Merge pull request #2238 from MoritzBrueckner/background-mode

Fix threading and publishing in background mode

blender/arm/handlers.py

@@ -1,5 +1,6 @@
 import importlib
 import os
+import queue
 import sys
 
 import bpy
@@ -89,19 +90,38 @@ def send_operator(op):
         else: # Rebuild
             make.patch()
 
-def always():
+
+def always() -> float:
     # Force ui redraw
-    if state.redraw_ui and context_screen != None:
+    if state.redraw_ui and context_screen is not None:
         for area in context_screen.areas:
             if area.type == 'VIEW_3D' or area.type == 'PROPERTIES':
                 area.tag_redraw()
         state.redraw_ui = False
     # TODO: depsgraph.updates only triggers material trees
     space = arm.utils.logic_editor_space(context_screen)
-    if space != None:
+    if space is not None:
         space.node_tree.arm_cached = False
     return 0.5
 
+
+def poll_threads() -> float:
+    """Polls the thread callback queue and if a thread has finished, it
+    is joined with the main thread and the corresponding callback is
+    executed in the main thread.
+    """
+    try:
+        thread, callback = make.thread_callback_queue.get(block=False)
+    except queue.Empty:
+        return 0.25
+
+    thread.join()
+    callback()
+
+    # Quickly check if another thread has finished
+    return 0.01
+
+
 appended_py_paths = []
 context_screen = None
 
@@ -181,7 +201,9 @@ def register():
     bpy.app.handlers.load_post.append(on_load_post)
     bpy.app.handlers.depsgraph_update_post.append(on_depsgraph_update_post)
     # bpy.app.handlers.undo_post.append(on_undo_post)
+
     bpy.app.timers.register(always, persistent=True)
+    bpy.app.timers.register(poll_threads, persistent=True)
 
     if arm.utils.get_fp() != '':
         appended_py_paths = []
@@ -198,6 +220,9 @@ def register():
 
 
 def unregister():
+    bpy.app.timers.unregister(poll_threads)
+    bpy.app.timers.unregister(always)
+
     bpy.app.handlers.load_post.remove(on_load_post)
     bpy.app.handlers.depsgraph_update_post.remove(on_depsgraph_update_post)
     # bpy.app.handlers.undo_post.remove(on_undo_post)

blender/arm/make.py

@@ -1,15 +1,16 @@
+import errno
 import glob
 import json
 import os
+from queue import Queue
+import shlex
 import shutil
-import time
 import stat
 import subprocess
 import threading
+import time
+from typing import Callable
 import webbrowser
-import shlex
-import errno
-import math
 
 import bpy
 
@@ -28,15 +29,42 @@ import arm.write_data as write_data
 scripts_mtime = 0 # Monitor source changes
 profile_time = 0
 
-def run_proc(cmd, done):
-    def fn(p, done):
-        p.wait()
-        if done != None:
+# Queue of threads and their done callbacks. Item format: [thread, done]
+thread_callback_queue = Queue(maxsize=0)
+
+
+def run_proc(cmd, done: Callable) -> subprocess.Popen:
+    """Creates a subprocess with the given command and returns it.
+
+    If Blender is not running in background mode, a thread is spawned
+    that waits until the subprocess has finished executing to not freeze
+    the UI, otherwise (in background mode) execution is blocked until
+    the subprocess has finished.
+
+    If `done` is not `None`, it is called afterwards in the main thread.
+    """
+    use_thread = not bpy.app.background
+
+    def wait_for_proc(proc: subprocess.Popen):
+        proc.wait()
+
+        if use_thread:
+            # Put the done callback into the callback queue so that it
+            # can be received by a polling function in the main thread
+            thread_callback_queue.put([threading.current_thread(), done], block=True)
+        else:
             done()
+
     p = subprocess.Popen(cmd)
-    threading.Thread(target=fn, args=(p, done)).start()
+
+    if use_thread:
+        threading.Thread(target=wait_for_proc, args=(p,)).start()
+    else:
+        wait_for_proc(p)
+
     return p
 
+
 def compile_shader_pass(res, raw_shaders_path, shader_name, defs, make_variants):
     os.chdir(raw_shaders_path + '/' + shader_name)
 

blender/arm/props_ui.py

@@ -626,7 +626,6 @@ class ARM_PT_ArmoryExporterPanel(bpy.types.Panel):
         row = layout.row(align=True)
         row.alignment = 'EXPAND'
         row.scale_y = 1.3
-        row.enabled = wrd.arm_exporterlist_index >= 0 and len(wrd.arm_exporterlist) > 0
         row.operator("arm.build_project", icon="MOD_BUILD")
         # row.operator("arm.patch_project")
         row.operator("arm.publish_project", icon="EXPORT")
@@ -1053,10 +1052,15 @@ class ArmoryStopButton(bpy.types.Operator):
         return{'FINISHED'}
 
 class ArmoryBuildProjectButton(bpy.types.Operator):
-    '''Build and compile project'''
+    """Build and compile project"""
     bl_idname = 'arm.build_project'
     bl_label = 'Build'
 
+    @classmethod
+    def poll(cls, context):
+        wrd = bpy.data.worlds['Arm']
+        return wrd.arm_exporterlist_index >= 0 and len(wrd.arm_exporterlist) > 0
+
     def execute(self, context):
         # Compare version Blender and Armory (major, minor)
         if not arm.utils.compare_version_blender_arm():
@@ -1093,10 +1097,15 @@ class ArmoryBuildProjectButton(bpy.types.Operator):
         return{'FINISHED'}
 
 class ArmoryPublishProjectButton(bpy.types.Operator):
-    '''Build project ready for publishing'''
+    """Build project ready for publishing."""
     bl_idname = 'arm.publish_project'
     bl_label = 'Publish'
 
+    @classmethod
+    def poll(cls, context):
+        wrd = bpy.data.worlds['Arm']
+        return wrd.arm_exporterlist_index >= 0 and len(wrd.arm_exporterlist) > 0
+
     def execute(self, context):
         # Compare version Blender and Armory (major, minor)
         if not arm.utils.compare_version_blender_arm():