Source code for spinnman.messages.scp.impl.sdram_alloc
# Copyright (c) 2015 The University of Manchester
#
# Licensed 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
#
# https://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.
import struct
from typing import Optional
from spinn_utilities.overrides import overrides
from spinnman.messages.scp import SCPRequestHeader
from spinnman.messages.scp.abstract_messages import (
AbstractSCPRequest, AbstractSCPResponse)
from spinnman.messages.scp.enums import AllocFree, SCPCommand, SCPResult
from spinnman.messages.sdp import SDPFlag, SDPHeader
from spinnman.exceptions import (
SpinnmanUnexpectedResponseCodeException, SpinnmanInvalidParameterException)
_ONE_WORD = struct.Struct("<I")
FLAG_RETRY_TAG = 4
class _AllocResponse(AbstractSCPResponse):
"""
An SCP response to a request to allocate space in SDRAM.
"""
__slots__ = (
"_base_address",
"_size")
def __init__(self, size: int):
super().__init__()
self._size = size
self._base_address: Optional[int] = None
@overrides(AbstractSCPResponse.read_data_bytestring)
def read_data_bytestring(self, data: bytes, offset: int):
result = self.scp_response_header.result
if result != SCPResult.RC_OK:
raise SpinnmanUnexpectedResponseCodeException(
"SDRAM Allocation", "CMD_ALLOC", result.name)
self._base_address = _ONE_WORD.unpack_from(data, offset)[0]
# check that the base address is not null (0 in python case) as
# this reflects a issue in the command on SpiNNaker side
if self._base_address == 0:
raise SpinnmanInvalidParameterException(
"SDRAM Allocation response base address", self._base_address,
f"Could not allocate {self._size} bytes of SDRAM")
@property
def base_address(self) -> int:
"""
The base address allocated, or 0 if none.
:rtype: int
"""
return self._base_address or 0
class SDRAMAlloc(AbstractSCPRequest[_AllocResponse]):
"""
An SCP Request to allocate space in the SDRAM space.
"""
__slots__ = "_size",
def __init__(self, x: int, y: int, app_id: int, size: int,
tag: Optional[int] = None, retry_tag: bool = True):
"""
:param int x:
The x-coordinate of the chip to allocate on, between 0 and 255
:param int y:
The y-coordinate of the chip to allocate on, between 0 and 255
:param int app_id: The ID of the application, between 0 and 255
:param int size: The size in bytes of memory to be allocated
:param int tag:
The tag for the SDRAM, a 8-bit (chip-wide) tag that can be
looked up by a SpiNNaker application to discover the address of
the allocated block. If `0` then no tag is applied.
:param bool retry_tag:
If a tag is used, add a safety check to retry the tag. This can
avoid issues with re-allocating memory on a retry message.
"""
# pylint: disable=too-many-arguments
extra_flag = 0
if retry_tag and tag is not None:
extra_flag = FLAG_RETRY_TAG
if tag is None:
tag = 0
elif not (0 <= tag < 256):
raise SpinnmanInvalidParameterException(
"tag",
"The tag param needs to be between 0 and 255, or None (in "
"which case 0 will be used by default)", str(tag))
# pylint: disable=unsupported-binary-operation
super().__init__(
SDPHeader(
flags=SDPFlag.REPLY_EXPECTED, destination_port=0,
destination_cpu=0, destination_chip_x=x,
destination_chip_y=y),
SCPRequestHeader(command=SCPCommand.CMD_ALLOC),
argument_1=(
(extra_flag << 16) |
(app_id << 8) |
AllocFree.ALLOC_SDRAM.value),
argument_2=size, argument_3=tag)
self._size = size
[docs]
@overrides(AbstractSCPRequest.get_scp_response)
def get_scp_response(self) -> _AllocResponse:
return _AllocResponse(self._size)