1  /* Common code for use by all hashlib related modules. */
       2  
       3  /*
       4   * Given a PyObject* obj, fill in the Py_buffer* viewp with the result
       5   * of PyObject_GetBuffer.  Sets an exception and issues the erraction
       6   * on any errors, e.g. 'return NULL' or 'goto error'.
       7   */
       8  #define GET_BUFFER_VIEW_OR_ERROR(obj, viewp, erraction) do { \
       9          if (PyUnicode_Check((obj))) { \
      10              PyErr_SetString(PyExc_TypeError, \
      11                              "Strings must be encoded before hashing");\
      12              erraction; \
      13          } \
      14          if (!PyObject_CheckBuffer((obj))) { \
      15              PyErr_SetString(PyExc_TypeError, \
      16                              "object supporting the buffer API required"); \
      17              erraction; \
      18          } \
      19          if (PyObject_GetBuffer((obj), (viewp), PyBUF_SIMPLE) == -1) { \
      20              erraction; \
      21          } \
      22          if ((viewp)->ndim > 1) { \
      23              PyErr_SetString(PyExc_BufferError, \
      24                              "Buffer must be single dimension"); \
      25              PyBuffer_Release((viewp)); \
      26              erraction; \
      27          } \
      28      } while(0)
      29  
      30  #define GET_BUFFER_VIEW_OR_ERROUT(obj, viewp) \
      31      GET_BUFFER_VIEW_OR_ERROR(obj, viewp, return NULL)
      32  
      33  /*
      34   * Helper code to synchronize access to the hash object when the GIL is
      35   * released around a CPU consuming hashlib operation. All code paths that
      36   * access a mutable part of obj must be enclosed in an ENTER_HASHLIB /
      37   * LEAVE_HASHLIB block or explicitly acquire and release the lock inside
      38   * a PY_BEGIN / END_ALLOW_THREADS block if they wish to release the GIL for
      39   * an operation.
      40   */
      41  
      42  #include "pythread.h"
      43  #define ENTER_HASHLIB(obj) \
      44      if ((obj)->lock) { \
      45          if (!PyThread_acquire_lock((obj)->lock, 0)) { \
      46              Py_BEGIN_ALLOW_THREADS \
      47              PyThread_acquire_lock((obj)->lock, 1); \
      48              Py_END_ALLOW_THREADS \
      49          } \
      50      }
      51  #define LEAVE_HASHLIB(obj) \
      52      if ((obj)->lock) { \
      53          PyThread_release_lock((obj)->lock); \
      54      }
      55  
      56  /* TODO(gps): We should probably make this a module or EVPobject attribute
      57   * to allow the user to optimize based on the platform they're using. */
      58  #define HASHLIB_GIL_MINSIZE 2048
      59