#!/usr/bin/env python3 #cython: language_level=3 from libc.stdint cimport uint32_t from cpython.pycapsule cimport PyCapsule_IsValid, PyCapsule_GetPointer import numpy as np cimport numpy as np cimport cython from numpy.random cimport bitgen_t from numpy.random import PCG64 np.import_array() @cython.boundscheck(False) @cython.wraparound(False) def uniform_mean(Py_ssize_t n): cdef Py_ssize_t i cdef bitgen_t *rng cdef const char *capsule_name = "BitGenerator" cdef double[::1] random_values cdef np.ndarray randoms x = PCG64() capsule = x.capsule if not PyCapsule_IsValid(capsule, capsule_name): raise ValueError("Invalid pointer to anon_func_state") rng = PyCapsule_GetPointer(capsule, capsule_name) random_values = np.empty(n) # Best practice is to acquire the lock whenever generating random values. # This prevents other threads from modifying the state. Acquiring the lock # is only necessary if the GIL is also released, as in this example. with x.lock, nogil: for i in range(n): random_values[i] = rng.next_double(rng.state) randoms = np.asarray(random_values) return randoms.mean() # This function is declared nogil so it can be used without the GIL below cdef uint32_t bounded_uint(uint32_t lb, uint32_t ub, bitgen_t *rng) nogil: cdef uint32_t mask, delta, val mask = delta = ub - lb mask |= mask >> 1 mask |= mask >> 2 mask |= mask >> 4 mask |= mask >> 8 mask |= mask >> 16 val = rng.next_uint32(rng.state) & mask while val > delta: val = rng.next_uint32(rng.state) & mask return lb + val @cython.boundscheck(False) @cython.wraparound(False) def bounded_uints(uint32_t lb, uint32_t ub, Py_ssize_t n): cdef Py_ssize_t i cdef bitgen_t *rng cdef uint32_t[::1] out cdef const char *capsule_name = "BitGenerator" x = PCG64() out = np.empty(n, dtype=np.uint32) capsule = x.capsule if not PyCapsule_IsValid(capsule, capsule_name): raise ValueError("Invalid pointer to anon_func_state") rng = PyCapsule_GetPointer(capsule, capsule_name) with x.lock, nogil: for i in range(n): out[i] = bounded_uint(lb, ub, rng) return np.asarray(out)