[PATCH v2 12/17] tools/ocaml/libs/mmap: mark mmap/munmap as blocking

[Edwin Török <edvin.torok@xxxxxxxxxx>]

These functions can potentially take some time,
so allow other OCaml code to proceed meanwhile (if any).

Signed-off-by: Edwin Török <edvin.torok@xxxxxxxxxx>
---
 tools/ocaml/libs/mmap/xenmmap_stubs.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/tools/ocaml/libs/mmap/xenmmap_stubs.c 
b/tools/ocaml/libs/mmap/xenmmap_stubs.c
index d7a97c76f5..e8d2d6add5 100644
--- a/tools/ocaml/libs/mmap/xenmmap_stubs.c
+++ b/tools/ocaml/libs/mmap/xenmmap_stubs.c
@@ -28,6 +28,7 @@
 #include <caml/fail.h>
 #include <caml/callback.h>
 #include <caml/unixsupport.h>
+#include <caml/signals.h>
 
 #define Wsize_bsize_round(n) (Wsize_bsize( (n) + sizeof(value) - 1 ))
 
@@ -69,7 +70,9 @@ CAMLprim value stub_mmap_init(value fd, value pflag, value 
mflag,
                caml_invalid_argument("negative offset");
        length = Int_val(len);
 
+       caml_enter_blocking_section();
        addr = mmap(NULL, length, c_pflag, c_mflag, Int_val(fd), 
Int_val(offset));
+       caml_leave_blocking_section();
        if (MAP_FAILED == addr)
                uerror("mmap", Nothing);
 
@@ -80,10 +83,15 @@ CAMLprim value stub_mmap_init(value fd, value pflag, value 
mflag,
 CAMLprim value stub_mmap_final(value intf)
 {
        CAMLparam1(intf);
+       struct mmap_interface interface = *Intf_val(intf);
 
-       if (Intf_val(intf)->addr != MAP_FAILED)
-               munmap(Intf_val(intf)->addr, Intf_val(intf)->len);
+       /* mark it as freed, in case munmap below fails, so we don't retry it */
        Intf_val(intf)->addr = MAP_FAILED;
+       if (interface.addr != MAP_FAILED) {
+               caml_enter_blocking_section();
+               munmap(interface.addr, interface.len);
+               caml_leave_blocking_section();
+       }
 
        CAMLreturn(Val_unit);
 }
-- 
2.25.1