ocaml: Fix thread safety of strings in bindings (RHBZ#604691).

[libguestfs.git] / ocaml / guestfs_c.c

diff --git a/ocaml/guestfs_c.c b/ocaml/guestfs_c.c
index 291c430..71f416a 100644 (file)
--- a/ocaml/guestfs_c.c
+++ b/ocaml/guestfs_c.c
@@ -16,6 +16,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <config.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -32,6 +33,19 @@
 
 #include "guestfs_c.h"
 
+/* This macro was added in OCaml 3.10.  Backport for earlier versions. */
+#ifndef CAMLreturnT
+#define CAMLreturnT(type, result) do{ \
+  type caml__temp_result = (result); \
+  caml_local_roots = caml__frame; \
+  return (caml__temp_result); \
+}while(0)
+#endif
+
+/* These prototypes are solely to quiet gcc warning.  */
+CAMLprim value ocaml_guestfs_create (void);
+CAMLprim value ocaml_guestfs_close (value gv);
+
 /* Allocate handles and deal with finalization. */
 static void
 guestfs_finalize (value gv)
@@ -41,7 +55,7 @@ guestfs_finalize (value gv)
 }
 
 static struct custom_operations guestfs_custom_operations = {
-  "guestfs_custom_operations",
+  (char *) "guestfs_custom_operations",
   guestfs_finalize,
   custom_compare_default,
   custom_hash_default,
@@ -62,29 +76,31 @@ Val_guestfs (guestfs_h *g)
   CAMLreturn (rv);
 }
 
-/* Handle errors. */
-/* XXX Like the current Perl bindings, this is unsafe in a multi-
- * threaded environment.
- */
-static char *last_error = NULL;
-
-static void
-error_handler (guestfs_h *g,
-              void *data,
-              const char *msg)
+void
+ocaml_guestfs_raise_error (guestfs_h *g, const char *func)
 {
-  if (last_error != NULL) free (last_error);
-  last_error = strdup (msg);
+  CAMLparam0 ();
+  CAMLlocal1 (v);
+  const char *msg;
+
+  msg = guestfs_last_error (g);
+
+  if (msg)
+    v = caml_copy_string (msg);
+  else
+    v = caml_copy_string (func);
+  caml_raise_with_arg (*caml_named_value ("ocaml_guestfs_error"), v);
+  CAMLnoreturn;
 }
 
 void
-ocaml_guestfs_raise_error (guestfs_h *g, const char *func)
+ocaml_guestfs_raise_closed (const char *func)
 {
   CAMLparam0 ();
   CAMLlocal1 (v);
 
-  v = caml_copy_string (last_error);
-  caml_raise_with_arg (*caml_named_value ("ocaml_guestfs_error"), v);
+  v = caml_copy_string (func);
+  caml_raise_with_arg (*caml_named_value ("ocaml_guestfs_closed"), v);
   CAMLnoreturn;
 }
 
@@ -100,7 +116,7 @@ ocaml_guestfs_create (void)
   if (g == NULL)
     caml_failwith ("failed to create guestfs handle");
 
-  guestfs_set_error_handler (g, error_handler, NULL);
+  guestfs_set_error_handler (g, NULL, NULL);
 
   gv = Val_guestfs (g);
   CAMLreturn (gv);
@@ -122,15 +138,15 @@ ocaml_guestfs_close (value gv)
 
 /* Copy string array value. */
 char **
-ocaml_guestfs_strings_val (value sv)
+ocaml_guestfs_strings_val (guestfs_h *g, value sv)
 {
   CAMLparam1 (sv);
   char **r;
-  int i;
+  unsigned int i;
 
-  r = malloc (sizeof (char *) * (Wosize_val (sv) + 1));
+  r = guestfs_safe_malloc (g, sizeof (char *) * (Wosize_val (sv) + 1));
   for (i = 0; i < Wosize_val (sv); ++i)
-    r[i] = String_val (Field (sv, i));
+    r[i] = guestfs_safe_strdup (g, String_val (Field (sv, i)));
   r[i] = NULL;
 
   CAMLreturnT (char **, r);
@@ -140,8 +156,9 @@ ocaml_guestfs_strings_val (value sv)
 void
 ocaml_guestfs_free_strings (char **argv)
 {
-  /* Don't free the actual strings - they are String_vals on
-   * the OCaml heap.
-   */
+  unsigned int i;
+
+  for (i = 0; argv[i] != NULL; ++i)
+    free (argv[i]);
   free (argv);
 }