在 nogil 中调用 cdef nogil 函数

Question

here 部分解决了这个问题，但我对解决方案不太满意，我想知道：

1. 有没有办法编写结构并将其映射到扩展类
2. 为什么会出现错误？函数是cdef和nogil，在GIL环境中调用就可以了

第一点对我来说非常重要，因为我将从utils 库中调用很多函数并以here 描述的方式编写所有内容将非常耗时。

代码（iPython 笔记本）：

%%cython
import numpy as np
cimport numpy as np
mingw_setup_args={'script_args': ["--compiler=mingw32", "--cython-cplus"], 'include_dirs': np.get_include()}
import pyximport; pyximport.install(setup_args=mingw_setup_args, reload_support=True, language_level=3)

from utils import blas_multiply

D_TYPE = np.dtype(np.float64)

cdef double[:,:] A = np.random.randn(100, 10, dtype=D_TYPE)
cdef double[:] b = np.random.randn(10, dtype=D_TYPE)
cdef double[:] out = np.zeros((A.shape[0], ), dtype=D_TYPE)

# blas_multiply(A, b, out) # works fine

with nogil:
    blas_multiply(A, b, out)

utils.pyx 文件

#!python
# distutils: language=c++
# cython: language_level=3

cimport cython
import numpy as np
cimport numpy as np
cimport scipy.linalg.cython_blas as blas

@cython.cdivision(True)
@cython.boundscheck(False)
@cython.wraparound(False)
@cython.nonecheck(False)
cpdef void blas_multiply(double[:,:] A, double[:] b, double[:] c) nogil:
    """
    calls dgemv from BLAS which computes y = alpha * trans(A) + beta * y
    A: m rows by k columns
    b: k rows by 1 columns
    c: k rows by 1 columns
    """
    cdef int m = A.shape[0]
    cdef int k = A.shape[1]
    cdef int n = 1
    cdef double alpha = 1.0
    cdef double beta = 0.0

    # for F contiguous arrays
    # blas.dgemv("N", &m, &k, &alpha, &A[0, 0], &m, &b[0], &n, &beta, &c[0], &n)

    # for C contiguous arrays
    blas.dgemv("T", &k, &m, &alpha, &A[0, 0], &k, &b[0], &n, &beta, &c[0], &n)

回溯：

Error compiling Cython file:
------------------------------------------------------------
...

# blas_multiply(A, b, out)
# print(out)

with nogil:
    blas_multiply(A, b, out)
                ^
------------------------------------------------------------

C:\Users\...\.ipython\cython\_cython_magic_6b53bffa20f1e5bcc572f847b4b26a3f.pyx:22:17: Discarding owned Python object not allowed without gil

Error compiling Cython file:
------------------------------------------------------------
...

# blas_multiply(A, b, out)
# print(out)

with nogil:
    blas_multiply(A, b, out)
                ^
------------------------------------------------------------

C:\Users\...\.ipython\cython\_cython_magic_6b53bffa20f1e5bcc572f847b4b26a3f.pyx:22:17: Calling gil-requiring function not allowed without gil

Error compiling Cython file:
------------------------------------------------------------
...

# blas_multiply(A, b, out)
# print(out)

with nogil:
    blas_multiply(A, b, out)
   ^
------------------------------------------------------------

C:\Users\...\.ipython\cython\_cython_magic_6b53bffa20f1e5bcc572f847b4b26a3f.pyx:22:4: Accessing Python global or builtin not allowed without gil

Error compiling Cython file:
------------------------------------------------------------
...

# blas_multiply(A, b, out)
# print(out)

with nogil:
    blas_multiply(A, b, out)
                ^
------------------------------------------------------------

C:\Users\...\.ipython\cython\_cython_magic_6b53bffa20f1e5bcc572f847b4b26a3f.pyx:22:17: Constructing Python tuple not allowed without gil

Error compiling Cython file:
------------------------------------------------------------
...

# blas_multiply(A, b, out)
# print(out)

with nogil:
    blas_multiply(A, b, out)
                 ^
------------------------------------------------------------

C:\Users\...\.ipython\cython\_cython_magic_6b53bffa20f1e5bcc572f847b4b26a3f.pyx:22:18: Converting to Python object not allowed without gil

Error compiling Cython file:
------------------------------------------------------------
...

# blas_multiply(A, b, out)
# print(out)

with nogil:
    blas_multiply(A, b, out)
                    ^
------------------------------------------------------------

C:\Users\...\.ipython\cython\_cython_magic_6b53bffa20f1e5bcc572f847b4b26a3f.pyx:22:21: Converting to Python object not allowed without gil

Error compiling Cython file:
------------------------------------------------------------
...

# blas_multiply(A, b, out)
# print(out)

with nogil:
    blas_multiply(A, b, out)
                       ^
------------------------------------------------------------

C:\Users\...\.ipython\cython\_cython_magic_6b53bffa20f1e5bcc572f847b4b26a3f.pyx:22:24: Converting to Python object not allowed without gil

Answer 1

from utils import blas_multiply

此导入 blas_multiply 作为 Python 函数（即比 cpdef 生成的包装器）。因此，它显示为一个通用的 Python 可调用对象，并且所有关于它是 nogil 的信息都丢失了。

你想要

from utils cimport blas_multiply

在编译时获取blas_multiply 的 Cython 定义。您需要在 .pxd 文件中声明 blas_multiply 的签名才能正常工作。