From 036443d020aa42e0f9352fadcd0d9e47ea0c11a5 Mon Sep 17 00:00:00 2001
From: Suyog Soti <suyog.soti@gmail.com>
Date: Tue, 30 Jul 2019 11:52:02 -0700
Subject: [PATCH 1/9] we dont need thread locks

---
 .../azure-core/azure/core/tracing/context.py  | 38 +++++--------------
 .../azure-core/tests/test_tracing_context.py  | 11 ++----
 2 files changed, 13 insertions(+), 36 deletions(-)

diff --git a/sdk/core/azure-core/azure/core/tracing/context.py b/sdk/core/azure-core/azure/core/tracing/context.py
index a00f88f2d854..f8761cd71502 100644
--- a/sdk/core/azure-core/azure/core/tracing/context.py
+++ b/sdk/core/azure-core/azure/core/tracing/context.py
@@ -29,8 +29,8 @@ class ContextProtocol(Protocol):
      Implements set and get variables in a thread safe way.
      """
 
-    def __init__(self, name, default, lock):
-        # type: (string, Any, threading.Lock) -> None
+    def __init__(self, name, default):
+        # type: (string, Any) -> None
         pass
 
     def clear(self):
@@ -54,11 +54,10 @@ class _AsyncContext(object):
     Uses contextvars to set and get variables globally in a thread safe way.
     """
 
-    def __init__(self, name, default, lock):
+    def __init__(self, name, default):
         self.name = name
         self.contextvar = contextvars.ContextVar(name)
         self.default = default if callable(default) else (lambda: default)
-        self.lock = lock
 
     def clear(self):
         # type: () -> None
@@ -78,8 +77,7 @@ def get(self):
     def set(self, value):
         # type: (Any) -> None
         """Set the value in the context."""
-        with self.lock:
-            self.contextvar.set(value)
+        self.contextvar.set(value)
 
 
 class _ThreadLocalContext(object):
@@ -88,11 +86,10 @@ class _ThreadLocalContext(object):
     """
     _thread_local = threading.local()
 
-    def __init__(self, name, default, lock):
-        # type: (str, Any, threading.Lock) -> None
+    def __init__(self, name, default):
+        # type: (str, Any) -> None
         self.name = name
         self.default = default if callable(default) else (lambda: default)
-        self.lock = lock
 
     def clear(self):
         # type: () -> None
@@ -112,16 +109,14 @@ def get(self):
     def set(self, value):
         # type: (Any) -> None
         """Set the value in the context."""
-        with self.lock:
-            setattr(self._thread_local, self.name, value)
+        setattr(self._thread_local, self.name, value)
 
 
-class TracingContext:
-    _lock = threading.Lock()
-
+class TracingContext(object):
     def __init__(self):
         # type: () -> None
-        self.current_span = TracingContext._get_context_class("current_span", None)
+        context_class = _AsyncContext if contextvars else _ThreadLocalContext
+        self.current_span = context_class("current_span", None)
 
     def with_current_context(self, func):
         # type: (Callable[[Any], Any]) -> Any
@@ -146,17 +141,4 @@ def call_with_current_context(*args, **kwargs):
 
         return call_with_current_context
 
-    @classmethod
-    def _get_context_class(cls, name, default_val):
-        # type: (str, Any) -> ContextProtocol
-        """
-        Returns an instance of the the context class that stores the variable.
-        :param name: The key to store the variable in the context class
-        :param default_val: The default value of the variable if unset
-        :return: An instance that implements the context protocol class
-        """
-        context_class = _AsyncContext if contextvars else _ThreadLocalContext
-        return context_class(name, default_val, cls._lock)
-
-
 tracing_context = TracingContext()
diff --git a/sdk/core/azure-core/tests/test_tracing_context.py b/sdk/core/azure-core/tests/test_tracing_context.py
index 59aa2c8a8b60..984d2ad480d3 100644
--- a/sdk/core/azure-core/tests/test_tracing_context.py
+++ b/sdk/core/azure-core/tests/test_tracing_context.py
@@ -34,19 +34,14 @@ def __exit__(self, exc_type, exc_val, exc_tb):
 
 
 class TestContext(unittest.TestCase):
-    def test_get_context_class(self):
-        with ContextHelper():
-            slot = tracing_context._get_context_class("temp", 1)
-            assert slot.get() == 1
-            slot.set(2)
-            assert slot.get() == 2
-
     def test_current_span(self):
         with ContextHelper():
-            assert tracing_context.current_span.get() is None
+            assert not tracing_context.current_span.get()
             val = mock.Mock(spec=AbstractSpan)
             tracing_context.current_span.set(val)
             assert tracing_context.current_span.get() == val
+            tracing_context.current_span.clear()
+            assert not tracing_context.current_span.get()
 
     def test_with_current_context(self):
         with ContextHelper(tracer_to_use=mock.Mock(AbstractSpan)):

From d6887e7b6cd6955d1f625c2e550731b3351c2ed0 Mon Sep 17 00:00:00 2001
From: Suyog Soti <suyog.soti@gmail.com>
Date: Tue, 30 Jul 2019 16:55:57 -0700
Subject: [PATCH 2/9] add contextvars

---
 sdk/core/azure-core/setup.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sdk/core/azure-core/setup.py b/sdk/core/azure-core/setup.py
index bdab06be195c..b11c543fcda0 100644
--- a/sdk/core/azure-core/setup.py
+++ b/sdk/core/azure-core/setup.py
@@ -62,6 +62,7 @@
     ]),
     install_requires=[
         'requests>=2.18.4',
+        'contextvars>=3.5'
     ],
     extras_require={
         ":python_version<'3.0'": ['azure-nspkg'],

From ce2904c1d77efd8dcb09648081b2c26c517a72b6 Mon Sep 17 00:00:00 2001
From: Suyog Soti <suyog.soti@gmail.com>
Date: Tue, 30 Jul 2019 17:11:42 -0700
Subject: [PATCH 3/9] fix version stuff

---
 sdk/core/azure-core/setup.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sdk/core/azure-core/setup.py b/sdk/core/azure-core/setup.py
index b11c543fcda0..e5bbaebb52c5 100644
--- a/sdk/core/azure-core/setup.py
+++ b/sdk/core/azure-core/setup.py
@@ -62,9 +62,9 @@
     ]),
     install_requires=[
         'requests>=2.18.4',
-        'contextvars>=3.5'
     ],
     extras_require={
         ":python_version<'3.0'": ['azure-nspkg'],
+        ":python_version>='3.5'": ['contextvars'],
     }
 )

From 1b688260be06d39ff3593b615cd780297e35f87a Mon Sep 17 00:00:00 2001
From: Suyog Soti <suyog.soti@gmail.com>
Date: Wed, 31 Jul 2019 13:51:22 -0700
Subject: [PATCH 4/9] mypy fixes

---
 .../azure-core/azure/core/tracing/common.py   | 20 +++++++++++++++--
 .../azure-core/azure/core/tracing/context.py  | 11 ++++++----
 .../azure/core/tracing/decorator.py           | 22 ++++++++++++++-----
 .../azure/core/tracing/decorator_async.py     | 22 ++++++++++++++-----
 .../azure/core/tracing/ext/opencensus_span.py |  2 +-
 5 files changed, 58 insertions(+), 19 deletions(-)

diff --git a/sdk/core/azure-core/azure/core/tracing/common.py b/sdk/core/azure-core/azure/core/tracing/common.py
index b0e425a14d10..8b024cf1d105 100644
--- a/sdk/core/azure-core/azure/core/tracing/common.py
+++ b/sdk/core/azure-core/azure/core/tracing/common.py
@@ -36,11 +36,27 @@
     TYPE_CHECKING = False
 
 if TYPE_CHECKING:
-    from typing import Any, Optional
+    from typing import Any, Optional, Union, Callable
+
+
+def get_function_and_class_name(func, *args):
+    # type: (Callable, List[Any]) -> str
+    """
+    Given a function and its unamed arguments, returns class_name.function_name. It assumes the first argument
+    is `self`. If there are no arguments then it only returns the function name.
+
+    :param func: the function passed in
+    :type func: `collections.abc.Callable`
+    :param args: List of arguments passed into the function
+    :type args: List[Any]
+    """
+    if args:
+        return "{}.{}".format(args[0].__class_.__name__, func.__name__) # pylint: disable=protected-access
+    return func.__name__
 
 
 def set_span_contexts(wrapped_span, span_instance=None):
-    # type: (AbstractSpan, Optional[AbstractSpan]) -> None
+    # type: (Union[AbstractSpan, None], Optional[AbstractSpan]) -> None
     """
     Set the sdk context and the implementation context. `span_instance` will be used to set the implementation context
     if passed in else will use `wrapped_span.span_instance`.
diff --git a/sdk/core/azure-core/azure/core/tracing/context.py b/sdk/core/azure-core/azure/core/tracing/context.py
index f8761cd71502..e27b8e4ce82e 100644
--- a/sdk/core/azure-core/azure/core/tracing/context.py
+++ b/sdk/core/azure-core/azure/core/tracing/context.py
@@ -29,8 +29,8 @@ class ContextProtocol(Protocol):
      Implements set and get variables in a thread safe way.
      """
 
-    def __init__(self, name, default):
-        # type: (string, Any) -> None
+    def __init__(self, name, default):  # pylint: disable=super-init-not-called
+        # type: (str, Any) -> None
         pass
 
     def clear(self):
@@ -55,8 +55,9 @@ class _AsyncContext(object):
     """
 
     def __init__(self, name, default):
+        # type: (str, Any) -> None
         self.name = name
-        self.contextvar = contextvars.ContextVar(name)
+        self.contextvar = contextvars.ContextVar(name)  # type: contextvars.ContextVar
         self.default = default if callable(default) else (lambda: default)
 
     def clear(self):
@@ -84,6 +85,7 @@ class _ThreadLocalContext(object):
     """
     Uses thread local storage to set and get variables globally in a thread safe way.
     """
+
     _thread_local = threading.local()
 
     def __init__(self, name, default):
@@ -115,7 +117,7 @@ def set(self, value):
 class TracingContext(object):
     def __init__(self):
         # type: () -> None
-        context_class = _AsyncContext if contextvars else _ThreadLocalContext
+        context_class = _AsyncContext if contextvars else _ThreadLocalContext  # type: ContextProtocol
         self.current_span = context_class("current_span", None)
 
     def with_current_context(self, func):
@@ -141,4 +143,5 @@ def call_with_current_context(*args, **kwargs):
 
         return call_with_current_context
 
+
 tracing_context = TracingContext()
diff --git a/sdk/core/azure-core/azure/core/tracing/decorator.py b/sdk/core/azure-core/azure/core/tracing/decorator.py
index 3986dcaf31ed..136fafed09ec 100644
--- a/sdk/core/azure-core/azure/core/tracing/decorator.py
+++ b/sdk/core/azure-core/azure/core/tracing/decorator.py
@@ -31,15 +31,23 @@
 from azure.core.settings import settings
 from azure.core.tracing.context import tracing_context
 
+try:
+    from typing import TYPE_CHECKING
+except ImportError:
+    TYPE_CHECKING = False
+
+if TYPE_CHECKING:
+    from typing import Callable, Any
+
 
 def distributed_trace(func=None, name_of_span=None):
-    # type: (Callable[[Any], Any], str) -> Callable[[Any], Any]
+    # type: (Callable, str) -> Callable[[Any], Any]
     if func is None:
         return functools.partial(distributed_trace, name_of_span=name_of_span)
 
     @functools.wraps(func)
-    def wrapper_use_tracer(self, *args, **kwargs):
-        # type: (Any) -> Any
+    def wrapper_use_tracer(*args, **kwargs):
+        # type: (Any, Any) -> Any
         passed_in_parent = kwargs.pop("parent_span", None)
         orig_wrapped_span = tracing_context.current_span.get()
         wrapper_class = settings.tracing_implementation()
@@ -50,18 +58,20 @@ def wrapper_use_tracer(self, *args, **kwargs):
         ans = None
         if parent_span is not None and orig_wrapped_span is None:
             common.set_span_contexts(parent_span)
-            name = name_of_span or self.__class__.__name__ + "." + func.__name__
+            name = (
+                name_of_span or getattr(func, "__qualname__", None) or common.get_function_and_class_name(func, *args)
+            )
             child = parent_span.span(name=name)
             child.start()
             common.set_span_contexts(child)
-            ans = func(self, *args, **kwargs)
+            ans = func(*args, **kwargs)
             child.finish()
             common.set_span_contexts(parent_span)
             if orig_wrapped_span is None and passed_in_parent is None and original_span_instance is None:
                 parent_span.finish()
             common.set_span_contexts(orig_wrapped_span, span_instance=original_span_instance)
         else:
-            ans = func(self, *args, **kwargs)
+            ans = func(*args, **kwargs)
         return ans
 
     return wrapper_use_tracer
diff --git a/sdk/core/azure-core/azure/core/tracing/decorator_async.py b/sdk/core/azure-core/azure/core/tracing/decorator_async.py
index 4df65fee77ef..2855d91a56ff 100644
--- a/sdk/core/azure-core/azure/core/tracing/decorator_async.py
+++ b/sdk/core/azure-core/azure/core/tracing/decorator_async.py
@@ -31,15 +31,23 @@
 from azure.core.settings import settings
 from azure.core.tracing.context import tracing_context
 
+try:
+    from typing import TYPE_CHECKING
+except ImportError:
+    TYPE_CHECKING = False
+
+if TYPE_CHECKING:
+    from typing import Callable, Any
+
 
 def distributed_trace_async(func=None, name_of_span=None):
-    # type: (Callable[[Any], Any], str) -> Callable[[Any], Any]
+    # type: (Callable, str) -> Callable[[Any], Any]
     if func is None:
         return functools.partial(distributed_trace_async, name_of_span=name_of_span)
 
     @functools.wraps(func)
-    async def wrapper_use_tracer(self, *args, **kwargs):
-        # type: (Any) -> Any
+    async def wrapper_use_tracer(*args, **kwargs):
+        # type: (Any, Any) -> Any
         passed_in_parent = kwargs.pop("parent_span", None)
         orig_wrapped_span = tracing_context.current_span.get()
         wrapper_class = settings.tracing_implementation()
@@ -50,18 +58,20 @@ async def wrapper_use_tracer(self, *args, **kwargs):
         ans = None
         if parent_span is not None and orig_wrapped_span is None:
             common.set_span_contexts(parent_span)
-            name = name_of_span or self.__class__.__name__ + "." + func.__name__
+            name = (
+                name_of_span or getattr(func, "__qualname__", None) or common.get_function_and_class_name(func, *args)
+            )
             child = parent_span.span(name=name)
             child.start()
             common.set_span_contexts(child)
-            ans = await func(self, *args, **kwargs)
+            ans = await func(*args, **kwargs)
             child.finish()
             common.set_span_contexts(parent_span)
             if orig_wrapped_span is None and passed_in_parent is None and original_span_instance is None:
                 parent_span.finish()
             common.set_span_contexts(orig_wrapped_span, span_instance=original_span_instance)
         else:
-            ans = await func(self, *args, **kwargs)
+            ans = await func(*args, **kwargs)
         return ans
 
     return wrapper_use_tracer
diff --git a/sdk/core/azure-core/azure/core/tracing/ext/opencensus_span.py b/sdk/core/azure-core/azure/core/tracing/ext/opencensus_span.py
index 7aeb79c77e36..ff21dab515f8 100644
--- a/sdk/core/azure-core/azure/core/tracing/ext/opencensus_span.py
+++ b/sdk/core/azure-core/azure/core/tracing/ext/opencensus_span.py
@@ -80,7 +80,7 @@ def to_header(self):
         :return: A key value pair dictionary
         """
         tracer_from_context = self.get_current_tracer()
-        temp_headers = {}
+        temp_headers = {} # type: Dict[str, str]
         if tracer_from_context is not None:
             ctx = tracer_from_context.span_context
             try:

From 6d50311e45a28cd35573cde409615d670d1aaea4 Mon Sep 17 00:00:00 2001
From: Suyog Soti <suyog.soti@gmail.com>
Date: Wed, 31 Jul 2019 16:59:34 -0700
Subject: [PATCH 5/9] added test for get_name and moved stuff in the function

---
 sdk/core/azure-core/azure/core/tracing/common.py       |  9 ++++++---
 sdk/core/azure-core/azure/core/tracing/decorator.py    |  4 +---
 .../azure-core/azure/core/tracing/decorator_async.py   |  4 +---
 sdk/core/azure-core/tests/test_tracing_decorator.py    | 10 ++++++++++
 4 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/sdk/core/azure-core/azure/core/tracing/common.py b/sdk/core/azure-core/azure/core/tracing/common.py
index 8b024cf1d105..38490a3ef3d9 100644
--- a/sdk/core/azure-core/azure/core/tracing/common.py
+++ b/sdk/core/azure-core/azure/core/tracing/common.py
@@ -50,9 +50,12 @@ def get_function_and_class_name(func, *args):
     :param args: List of arguments passed into the function
     :type args: List[Any]
     """
-    if args:
-        return "{}.{}".format(args[0].__class_.__name__, func.__name__) # pylint: disable=protected-access
-    return func.__name__
+    try:
+        return func.__qualname__
+    except AttributeError:
+        if args:
+            return "{}.{}".format(args[0].__class_.__name__, func.__name__)  # pylint: disable=protected-access
+        return func.__name__
 
 
 def set_span_contexts(wrapped_span, span_instance=None):
diff --git a/sdk/core/azure-core/azure/core/tracing/decorator.py b/sdk/core/azure-core/azure/core/tracing/decorator.py
index 136fafed09ec..7b6ebb26cf45 100644
--- a/sdk/core/azure-core/azure/core/tracing/decorator.py
+++ b/sdk/core/azure-core/azure/core/tracing/decorator.py
@@ -58,9 +58,7 @@ def wrapper_use_tracer(*args, **kwargs):
         ans = None
         if parent_span is not None and orig_wrapped_span is None:
             common.set_span_contexts(parent_span)
-            name = (
-                name_of_span or getattr(func, "__qualname__", None) or common.get_function_and_class_name(func, *args)
-            )
+            name = name_of_span or common.get_function_and_class_name(func, *args)
             child = parent_span.span(name=name)
             child.start()
             common.set_span_contexts(child)
diff --git a/sdk/core/azure-core/azure/core/tracing/decorator_async.py b/sdk/core/azure-core/azure/core/tracing/decorator_async.py
index 2855d91a56ff..0719a9c016c3 100644
--- a/sdk/core/azure-core/azure/core/tracing/decorator_async.py
+++ b/sdk/core/azure-core/azure/core/tracing/decorator_async.py
@@ -58,9 +58,7 @@ async def wrapper_use_tracer(*args, **kwargs):
         ans = None
         if parent_span is not None and orig_wrapped_span is None:
             common.set_span_contexts(parent_span)
-            name = (
-                name_of_span or getattr(func, "__qualname__", None) or common.get_function_and_class_name(func, *args)
-            )
+            name = name_of_span or common.get_function_and_class_name(func, *args)
             child = parent_span.span(name=name)
             child.start()
             common.set_span_contexts(child)
diff --git a/sdk/core/azure-core/tests/test_tracing_decorator.py b/sdk/core/azure-core/tests/test_tracing_decorator.py
index 764c09396255..c51b87a95772 100644
--- a/sdk/core/azure-core/tests/test_tracing_decorator.py
+++ b/sdk/core/azure-core/tests/test_tracing_decorator.py
@@ -68,7 +68,17 @@ def check_name_is_different(self):
         time.sleep(0.001)
 
 
+def random_function():
+    pass
+
+
 class TestCommon(object):
+    def test_get_function_and_class_name(self):
+        with ContextHelper():
+            client = MockClient()
+            assert common.get_function_and_class_name(client.get_foo) == "MockClient.get_foo"
+            assert common.get_function_and_class_name(random_function) == "random_function"
+
     def test_set_span_context(self):
         with ContextHelper(environ={"AZURE_SDK_TRACING_IMPLEMENTATION": "opencensus"}):
             wrapper = settings.tracing_implementation()

From 15a1cef53cf842be59b096f065c94298d6319445 Mon Sep 17 00:00:00 2001
From: Suyog Soti <suyog.soti@gmail.com>
Date: Thu, 1 Aug 2019 09:44:42 -0700
Subject: [PATCH 6/9] small ci fix

---
 sdk/core/azure-core/azure/core/tracing/common.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sdk/core/azure-core/azure/core/tracing/common.py b/sdk/core/azure-core/azure/core/tracing/common.py
index 38490a3ef3d9..f245e600276f 100644
--- a/sdk/core/azure-core/azure/core/tracing/common.py
+++ b/sdk/core/azure-core/azure/core/tracing/common.py
@@ -54,7 +54,7 @@ def get_function_and_class_name(func, *args):
         return func.__qualname__
     except AttributeError:
         if args:
-            return "{}.{}".format(args[0].__class_.__name__, func.__name__)  # pylint: disable=protected-access
+            return "{}.{}".format(args[0].__class__.__name__, func.__name__)  # pylint: disable=protected-access
         return func.__name__
 
 

From 87e72261174284ccfdb19774c335a9a7ab5f8b24 Mon Sep 17 00:00:00 2001
From: Suyog Soti <suyog.soti@gmail.com>
Date: Thu, 1 Aug 2019 17:07:56 -0700
Subject: [PATCH 7/9] more mypy fixes

---
 .../azure-core/azure/core/tracing/abstract_span.py    |  2 +-
 sdk/core/azure-core/azure/core/tracing/common.py      |  4 ++--
 sdk/core/azure-core/azure/core/tracing/context.py     | 10 ++++++----
 .../azure/core/tracing/ext/opencensus_span.py         | 11 +++++------
 sdk/core/azure-core/tests/test_tracing_decorator.py   |  2 +-
 5 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/sdk/core/azure-core/azure/core/tracing/abstract_span.py b/sdk/core/azure-core/azure/core/tracing/abstract_span.py
index 9b7ca6753c0a..e5597d48df5e 100644
--- a/sdk/core/azure-core/azure/core/tracing/abstract_span.py
+++ b/sdk/core/azure-core/azure/core/tracing/abstract_span.py
@@ -17,7 +17,7 @@
 try:
     from typing_extensions import Protocol
 except ImportError:
-    Protocol = object
+    Protocol = object  # type: ignore
 
 
 class AbstractSpan(Protocol):
diff --git a/sdk/core/azure-core/azure/core/tracing/common.py b/sdk/core/azure-core/azure/core/tracing/common.py
index f245e600276f..22cea6315e73 100644
--- a/sdk/core/azure-core/azure/core/tracing/common.py
+++ b/sdk/core/azure-core/azure/core/tracing/common.py
@@ -36,7 +36,7 @@
     TYPE_CHECKING = False
 
 if TYPE_CHECKING:
-    from typing import Any, Optional, Union, Callable
+    from typing import Any, Optional, Union, Callable, List
 
 
 def get_function_and_class_name(func, *args):
@@ -77,7 +77,7 @@ def set_span_contexts(wrapped_span, span_instance=None):
 
 
 def get_parent_span(parent_span):
-    # type: (Any) -> Tuple(AbstractSpan, AbstractSpan, Any)
+    # type: (Any) -> Optional[AbstractSpan]
     """
     Returns the current span so that the function's span will be its child. It will create a new span if there is
     no current span in any of the context.
diff --git a/sdk/core/azure-core/azure/core/tracing/context.py b/sdk/core/azure-core/azure/core/tracing/context.py
index e27b8e4ce82e..ecf822bf6fd7 100644
--- a/sdk/core/azure-core/azure/core/tracing/context.py
+++ b/sdk/core/azure-core/azure/core/tracing/context.py
@@ -13,7 +13,7 @@
     TYPE_CHECKING = False
 
 if TYPE_CHECKING:
-    from typing import Any, Callable
+    from typing import Any, Callable, Optional, Type, Union
     from typing_extensions import Protocol
 else:
     Protocol = object
@@ -21,7 +21,7 @@
 try:
     import contextvars
 except ImportError:
-    contextvars = None
+    pass
 
 
 class ContextProtocol(Protocol):
@@ -117,8 +117,10 @@ def set(self, value):
 class TracingContext(object):
     def __init__(self):
         # type: () -> None
-        context_class = _AsyncContext if contextvars else _ThreadLocalContext  # type: ContextProtocol
-        self.current_span = context_class("current_span", None)
+        try:
+            self.current_span = _AsyncContext("current_span", None)  # type: Union[_AsyncContext, _ThreadLocalContext]
+        except NameError:
+            self.current_span = _ThreadLocalContext("current_span", None)
 
     def with_current_context(self, func):
         # type: (Callable[[Any], Any]) -> Any
diff --git a/sdk/core/azure-core/azure/core/tracing/ext/opencensus_span.py b/sdk/core/azure-core/azure/core/tracing/ext/opencensus_span.py
index ff21dab515f8..c1fd6eb6a4e0 100644
--- a/sdk/core/azure-core/azure/core/tracing/ext/opencensus_span.py
+++ b/sdk/core/azure-core/azure/core/tracing/ext/opencensus_span.py
@@ -5,6 +5,7 @@
 """Implements azure.core.tracing.AbstractSpan to wrap opencensus spans."""
 
 from opencensus.trace import Span, execution_context
+from opencensus.trace.tracer import Tracer
 from opencensus.trace.span import SpanKind
 from opencensus.trace.link import Link
 from opencensus.trace.propagation import trace_context_http_header_format
@@ -34,10 +35,8 @@ def __init__(self, span=None, name="span"):
         :param name: The name of the OpenCensus span to create if a new span is needed
         :type name: str
         """
-        if not span:
-            tracer = self.get_current_tracer()
-            span = tracer.start_span(name=name) # type: Span
-        self._span_instance = span
+        tracer = self.get_current_tracer()
+        self._span_instance = span or tracer.start_span(name=name)
         self._span_component = "component"
         self._http_user_agent = "http.user_agent"
         self._http_method = "http.method"
@@ -146,7 +145,7 @@ def get_current_span(cls):
 
     @classmethod
     def get_current_tracer(cls):
-        # type: () -> tracer_module.Tracer
+        # type: () -> Tracer
         """
         Get the current tracer from the execution context. Return None otherwise.
         """
@@ -165,7 +164,7 @@ def set_current_span(cls, span):
 
     @classmethod
     def set_current_tracer(cls, tracer):
-        # type: (tracer_module.Tracer) -> None
+        # type: (Tracer) -> None
         """
         Set the given tracer as the current tracer in the execution context.
         :param tracer: The tracer to set the current tracer as
diff --git a/sdk/core/azure-core/tests/test_tracing_decorator.py b/sdk/core/azure-core/tests/test_tracing_decorator.py
index c51b87a95772..5c5a1df7b9e6 100644
--- a/sdk/core/azure-core/tests/test_tracing_decorator.py
+++ b/sdk/core/azure-core/tests/test_tracing_decorator.py
@@ -76,7 +76,7 @@ class TestCommon(object):
     def test_get_function_and_class_name(self):
         with ContextHelper():
             client = MockClient()
-            assert common.get_function_and_class_name(client.get_foo) == "MockClient.get_foo"
+            assert common.get_function_and_class_name(client.get_foo, client) == "MockClient.get_foo"
             assert common.get_function_and_class_name(random_function) == "random_function"
 
     def test_set_span_context(self):

From 471b1c7f40e354802e6053baadaedb22d9126dcb Mon Sep 17 00:00:00 2001
From: Suyog Soti <suyog.soti@gmail.com>
Date: Thu, 1 Aug 2019 17:10:46 -0700
Subject: [PATCH 8/9] get rid of dependency

---
 sdk/core/azure-core/setup.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/sdk/core/azure-core/setup.py b/sdk/core/azure-core/setup.py
index e5bbaebb52c5..bdab06be195c 100644
--- a/sdk/core/azure-core/setup.py
+++ b/sdk/core/azure-core/setup.py
@@ -65,6 +65,5 @@
     ],
     extras_require={
         ":python_version<'3.0'": ['azure-nspkg'],
-        ":python_version>='3.5'": ['contextvars'],
     }
 )

From 78ef0ad6579aa27361eb31195b863178b5b2b961 Mon Sep 17 00:00:00 2001
From: Suyog Soti <suyog.soti@gmail.com>
Date: Thu, 1 Aug 2019 17:19:55 -0700
Subject: [PATCH 9/9] all use same context

---
 .../azure-core/tests/test_tracing_context.py  | 21 ++-----------------
 1 file changed, 2 insertions(+), 19 deletions(-)

diff --git a/sdk/core/azure-core/tests/test_tracing_context.py b/sdk/core/azure-core/tests/test_tracing_context.py
index 984d2ad480d3..875c98105348 100644
--- a/sdk/core/azure-core/tests/test_tracing_context.py
+++ b/sdk/core/azure-core/tests/test_tracing_context.py
@@ -3,6 +3,7 @@
 # Licensed under the MIT License.
 # ------------------------------------
 import unittest
+
 try:
     from unittest import mock
 except ImportError:
@@ -11,28 +12,10 @@
 from azure.core.tracing.context import tracing_context
 from azure.core.tracing import AbstractSpan
 from azure.core.settings import settings
+from tracing_common import ContextHelper
 import os
 
 
-class ContextHelper(object):
-    def __init__(self, environ={}, tracer_to_use=None):
-        self.orig_sdk_context_span = tracing_context.current_span.get()
-        self.os_env = mock.patch.dict(os.environ, environ)
-        self.tracer_to_use = tracer_to_use
-
-    def __enter__(self):
-        self.orig_sdk_context_span = tracing_context.current_span.get()
-        tracing_context.current_span.clear()
-        settings.tracing_implementation.set_value(self.tracer_to_use)
-        self.os_env.start()
-        return self
-
-    def __exit__(self, exc_type, exc_val, exc_tb):
-        tracing_context.current_span.set(self.orig_sdk_context_span)
-        settings.tracing_implementation.unset_value()
-        self.os_env.stop()
-
-
 class TestContext(unittest.TestCase):
     def test_current_span(self):
         with ContextHelper():