From 619620c6720435f8848aff01c1e747df934f6ee1 Mon Sep 17 00:00:00 2001
From: jonson <jonson@dajodi.com>
Date: Sat, 2 May 2020 14:55:12 -0400
Subject: [PATCH] Initialize thread local value on each thread

---
 btalib/indicator.py     |  2 +-
 btalib/meta/lines.py    |  4 ++--
 btalib/meta/metadata.py | 19 ++++++++++++++++++-
 3 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/btalib/indicator.py b/btalib/indicator.py
index 7cc6abc..4417ff2 100644
--- a/btalib/indicator.py
+++ b/btalib/indicator.py
@@ -16,7 +16,7 @@
 ]
 
 
-metadata.callstack = []  # keep indicators which are currently being executed
+metadata.register('callstack', list) # keep indicators which are currently being executed
 
 
 _NAMES_IND = {}
diff --git a/btalib/meta/lines.py b/btalib/meta/lines.py
index 3c501c8..d4f2a04 100644
--- a/btalib/meta/lines.py
+++ b/btalib/meta/lines.py
@@ -607,8 +607,8 @@ def _applymulti(self, func, *args, raw=False, **kwargs):
 # instances, to avoid having them declared as attributes. Or else __setattr__
 # would set them as Line objects (or logic would be needed in __setattr__ to
 # avoid assigning an object not the real value
-metadata.minperiods = {}
-metadata.minperiod = {}
+metadata.register('minperiods', dict)
+metadata.register('minperiod', dict)
 
 
 class Lines:
diff --git a/btalib/meta/metadata.py b/btalib/meta/metadata.py
index 4180a6a..0a54fbb 100644
--- a/btalib/meta/metadata.py
+++ b/btalib/meta/metadata.py
@@ -8,4 +8,21 @@
 
 __all__ = ['metadata']
 
-metadata = threading.local()
+
+class Metadata(object):
+
+    def __init__(self):
+        self._metadata = threading.local()
+
+    @classmethod
+    def register(cls, name, default=None):
+
+        def get_or_default(self):
+            if not hasattr(self._metadata, name):
+                setattr(self._metadata, name, default())
+            return getattr(self._metadata, name)
+
+        setattr(cls, name, property(get_or_default))
+
+
+metadata = Metadata()