plugins/python/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_PYTHON_PLUGIN_H
  34 #define NBDKIT_PYTHON_PLUGIN_H
  35
  36 /* Include these headers from one place because we have to make sure
  37  * we always set these #defines identically before inclusion.
  38  */
  39 #define PY_SSIZE_T_CLEAN 1
  40 #include <Python.h>
  41
  42 #define NBDKIT_API_VERSION 2
  43 #include <nbdkit-plugin.h>
  44
  45 /* All callbacks that want to call any Py* function should use this
  46  * macro.  See
  47  * https://docs.python.org/3/c-api/init.html#non-python-created-threads
  48  */
  49 #define ACQUIRE_PYTHON_GIL_FOR_CURRENT_SCOPE            \
  50   __attribute__ ((cleanup (cleanup_release)))           \
  51   CLANG_UNUSED_VARIABLE_WORKAROUND                      \
  52   PyGILState_STATE gstate = PyGILState_Ensure ()
  53 static inline void
  54 cleanup_release (PyGILState_STATE *gstateptr)
  55 {
  56   PyGILState_Release (*gstateptr);
  57 }
  58
  59 extern const char *script;
  60 extern PyObject *module;
  61 extern int py_api_version;
  62 extern __thread int last_error;
  63
  64 /* helpers.c */
  65 extern int callback_defined (const char *name, PyObject **obj_rtn);
  66 extern char *python_to_string (PyObject *str);
  67
  68 /* errors.c */
  69 extern int check_python_failure (const char *callback);
  70
  71 /* modfunctions.c */
  72 extern PyMODINIT_FUNC create_nbdkit_module (void);
  73
  74 #endif /* NBDKIT_PYTHON_PLUGIN_H */