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# Copied from https://github.com/sagemath/cysignals/blob/master/src/cysignals/memory.pxd.
# Note that this is no longer interruption safe, as we efficiently remove ``sig_block``/``sig_unblock``.
"""
Memory allocation functions which are interrupt-safe
The ``sig_`` variants are simple wrappers around the corresponding C
functions. The ``check_`` variants check the return value and raise
``MemoryError`` in case of failure.
"""
#*****************************************************************************
# Copyright (C) 2011-2016 Jeroen Demeyer <J.Demeyer@UGent.be>
#
# cysignals is free software: you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# cysignals is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with cysignals. If not, see <http://www.gnu.org/licenses/>.
#
#*****************************************************************************
cimport cython
from libc.stdlib cimport malloc, calloc, realloc, free
from .signals cimport sig_block, sig_unblock
cdef extern from *:
int unlikely(int) nogil # Defined by Cython
cdef inline void* sig_malloc "sig_malloc"(size_t n) nogil:
sig_block()
cdef void* ret = malloc(n)
sig_unblock()
return ret
cdef inline void* sig_realloc "sig_realloc"(void* ptr, size_t size) nogil:
sig_block()
cdef void* ret = realloc(ptr, size)
sig_unblock()
return ret
cdef inline void* sig_calloc "sig_calloc"(size_t nmemb, size_t size) nogil:
sig_block()
cdef void* ret = calloc(nmemb, size)
sig_unblock()
return ret
cdef inline void sig_free "sig_free"(void* ptr) nogil:
sig_block()
free(ptr)
sig_unblock()
@cython.cdivision(True)
cdef inline size_t mul_overflowcheck(size_t a, size_t b) nogil:
"""
Return a*b, checking for overflow. Assume that a > 0.
If overflow occurs, return <size_t>(-1).
We assume that malloc(<size_t>-1) always fails.
"""
# If a and b both less than MUL_NO_OVERFLOW, no overflow can occur
cdef size_t MUL_NO_OVERFLOW = ((<size_t>1) << (4*sizeof(size_t)))
if a >= MUL_NO_OVERFLOW or b >= MUL_NO_OVERFLOW:
if unlikely(b > (<size_t>-1) // a):
return <size_t>(-1)
return a*b
cdef inline void* check_allocarray(size_t nmemb, size_t size) except? NULL:
"""
Allocate memory for ``nmemb`` elements of size ``size``.
"""
if nmemb == 0:
return NULL
cdef size_t n = mul_overflowcheck(nmemb, size)
cdef void* ret = sig_malloc(n)
if unlikely(ret == NULL):
raise MemoryError("failed to allocate %s * %s bytes" % (nmemb, size))
return ret
cdef inline void* check_reallocarray(void* ptr, size_t nmemb, size_t size) except? NULL:
"""
Re-allocate memory at ``ptr`` to hold ``nmemb`` elements of size
``size``. If ``ptr`` equals ``NULL``, this behaves as
``check_allocarray``.
When ``nmemb`` equals 0, then free the memory at ``ptr``.
"""
if nmemb == 0:
sig_free(ptr)
return NULL
cdef size_t n = mul_overflowcheck(nmemb, size)
cdef void* ret = sig_realloc(ptr, n)
if unlikely(ret == NULL):
raise MemoryError("failed to allocate %s * %s bytes" % (nmemb, size))
return ret
cdef inline void* check_malloc(size_t n) except? NULL:
"""
Allocate ``n`` bytes of memory.
"""
if n == 0:
return NULL
cdef void* ret = sig_malloc(n)
if unlikely(ret == NULL):
raise MemoryError("failed to allocate %s bytes" % n)
return ret
cdef inline void* check_realloc(void* ptr, size_t n) except? NULL:
"""
Re-allocate memory at ``ptr`` to hold ``n`` bytes.
If ``ptr`` equals ``NULL``, this behaves as ``check_malloc``.
"""
if n == 0:
sig_free(ptr)
return NULL
cdef void* ret = sig_realloc(ptr, n)
if unlikely(ret == NULL):
raise MemoryError("failed to allocate %s bytes" % n)
return ret
cdef inline void* check_calloc(size_t nmemb, size_t size) except? NULL:
"""
Allocate memory for ``nmemb`` elements of size ``size``. The
resulting memory is zeroed.
"""
if nmemb == 0:
return NULL
cdef void* ret = sig_calloc(nmemb, size)
if unlikely(ret == NULL):
raise MemoryError("failed to allocate %s * %s bytes" % (nmemb, size))
return ret
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