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# Copyright (c) 2015 Mark D. Hill and David A. Wood.
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from m5.params import *
from m5.proxy import *
from m5.SimObject import SimObject

# A MessageBuffer inserts random delays to enqueued messages when the
# randomization param is set to 'enabled' or when globally enabled for the
# RubySystem and the param is set to 'ruby_system' (default). 'disabled'
# completely prevents randomization.
class MessageRandomization(ScopedEnum):
    vals = ['disabled', 'enabled', 'ruby_system']

class MessageBuffer(SimObject):
    type = 'MessageBuffer'
    cxx_class = 'gem5::ruby::MessageBuffer'
    cxx_header = "mem/ruby/network/MessageBuffer.hh"

    ordered = Param.Bool(False, "Whether the buffer is ordered")
    buffer_size = Param.Unsigned(0, "Maximum number of entries to buffer \
                                     (0 allows infinite entries)")
    randomization = Param.MessageRandomization('ruby_system',
                                       "Randomization parameter")
    allow_zero_latency = Param.Bool(False, "Allows messages to be enqueued \
                                            with zero latency. This is useful \
                                            for internall trigger queues and \
                                            should not be used if this msg. \
                                            buffer connects different objects")

    out_port = RequestPort("Request port to MessageBuffer receiver")
    master = DeprecatedParam(out_port, '`master` is now called `out_port`')
    in_port = ResponsePort("Response port from MessageBuffer sender")
    slave = DeprecatedParam(in_port, '`slave` is now called `in_port`')
    max_dequeue_rate = Param.Unsigned(0, "Maximum number of messages that can \
                                          be dequeued per cycle \
                                    (0 allows dequeueing all ready messages)")
    routing_priority = Param.Int(0, "Buffer priority when messages are \
                                     consumed by the network. Smaller value \
                                     means higher priority")