lightning/tests/trainer/test_trainer.py

1916 lines
69 KiB
Python

# Copyright The PyTorch Lightning team.
#
# 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
#
# 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.
import gc
import logging
import math
import os
import pickle
import sys
from argparse import Namespace
from copy import deepcopy
from pathlib import Path
from unittest.mock import ANY, call, patch
import cloudpickle
import pytest
import torch
from omegaconf import OmegaConf
from torch.nn.parallel.distributed import DistributedDataParallel
from torch.optim import SGD
from torch.utils.data import DataLoader
import tests.helpers.utils as tutils
from pytorch_lightning import Callback, LightningDataModule, LightningModule, Trainer
from pytorch_lightning.callbacks import EarlyStopping, ModelCheckpoint
from pytorch_lightning.callbacks.prediction_writer import BasePredictionWriter
from pytorch_lightning.core.saving import load_hparams_from_tags_csv, load_hparams_from_yaml, save_hparams_to_tags_csv
from pytorch_lightning.loggers import TensorBoardLogger
from pytorch_lightning.overrides.distributed import IndexBatchSamplerWrapper, UnrepeatedDistributedSampler
from pytorch_lightning.plugins import DDPSpawnPlugin
from pytorch_lightning.trainer.states import TrainerFn
from pytorch_lightning.utilities import DeviceType, DistributedType
from pytorch_lightning.utilities.cloud_io import load as pl_load
from pytorch_lightning.utilities.exceptions import DeadlockDetectedException, MisconfigurationException
from pytorch_lightning.utilities.seed import seed_everything
from tests.base import EvalModelTemplate
from tests.helpers import BoringModel, RandomDataset
from tests.helpers.runif import RunIf
@pytest.mark.parametrize("url_ckpt", [True, False])
def test_no_val_module(monkeypatch, tmpdir, tmpdir_server, url_ckpt):
"""Tests use case where trainer saves the model, and user loads it from tags independently."""
# set $TORCH_HOME, which determines torch hub's cache path, to tmpdir
monkeypatch.setenv("TORCH_HOME", str(tmpdir))
model = EvalModelTemplate()
# logger file to get meta
logger = tutils.get_default_logger(tmpdir)
trainer = Trainer(default_root_dir=tmpdir, max_epochs=1, logger=logger, callbacks=[ModelCheckpoint(dirpath=tmpdir)])
# fit model
trainer.fit(model)
# training complete
assert trainer.state.finished, f"Training failed with {trainer.state}"
# save model
new_weights_path = os.path.join(tmpdir, "save_test.ckpt")
trainer.save_checkpoint(new_weights_path)
# assert ckpt has hparams
ckpt = torch.load(new_weights_path)
assert LightningModule.CHECKPOINT_HYPER_PARAMS_KEY in ckpt.keys(), "hyper_parameters missing from checkpoints"
# load new model
hparams_path = tutils.get_data_path(logger, path_dir=tmpdir)
hparams_path = os.path.join(hparams_path, "hparams.yaml")
ckpt_path = (
f"http://{tmpdir_server[0]}:{tmpdir_server[1]}/{os.path.basename(new_weights_path)}"
if url_ckpt
else new_weights_path
)
model_2 = EvalModelTemplate.load_from_checkpoint(checkpoint_path=ckpt_path, hparams_file=hparams_path)
model_2.eval()
@pytest.mark.parametrize("url_ckpt", [True, False])
def test_no_val_end_module(monkeypatch, tmpdir, tmpdir_server, url_ckpt):
"""Tests use case where trainer saves the model, and user loads it from tags independently."""
# set $TORCH_HOME, which determines torch hub's cache path, to tmpdir
monkeypatch.setenv("TORCH_HOME", tmpdir)
model = EvalModelTemplate()
# logger file to get meta
logger = tutils.get_default_logger(tmpdir)
# fit model
trainer = Trainer(default_root_dir=tmpdir, max_epochs=1, logger=logger, callbacks=[ModelCheckpoint(dirpath=tmpdir)])
trainer.fit(model)
# training complete
assert trainer.state.finished, f"Training failed with {trainer.state}"
# save model
new_weights_path = os.path.join(tmpdir, "save_test.ckpt")
trainer.save_checkpoint(new_weights_path)
# load new model
hparams_path = tutils.get_data_path(logger, path_dir=tmpdir)
hparams_path = os.path.join(hparams_path, "hparams.yaml")
ckpt_path = (
f"http://{tmpdir_server[0]}:{tmpdir_server[1]}/{os.path.basename(new_weights_path)}"
if url_ckpt
else new_weights_path
)
model_2 = EvalModelTemplate.load_from_checkpoint(checkpoint_path=ckpt_path, hparams_file=hparams_path)
model_2.eval()
@pytest.mark.parametrize("url_ckpt", [True, False])
def test_strict_model_load(monkeypatch, tmpdir, tmpdir_server, url_ckpt):
"""Tests use case where trainer saves the model, and user loads it from tags independently."""
# set $TORCH_HOME, which determines torch hub's cache path, to tmpdir
monkeypatch.setenv("TORCH_HOME", tmpdir)
model = EvalModelTemplate()
# Extra layer
model.c_d3 = torch.nn.Linear(model.hidden_dim, model.hidden_dim)
# logger file to get meta
logger = tutils.get_default_logger(tmpdir)
# fit model
trainer = Trainer(default_root_dir=tmpdir, max_epochs=1, logger=logger, callbacks=[ModelCheckpoint(dirpath=tmpdir)])
trainer.fit(model)
# training complete
assert trainer.state.finished, f"Training failed with {trainer.state}"
# save model
new_weights_path = os.path.join(tmpdir, "save_test.ckpt")
trainer.save_checkpoint(new_weights_path)
# load new model
hparams_path = tutils.get_data_path(logger, path_dir=tmpdir)
hparams_path = os.path.join(hparams_path, "hparams.yaml")
ckpt_path = (
f"http://{tmpdir_server[0]}:{tmpdir_server[1]}/{os.path.basename(new_weights_path)}"
if url_ckpt
else new_weights_path
)
try:
EvalModelTemplate.load_from_checkpoint(checkpoint_path=ckpt_path, hparams_file=hparams_path)
# todo: specify the possible exception
except Exception:
failed = True
else:
failed = False
assert failed, "Model should not been loaded since the extra layer added."
failed = False
try:
EvalModelTemplate.load_from_checkpoint(checkpoint_path=ckpt_path, hparams_file=hparams_path, strict=False)
# todo: specify the possible exception
except Exception:
failed = True
assert not failed, "Model should be loaded due to strict=False."
@pytest.mark.parametrize("accumulate_grad_batches", (1, 2, 3))
def test_trainer_accumulate_grad_batches_zero_grad(tmpdir, accumulate_grad_batches):
with patch("torch.optim.SGD.zero_grad") as sgd_zero_grad:
model = BoringModel()
trainer = Trainer(
default_root_dir=tmpdir,
limit_train_batches=20,
limit_val_batches=1,
max_epochs=1,
weights_summary=None,
accumulate_grad_batches=accumulate_grad_batches,
)
trainer.fit(model)
assert sgd_zero_grad.call_count == math.ceil(trainer.limit_train_batches / accumulate_grad_batches)
@pytest.mark.parametrize(
["accumulate_grad_batches", "limit_train_batches"],
[
({1: 2, 3: 4}, 1.0),
({1: 2, 3: 4}, 0.5), # not to be divisible by accumulate_grad_batches on purpose
(3, 1.0),
(3, 0.8), # not to be divisible by accumulate_grad_batches on purpose
(4, 1.0),
(4, 0.7), # not to be divisible by accumulate_grad_batches on purpose
],
)
def test_gradient_accumulation_scheduling_last_batch(tmpdir, accumulate_grad_batches, limit_train_batches):
"""Verify optimizer.step() applied to last batch while grad accumulation"""
class TestModel(BoringModel):
def state_dict(self, *args, **kwargs):
return deepcopy(super().state_dict(*args, **kwargs))
def check(self, d1, d2, equal=True):
keys = d1.keys() | d2.keys()
values = [torch.equal(d1[k], d2[k]) for k in keys]
return all(values) if equal else not any(values)
def backward(self, *args, **kwargs) -> None:
pre_bwd_state_dict = self.state_dict()
assert self.check(self.start_state_dict, pre_bwd_state_dict)
out = super().backward(*args, **kwargs)
# state dict is equal, just the gradients changed
assert self.check(pre_bwd_state_dict, self.state_dict())
return out
def optimizer_step(self, *args, **kwargs):
pre_opt_step_state_dict = self.state_dict()
assert self.check(self.start_state_dict, pre_opt_step_state_dict)
# this calls `backward` and `on_after_backward` inside the closure
out = super().optimizer_step(*args, **kwargs)
# the state dict changed
assert self.check(pre_opt_step_state_dict, self.state_dict(), equal=False)
self.opt_step_called = True
return out
def on_train_batch_start(self, *_):
self.start_state_dict = self.state_dict()
self.opt_step_called = False
def on_train_batch_end(self, outputs, batch, batch_idx, *_):
end_state_dict = self.state_dict()
is_last_batch = (batch_idx + 1) == self.trainer.num_training_batches
if is_last_batch or self.opt_step_called:
assert self.check(self.start_state_dict, end_state_dict, equal=False)
else:
assert self.check(self.start_state_dict, end_state_dict)
model = TestModel()
trainer = Trainer(
accumulate_grad_batches=accumulate_grad_batches,
max_epochs=2,
limit_train_batches=limit_train_batches,
limit_val_batches=0,
default_root_dir=tmpdir,
progress_bar_refresh_rate=0,
)
trainer.fit(model)
def test_loading_meta_tags(tmpdir):
"""test for backward compatibility to meta_tags.csv"""
tutils.reset_seed()
hparams = EvalModelTemplate.get_default_hparams()
# save tags
logger = tutils.get_default_logger(tmpdir)
logger.log_hyperparams(Namespace(some_str="a_str", an_int=1, a_float=2.0))
logger.log_hyperparams(hparams)
logger.save()
# load hparams
path_expt_dir = tutils.get_data_path(logger, path_dir=tmpdir)
hparams_path = os.path.join(path_expt_dir, TensorBoardLogger.NAME_HPARAMS_FILE)
hparams = load_hparams_from_yaml(hparams_path)
# save as legacy meta_tags.csv
tags_path = os.path.join(path_expt_dir, "meta_tags.csv")
save_hparams_to_tags_csv(tags_path, hparams)
tags = load_hparams_from_tags_csv(tags_path)
assert hparams == tags
def test_loading_yaml(tmpdir):
tutils.reset_seed()
hparams = EvalModelTemplate.get_default_hparams()
# save tags
logger = tutils.get_default_logger(tmpdir)
logger.log_hyperparams(Namespace(some_str="a_str", an_int=1, a_float=2.0))
logger.log_hyperparams(hparams)
logger.save()
# load hparams
path_expt_dir = tutils.get_data_path(logger, path_dir=tmpdir)
hparams_path = os.path.join(path_expt_dir, "hparams.yaml")
tags = load_hparams_from_yaml(hparams_path)
assert tags["batch_size"] == 32 and tags["hidden_dim"] == 1000
@pytest.mark.parametrize(
"save_top_k,save_last,expected_files",
[
pytest.param(-1, False, [f"epoch={i}.ckpt" for i in range(5)], id="CASE K=-1 (all)"),
pytest.param(1, False, {"epoch=4.ckpt"}, id="CASE K=1 (2.5, epoch 4)"),
pytest.param(2, False, [f"epoch={i}.ckpt" for i in (2, 4)], id="CASE K=2 (2.5 epoch 4, 2.8 epoch 2)"),
pytest.param(4, False, [f"epoch={i}.ckpt" for i in range(1, 5)], id="CASE K=4 (save all 4 base)"),
pytest.param(3, False, [f"epoch={i}.ckpt" for i in range(2, 5)], id="CASE K=3 (save the 2nd, 3rd, 4th model)"),
pytest.param(1, True, {"epoch=4.ckpt", "last.ckpt"}, id="CASE K=1 (save the 4th model and the last model)"),
],
)
def test_model_checkpoint_options(tmpdir, save_top_k, save_last, expected_files):
"""Test ModelCheckpoint options."""
def mock_save_function(filepath, *args):
open(filepath, "a").close()
# simulated losses
losses = [10, 9, 2.8, 5, 2.5]
checkpoint_callback = ModelCheckpoint(
dirpath=tmpdir,
filename="{epoch}",
monitor="checkpoint_on",
save_top_k=save_top_k,
save_last=save_last,
verbose=True,
)
trainer = Trainer()
trainer.state.fn = TrainerFn.FITTING
trainer.save_checkpoint = mock_save_function
# emulate callback's calls during the training
for i, loss in enumerate(losses):
trainer.fit_loop.current_epoch = i
trainer.fit_loop.global_step = i
trainer.callback_metrics.update({"checkpoint_on": loss})
checkpoint_callback.on_validation_end(trainer, trainer.lightning_module)
file_lists = set(os.listdir(tmpdir))
assert len(file_lists) == len(
expected_files
), f"Should save {len(expected_files)} models when save_top_k={save_top_k} but found={file_lists}"
# verify correct naming
for fname in expected_files:
assert fname in file_lists
def test_model_checkpoint_only_weights(tmpdir):
"""Tests use case where ModelCheckpoint is configured to save only model weights, and
user tries to load checkpoint to resume training.
"""
model = EvalModelTemplate()
trainer = Trainer(
default_root_dir=tmpdir,
max_epochs=1,
callbacks=[ModelCheckpoint(dirpath=tmpdir, monitor="early_stop_on", save_weights_only=True)],
)
# fit model
trainer.fit(model)
# training complete
assert trainer.state.finished, f"Training failed with {trainer.state}"
checkpoint_path = list(trainer.checkpoint_callback.best_k_models.keys())[0]
# assert saved checkpoint has no trainer data
checkpoint = torch.load(checkpoint_path)
assert "optimizer_states" not in checkpoint, "checkpoint should contain only model weights"
assert "lr_schedulers" not in checkpoint, "checkpoint should contain only model weights"
# assert loading model works when checkpoint has only weights
assert EvalModelTemplate.load_from_checkpoint(checkpoint_path=checkpoint_path)
# directly save model
new_weights_path = os.path.join(tmpdir, "save_test.ckpt")
trainer.save_checkpoint(new_weights_path, weights_only=True)
# assert saved checkpoint has no trainer data
checkpoint = torch.load(new_weights_path)
assert "optimizer_states" not in checkpoint, "checkpoint should contain only model weights"
assert "lr_schedulers" not in checkpoint, "checkpoint should contain only model weights"
# assert restoring train state fails
with pytest.raises(KeyError, match="checkpoint contains only the model"):
trainer.checkpoint_connector.restore(new_weights_path)
def test_model_freeze_unfreeze():
model = EvalModelTemplate()
model.freeze()
model.unfreeze()
@pytest.mark.parametrize("url_ckpt", [True, False])
def test_resume_from_checkpoint_epoch_restored(monkeypatch, tmpdir, tmpdir_server, url_ckpt):
"""Verify resuming from checkpoint runs the right number of epochs"""
# set $TORCH_HOME, which determines torch hub's cache path, to tmpdir
monkeypatch.setenv("TORCH_HOME", tmpdir)
class TestModel(BoringModel):
# Model that tracks epochs and batches seen
num_epochs_end_seen = 0
num_batches_seen = 0
num_on_load_checkpoint_called = 0
def on_epoch_end(self):
self.num_epochs_end_seen += 1
def on_train_batch_start(self, *_):
self.num_batches_seen += 1
def on_load_checkpoint(self, _):
self.num_on_load_checkpoint_called += 1
model = TestModel()
trainer = Trainer(
max_epochs=2,
limit_train_batches=0.65,
limit_val_batches=1,
callbacks=[ModelCheckpoint(dirpath=tmpdir, monitor="early_stop_on", save_top_k=-1)],
default_root_dir=tmpdir,
val_check_interval=1.0,
progress_bar_refresh_rate=0,
logger=False,
weights_summary=None,
)
trainer.fit(model)
# `on_epoch_end` will be called once for val_sanity, twice for train, twice for val
assert model.num_epochs_end_seen == 1 + 2 + 2
assert model.num_batches_seen == trainer.num_training_batches * 2
assert model.num_on_load_checkpoint_called == 0
# Other checkpoints can be uncommented if/when resuming mid-epoch is supported
checkpoints = Path(trainer.checkpoint_callback.dirpath).glob("*.ckpt")
if url_ckpt:
# transform local paths into url checkpoints
ip, port = tmpdir_server
checkpoints = [f"http://{ip}:{port}/" + ckpt.name for ckpt in checkpoints]
for ckpt in checkpoints:
next_model = TestModel()
state = pl_load(ckpt)
# Resume training
new_trainer = Trainer(default_root_dir=tmpdir, resume_from_checkpoint=ckpt, max_epochs=2)
new_trainer.fit(next_model)
assert state["global_step"] + next_model.num_batches_seen == trainer.num_training_batches * trainer.max_epochs
assert next_model.num_on_load_checkpoint_called == 1
def test_trainer_max_steps_and_epochs(tmpdir):
"""Verify model trains according to specified max steps"""
model = BoringModel()
num_train_samples = math.floor(len(model.train_dataloader()) * 0.5)
# define less train steps than epochs
trainer_kwargs = {
"limit_train_batches": 0.5,
"default_root_dir": tmpdir,
"max_epochs": 3,
"max_steps": num_train_samples + 10,
"logger": False,
"weights_summary": None,
"progress_bar_refresh_rate": 0,
}
trainer = Trainer(**trainer_kwargs)
trainer.fit(model)
assert trainer.state.finished, f"Training failed with {trainer.state}"
assert trainer.global_step == trainer.max_steps, "Model did not stop at max_steps"
# define less train epochs than steps
trainer_kwargs["max_epochs"] = 2
trainer_kwargs["max_steps"] = 3 * 2 * num_train_samples
trainer = Trainer(**trainer_kwargs)
trainer.fit(model)
assert trainer.state.finished, f"Training failed with {trainer.state}"
assert trainer.global_step == num_train_samples * trainer.max_epochs
assert trainer.current_epoch == trainer.max_epochs - 1, "Model did not stop at max_epochs"
def test_trainer_min_steps_and_epochs(tmpdir):
"""Verify model trains according to specified min steps"""
model = EvalModelTemplate()
num_train_samples = math.floor(len(model.train_dataloader()) * 0.5)
trainer_kwargs = {
"limit_train_batches": 0.5,
"default_root_dir": tmpdir,
# define callback for stopping the model
"callbacks": [EarlyStopping(monitor="early_stop_on", min_delta=1.0)],
"val_check_interval": 2,
"min_epochs": 1,
"max_epochs": 7,
# define less min steps than 1 epoch
"min_steps": num_train_samples // 2,
"logger": False,
"weights_summary": None,
"progress_bar_refresh_rate": 0,
}
trainer = Trainer(**trainer_kwargs)
trainer.fit(model)
assert trainer.state.finished, f"Training failed with {trainer.state}"
assert trainer.current_epoch > 0
assert trainer.global_step >= num_train_samples, "Model did not train for at least min_epochs"
# define less epochs than min_steps
trainer_kwargs["min_steps"] = math.floor(num_train_samples * 1.5)
trainer = Trainer(**trainer_kwargs)
trainer.fit(model)
assert trainer.state.finished, f"Training failed with {trainer.state}"
assert trainer.current_epoch > 0
assert trainer.global_step >= math.floor(num_train_samples * 1.5), "Model did not train for at least min_steps"
def test_trainer_min_steps_and_min_epochs_not_reached(tmpdir, caplog):
"""Test that min_epochs/min_steps in Trainer are enforced even if EarlyStopping is triggered."""
class TestModel(BoringModel):
training_step_invoked = 0
def training_step(self, batch, batch_idx):
output = super().training_step(batch, batch_idx)
output["loss"] = output["loss"] * 0.0 # force minimal loss to trigger early stopping
self.log("loss", output["loss"])
self.training_step_invoked += 1
assert not self.trainer.should_stop
return output
model = TestModel()
early_stop = EarlyStopping(monitor="loss", patience=0, check_on_train_epoch_end=True)
min_epochs = 5
trainer = Trainer(
default_root_dir=tmpdir,
progress_bar_refresh_rate=0,
min_epochs=min_epochs,
limit_val_batches=0,
limit_train_batches=2,
callbacks=[early_stop],
)
with caplog.at_level(logging.INFO, logger="pytorch_lightning.trainer.trainer"):
trainer.fit(model)
message = f"minimum epochs ({min_epochs}) or minimum steps (None) has not been met. Training will continue"
num_messages = sum(1 for record in caplog.records if message in record.message)
assert num_messages == min_epochs - 2
assert model.training_step_invoked == min_epochs * 2
def test_trainer_max_steps_accumulate_batches(tmpdir):
"""Verify model trains according to specified max steps with grad accumulated batches"""
model = BoringModel()
num_train_samples = math.floor(len(model.train_dataloader()) * 0.5)
# define less train steps than epochs
trainer = Trainer(
limit_train_batches=0.5,
default_root_dir=tmpdir,
max_steps=num_train_samples + 10,
accumulate_grad_batches=10,
logger=False,
weights_summary=None,
progress_bar_refresh_rate=0,
)
trainer.fit(model)
assert trainer.state.finished, f"Training failed with {trainer.state}"
assert trainer.global_step == trainer.max_steps, "Model did not stop at max_steps"
def test_benchmark_option(tmpdir):
"""Verify benchmark option."""
model = EvalModelTemplate()
model.val_dataloader = model.val_dataloader__multiple
# verify torch.backends.cudnn.benchmark is not turned on
assert not torch.backends.cudnn.benchmark
# fit model
trainer = Trainer(default_root_dir=tmpdir, max_epochs=1, benchmark=True)
trainer.fit(model)
# verify training completed
assert trainer.state.finished, f"Training failed with {trainer.state}"
# verify torch.backends.cudnn.benchmark is not turned off
assert torch.backends.cudnn.benchmark
@pytest.mark.parametrize("ckpt_path", (None, "best", "specific"))
@pytest.mark.parametrize("save_top_k", (-1, 0, 1, 2))
@pytest.mark.parametrize("fn", ("validate", "test", "predict"))
def test_tested_checkpoint_path(tmpdir, ckpt_path, save_top_k, fn):
class TestModel(BoringModel):
def validation_step(self, batch, batch_idx):
self.log("foo", -batch_idx)
return super().validation_step(batch, batch_idx)
def test_step(self, *args):
return self.validation_step(*args)
def predict_step(self, batch, *_):
return self(batch)
model = TestModel()
model.test_epoch_end = None
trainer = Trainer(
max_epochs=2,
limit_val_batches=1,
limit_test_batches=1,
limit_predict_batches=1,
progress_bar_refresh_rate=0,
default_root_dir=tmpdir,
callbacks=[ModelCheckpoint(monitor="foo", save_top_k=save_top_k)],
)
trainer.fit(model)
trainer_fn = getattr(trainer, fn)
path_attr = f"{fn}{'d' if fn == 'validate' else 'ed'}_ckpt_path"
assert getattr(trainer, path_attr) is None
if ckpt_path == "best":
# ckpt_path is 'best', meaning we load the best weights
if save_top_k == 0:
with pytest.raises(MisconfigurationException, match=".*is not configured to save the best.*"):
trainer_fn(ckpt_path=ckpt_path)
with pytest.raises(MisconfigurationException, match=".*is not configured to save the best.*"):
trainer_fn(model, ckpt_path=ckpt_path)
else:
trainer_fn(ckpt_path=ckpt_path)
assert getattr(trainer, path_attr) == trainer.checkpoint_callback.best_model_path
trainer_fn(model, ckpt_path=ckpt_path)
assert getattr(trainer, path_attr) == trainer.checkpoint_callback.best_model_path
elif ckpt_path is None:
# ckpt_path is None, meaning we don't load any checkpoints and use the provided model
trainer_fn(model, ckpt_path=ckpt_path)
assert getattr(trainer, path_attr) is None
if save_top_k > 0:
# ckpt_path is None with no model provided means load the best weights
with pytest.warns(UserWarning, match="The best model of the previous `fit` call will be used"):
trainer_fn(ckpt_path=ckpt_path)
assert getattr(trainer, path_attr) == trainer.checkpoint_callback.best_model_path
else:
# specific checkpoint, pick one from saved ones
if save_top_k == 0:
with pytest.raises(FileNotFoundError):
trainer_fn(ckpt_path="random.ckpt")
else:
ckpt_path = str(
list((Path(tmpdir) / f"lightning_logs/version_{trainer.logger.version}/checkpoints").iterdir())[
0
].absolute()
)
trainer_fn(ckpt_path=ckpt_path)
assert getattr(trainer, path_attr) == ckpt_path
trainer_fn(model, ckpt_path=ckpt_path)
assert getattr(trainer, path_attr) == ckpt_path
def test_disabled_training(tmpdir):
"""Verify that `limit_train_batches=0` disables the training loop unless `fast_dev_run=True`."""
class CurrentModel(BoringModel):
training_step_invoked = False
training_epoch_end_invoked = False
def training_step(self, *args, **kwargs):
self.training_step_invoked = True
return super().training_step(*args, **kwargs)
def training_epoch_end(self, *args, **kwargs):
self.training_epoch_end_invoked = True
return super().training_epoch_end(*args, **kwargs)
model = CurrentModel()
trainer_options = dict(
default_root_dir=tmpdir,
progress_bar_refresh_rate=0,
max_epochs=2,
limit_train_batches=0.0,
limit_val_batches=0.2,
fast_dev_run=False,
)
before_state_dict = deepcopy(model.state_dict())
trainer = Trainer(**trainer_options)
trainer.fit(model)
after_state_dict = model.state_dict()
for key in before_state_dict.keys():
assert torch.all(torch.eq(before_state_dict[key], after_state_dict[key]))
# check that limit_train_batches=0 turns off training
assert trainer.state.finished, f"Training failed with {trainer.state}"
assert trainer.current_epoch == 0
assert not model.training_step_invoked, "`training_step` should not run when `limit_train_batches=0`"
assert not model.training_epoch_end_invoked, "`training_epoch_end` should not run when `limit_train_batches=0`"
# check that limit_train_batches has no influence when fast_dev_run is turned on
model = CurrentModel()
trainer_options.update(fast_dev_run=True)
before_state_dict = deepcopy(model.state_dict())
trainer = Trainer(**trainer_options)
trainer.fit(model)
after_state_dict = model.state_dict()
for key in before_state_dict.keys():
assert not torch.all(torch.eq(before_state_dict[key], after_state_dict[key]))
assert trainer.state.finished, f"Training failed with {trainer.state}"
assert trainer.current_epoch == 0
assert model.training_step_invoked, "did not run `training_step` with `fast_dev_run=True`"
assert model.training_epoch_end_invoked, "did not run `training_epoch_end` with `fast_dev_run=True`"
def test_disabled_validation(tmpdir):
"""Verify that `limit_val_batches=0` disables the validation loop unless `fast_dev_run=True`."""
class CurrentModel(EvalModelTemplate):
validation_step_invoked = False
validation_epoch_end_invoked = False
def validation_step(self, *args, **kwargs):
self.validation_step_invoked = True
return super().validation_step(*args, **kwargs)
def validation_epoch_end(self, *args, **kwargs):
self.validation_epoch_end_invoked = True
return super().validation_epoch_end(*args, **kwargs)
hparams = EvalModelTemplate.get_default_hparams()
model = CurrentModel(**hparams)
trainer_options = dict(
default_root_dir=tmpdir,
progress_bar_refresh_rate=0,
max_epochs=2,
limit_train_batches=0.4,
limit_val_batches=0.0,
fast_dev_run=False,
)
trainer = Trainer(**trainer_options)
trainer.fit(model)
# check that limit_val_batches=0 turns off validation
assert trainer.state.finished, f"Training failed with {trainer.state}"
assert trainer.current_epoch == 1
assert not model.validation_step_invoked, "`validation_step` should not run when `limit_val_batches=0`"
assert not model.validation_epoch_end_invoked, "`validation_epoch_end` should not run when `limit_val_batches=0`"
# check that limit_val_batches has no influence when fast_dev_run is turned on
model = CurrentModel(**hparams)
trainer_options.update(fast_dev_run=True)
trainer = Trainer(**trainer_options)
trainer.fit(model)
assert trainer.state.finished, f"Training failed with {trainer.state}"
assert trainer.current_epoch == 0
assert model.validation_step_invoked, "did not run `validation_step` with `fast_dev_run=True`"
assert model.validation_epoch_end_invoked, "did not run `validation_epoch_end` with `fast_dev_run=True`"
def test_nan_loss_detection(tmpdir):
class CurrentModel(BoringModel):
test_batch_inf = 3
def training_step(self, batch, batch_idx):
output = super().training_step(batch, batch_idx)
if batch_idx == self.test_batch_inf:
if isinstance(output, dict):
output["loss"] *= torch.tensor(math.inf) # make loss infinite
else:
output /= 0
return output
model = CurrentModel()
# fit model
trainer = Trainer(default_root_dir=tmpdir, max_steps=(model.test_batch_inf + 1), terminate_on_nan=True)
with pytest.raises(ValueError, match=r".*The loss returned in `training_step` is.*"):
trainer.fit(model)
assert trainer.global_step == model.test_batch_inf
for param in model.parameters():
assert torch.isfinite(param).all()
def test_nan_params_detection(tmpdir):
class CurrentModel(BoringModel):
test_batch_nan = 3
def on_after_backward(self):
if self.global_step == self.test_batch_nan:
# simulate parameter that became nan
torch.nn.init.constant_(self.layer.bias, math.nan)
model = CurrentModel()
trainer = Trainer(default_root_dir=tmpdir, max_steps=(model.test_batch_nan + 1), terminate_on_nan=True)
with pytest.raises(ValueError, match=r".*Detected nan and/or inf values in `layer.bias`.*"):
trainer.fit(model)
assert trainer.global_step == model.test_batch_nan
# after aborting the training loop, model still has nan-valued params
params = torch.cat([param.view(-1) for param in model.parameters()])
assert not torch.isfinite(params).all()
def test_trainer_interrupted_flag(tmpdir):
"""Test the flag denoting that a user interrupted training."""
model = EvalModelTemplate()
class InterruptCallback(Callback):
def __init__(self):
super().__init__()
def on_train_batch_start(self, trainer, pl_module, batch, batch_idx, dataloader_idx):
raise KeyboardInterrupt
class HandleInterruptCallback(Callback):
def __init__(self):
super().__init__()
self.exc_info = None
def on_keyboard_interrupt(self, trainer, pl_module):
self.exc_info = sys.exc_info()
interrupt_callback = InterruptCallback()
handle_interrupt_callback = HandleInterruptCallback()
trainer = Trainer(
callbacks=[interrupt_callback, handle_interrupt_callback],
max_epochs=1,
limit_val_batches=0.1,
limit_train_batches=0.2,
progress_bar_refresh_rate=0,
logger=False,
default_root_dir=tmpdir,
)
assert not trainer.interrupted
assert handle_interrupt_callback.exc_info is None
trainer.fit(model)
assert trainer.interrupted
assert isinstance(handle_interrupt_callback.exc_info[1], KeyboardInterrupt)
def test_gradient_clipping(tmpdir):
"""
Test gradient clipping
"""
tutils.reset_seed()
model = EvalModelTemplate()
trainer = Trainer(max_steps=1, max_epochs=1, gradient_clip_val=1.0, default_root_dir=tmpdir)
old_training_step_and_backward = trainer.fit_loop.epoch_loop.batch_loop.training_step_and_backward
def training_step_and_backward(split_batch, batch_idx, opt_idx, optimizer, hiddens):
"""
wrap the forward step in a closure so second order methods work
"""
# test that gradient is clipped correctly
ret_val = old_training_step_and_backward(split_batch, batch_idx, opt_idx, optimizer, hiddens)
parameters = model.parameters()
grad_norm = torch.norm(torch.stack([torch.norm(p.grad.detach(), 2) for p in parameters]), 2)
assert (grad_norm - 1.0).abs() < 0.01, f"Gradient norm != 1.0: {grad_norm}"
return ret_val
trainer.fit_loop.epoch_loop.batch_loop.training_step_and_backward = training_step_and_backward
# for the test
model.prev_called_batch_idx = 0
trainer.fit(model)
def test_gradient_clipping_by_value(tmpdir):
"""
Test gradient clipping by value
"""
tutils.reset_seed()
model = BoringModel()
grad_clip_val = 1e-10
trainer = Trainer(
max_steps=1,
max_epochs=1,
gradient_clip_val=grad_clip_val,
gradient_clip_algorithm="value",
default_root_dir=tmpdir,
)
old_training_step_and_backward = trainer.fit_loop.epoch_loop.batch_loop.training_step_and_backward
def training_step_and_backward(split_batch, batch_idx, opt_idx, optimizer, hiddens):
"""
wrap the forward step in a closure so second order methods work
"""
# test that gradient is clipped correctly
ret_val = old_training_step_and_backward(split_batch, batch_idx, opt_idx, optimizer, hiddens)
parameters = model.parameters()
grad_max_list = [torch.max(p.grad.detach().abs()) for p in parameters]
grad_max = torch.max(torch.stack(grad_max_list))
assert (
abs(grad_max.item() - grad_clip_val) < 1e-11
), f"Gradient max value {grad_max} != grad_clip_val {grad_clip_val} ."
return ret_val
trainer.fit_loop.epoch_loop.batch_loop.training_step_and_backward = training_step_and_backward
# for the test
model.prev_called_batch_idx = 0
trainer.fit(model)
@RunIf(min_gpus=1, amp_native=True)
def test_gradient_clipping_fp16(tmpdir):
"""
Test gradient clipping with fp16
"""
tutils.reset_seed()
model = EvalModelTemplate()
trainer = Trainer(max_steps=1, max_epochs=1, precision=16, gpus=1, gradient_clip_val=1.0, default_root_dir=tmpdir)
old_training_step_and_backward = trainer.fit_loop.epoch_loop.batch_loop.training_step_and_backward
def training_step_and_backward(split_batch, batch_idx, opt_idx, optimizer, hiddens):
"""
wrap the forward step in a closure so second order methods work
"""
# test that gradient is clipped correctly
ret_val = old_training_step_and_backward(split_batch, batch_idx, opt_idx, optimizer, hiddens)
parameters = model.parameters()
grad_norm = torch.norm(torch.stack([torch.norm(p.grad.detach(), 2) for p in parameters]), 2)
assert (grad_norm - 1.0).abs() < 0.01, f"Gradient norm != 1.0: {grad_norm}"
return ret_val
trainer.fit_loop.epoch_loop.batch_loop.training_step_and_backward = training_step_and_backward
model.prev_called_batch_idx = 0
trainer.fit(model)
@RunIf(min_gpus=1, amp_native=True)
def test_gradient_clipping_by_value_fp16(tmpdir):
"""
Test gradient clipping by value with fp16
"""
tutils.reset_seed()
model = BoringModel()
grad_clip_val = 1e-10
trainer = Trainer(
max_steps=1,
max_epochs=1,
precision=16,
gpus=1,
gradient_clip_val=grad_clip_val,
gradient_clip_algorithm="value",
default_root_dir=tmpdir,
)
old_training_step_and_backward = trainer.fit_loop.epoch_loop.batch_loop.training_step_and_backward
def training_step_and_backward(split_batch, batch_idx, opt_idx, optimizer, hiddens):
"""
wrap the forward step in a closure so second order methods work
"""
# test that gradient is clipped correctly
ret_val = old_training_step_and_backward(split_batch, batch_idx, opt_idx, optimizer, hiddens)
parameters = model.parameters()
grad_max_list = [torch.max(p.grad.detach().abs()) for p in parameters]
grad_max = torch.max(torch.stack(grad_max_list))
assert (
abs(grad_max.item() - grad_clip_val) < 1e-11
), f"Gradient max value {grad_max} != grad_clip_val {grad_clip_val} ."
return ret_val
trainer.fit_loop.epoch_loop.batch_loop.training_step_and_backward = training_step_and_backward
model.prev_called_batch_idx = 0
trainer.fit(model)
def test_gpu_choice(tmpdir):
trainer_options = dict(default_root_dir=tmpdir)
# Only run if CUDA is available
if not torch.cuda.is_available():
return
num_gpus = torch.cuda.device_count()
Trainer(**trainer_options, gpus=num_gpus, auto_select_gpus=True)
with pytest.raises(RuntimeError, match=r".*No GPUs available.*"):
Trainer(**trainer_options, gpus=num_gpus + 1, auto_select_gpus=True)
@pytest.mark.parametrize("limit_val_batches", [0.0, 1, 1.0, 0.5, 5])
def test_num_sanity_val_steps(tmpdir, limit_val_batches):
"""
Test that the number of sanity check batches is clipped to `limit_val_batches`.
"""
model = EvalModelTemplate()
model.validation_step = model.validation_step__multiple_dataloaders
model.validation_epoch_end = model.validation_epoch_end__multiple_dataloaders
num_sanity_val_steps = 4
trainer = Trainer(
default_root_dir=tmpdir,
num_sanity_val_steps=num_sanity_val_steps,
limit_val_batches=limit_val_batches,
max_steps=1,
)
assert trainer.num_sanity_val_steps == num_sanity_val_steps
with patch.object(
trainer.fit_loop.epoch_loop.val_loop.epoch_loop,
"evaluation_step",
wraps=trainer.fit_loop.epoch_loop.val_loop.epoch_loop.evaluation_step,
) as mocked:
val_dataloaders = model.val_dataloader__multiple_mixed_length()
trainer.fit(model, val_dataloaders=val_dataloaders)
assert mocked.call_count == sum(
min(num_sanity_val_steps, num_batches) for num_batches in trainer.num_val_batches
)
@pytest.mark.parametrize("limit_val_batches", [0.0, 1, 1.0, 0.3])
def test_num_sanity_val_steps_neg_one(tmpdir, limit_val_batches):
"""
Test that `num_sanity_val_steps=-1` runs through all validation data once, and as many batches as
limited by `limit_val_batches` Trainer argument.
"""
model = EvalModelTemplate()
model.validation_step = model.validation_step__multiple_dataloaders
model.validation_epoch_end = model.validation_epoch_end__multiple_dataloaders
trainer = Trainer(
default_root_dir=tmpdir, num_sanity_val_steps=-1, limit_val_batches=limit_val_batches, max_steps=1
)
assert trainer.num_sanity_val_steps == float("inf")
with patch.object(
trainer.fit_loop.epoch_loop.val_loop.epoch_loop,
"evaluation_step",
wraps=trainer.fit_loop.epoch_loop.val_loop.epoch_loop.evaluation_step,
) as mocked:
val_dataloaders = model.val_dataloader__multiple()
trainer.fit(model, val_dataloaders=val_dataloaders)
assert mocked.call_count == sum(trainer.num_val_batches)
@pytest.mark.parametrize(
"trainer_kwargs,expected",
[
(
dict(accelerator=None, gpus=None),
dict(_distrib_type=None, _device_type=DeviceType.CPU, num_gpus=0, num_processes=1),
),
(
dict(accelerator="dp", gpus=None),
dict(_distrib_type=None, _device_type=DeviceType.CPU, num_gpus=0, num_processes=1),
),
(
dict(accelerator="ddp", gpus=None),
dict(_distrib_type=None, _device_type=DeviceType.CPU, num_gpus=0, num_processes=1),
),
(
dict(accelerator="ddp", num_processes=2, gpus=None),
dict(_distrib_type=DistributedType.DDP, _device_type=DeviceType.CPU, num_gpus=0, num_processes=2),
),
(
dict(accelerator="ddp", num_nodes=2, gpus=None),
dict(_distrib_type=DistributedType.DDP, _device_type=DeviceType.CPU, num_gpus=0, num_processes=1),
),
(
dict(accelerator="ddp_cpu", num_processes=2, gpus=None),
dict(_distrib_type=DistributedType.DDP_SPAWN, _device_type=DeviceType.CPU, num_gpus=0, num_processes=2),
),
(
dict(accelerator="ddp2", gpus=None),
dict(_distrib_type=None, _device_type=DeviceType.CPU, num_gpus=0, num_processes=1),
),
(
dict(accelerator=None, gpus=1),
dict(_distrib_type=None, _device_type=DeviceType.GPU, num_gpus=1, num_processes=1),
),
(
dict(accelerator="dp", gpus=1),
dict(_distrib_type=DistributedType.DP, _device_type=DeviceType.GPU, num_gpus=1, num_processes=1),
),
(
dict(accelerator="ddp", gpus=1),
dict(_distrib_type=DistributedType.DDP, _device_type=DeviceType.GPU, num_gpus=1, num_processes=1),
),
(
dict(accelerator="ddp_cpu", num_processes=2, gpus=1),
dict(_distrib_type=DistributedType.DDP_SPAWN, _device_type=DeviceType.CPU, num_gpus=0, num_processes=2),
),
(
dict(accelerator="ddp2", gpus=1),
dict(_distrib_type=DistributedType.DDP2, _device_type=DeviceType.GPU, num_gpus=1, num_processes=1),
),
(
dict(accelerator=None, gpus=2),
dict(_distrib_type=DistributedType.DDP_SPAWN, _device_type=DeviceType.GPU, num_gpus=2, num_processes=2),
),
(
dict(accelerator="dp", gpus=2),
dict(_distrib_type=DistributedType.DP, _device_type=DeviceType.GPU, num_gpus=2, num_processes=1),
),
(
dict(accelerator="ddp", gpus=2),
dict(_distrib_type=DistributedType.DDP, _device_type=DeviceType.GPU, num_gpus=2, num_processes=2),
),
(
dict(accelerator="ddp2", gpus=2),
dict(_distrib_type=DistributedType.DDP2, _device_type=DeviceType.GPU, num_gpus=2, num_processes=1),
),
(
dict(accelerator="ddp2", num_processes=2, gpus=None),
dict(_distrib_type=DistributedType.DDP, _device_type=DeviceType.CPU, num_gpus=0, num_processes=2),
),
(
dict(accelerator="dp", num_processes=2, gpus=None),
dict(_distrib_type=DistributedType.DDP, _device_type=DeviceType.CPU, num_gpus=0, num_processes=2),
),
],
)
def test_trainer_config(trainer_kwargs, expected, monkeypatch):
if trainer_kwargs["gpus"] is not None:
monkeypatch.setattr(torch.cuda, "is_available", lambda: True)
monkeypatch.setattr(torch.cuda, "device_count", lambda: trainer_kwargs["gpus"])
trainer = Trainer(**trainer_kwargs)
assert len(expected) == 4
for k, v in expected.items():
assert getattr(trainer, k) == v, f"Failed {k}: {v}"
def test_trainer_subclassing():
model = EvalModelTemplate()
# First way of pulling out args from signature is to list them
class TrainerSubclass(Trainer):
def __init__(self, custom_arg, *args, custom_kwarg="test", **kwargs):
super().__init__(*args, **kwargs)
self.custom_arg = custom_arg
self.custom_kwarg = custom_kwarg
trainer = TrainerSubclass(123, custom_kwarg="custom", fast_dev_run=True)
trainer.fit(model)
assert trainer.state.finished, f"Training failed with {trainer.state}"
assert trainer.custom_arg == 123
assert trainer.custom_kwarg == "custom"
assert trainer.fast_dev_run
# Second way is to pop from the dict
# It's a special case because Trainer does not have any positional args
class TrainerSubclass(Trainer):
def __init__(self, **kwargs):
self.custom_arg = kwargs.pop("custom_arg", 0)
self.custom_kwarg = kwargs.pop("custom_kwarg", "test")
super().__init__(**kwargs)
trainer = TrainerSubclass(custom_kwarg="custom", fast_dev_run=True)
trainer.fit(model)
assert trainer.state.finished, f"Training failed with {trainer.state}"
assert trainer.custom_kwarg == "custom"
assert trainer.fast_dev_run
# when we pass in an unknown arg, the base class should complain
with pytest.raises(TypeError, match=r"__init__\(\) got an unexpected keyword argument 'abcdefg'"):
TrainerSubclass(abcdefg="unknown_arg")
@pytest.mark.parametrize(
"trainer_params", [OmegaConf.create(dict(max_epochs=1, gpus=1)), OmegaConf.create(dict(max_epochs=1, gpus=[0]))]
)
@RunIf(min_gpus=1)
def test_trainer_omegaconf(trainer_params):
Trainer(**trainer_params)
def test_trainer_pickle(tmpdir):
trainer = Trainer(max_epochs=1, default_root_dir=tmpdir)
pickle.dumps(trainer)
cloudpickle.dumps(trainer)
@pytest.mark.parametrize("stage", ("fit", "validate", "test"))
def test_trainer_setup_call(tmpdir, stage):
"""Test setup call gets the correct stage"""
class CurrentModel(BoringModel):
def setup(self, stage):
self.stage = stage
class TrainerSubclass(Trainer):
def setup(self, model, stage):
assert model is not None
self.stage = stage
model = CurrentModel()
# fit model
trainer = TrainerSubclass(default_root_dir=tmpdir, max_epochs=1, checkpoint_callback=False)
if stage == "fit":
trainer.fit(model)
elif stage == "validate":
trainer.validate(model)
else:
trainer.test(model)
assert trainer.stage == stage
assert trainer.lightning_module.stage == stage
@pytest.mark.parametrize("train_batches, max_steps, log_interval", [(10, 10, 1), (3, 10, 1), (3, 10, 5)])
@patch("pytorch_lightning.loggers.tensorboard.TensorBoardLogger.log_metrics")
def test_log_every_n_steps(log_metrics_mock, tmpdir, train_batches, max_steps, log_interval):
class TestModel(BoringModel):
def training_step(self, *args, **kwargs):
self.log("foo", -1)
return super().training_step(*args, **kwargs)
model = TestModel()
trainer = Trainer(
default_root_dir=tmpdir,
log_every_n_steps=log_interval,
flush_logs_every_n_steps=log_interval,
limit_train_batches=train_batches,
limit_val_batches=0,
max_steps=max_steps,
)
trainer.fit(model)
expected_calls = [call(metrics=ANY, step=s) for s in range(log_interval - 1, max_steps, log_interval)]
log_metrics_mock.assert_has_calls(expected_calls)
class TestLightningDataModule(LightningDataModule):
def __init__(self, dataloaders):
super().__init__()
self._dataloaders = dataloaders
def test_dataloader(self):
return self._dataloaders
def predict_dataloader(self):
return self._dataloaders
class CustomPredictionWriter(BasePredictionWriter):
write_on_batch_end_called = False
write_on_epoch_end_called = False
def __init__(self, output_dir: str, *args, **kwargs):
super().__init__(*args, **kwargs)
self.output_dir = output_dir
def write_on_batch_end(self, trainer, pl_module, prediction, batch_indices, *args, **kwargs):
assert prediction.shape == torch.Size([1, 2])
if trainer.accelerator_connector.is_distributed:
assert len(batch_indices) == 1
else:
assert batch_indices is None
self.write_on_batch_end_called = True
def write_on_epoch_end(self, trainer, pl_module, predictions, batch_indices):
expected = 1 if trainer.accelerator_connector.is_distributed else 2
assert len(predictions) == 2
assert len(predictions[0]) == expected
if trainer.accelerator_connector.is_distributed:
assert len(batch_indices) == 2
assert len(batch_indices[0]) == expected
else:
assert batch_indices is None
self.write_on_epoch_end_called = True
def on_predict_epoch_end(self, trainer, pl_module, outputs):
if trainer.accelerator_connector.is_distributed:
for idx in range(2):
assert isinstance(trainer.predict_dataloaders[idx].batch_sampler.sampler, UnrepeatedDistributedSampler)
assert isinstance(trainer.predict_dataloaders[idx].batch_sampler, IndexBatchSamplerWrapper)
super().on_predict_epoch_end(trainer, pl_module, outputs)
def predict(
tmpdir, accelerator, gpus, num_processes, model=None, plugins=None, datamodule=True, pbrr=None, use_callbacks=True
):
dataloaders = [torch.utils.data.DataLoader(RandomDataset(32, 2)), torch.utils.data.DataLoader(RandomDataset(32, 2))]
model = model or BoringModel()
dm = TestLightningDataModule(dataloaders)
cb = CustomPredictionWriter(tmpdir, write_interval="batch")
cb_1 = CustomPredictionWriter(tmpdir, write_interval="epoch")
trainer = Trainer(
default_root_dir=tmpdir,
max_epochs=1,
log_every_n_steps=1,
weights_summary=None,
accelerator=accelerator,
gpus=gpus,
num_processes=num_processes,
plugins=plugins,
progress_bar_refresh_rate=pbrr,
callbacks=[cb, cb_1] if use_callbacks else [],
)
if accelerator == "ddp_spawn":
with pytest.raises(MisconfigurationException):
trainer.predict(model, datamodule=dm, return_predictions=True)
if datamodule:
results = trainer.predict(model, datamodule=dm)
else:
results = trainer.predict(model, dataloaders=dataloaders)
if not isinstance(trainer.training_type_plugin, DDPSpawnPlugin):
if use_callbacks:
assert cb.write_on_batch_end_called
assert not cb.write_on_epoch_end_called
assert not cb_1.write_on_batch_end_called
assert cb_1.write_on_epoch_end_called
num_samples = 1 if accelerator == "ddp" else 2
assert len(results) == 2
assert len(results[0]) == num_samples
assert results[0][0].shape == torch.Size([1, 2])
def test_trainer_predict_no_return(tmpdir):
"""
Test trainer.predict warns when nothing is returned
"""
class CustomBoringModel(BoringModel):
def predict_step(self, batch, batch_idx, dataloader_idx=None):
if (batch_idx + 1) % 2 == 0:
return
return super().predict_step(batch, batch_idx, dataloader_idx)
with pytest.warns(UserWarning, match="predict returned None"):
predict(tmpdir, None, None, 1, model=CustomBoringModel(), use_callbacks=False)
def test_trainer_predict_grad(tmpdir):
class CustomBoringModel(BoringModel):
def predict_step(self, batch, batch_idx, dataloader_idx=None):
assert batch.expand_as(batch).grad_fn is None
return super().predict_step(batch, batch_idx, dataloader_idx)
predict(tmpdir, None, None, 1, model=CustomBoringModel(), use_callbacks=False)
x = torch.zeros(1, requires_grad=True)
assert x.expand_as(x).grad_fn is not None
@pytest.mark.parametrize("progress_bar_refresh_rate", [0, 5, None])
@pytest.mark.parametrize("datamodule", [False, True])
def test_trainer_predict_cpu(tmpdir, datamodule, progress_bar_refresh_rate):
predict(tmpdir, None, None, 1, datamodule=datamodule, pbrr=progress_bar_refresh_rate)
@RunIf(min_gpus=2, special=True)
@pytest.mark.parametrize("num_gpus", [1, 2])
def test_trainer_predict_dp(tmpdir, num_gpus):
predict(tmpdir, "dp", num_gpus, None)
@RunIf(min_gpus=2, special=True, fairscale=True)
def test_trainer_predict_ddp(tmpdir):
predict(tmpdir, "ddp", 2, None)
@RunIf(min_gpus=2, skip_windows=True, special=True)
def test_trainer_predict_ddp_spawn(tmpdir):
predict(tmpdir, "ddp_spawn", 2, None)
@RunIf(min_gpus=2, special=True)
def test_trainer_predict_1_gpu(tmpdir):
predict(tmpdir, None, 1, None)
@RunIf(skip_windows=True)
def test_trainer_predict_ddp_cpu(tmpdir):
predict(tmpdir, "ddp_cpu", 0, 2)
@patch("torch.cuda.device_count", return_value=2)
@patch("torch.cuda.is_available", return_value=True)
def test_spawn_predict_return_predictions(*_):
"""
Test that `return_predictions=True` raise a MisconfigurationException with spawn training type plugins.
"""
model = BoringModel()
def run(expected_plugin, **trainer_kwargs):
trainer = Trainer(**trainer_kwargs, fast_dev_run=True)
assert isinstance(trainer.training_type_plugin, expected_plugin)
with pytest.raises(MisconfigurationException, match="`return_predictions` should be set to `False`"):
trainer.predict(model, dataloaders=model.train_dataloader(), return_predictions=True)
run(DDPSpawnPlugin, accelerator="ddp_spawn", gpus=2)
run(DDPSpawnPlugin, accelerator="ddp_cpu", num_processes=2)
@pytest.mark.parametrize("return_predictions", [None, False, True])
@pytest.mark.parametrize("precision", [32, 64])
def test_predict_return_predictions_cpu(return_predictions, precision, tmpdir):
"""
Test that `return_predictions=True`.
"""
seed_everything(42)
model = BoringModel()
trainer = Trainer(default_root_dir=tmpdir, fast_dev_run=True, precision=precision)
preds = trainer.predict(model, dataloaders=model.train_dataloader(), return_predictions=return_predictions)
if return_predictions or return_predictions is None:
assert len(preds) == 1
assert preds[0].shape == torch.Size([1, 2])
assert preds[0].dtype == (torch.float64 if precision == 64 else torch.float32)
@pytest.mark.parametrize(
["limit_train_batches", "global_step", "num_training_batches", "current_epoch", "should_train"],
[(0.2, 0, 0, 0, False), (0.5, 10, 2, 4, True)],
)
def test_disabled_training_for_insufficient_limit_train_batches(
tmpdir, limit_train_batches, global_step, num_training_batches, current_epoch, should_train
):
"""
Verify when `limit_train_batches` is float & between [0.0, 1.0] and
`int(self.num_training_batches * self.limit_train_batches) == 0`, the training loop is disabled.
"""
class CurrentModel(BoringModel):
training_step_invoked = False
training_epoch_end_invoked = False
def training_step(self, *args, **kwargs):
self.training_step_invoked = True
return super().training_step(*args, **kwargs)
def training_epoch_end(self, *args, **kwargs):
self.training_epoch_end_invoked = True
return super().training_epoch_end(*args, **kwargs)
dataset_len = 100
batch_size = 25
train = RandomDataset(32, length=dataset_len)
train_loader = DataLoader(train, batch_size=batch_size)
model = CurrentModel()
trainer = Trainer(default_root_dir=tmpdir, max_epochs=5, limit_train_batches=limit_train_batches)
trainer.fit(model, train_loader)
params_string = f"""`limit_train_batches={limit_train_batches}`, `dataset_len={dataset_len}`
& `batch_size={batch_size}` as
`num_training_batches={num_training_batches}`"""
if should_train:
error_string = f"should run with {params_string}"
else:
error_string = f"should not run with {params_string}"
assert trainer.state.finished, f"Training failed with {trainer.state}"
assert trainer.global_step == global_step
assert trainer.num_training_batches == num_training_batches
assert trainer.current_epoch == current_epoch
assert model.training_step_invoked == should_train, f"`training_step` {error_string}"
assert model.training_epoch_end_invoked == should_train, f"`training_epoch_end` {error_string}"
@pytest.mark.parametrize(["max_steps", "max_epochs", "global_step"], [(10, 5, 10), (20, None, 20)])
def test_repeated_fit_calls_with_max_epochs_and_steps(tmpdir, max_steps, max_epochs, global_step):
"""
Ensure that the training loop is bound by `max_steps` and
`max_epochs` for repeated calls of `trainer.fit`, and
disabled if the limit is reached
"""
dataset_len = 200
batch_size = 10
train_data = DataLoader(RandomDataset(32, dataset_len), batch_size=batch_size)
model = BoringModel()
trainer = Trainer(default_root_dir=tmpdir, max_steps=max_steps, max_epochs=max_epochs)
trainer.fit(model, train_data)
assert trainer.global_step == global_step
trainer.fit(model, train_data)
assert trainer.global_step == global_step
def test_trainer_access_in_configure_optimizers(tmpdir):
"""
Verify that the configure optimizer function can reference the trainer.
"""
class TestModel(BoringModel):
def configure_optimizers(self):
assert self.trainer is not None, "Expect to have access to the trainer within `configure_optimizers`"
train_data = torch.utils.data.DataLoader(RandomDataset(32, 64))
model = TestModel()
trainer = Trainer(default_root_dir=tmpdir, fast_dev_run=True)
trainer.fit(model, train_data)
@RunIf(min_gpus=1)
def test_setup_hook_move_to_device_correctly(tmpdir):
"""
Verify that if a user defines a layer in the setup hook function, this is moved to the correct device.
"""
class TestModel(BoringModel):
def setup(self, stage: str) -> None:
self.new_layer = torch.nn.Linear(2, 2)
def training_step(self, batch, batch_idx):
output = self.layer(batch)
# will crash if not moved to correct device
output = self.new_layer(output)
loss = self.loss(batch, output)
return {"loss": loss}
# fake data
train_data = torch.utils.data.DataLoader(RandomDataset(32, 64))
# model
model = TestModel()
trainer = Trainer(default_root_dir=tmpdir, fast_dev_run=True, gpus=1)
trainer.fit(model, train_data)
def test_train_loop_system(tmpdir):
"""
Test the following methods are called in the order in automatic optimization.
1. optimizer.step (skip when gradient accumulation)
2. model.training_step
3. optimizer.zero_grad (run when the first batch of gradient accumulation)
4. model.backward
Note that the order is NOT `training_step`->`zero_grad`->`backward`->`step`.
This is because `optimizer.step(closure)` calls `closure()` which then calls
the three remaining methods `training_step`, `zero_grad` and `backward` inside.
"""
called_methods = []
trainer_options = dict(
default_root_dir=tmpdir,
max_epochs=1,
limit_train_batches=5,
limit_val_batches=1,
limit_test_batches=1,
progress_bar_refresh_rate=0,
)
class TestOptimizer(SGD):
def step(self, *args, **kwargs):
called_methods.append("step")
return super().step(*args, **kwargs)
def zero_grad(self, *args, **kwargs):
called_methods.append("zero_grad")
return super().zero_grad(*args, **kwargs)
class TestModel(BoringModel):
def configure_optimizers(self):
return TestOptimizer(self.parameters(), lr=0.1)
def training_step(self, *args, **kwargs):
called_methods.append("training_step")
return super().training_step(*args, **kwargs)
def backward(self, *args, **kwargs):
called_methods.append("backward")
return super().backward(*args, **kwargs)
model = TestModel()
trainer = Trainer(**trainer_options)
# No methods are called yet.
assert called_methods == []
trainer.fit(model)
assert called_methods == ["step", "training_step", "zero_grad", "backward"] * trainer.limit_train_batches
called_methods.clear()
trainer = Trainer(**trainer_options, accumulate_grad_batches=3)
# No methods are called yet.
assert called_methods == []
trainer.fit(model)
assert called_methods == [
# 0
"training_step",
"zero_grad",
"backward",
# 1
"training_step",
"backward",
# 2
"step",
"training_step",
"backward",
# 3
"training_step",
"zero_grad",
"backward",
# 4
"step",
"training_step",
"backward",
]
def test_init_optimizers_resets_lightning_optimizers(tmpdir):
"""Test that the Trainer resets the `lightning_optimizers` list everytime new optimizers get initialized."""
def compare_optimizers():
assert trainer.lightning_optimizers[0].optimizer is trainer.optimizers[0]
model = BoringModel()
model.lr = 0.2
trainer = Trainer(default_root_dir=tmpdir, max_epochs=1, auto_lr_find=True)
trainer.tune(model)
compare_optimizers()
trainer.fit(model)
compare_optimizers()
trainer.fit_loop.max_epochs = 2 # simulate multiple fit calls
trainer.fit(model)
compare_optimizers()
def test_check_val_every_n_epoch_exception(tmpdir):
with pytest.raises(MisconfigurationException, match="should be an integer."):
Trainer(default_root_dir=tmpdir, max_epochs=1, check_val_every_n_epoch=1.2)
def test_trainer_attach_data_pipeline_to_model(tmpdir):
class DataPipeline:
pass
class TestDataModule(LightningDataModule):
data_pipeline = DataPipeline()
def train_dataloader(self):
return DataLoader(RandomDataset(32, 64))
def val_dataloader(self):
return DataLoader(RandomDataset(32, 64))
def test_dataloader(self):
return DataLoader(RandomDataset(32, 64))
class TestCallback(Callback):
def on_fit_start(self, trainer, pl_module: LightningModule) -> None:
"""Called when fit begins"""
assert isinstance(pl_module.data_pipeline, DataPipeline)
model = BoringModel()
dm = TestDataModule()
trainer = Trainer(default_root_dir=tmpdir, max_epochs=1, callbacks=[TestCallback()])
trainer.fit(model, datamodule=dm)
def test_exception_when_testing_or_validating_with_fast_dev_run(tmpdir):
trainer = Trainer(default_root_dir=tmpdir, fast_dev_run=True)
model = BoringModel()
trainer.fit(model)
with pytest.raises(MisconfigurationException, match=r"\.validate\(\)` with `fast_dev_run=True"):
trainer.validate()
with pytest.raises(MisconfigurationException, match=r"\.test\(\)` with `fast_dev_run=True"):
trainer.test()
class TrainerStagesModel(BoringModel):
def on_train_start(self) -> None:
assert self.trainer.model.training
assert self.training
def on_validation_start(self) -> None:
assert not self.trainer.model.training
assert not self.training
def on_test_start(self) -> None:
assert not self.trainer.model.training
assert not self.training
def on_predict_start(self) -> None:
assert not self.trainer.model.training
assert not self.training
@pytest.mark.parametrize(
"accelerator,num_processes", [(None, 1), pytest.param("ddp_cpu", 2, marks=RunIf(skip_windows=True))]
)
def test_model_in_correct_mode_during_stages(tmpdir, accelerator, num_processes):
model = TrainerStagesModel()
trainer = Trainer(default_root_dir=tmpdir, accelerator=accelerator, num_processes=num_processes, fast_dev_run=True)
trainer.fit(model)
trainer.validate(model)
trainer.test(model)
trainer.predict(model, model.val_dataloader())
class TestDummyModelForCheckpoint(BoringModel):
def validation_step(self, batch, batch_idx):
output = self.layer(batch)
loss = self.loss(batch, output)
self.log("x", loss)
def validation_epoch_end(self, outputs) -> None:
pass
@RunIf(skip_windows=True)
def test_fit_test_synchronization(tmpdir):
"""Test that the trainer synchronizes processes before returning control back to the caller."""
tutils.set_random_master_port()
model = TestDummyModelForCheckpoint()
checkpoint = ModelCheckpoint(dirpath=tmpdir, monitor="x", mode="min", save_top_k=1)
trainer = Trainer(
default_root_dir=tmpdir, max_epochs=2, accelerator="ddp_cpu", num_processes=2, callbacks=[checkpoint]
)
trainer.fit(model)
assert os.path.exists(checkpoint.best_model_path), f"Could not find checkpoint at rank {trainer.global_rank}"
trainer.test()
class CustomCallbackOnLoadCheckpoint(Callback):
def on_save_checkpoint(self, trainer, pl_module, checkpoint) -> dict:
return {"a": None}
def test_on_load_checkpoint_missing_callbacks(tmpdir):
"""Test a warning appears when callbacks in the checkpoint don't match callbacks provided when resuming."""
model = BoringModel()
chk = ModelCheckpoint(dirpath=tmpdir, save_last=True)
trainer = Trainer(default_root_dir=tmpdir, max_epochs=3, callbacks=[chk, CustomCallbackOnLoadCheckpoint()])
trainer.fit(model)
trainer = Trainer(
default_root_dir=tmpdir, max_epochs=5, resume_from_checkpoint=chk.last_model_path, progress_bar_refresh_rate=1
)
with pytest.warns(UserWarning, match="CustomCallbackOnLoadCheckpoint"):
trainer.fit(model)
def test_module_current_fx_attributes_reset(tmpdir):
"""Ensure that lightning module's attributes related to current fx are reset at the end of execution."""
model = BoringModel()
trainer = Trainer(default_root_dir=tmpdir, fast_dev_run=1, checkpoint_callback=False, logger=False)
trainer.fit(model)
assert model._current_fx_name is None
assert model._current_dataloader_idx is None
trainer.test(model)
assert model._current_fx_name is None
assert model._current_dataloader_idx is None
def test_exception_when_lightning_module_is_not_set_on_trainer():
trainer = Trainer()
with pytest.raises(MisconfigurationException, match=r"`model` must be provided.*validate"):
trainer.validate()
with pytest.raises(MisconfigurationException, match=r"`model` must be provided.*test"):
trainer.test()
with pytest.raises(MisconfigurationException, match=r"`model` must be provided.*predict"):
trainer.predict()
@RunIf(min_gpus=2, special=True)
def test_ddp_terminate_when_deadlock_is_detected(tmpdir):
"""Test that DDP kills the remaining processes when only one rank is throwing an exception."""
class CustomException(Exception):
pass
class TestModel(BoringModel):
def training_step(self, batch, batch_idx):
if batch_idx == 1 and self.trainer.is_global_zero:
# rank 0: raises an exception
# rank 1: continues training but will hang on the next barrier in the training loop
raise CustomException
return super().training_step(batch, batch_idx)
model = TestModel()
trainer = Trainer(
default_root_dir=tmpdir, max_epochs=1, limit_train_batches=5, num_sanity_val_steps=0, gpus=2, accelerator="ddp"
)
# simulate random failure in training_step on rank 0
with pytest.raises(DeadlockDetectedException, match="CustomException"):
trainer.fit(model)
@RunIf(min_gpus=1)
def test_multiple_trainer_constant_memory_allocated(tmpdir):
"""
This tests ensures calling the trainer several times reset the memory back to 0.
"""
class TestModel(BoringModel):
def training_step(self, batch, batch_idx):
loss = super().training_step(batch, batch_idx)
self.log("train_loss", loss["loss"])
return loss
def configure_optimizers(self):
return torch.optim.Adam(self.layer.parameters(), lr=0.1)
class Check(Callback):
def on_epoch_start(self, trainer, *_):
assert isinstance(trainer.training_type_plugin.model, DistributedDataParallel)
initial = torch.cuda.memory_allocated(0)
model = TestModel()
trainer_kwargs = dict(
default_root_dir=tmpdir,
fast_dev_run=True,
gpus=1,
accelerator="ddp",
progress_bar_refresh_rate=0,
callbacks=Check(),
)
trainer = Trainer(**trainer_kwargs)
trainer.fit(model)
assert trainer.training_type_plugin.model is model
assert list(trainer.optimizers[0].state.values())[0]["exp_avg_sq"].device == torch.device("cpu")
assert trainer.callback_metrics["train_loss"].device == torch.device("cpu")
# before measuring the memory force release any leftover allocations, including CUDA tensors
gc.collect()
memory_1 = torch.cuda.memory_allocated(0)
assert memory_1 == initial
deepcopy(trainer)
# before measuring the memory force release any leftover allocations, including CUDA tensors
gc.collect()
memory_2 = torch.cuda.memory_allocated(0)
assert memory_2 == initial
trainer_2 = Trainer(**trainer_kwargs)
trainer_2.fit(model)
# before measuring the memory force release any leftover allocations, including CUDA tensors
gc.collect()
memory_3 = torch.cuda.memory_allocated(0)
assert memory_3 == initial