Coverage for local/lib/python2.7/site-packages/sage/ext/memory_allocator.pyx : 81%

from cysignals.memory cimport * 

cdef extern from *: 

int unlikely(int) nogil # Defined by Cython 

cdef class MemoryAllocator: 

r""" 

An object for memory allocation, whose resources are freed upon 

``__dealloc__``. 

EXAMPLES:: 

sage: cython( 

....: ''' 

....: from sage.ext.memory_allocator cimport MemoryAllocator 

....: cdef MemoryAllocator mem = MemoryAllocator() 

....: for n in range(100): 

....: mem.malloc(n) 

....: mem.calloc(n, n) 

....: mem.allocarray(n, n) 

....: ''') 

""" 

def __cinit__(self): 

""" 

EXAMPLES:: 

sage: cython( 

....: ''' 

....: from sage.ext.memory_allocator cimport MemoryAllocator 

....: cdef MemoryAllocator mem = MemoryAllocator.__new__(MemoryAllocator) 

....: mem.malloc(10000) 

....: print(mem.n) 

....: print(mem.size) 

....: ''') 

1 

16 

""" 

self.n = 0 

self.size = 16 

self.pointers = self.static_pointers 

cdef int resize(self, size_t new_size) except -1: 

r""" 

Resize the list of pointers to contain ``new_size`` elements. 

It is required that ``new_size`` is at least ``self.n``, but 

this condition is not checked. 

""" 

cdef size_t i 

if self.pointers == self.static_pointers: 

# Case 1: allocate pointers for the first time 

self.pointers = <void **>check_allocarray(new_size, sizeof(void*)) 

for i in range(self.n): 

self.pointers[i] = self.static_pointers[i] 

else: 

# Case 2: resize pointers 

self.pointers = <void **>check_reallocarray(self.pointers, new_size, sizeof(void*)) 

self.size = new_size 

cdef inline int enlarge_if_needed(self) except -1: 

r""" 

Enlarge the list of pointers if needed such that there is at 

least one free entry. 

""" 

if unlikely(self.n >= self.size): 

return self.resize(self.size * 2) 

cdef void * malloc(self, size_t size) except? NULL: 

r""" 

Returns a new pointer and stores it to be automatically freed later. 

""" 

self.enlarge_if_needed() 

cdef void * val = check_malloc(size) 

self.pointers[self.n] = val 

self.n += 1 

return val 

cdef void * calloc(self, size_t nmemb, size_t size) except? NULL: 

r""" 

Returns a new pointer and stores it to be automatically freed later. 

""" 

self.enlarge_if_needed() 

cdef void * val = check_calloc(nmemb, size) 

self.pointers[self.n] = val 

self.n += 1 

return val 

cdef void * allocarray(self, size_t nmemb, size_t size) except? NULL: 

r""" 

Returns a new pointer and stores it to be automatically freed later. 

""" 

self.enlarge_if_needed() 

cdef void * val = check_allocarray(nmemb, size) 

self.pointers[self.n] = val 

self.n += 1 

return val 

def __dealloc__(self): 

r""" 

Free the allocated resources 

EXAMPLES:: 

sage: from sage.ext.memory_allocator import MemoryAllocator 

sage: _ = MemoryAllocator() 

""" 

cdef size_t i 

for i in range(self.n): 

sig_free(self.pointers[i]) 

if self.pointers != self.static_pointers: 

sig_free(self.pointers)