/usr/local/lib64/python3.6/site-packages/pyarrow
Edit: /usr/local/lib64/python3.6/site-packages/pyarrow/memory.pxi (7451B)
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# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
# cython: profile=False
# distutils: language = c++
# cython: embedsignature = True
cdef class MemoryPool(_Weakrefable):
"""
Base class for memory allocation.
Besides tracking its number of allocated bytes, a memory pool also
takes care of the required 64-byte alignment for Arrow data.
"""
def __init__(self):
raise TypeError("Do not call {}'s constructor directly, "
"use pyarrow.*_memory_pool instead."
.format(self.__class__.__name__))
cdef void init(self, CMemoryPool* pool):
self.pool = pool
def release_unused(self):
"""
Attempt to return to the OS any memory being held onto by the pool.
This function should not be called except potentially for
benchmarking or debugging as it could be expensive and detrimental to
performance.
This is best effort and may not have any effect on some memory pools
or in some situations (e.g. fragmentation).
"""
cdef CMemoryPool* pool = c_get_memory_pool()
with nogil:
pool.ReleaseUnused()
def bytes_allocated(self):
"""
Return the number of bytes that are currently allocated from this
memory pool.
"""
return self.pool.bytes_allocated()
def max_memory(self):
"""
Return the peak memory allocation in this memory pool.
This can be an approximate number in multi-threaded applications.
None is returned if the pool implementation doesn't know how to
compute this number.
"""
ret = self.pool.max_memory()
return ret if ret >= 0 else None
@property
def backend_name(self):
"""
The name of the backend used by this MemoryPool (e.g. "jemalloc").
"""
return frombytes(self.pool.backend_name())
cdef CMemoryPool* maybe_unbox_memory_pool(MemoryPool memory_pool):
if memory_pool is None:
return c_get_memory_pool()
else:
return memory_pool.pool
cdef class LoggingMemoryPool(MemoryPool):
cdef:
unique_ptr[CLoggingMemoryPool] logging_pool
def __init__(self):
raise TypeError("Do not call {}'s constructor directly, "
"use pyarrow.logging_memory_pool instead."
.format(self.__class__.__name__))
cdef class ProxyMemoryPool(MemoryPool):
"""
Memory pool implementation that tracks the number of bytes and
maximum memory allocated through its direct calls, while redirecting
to another memory pool.
"""
cdef:
unique_ptr[CProxyMemoryPool] proxy_pool
def __init__(self):
raise TypeError("Do not call {}'s constructor directly, "
"use pyarrow.proxy_memory_pool instead."
.format(self.__class__.__name__))
def default_memory_pool():
"""
Return the process-global memory pool.
"""
cdef:
MemoryPool pool = MemoryPool.__new__(MemoryPool)
pool.init(c_get_memory_pool())
return pool
def proxy_memory_pool(MemoryPool parent):
"""
Create and return a MemoryPool instance that redirects to the
*parent*, but with separate allocation statistics.
Parameters
----------
parent : MemoryPool
The real memory pool that should be used for allocations.
"""
cdef ProxyMemoryPool out = ProxyMemoryPool.__new__(ProxyMemoryPool)
out.proxy_pool.reset(new CProxyMemoryPool(parent.pool))
out.init(out.proxy_pool.get())
return out
def logging_memory_pool(MemoryPool parent):
"""
Create and return a MemoryPool instance that redirects to the
*parent*, but also dumps allocation logs on stderr.
Parameters
----------
parent : MemoryPool
The real memory pool that should be used for allocations.
"""
cdef LoggingMemoryPool out = LoggingMemoryPool.__new__(
LoggingMemoryPool, parent)
out.logging_pool.reset(new CLoggingMemoryPool(parent.pool))
out.init(out.logging_pool.get())
return out
def system_memory_pool():
"""
Return a memory pool based on the C malloc heap.
"""
cdef:
MemoryPool pool = MemoryPool.__new__(MemoryPool)
pool.init(c_system_memory_pool())
return pool
def jemalloc_memory_pool():
"""
Return a memory pool based on the jemalloc heap.
NotImplementedError is raised if jemalloc support is not enabled.
"""
cdef:
CMemoryPool* c_pool
MemoryPool pool = MemoryPool.__new__(MemoryPool)
check_status(c_jemalloc_memory_pool(&c_pool))
pool.init(c_pool)
return pool
def mimalloc_memory_pool():
"""
Return a memory pool based on the mimalloc heap.
NotImplementedError is raised if mimalloc support is not enabled.
"""
cdef:
CMemoryPool* c_pool
MemoryPool pool = MemoryPool.__new__(MemoryPool)
check_status(c_mimalloc_memory_pool(&c_pool))
pool.init(c_pool)
return pool
def set_memory_pool(MemoryPool pool):
"""
Set the default memory pool.
Parameters
----------
pool : MemoryPool
The memory pool that should be used by default.
"""
c_set_default_memory_pool(pool.pool)
cdef MemoryPool _default_memory_pool = default_memory_pool()
cdef LoggingMemoryPool _logging_memory_pool = logging_memory_pool(
_default_memory_pool)
def log_memory_allocations(enable=True):
"""
Enable or disable memory allocator logging for debugging purposes
Parameters
----------
enable : bool, default True
Pass False to disable logging
"""
if enable:
set_memory_pool(_logging_memory_pool)
else:
set_memory_pool(_default_memory_pool)
def total_allocated_bytes():
"""
Return the currently allocated bytes from the default memory pool.
Other memory pools may not be accounted for.
"""
cdef CMemoryPool* pool = c_get_memory_pool()
return pool.bytes_allocated()
def jemalloc_set_decay_ms(decay_ms):
"""
Set arenas.dirty_decay_ms and arenas.muzzy_decay_ms to indicated number of
milliseconds. A value of 0 (the default) results in dirty / muzzy memory
pages being released right away to the OS, while a higher value will result
in a time-based decay. See the jemalloc docs for more information
It's best to set this at the start of your application.
Parameters
----------
decay_ms : int
Number of milliseconds to set for jemalloc decay conf parameters. Note
that this change will only affect future memory arenas
"""
check_status(c_jemalloc_set_decay_ms(decay_ms))