Implement support for non-coalescing maps on MinGW.
- Do not reallocate huge objects in place if the number of backing
chunks would change.
- Do not cache multi-chunk mappings.
This resolves #213.
diff --git a/configure.ac b/configure.ac
index 0497eaf..502dd39 100644
--- a/configure.ac
+++ b/configure.ac
@@ -258,6 +258,7 @@
dnl definitions need to be seen before any headers are included, which is a pain
dnl to make happen otherwise.
default_munmap="1"
+maps_coalesce="1"
case "${host}" in
*-*-darwin* | *-*-ios*)
CFLAGS="$CFLAGS"
@@ -341,6 +342,7 @@
abi="pecoff"
force_tls="0"
force_lazy_lock="1"
+ maps_coalesce="0"
RPATH=""
so="dll"
if test "x$je_cv_msvc" = "xyes" ; then
@@ -862,6 +864,12 @@
fi
AC_SUBST([enable_tcache])
+dnl Indicate whether adjacent virtual memory mappings automatically coalesce
+dnl (and fragment on demand).
+if test "x${maps_coalesce}" = "x1" ; then
+ AC_DEFINE([JEMALLOC_MAPS_COALESCE], [ ])
+fi
+
dnl Enable VM deallocation via munmap() by default.
AC_ARG_ENABLE([munmap],
[AS_HELP_STRING([--disable-munmap], [Disable VM deallocation via munmap(2)])],
@@ -873,6 +881,10 @@
],
[enable_munmap="${default_munmap}"]
)
+if test "x$enable_munmap" = "x0" -a "x${maps_coalesce}" = "x0" ; then
+ AC_MSG_RESULT([Forcing munmap to avoid non-coalescing map issues])
+ enable_munmap="1"
+fi
if test "x$enable_munmap" = "x1" ; then
AC_DEFINE([JEMALLOC_MUNMAP], [ ])
fi