid access parameter.");
}
+#ifdef __APPLE__
+ /* Issue #11277: fsync(2) is not enough on OS X - a special, OS X specific
+ fcntl(2) is necessary to force DISKSYNC and get around mmap(2) bug */
+ if (fd != -1)
+ (void)fcntl(fd, F_FULLFSYNC);
+#endif
#ifdef HAVE_FSTAT
# ifdef __VMS
/* on OpenVMS we must ensure that all bytes are written to the file */