[AutoScheduler] Propogate global autotvm state to PopenPool workers (#…

…8913)

* [AutoScheduler] Propogate global autotvm state to PopenPool workers

* Fix

* lint

python/tvm/auto_scheduler/measure.py

@@ -43,6 +43,7 @@
 from tvm.driver import build_module
 from tvm.ir import transform
 from tvm.autotvm.measure.measure_methods import set_cuda_target_arch
+from tvm.autotvm.env import AutotvmGlobalScope, reset_global_scope
 from tvm.contrib import tar, ndk
 from tvm.contrib.popen_pool import PopenWorker, PopenPoolExecutor, StatusKind
 from tvm.target import Target
@@ -692,7 +693,9 @@ def local_builder_build(inputs, timeout, n_parallel, build_func="default", verbo
     res : List[BuildResult]
         The build results of these MeasureInputs.
     """
-    executor = PopenPoolExecutor(n_parallel, timeout)
+    executor = PopenPoolExecutor(
+        n_parallel, timeout, reset_global_scope, (AutotvmGlobalScope.current,)
+    )
     tuple_res = executor.map_with_error_catching(
         local_build_worker,
         [

python/tvm/autotvm/env.py

@@ -30,3 +30,10 @@ def __init__(self):
 
 
 GLOBAL_SCOPE = AutotvmGlobalScope()
+
+
+def reset_global_scope(global_scope):
+    """Reset global autotvm state. This is needed to initialize PopenPool workers."""
+    global GLOBAL_SCOPE
+    GLOBAL_SCOPE = global_scope
+    AutotvmGlobalScope.current = global_scope