fix multiprocess datasetpredictor

tensorpack/predict/concurrency.py

@@ -59,8 +59,8 @@ class MultiProcessQueuePredictWorker(MultiProcessPredictWorker):
         super(MultiProcessQueuePredictWorker, self).__init__(idx, config)
         self.inqueue = inqueue
         self.outqueue = outqueue
-        assert isinstance(self.inqueue, multiprocessing.Queue)
-        assert isinstance(self.outqueue, multiprocessing.Queue)
+        assert isinstance(self.inqueue, multiprocessing.queues.Queue)
+        assert isinstance(self.outqueue, multiprocessing.queues.Queue)
 
     def run(self):
         self._init_runtime()

tensorpack/predict/dataset.py

@@ -12,6 +12,8 @@ import os
 from ..dataflow import DataFlow, BatchData
 from ..dataflow.dftools import dataflow_to_process_queue
 from ..utils.concurrency import ensure_proc_terminate, OrderedResultGatherProc, DIE
+from ..utils import logger
+from ..utils.gpu import change_gpu
 
 from .concurrency import MultiProcessQueuePredictWorker
 from .common import PredictConfig
@@ -89,9 +91,9 @@ class MultiProcessDatasetPredictor(DatasetPredictorBase):
                 # TODO number of GPUs not checked
                 gpus = list(range(self.nr_proc))
         else:
-            gpus = [''] * self.nr_proc
+            gpus = ['-1'] * self.nr_proc
         self.workers = [MultiProcessQueuePredictWorker(
-                    i, gpus[i], self.inqueue, self.outqueue, self.config)
+                    i, self.inqueue, self.outqueue, self.config)
                         for i in range(self.nr_proc)]
         self.result_queue = OrderedResultGatherProc(
                 self.outqueue, nr_producer=self.nr_proc)

tensorpack/utils/gpu.py

@@ -9,7 +9,10 @@ from .utils import change_env
 __all__ = ['change_gpu', 'get_nr_gpu', 'get_gpus']
 
 def change_gpu(val):
-    return change_env('CUDA_VISIBLE_DEVICES', str(val))
+    val = str(val)
+    if val == '-1':
+        val = ''
+    return change_env('CUDA_VISIBLE_DEVICES', val)
 
 def get_nr_gpu():
     env = os.environ.get('CUDA_VISIBLE_DEVICES', None)