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"""Meta schedule tuning utilities for Hexagon."""
import os
import tempfile
from typing import Callable, Dict, List, Optional
import tvm

from tvm.ir.module import IRModule
from tvm.runtime import Module, NDArray
from tvm.target import Target
from tvm.driver import build as tvm_build
from tvm.tir.transform import RemoveWeightLayoutRewriteBlock
from tvm.contrib.popen_pool import PopenPoolExecutor
from tvm.meta_schedule.utils import cpu_count, derived_object
from tvm.meta_schedule.builder import LocalBuilder
from tvm.meta_schedule.runner import (
    EvaluatorConfig,
    RunnerInput,
    RunnerFuture,
    PyRunner,
)
from tvm.meta_schedule.runner.rpc_runner import (
    default_alloc_argument,
    default_run_evaluator,
    RPCRunnerFuture,
)

from .build import HexagonLauncherRPC
from .tools import export_module


@derived_object
class HexagonRPCRunner(PyRunner):
    """RPCRunner for Hexagon. See the documentation of RPCRunner for more details."""

    def __init__(
        self,
        hexagon_launcher: HexagonLauncherRPC,
        evaluator_config: Optional[EvaluatorConfig] = None,
        cooldown_sec: float = 0.0,
        alloc_repeat: int = 1,
        max_workers: Optional[int] = None,
        initializer: Optional[Callable[[], None]] = None,
    ):
        """
        Parameters
        ----------
        hexagon_launcher : HexagonLauncherRPC
            The RPC launcher for Hexagon. It is needed for creating hexagon.Session
            object inside the worker function.
        evaluator_config: EvaluatorConfig
            The evaluator configuration.
        cooldown_sec: float
            The cooldown in seconds.
        alloc_repeat: int
            The number of times to random fill the allocation.
        max_workers: Optional[int] = None
            The maximum number of connections. Defaults to number of logical CPU cores.
        initializer: Optional[Callable[[], None]]
            The initializer function.
        """

        super().__init__()
        self.hexagon_launcher = hexagon_launcher
        self.evaluator_config = EvaluatorConfig._normalized(evaluator_config)
        self.cooldown_sec = cooldown_sec
        self.alloc_repeat = alloc_repeat
        if max_workers is None:
            max_workers = cpu_count(logical=True)
        self.pool = PopenPoolExecutor(
            max_workers=max_workers,
            timeout=100,
            initializer=initializer,
        )

    def run(self, runner_inputs: List[RunnerInput]) -> List[RunnerFuture]:
        results = []
        for runner_input in runner_inputs:
            future = RPCRunnerFuture(
                future=self.pool.submit(
                    _worker_func,
                    self.hexagon_launcher,
                    self.evaluator_config,
                    self.alloc_repeat,
                    str(runner_input.artifact_path),
                    tuple(arg_info.as_json() for arg_info in runner_input.args_info),
                ),
                timeout_sec=100,
            )
            results.append(future)
        return results


def _worker_func(hexagon_launcher, evaluator_config, alloc_repeat, artifact_path, args_info):
    with hexagon_launcher.create_session() as session:
        device = session.device
        _, remote_path = os.path.split(artifact_path)
        uploaded = session.upload(artifact_path, remote_path)
        rt_mod = session.load_module(uploaded)
        repeated_args = default_alloc_argument(
            session,
            device,
            args_info,
            alloc_repeat,
        )
        costs = default_run_evaluator(
            session,
            rt_mod,
            device,
            evaluator_config,
            repeated_args,
        )
    return costs


def get_hexagon_local_builder(
    pass_context: tvm.transform.PassContext = None,
    max_workers: Optional[int] = None,
    timeout_sec: float = 30.0,
):
    """Return Hexagon-compatible Builder for meta schedule."""

    def export_func(mod):
        binary_path = export_module(mod, tempfile.mkdtemp())
        return str(binary_path)

    def default_build_with_context(
        mod: IRModule, target: Target, _params: Optional[Dict[str, NDArray]]
    ) -> Module:
        with pass_context:
            mod = RemoveWeightLayoutRewriteBlock(skip_ndarray_rewrite=True)(mod)
            return tvm_build(mod, target=target)

    if pass_context is not None:
        return LocalBuilder(
            f_build=default_build_with_context,
            f_export=export_func,
            max_workers=max_workers,
            timeout_sec=timeout_sec,
        )
    else:
        return LocalBuilder(f_export=export_func, max_workers=max_workers, timeout_sec=timeout_sec)


def get_hexagon_rpc_runner(
    hexagon_launcher: HexagonLauncherRPC,
    number=3,
    repeat=1,
    min_repeat_ms=100,
    max_workers: Optional[int] = None,
):
    """Return Hexagon-compatible RPC Runner for meta schedule.

    Parameters
    ----------
    hexagon_launcher : HexagonLauncherRPC
        The RPC launcher for Hexagon.
    number: int
        The number of times to run this function for taking average.
        We call these runs as one `repeat` of measurement.
    repeat: int
        The number of times to repeat the measurement.
        In total, the function will be invoked (1 + number x repeat) times,
        where the first one is warm up and will be discarded.
        The returned result contains `repeat` costs,
        each of which is an average of `number` costs.
    min_repeat_ms: int
        Minimum repeat time in ms. if the execution latency is too short,
        increase the number of runs to the given time (in ms) to reduce the measurement error.
    """
    evaluator_config = EvaluatorConfig(
        number=number,
        repeat=repeat,
        min_repeat_ms=min_repeat_ms,
        enable_cpu_cache_flush=False,
    )

    return HexagonRPCRunner(hexagon_launcher, evaluator_config, max_workers=max_workers)
