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      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                             "Unicode-objects 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 #ifdef WITH_THREAD
     43 #include "pythread.h"
     44     #define ENTER_HASHLIB(obj) \
     45         if ((obj)->lock) { \
     46             if (!PyThread_acquire_lock((obj)->lock, 0)) { \
     47                 Py_BEGIN_ALLOW_THREADS \
     48                 PyThread_acquire_lock((obj)->lock, 1); \
     49                 Py_END_ALLOW_THREADS \
     50             } \
     51         }
     52     #define LEAVE_HASHLIB(obj) \
     53         if ((obj)->lock) { \
     54             PyThread_release_lock((obj)->lock); \
     55         }
     56 #else
     57     #define ENTER_HASHLIB(obj)
     58     #define LEAVE_HASHLIB(obj)
     59 #endif
     60 
     61 /* TODO(gps): We should probably make this a module or EVPobject attribute
     62  * to allow the user to optimize based on the platform they're using. */
     63 #define HASHLIB_GIL_MINSIZE 2048
     64 
     65