Bug fix for multithreaded rendering. (openai#85)

* Bug fix. * Improvements suggested by PW.
Kallinteris-Andreas · Aug 3, 2017 · 56929b9 · 56929b9
1 parent aa82c0e
commit 56929b9
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Showing 3 changed files with 45 additions and 14 deletions.
diff --git a/mujoco_py/mjsim.pyx b/mujoco_py/mjsim.pyx
@@ -1,5 +1,8 @@
 from xml.dom import minidom
 from mujoco_py.utils import remove_empty_lines
+from threading import Lock
+
+_MjSim_render_lock = Lock()
 
 
 cdef class MjSim(object):
@@ -122,16 +125,17 @@ cdef class MjSim(object):
             camera_id = self.model.camera_name2id(camera_name)
 
         if mode == 'offscreen':
-            if self._render_context_offscreen is None:
-                render_context = MjRenderContextOffscreen(
-                    self, device_id=device_id)
-            else:
-                render_context = self._render_context_offscreen
-
-            render_context.render(
-                width=width, height=height, camera_id=camera_id)
-            return render_context.read_pixels(
-                width, height, depth=depth)
+            with _MjSim_render_lock:
+                if self._render_context_offscreen is None:
+                    render_context = MjRenderContextOffscreen(
+                        self, device_id=device_id)
+                else:
+                    render_context = self._render_context_offscreen
+
+                render_context.render(
+                    width=width, height=height, camera_id=camera_id)
+                return render_context.read_pixels(
+                    width, height, depth=depth)
         elif mode == 'window':
             if self._render_context_window is None:
                 from mujoco_py.mjviewer import MjViewer

diff --git a/mujoco_py/tests/test_cymj.py b/mujoco_py/tests/test_cymj.py
@@ -10,9 +10,7 @@
 from mujoco_py import const, cymj
 from mujoco_py.tests.utils import compare_imgs, requires_rendering
 import scipy.misc
-import os
-import shutil
-import glob
+from threading import Thread, Event
 from multiprocessing import get_context
 import sys
 
@@ -22,6 +20,7 @@
     <worldbody>
         <light name="light1" diffuse=".5 .5 .5" pos="0 0 3" dir="0 0 -1"/>
         <camera name="camera1" pos="3 0 0" zaxis="1 0 0" />
+        <camera name="camera2" pos="4 0 0" zaxis="1 0 0" />
         <geom name="geom1" pos="0.5 0.4 0.3" type="plane" size="1 1 0.1" rgba=".9 0 0 1"/>
         <body pos="0 0 1" name="body1">
             <joint name="joint1" type="free"/>
@@ -650,6 +649,34 @@ def test_sensors():
     sim.data.get_sensor("touchsensor")
 
 
+@requires_rendering
+def test_concurrent_rendering():
+    '''Best-effort testing that concurrent multi-threaded rendering works. 
+    The test has no guarantees around being deterministic, but if it fails 
+    you know something is wrong with concurrent rendering. If it passes, 
+    things are probably working.'''
+    def func(sim, event):
+        event.wait()
+        sim.data.qpos[:] = 0.0
+        sim.forward()
+        img1 = sim.render(width=40, height=40, camera_name="camera1")
+        assert np.sum(img1[:]) == 23255
+        img2 = sim.render(width=40, height=40, camera_name="camera2")
+        assert np.sum(img2[:]) == 12007
+
+    model = load_model_from_xml(BASIC_MODEL_XML)
+    sim = MjSim(model)
+    sim.render(100, 100)
+    event = Event()
+    threads = []
+    for _ in range(100):
+        thread = Thread(target=func, args=(sim, event))
+        threads.append(thread)
+        thread.start()
+    event.set()
+    for thread in threads:
+        thread.join()
+
 @requires_rendering
 def test_high_res():
     model = load_model_from_xml(BASIC_MODEL_XML)

diff --git a/mujoco_py/version.py b/mujoco_py/version.py
@@ -1,6 +1,6 @@
 __all__ = ['__version__', 'get_version']
 
-version_info = (1, 50, 1, 12)
+version_info = (1, 50, 1, 14)
 # format:
 # ('mujoco_major', 'mujoco_minor', 'mujoco_py_major', 'mujoco_py_minor')