plugins/ocaml/plugin.h

   1 /* nbdkit
   2  * Copyright Red Hat
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  * * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * * Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * * Neither the name of Red Hat nor the names of its contributors may be
  16  * used to endorse or promote products derived from this software without
  17  * specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  22  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  26  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  27  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  29  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #ifndef NBDKIT_OCAML_PLUGIN_H
  34 #define NBDKIT_OCAML_PLUGIN_H
  35
  36 /* Replacement if caml_alloc_initialized_string is missing, added
  37  * to OCaml runtime in 2017.
  38  */
  39 #ifndef HAVE_CAML_ALLOC_INITIALIZED_STRING
  40 static inline value
  41 caml_alloc_initialized_string (mlsize_t len, const char *p)
  42 {
  43   value sv = caml_alloc_string (len);
  44   memcpy ((char *) String_val (sv), p, len);
  45   return sv;
  46 }
  47 #endif
  48
  49 /* For functions which call into OCaml code, call
  50  * caml_leave_blocking_section() to prevent other threads running,
  51  * then caml_enter_blocking_section() on return to C code.  This macro
  52  * ensures that the calls are paired properly.
  53  */
  54 #define LEAVE_BLOCKING_SECTION_FOR_CURRENT_SCOPE() \
  55   __attribute__ ((unused, cleanup (cleanup_enter_blocking_section))) \
  56   int _unused;                                              \
  57   caml_leave_blocking_section ()
  58 static inline void
  59 cleanup_enter_blocking_section (int *unused)
  60 {
  61   caml_enter_blocking_section ();
  62 }
  63
  64 #endif /* NBDKIT_OCAML_PLUGIN_H */