Merge branch 'master' into node_bad_message_handling

29 files changed, 511 insertions, 701 deletions

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 3f7519a1d7..b4e958d3b2 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -45,9 +45,13 @@ In order to run most of the available tests, one would need to run:
 
 `./tools/run_tests/run_tests.py`
 
-If you want to run all the possible tests for any of the languages {c, c++, node, php, python}, do this:
+If you want to run tests for any of the languages {c, c++, csharp, node, objc, php, python, ruby}, do this:
 
-`./tools/run_tests/run_tests.py -l <lang> -c all`
+`./tools/run_tests/run_tests.py -l <lang>`
+
+To know about the list of available commands, do this:
+
+`./tools/run_tests/run_tests.py -h`
 
 ## Adding or removing source code
 
diff --git a/INSTALL.md b/INSTALL.md
index d9411db021..454a8b7b2f 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -3,7 +3,7 @@
 For language-specific installation instructions for gRPC runtime, please
 refer to these documents
 
- * [C++](examples/cpp)
+ * [C++](examples/cpp): Currently to install gRPC for C++, you need to build from source as described below.
  * [C#](src/csharp): NuGet package `Grpc`
  * [Go](https://github.com/grpc/grpc-go): `go get google.golang.org/grpc`
  * [Java](https://github.com/grpc/grpc-java)
@@ -32,6 +32,17 @@ terminal:
  $ [sudo] xcode-select --install
 ```
 
+##Protoc
+
+By default gRPC uses [protocol buffers](https://github.com/google/protobuf),
+you will need the `protoc` compiler to generate stub server and client code.
+
+If you compile gRPC from source, as described below, the Makefile will
+automatically try and compile the `protoc` in third_party if you cloned the
+repository recursively and it detects that you don't already have it
+installed.
+
+
 #Build from Source
 
 For developers who are interested to contribute, here is how to compile the
diff --git a/examples/README.md b/examples/README.md
index cd85417ca2..287a80266c 100644
--- a/examples/README.md
+++ b/examples/README.md
@@ -1,450 +1,27 @@
+# Examples
 
-# Getting started
+This directory contains code examples for all the C-based gRPC implementations: C++, Node.js, Python, Ruby, Objective-C, PHP, and C#. You can find examples and instructions specific to your
+favourite language in the relevant subdirectory.
+
+Examples for Go and Java gRPC live in their own repositories:
 
-Welcome to the developer documentation for gRPC, a language-neutral,
-platform-neutral remote procedure call (RPC) system developed at Google.
+* [Java](https://github.com/grpc/grpc-java/tree/master/examples)
+* [Android Java](https://github.com/grpc/grpc-java/tree/master/examples/android)
+* [Go](https://github.com/grpc/grpc-go/tree/master/examples)
 
-This document introduces you to gRPC with a quick overview and a simple
-Hello World example. You'll find more tutorials and reference docs in this repository - more documentation is coming soon!
+For more comprehensive documentation, including an [overview](http://www.grpc.io/docs/) and tutorials that use this example code, visit [grpc.io](http://www.grpc.io/docs/).
 
-<a name="quickstart"></a>
 ## Quick start
-You can find quick start guides for each language, including installation instructions, examples, and tutorials here:
+
+Each example directory has quick start instructions for the appropriate language, including installation instructions and how to run our simplest Hello World example:
+
 * [C++](cpp)
-* [Java](https://github.com/grpc/grpc-java/tree/master/examples)
-* [Go](https://github.com/grpc/grpc-go/tree/master/examples)
 * [Ruby](ruby)
 * [Node.js](node)
-* [Android Java](https://github.com/grpc/grpc-java/tree/master/examples/android)
 * [Python](python/helloworld)
 * [C#](csharp)
 * [Objective-C](objective-c/helloworld)
 * [PHP](php)
 
-## What's in this repository?
-
-The `examples` directory contains documentation, resources, and examples
-for all gRPC users. You can find examples and instructions specific to your
-favourite language in the relevant subdirectory.
-
-You can find out about the gRPC source code repositories in
-[`grpc`](https://github.com/grpc/grpc). Each repository provides instructions
-for building the appropriate libraries for your language.
-
-
-## What is gRPC?
-
-In gRPC a *client* application can directly call
-methods on a *server* application on a different machine as if it was a
-local object, making it easier for you to create distributed applications and
-services. As in many RPC systems, gRPC is based around the idea of defining
-a *service*, specifying the methods that can be called remotely with their
-parameters and return types. On the server side, the server implements this
-interface and runs a gRPC server to handle client calls. On the client side,
-the client has a *stub* that provides exactly the same methods as the server.
-
-<!--TODO: diagram-->
-
-gRPC clients and servers can run and talk to each other in a variety of
-environments - from servers inside Google to your own desktop - and can
-be written in any of gRPC's [supported languages](#quickstart). So, for
-example, you can easily create a gRPC server in Java with clients in Go,
-Python, or Ruby. In addition, the latest Google APIs will have gRPC versions
-of their interfaces, letting you easily build Google functionality into
-your applications.
-
-<a name="protocolbuffers"></a>
-### Working with protocol buffers
-
-By default gRPC uses *protocol buffers*, Google’s
-mature open source mechanism for serializing structured data (although it
-can be used with other data formats such as JSON). As you'll
-see in our example below, you define gRPC services using *proto files*,
-with method parameters and return types specified as protocol buffer message
-types. You
-can find out lots more about protocol buffers in the [Protocol Buffers
-documentation](https://developers.google.com/protocol-buffers/docs/overview).
-
-#### Protocol buffer versions
-
-While protocol buffers have been available for open source users for some
-time, our examples use a new flavour of protocol buffers called proto3,
-which has a slightly simplified syntax, some useful new features, and supports
-lots more languages. This is currently available as an alpha release in
-Java, C++, Java_nano (Android Java), Python, and Ruby from [the protocol buffers Github
-repo](https://github.com/google/protobuf/releases), as well as a Go language
-generator from [the golang/protobuf Github repo](https://github.com/golang/protobuf), with more languages in development. You can find out more in the [proto3 language guide](https://developers.google.com/protocol-buffers/docs/proto3), and see
-the major differences from the current default version in the [release notes](https://github.com/google/protobuf/releases). More proto3 documentation is coming soon.
-
-In general, while you *can* use proto2 (the current default protocol buffers version), we recommend that you use proto3 with gRPC as it lets you use the full range of gRPC-supported languages, as well as avoiding compatibility
-issues with proto2 clients talking to proto3 servers and vice versa.
-
-<a name="hello"></a>
-## Hello gRPC!
-
-Now that you know a bit more about gRPC, the easiest way to see how it
-works is to look at a simple example. Our Hello World walks you through the
-construction of a simple gRPC client-server application, showing you how to:
-
-- Create a protocol buffers schema that defines a simple RPC service with
-a single
-Hello World method.
-- Create a Java server that implements this interface.
-- Create a Java client that accesses the Java server.
-- Create a Go client that accesses
-the same Java server.
-
-The complete code for the example is available in the `examples`
-directory. We use the Git versioning system for source code management:
-however, you don't need to know anything about Git to follow along other
-than how to install and run a few git commands.
-
-This is an introductory example rather than a comprehensive tutorial, so
-don't worry if you're not a Go or
-Java developer - the concepts are similar for all languages, and you can
-find more implementations of our Hello World example in other languages (and full tutorials where available) in
-the [language-specific folders](#quickstart) in this repository. Complete tutorials and
-reference documentation for all gRPC languages are coming soon.
-
-<a name="setup"></a>
-### Setup
-
-This section explains how to set up your local machine to work with
-the example code. If you just want to read the example, you can go straight
-to the [next step](#servicedef).
-
-#### Install Git
-
-You can download and install Git from http://git-scm.com/download. Once
-installed you should have access to the git command line tool. The main
-commands that you will need to use are:
-
-- git clone ... : clone a remote repository onto your local machine
-- git checkout ... : check out a particular branch or a tagged version of
-the code to hack on
-
-#### Install gRPC
-
-To build and install gRPC plugins and related tools:
-- For Java, see the [Java quick start](https://github.com/grpc/grpc-java).
-- For Go, see the [Go quick start](https://github.com/grpc/grpc-go).
-
-#### Get the source code
-
-The example code for our Java example lives in the `grpc-java`
-GitHub repository. Clone this repository to your local machine by running the
-following command:
-
-
-```
-git clone https://github.com/grpc/grpc-java.git
-```
-
-Change your current directory to grpc-java/examples
-
-```
-cd grpc-java/examples
-```
-
-
-
-<a name="servicedef"></a>
-### Defining a service
-
-The first step in creating our example is to define a *service*: an RPC
-service specifies the methods that can be called remotely with their parameters
-and return types. As you saw in the
-[overview](#protocolbuffers) above, gRPC does this using [protocol
-buffers](https://developers.google.com/protocol-buffers/docs/overview). We
-use the protocol buffers interface definition language (IDL) to define our
-service methods, and define the parameters and return
-types as protocol buffer message types. Both the client and the
-server use interface code generated from the service definition.
-
-Here's our example service definition, defined using protocol buffers IDL in
-[helloworld.proto](https://github.com/grpc/grpc-java/tree/master/examples/src/main/proto). The `Greeter`
-service has one method, `SayHello`, that lets the server receive a single
-`HelloRequest`
-message from the remote client containing the user's name, then send back
-a greeting in a single `HelloReply`. This is the simplest type of RPC you
-can specify in gRPC - you can find out about other types in the tutorial for your chosen language.
-
-```proto
-syntax = "proto3";
-
-option java_package = "io.grpc.examples";
-
-package helloworld;
-
-// The greeter service definition.
-service Greeter {
-  // Sends a greeting
-  rpc SayHello (HelloRequest) returns (HelloReply) {}
-}
-
-// The request message containing the user's name.
-message HelloRequest {
-  string name = 1;
-}
-
-// The response message containing the greetings
-message HelloReply {
-  string message = 1;
-}
-
-```
-
-<a name="generating"></a>
-### Generating gRPC code
-
-Once we've defined our service, we use the protocol buffer compiler
-`protoc` to generate the special client and server code we need to create
-our application - right now we're going to generate Java code, though you
-can generate gRPC code in any gRPC-supported language (as you'll see later
-in this example). The generated code contains both stub code for clients to
-use and an abstract interface for servers to implement, both with the method
-defined in our `Greeter` service.
-
-(If you didn't install the gRPC plugins and protoc on your system and are just reading along with
-the example, you can skip this step and move
-onto the next one where we examine the generated code.)
-
-For simplicity, we've provided a [Gradle build file](https://github.com/grpc/grpc-java/blob/master/examples/build.gradle) with our Java examples that runs `protoc` for you with the appropriate plugin, input, and output:
-
-```shell
-../gradlew build
-```
-
-This generates the following classes from our .proto, which contain all the generated code
-we need to create our example:
-
-- `Helloworld.java`, which
-has all the protocol buffer code to populate, serialize, and retrieve our
-`HelloRequest` and `HelloReply` message types
-- `GreeterGrpc.java`, which contains (along with some other useful code):
-    - an interface for `Greeter` servers to implement
-
-    ```java
-  public static interface Greeter {
-      public void sayHello(io.grpc.examples.Helloworld.HelloRequest request,
-          io.grpc.stub.StreamObserver<io.grpc.examples.Helloworld.HelloReply> responseObserver);
-  }
-    ```
-
-    - _stub_ classes that clients can use to talk to a `Greeter` server. As you can see, they also implement the `Greeter` interface.
-
-  ```java
-  public static class GreeterStub extends
-      io.grpc.stub.AbstractStub<GreeterStub, GreeterServiceDescriptor>
-      implements Greeter {
-   ...
-  }
-  ```
-
-<a name="server"></a>
-### Writing a server
-
-Now let's write some code! First we'll create a server application to implement
-our service. Note that we're not going to go into a lot of detail about how
-to create a server in this section. More detailed information will be in the
-tutorial for your chosen language: check if there's one available yet in the relevant [quick start](#quickstart).
-
-Our server application has two classes:
-
-- a main server class that hosts the service implementation and allows access over the
-network: [HelloWorldServer.java](https://github.com/grpc/grpc-java/blob/master/examples/src/main/java/io/grpc/examples/helloworld/HelloWorldServer.java).
-
-
-- a simple service implementation class [GreeterImpl.java](https://github.com/grpc/grpc-java/blob/master/examples/src/main/java/io/grpc/examples/helloworld/HelloWorldServer.java#L51).
-
-
-#### Service implementation
-
-[GreeterImpl.java](https://github.com/grpc/grpc-java/blob/master/examples/src/main/java/io/grpc/examples/helloworld/HelloWorldServer.java#L51)
-actually implements our `Greeter` service's required behaviour.
-
-As you can see, the class `GreeterImpl` implements the interface
-`GreeterGrpc.Greeter` that we [generated](#generating) from our proto
-[IDL](https://github.com/grpc/grpc-java/tree/master/examples/src/main/proto) by implementing the method `sayHello`:
-
-```java
-    @Override
-    public void sayHello(HelloRequest req, StreamObserver<HelloReply> responseObserver) {
-      HelloReply reply = HelloReply.newBuilder().setMessage("Hello " + req.getName()).build();
-      responseObserver.onValue(reply);
-      responseObserver.onCompleted();
-    }
-```
-- `sayHello` takes two parameters:
-    - `HelloRequest`: the request
-    - `StreamObserver<HelloReply>`: a response observer, which is
-    a special interface for the server to call with its response
-
-To return our response to the client and complete the call:
-
-1. We construct and populate a `HelloReply` response object with our exciting
-message, as specified in our interface definition.
-2. We return the `HelloReply` to the client and then specify that we've finished dealing with the RPC.
-
-
-#### Server implementation
-
-[HelloWorldServer.java](https://github.com/grpc/grpc-java/blob/master/examples/src/main/java/io/grpc/examples/helloworld/HelloWorldServer.java)
-shows the other main feature required to provide a gRPC service; making the service
-implementation available from the network.
-
-```java
-  /* The port on which the server should run */
-  private int port = 50051;
-  private ServerImpl server;
-
-  private void start() throws Exception {
-    server = NettyServerBuilder.forPort(port)
-        .addService(GreeterGrpc.bindService(new GreeterImpl()))
-        .build().start();
-    logger.info("Server started, listening on " + port);
-    Runtime.getRuntime().addShutdownHook(new Thread() {
-      @Override
-      public void run() {
-        // Use stderr here since the logger may have been reset by its JVM shutdown hook.
-        System.err.println("*** shutting down gRPC server since JVM is shutting down");
-        HelloWorldServer.this.stop();
-        System.err.println("*** server shut down");
-      }
-    });
-  }
-
-```
-
-Here we create an appropriate gRPC server, binding the `Greeter` service
-implementation that we created to a port. Then we start the server running: the server is now ready to receive
-requests from `Greeter` service clients on our specified port. We'll cover
-how all this works in a bit more detail in our language-specific documentation.
-
-<a name="client"></a>
-### Writing a client
-
-Client-side gRPC is pretty simple. In this step, we'll use the generated code
-to write a simple client that can access the `Greeter` server we created
-in the [previous section](#server). You can see the complete client code in
-[HelloWorldClient.java](https://github.com/grpc/grpc-java/blob/master/examples/src/main/java/io/grpc/examples/helloworld/HelloWorldClient.java).
-
-Again, we're not going to go into much detail about how to implement a client;
-we'll leave that for the tutorial.
-
-#### Connecting to the service
-
-First let's look at how we connect to the `Greeter` server. First we need
-to create a gRPC channel, specifying the hostname and port of the server we
-want to connect to. Then we use the channel to construct the stub instance.
-
-
-```java
-  private final ChannelImpl channel;
-  private final GreeterGrpc.GreeterBlockingStub blockingStub;
-
-  public HelloWorldClient(String host, int port) {
-    channel =
-        NettyChannelBuilder.forAddress(host, port).negotiationType(NegotiationType.PLAINTEXT)
-            .build();
-    blockingStub = GreeterGrpc.newBlockingStub(channel);
-  }
-
-```
-
-In this case, we create a blocking stub. This means that the RPC call waits
-for the server to respond, and will either return a response or raise an
-exception. gRPC Java has other kinds of stubs that make non-blocking calls
-to the server, where the response is returned asynchronously.
-
-#### Calling an RPC
-
-Now we can contact the service and obtain a greeting:
-
-1. We construct and fill in a `HelloRequest` to send to the service.
-2. We call the stub's `hello()` RPC with our request and get a `HelloReply`
-back, from which we can get our greeting.
-
-
-```java
-    HelloRequest req = HelloRequest.newBuilder().setName(name).build();
-    HelloReply reply = blockingStub.sayHello(req);
-
-```
-
-<a name="run"></a>
-### Try it out!
-
-Our [Gradle build file](https://github.com/grpc/grpc-java/blob/master/examples/build.gradle) simplifies building and running the examples.
-
-You can build and run the server from the `grpc-java` root folder with:
-
-```sh
-$ ./gradlew :grpc-examples:helloWorldServer
-```
-
-and in another terminal window confirm that it receives a message.
-
-```sh
-$  ./gradlew :grpc-examples:helloWorldClient
-```
-
-### Adding another client
-
-Finally, let's look at one of gRPC's most useful features - interoperability
-between code in different languages. So far, we've just looked at Java code
-generated from and implementing our `Greeter` service definition. However,
-as you'll see if you look at the language-specific subdirectories
-in this repository, we've also generated and implemented `Greeter`
-in some of gRPC's other supported languages. Each service
-and client uses interface code generated from the same proto
-that we used for the Java example.
-
-So, for example, if we visit the [`go` example
-directory](https://github.com/grpc/grpc-go/tree/master/examples) and look at the
-[`greeter_client`](https://github.com/grpc/grpc-go/blob/master/examples/greeter_client/main.go),
-we can see that like the Java client, it connects to a `Greeter` service
-at `localhost:50051` and uses a stub to call the `SayHello` method with a
-`HelloRequest`:
-
-```go
-const (
-	address = "localhost:50051"
-	defaultName = "world"
-)
-
-func main() {
-	// Set up a connection to the server.
-	conn, err := grpc.Dial(address)
-	if err != nil {
-		log.Fatalf("did not connect: %v", err)
-	}
-	defer conn.Close()
-	c := pb.NewGreeterClient(conn)
-
-	// Contact the server and print out its response.
-	name := defaultName
-	if len(os.Args) > 1 {
-		name = os.Args[1]
-	}
-	r, err := c.SayHello(context.Background(), &pb.HelloRequest{Name:
-	name})
-	if err != nil {
-		log.Fatalf("could not greet: %v", err)
-	}
-	log.Printf("Greeting: %s", r.Message)
-}
-```
-
-
-If we run the Java server from earlier in another terminal window, we can
-run the Go client and connect to it just like the Java client, even though
-it's written in a different language.
 
-```
-$ greeter_client
-```
-## Read more!
 
-- You can find links to language-specific tutorials, examples, and other docs in each language's [quick start](#quickstart).
-- [gRPC Authentication Support](http://www.grpc.io/docs/guides/auth.html) introduces authentication support in gRPC with supported mechanisms and examples.
diff --git a/examples/cpp/README.md b/examples/cpp/README.md
index e4b0eb698b..d93cbacf7b 100644
--- a/examples/cpp/README.md
+++ b/examples/cpp/README.md
@@ -2,7 +2,7 @@
 
 ## Installation
 
-To install gRPC on your system, follow the instructions [here](../../INSTALL.md).
+To install gRPC on your system, follow the instructions to build from source [here](../../INSTALL.md). This also installs the protocol buffer compiler `protoc` (if you don't have it already), and the C++ gRPC plugin for `protoc`.
 
 ## Hello C++ gRPC!
 
diff --git a/examples/php/README.md b/examples/php/README.md
index 8fb060863a..ea9ccb6790 100644
--- a/examples/php/README.md
+++ b/examples/php/README.md
@@ -4,16 +4,15 @@ gRPC in 3 minutes (PHP)
 PREREQUISITES
 -------------
 
-This requires PHP 5.5 or greater.
+This requires `php` >=5.5, `phpize`, `pecl`, `phpunit`
 
 INSTALL
 -------
- - On Mac OS X, install [homebrew][]. Run the following command to install gRPC.
+ - Install the gRPC PHP extension
 
    ```sh
-   $ curl -fsSL https://goo.gl/getgrpc | bash -s php
+   $ [sudo] pecl install grpc-beta
    ```
-   This will download and run the [gRPC install script][] and compile the gRPC PHP extension.
 
  - Clone this repository
 
@@ -37,6 +36,7 @@ TRY IT!
    Please follow the instruction in [Node][] to run the server
    ```
    $ cd examples/node
+   $ npm install
    $ nodejs greeter_server.js
    ```
 
@@ -58,7 +58,5 @@ TUTORIAL
 
 You can find a more detailed tutorial in [gRPC Basics: PHP][]
 
-[homebrew]:http://brew.sh
-[gRPC install script]:https://raw.githubusercontent.com/grpc/homebrew-grpc/master/scripts/install
 [Node]:https://github.com/grpc/grpc/tree/master/examples/node
 [gRPC Basics: PHP]:http://www.grpc.io/docs/tutorials/basic/php.html
diff --git a/examples/python/route_guide/route_guide_server.py b/examples/python/route_guide/route_guide_server.py
index f23b98bf36..f95b36b073 100644
--- a/examples/python/route_guide/route_guide_server.py
+++ b/examples/python/route_guide/route_guide_server.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -128,7 +128,7 @@ def serve():
     while True:
       time.sleep(_ONE_DAY_IN_SECONDS)
   except KeyboardInterrupt:
-    server.stop()
+    server.stop(0)
 
 if __name__ == '__main__':
   serve()
diff --git a/setup.py b/setup.py
index cfb578e215..45ff2cec89 100644
--- a/setup.py
+++ b/setup.py
@@ -108,8 +108,13 @@ if "linux" in sys.platform or "darwin" in sys.platform:
 
 def cython_extensions(package_names, module_names, extra_sources, include_dirs,
                       libraries, define_macros, build_with_cython=False):
+  # Set compiler directives linetrace argument only if we care about tracing;
+  # this is due to Cython having different behavior between linetrace being
+  # False and linetrace being unset. See issue #5689.
+  cython_compiler_directives = {}
   if ENABLE_CYTHON_TRACING:
     define_macros = define_macros + [('CYTHON_TRACE_NOGIL', 1)]
+    cython_compiler_directives['linetrace'] = True
   file_extension = 'pyx' if build_with_cython else 'c'
   module_files = [os.path.join(PYTHON_STEM,
                                name.replace('.', '/') + '.' + file_extension)
@@ -129,7 +134,7 @@ def cython_extensions(package_names, module_names, extra_sources, include_dirs,
     return Cython.Build.cythonize(
         extensions,
         include_path=include_dirs,
-        compiler_directives={'linetrace': bool(ENABLE_CYTHON_TRACING)})
+        compiler_directives=cython_compiler_directives)
   else:
     return extensions
 
@@ -154,6 +159,7 @@ INSTALL_REQUIRES = (
 
 SETUP_REQUIRES = (
     'sphinx>=1.3',
+    'sphinx_rtd_theme>=0.1.8'
 ) + INSTALL_REQUIRES
 
 COMMAND_CLASS = {
@@ -165,6 +171,7 @@ COMMAND_CLASS = {
     'build_tagged_ext': precompiled.BuildTaggedExt,
     'gather': commands.Gather,
     'run_interop': commands.RunInterop,
+    'test_lite': commands.TestLite
 }
 
 # Ensure that package data is copied over before any commands have been run:
diff --git a/src/core/channel/client_channel.c b/src/core/channel/client_channel.c
index d4ba950818..f021a8ae32 100644
--- a/src/core/channel/client_channel.c
+++ b/src/core/channel/client_channel.c
@@ -165,7 +165,6 @@ static void cc_on_config_changed(grpc_exec_ctx *exec_ctx, void *arg,
   channel_data *chand = arg;
   grpc_lb_policy *lb_policy = NULL;
   grpc_lb_policy *old_lb_policy;
-  grpc_resolver *old_resolver;
   grpc_connectivity_state state = GRPC_CHANNEL_TRANSIENT_FAILURE;
   int exit_idle = 0;
 
@@ -201,28 +200,25 @@ static void cc_on_config_changed(grpc_exec_ctx *exec_ctx, void *arg,
   }
 
   if (iomgr_success && chand->resolver) {
-    grpc_resolver *resolver = chand->resolver;
-    GRPC_RESOLVER_REF(resolver, "channel-next");
     grpc_connectivity_state_set(exec_ctx, &chand->state_tracker, state,
                                 "new_lb+resolver");
     if (lb_policy != NULL) {
       watch_lb_policy(exec_ctx, chand, lb_policy, state);
     }
-    gpr_mu_unlock(&chand->mu_config);
     GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver");
-    grpc_resolver_next(exec_ctx, resolver, &chand->incoming_configuration,
+    grpc_resolver_next(exec_ctx, chand->resolver,
+                       &chand->incoming_configuration,
                        &chand->on_config_changed);
-    GRPC_RESOLVER_UNREF(exec_ctx, resolver, "channel-next");
+    gpr_mu_unlock(&chand->mu_config);
   } else {
-    old_resolver = chand->resolver;
-    chand->resolver = NULL;
+    if (chand->resolver != NULL) {
+      grpc_resolver_shutdown(exec_ctx, chand->resolver);
+      GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel");
+      chand->resolver = NULL;
+    }
     grpc_connectivity_state_set(exec_ctx, &chand->state_tracker,
                                 GRPC_CHANNEL_FATAL_FAILURE, "resolver_gone");
     gpr_mu_unlock(&chand->mu_config);
-    if (old_resolver != NULL) {
-      grpc_resolver_shutdown(exec_ctx, old_resolver);
-      GRPC_RESOLVER_UNREF(exec_ctx, old_resolver, "channel");
-    }
   }
 
   if (exit_idle) {
@@ -247,7 +243,6 @@ static void cc_start_transport_op(grpc_exec_ctx *exec_ctx,
                                   grpc_channel_element *elem,
                                   grpc_transport_op *op) {
   channel_data *chand = elem->channel_data;
-  grpc_resolver *destroy_resolver = NULL;
 
   grpc_exec_ctx_enqueue(exec_ctx, op->on_consumed, true, NULL);
 
@@ -279,7 +274,8 @@ static void cc_start_transport_op(grpc_exec_ctx *exec_ctx,
   if (op->disconnect && chand->resolver != NULL) {
     grpc_connectivity_state_set(exec_ctx, &chand->state_tracker,
                                 GRPC_CHANNEL_FATAL_FAILURE, "disconnect");
-    destroy_resolver = chand->resolver;
+    grpc_resolver_shutdown(exec_ctx, chand->resolver);
+    GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel");
     chand->resolver = NULL;
     if (chand->lb_policy != NULL) {
       grpc_pollset_set_del_pollset_set(exec_ctx,
@@ -290,11 +286,6 @@ static void cc_start_transport_op(grpc_exec_ctx *exec_ctx,
     }
   }
   gpr_mu_unlock(&chand->mu_config);
-
-  if (destroy_resolver) {
-    grpc_resolver_shutdown(exec_ctx, destroy_resolver);
-    GRPC_RESOLVER_UNREF(exec_ctx, destroy_resolver, "channel");
-  }
 }
 
 typedef struct {
diff --git a/src/core/channel/subchannel_call_holder.c b/src/core/channel/subchannel_call_holder.c
index 8f46885a04..9c087dc2a1 100644
--- a/src/core/channel/subchannel_call_holder.c
+++ b/src/core/channel/subchannel_call_holder.c
@@ -174,17 +174,15 @@ static void subchannel_ready(grpc_exec_ctx *exec_ctx, void *arg, bool success) {
   holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
   if (holder->connected_subchannel == NULL) {
     fail_locked(exec_ctx, holder);
+  } else if (1 == gpr_atm_acq_load(&holder->subchannel_call)) {
+    /* already cancelled before subchannel became ready */
+    fail_locked(exec_ctx, holder);
   } else {
-    if (!gpr_atm_rel_cas(
-            &holder->subchannel_call, 0,
-            (gpr_atm)(uintptr_t)grpc_connected_subchannel_create_call(
-                exec_ctx, holder->connected_subchannel, holder->pollset))) {
-      GPR_ASSERT(gpr_atm_acq_load(&holder->subchannel_call) == 1);
-      /* if this cas fails, the call was cancelled before the pick completed */
-      fail_locked(exec_ctx, holder);
-    } else {
-      retry_waiting_locked(exec_ctx, holder);
-    }
+    gpr_atm_rel_store(
+        &holder->subchannel_call,
+        (gpr_atm)(uintptr_t)grpc_connected_subchannel_create_call(
+            exec_ctx, holder->connected_subchannel, holder->pollset));
+    retry_waiting_locked(exec_ctx, holder);
   }
   gpr_mu_unlock(&holder->mu);
   GRPC_CALL_STACK_UNREF(exec_ctx, holder->owning_call, "pick_subchannel");
diff --git a/src/core/iomgr/timer_heap.c b/src/core/iomgr/timer_heap.c
index 9d8be5c1fc..b5df566c45 100644
--- a/src/core/iomgr/timer_heap.c
+++ b/src/core/iomgr/timer_heap.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -46,7 +46,7 @@
 static void adjust_upwards(grpc_timer **first, uint32_t i, grpc_timer *t) {
   while (i > 0) {
     uint32_t parent = (uint32_t)(((int)i - 1) / 2);
-    if (gpr_time_cmp(first[parent]->deadline, t->deadline) >= 0) break;
+    if (gpr_time_cmp(first[parent]->deadline, t->deadline) <= 0) break;
     first[i] = first[parent];
     first[i]->heap_index = i;
     i = parent;
@@ -62,16 +62,14 @@ static void adjust_downwards(grpc_timer **first, uint32_t i, uint32_t length,
                              grpc_timer *t) {
   for (;;) {
     uint32_t left_child = 1u + 2u * i;
-    uint32_t right_child;
-    uint32_t next_i;
     if (left_child >= length) break;
-    right_child = left_child + 1;
-    next_i = right_child < length &&
-                     gpr_time_cmp(first[left_child]->deadline,
-                                  first[right_child]->deadline) < 0
-                 ? right_child
-                 : left_child;
-    if (gpr_time_cmp(t->deadline, first[next_i]->deadline) >= 0) break;
+    uint32_t right_child = left_child + 1;
+    uint32_t next_i = right_child < length &&
+                              gpr_time_cmp(first[left_child]->deadline,
+                                           first[right_child]->deadline) > 0
+                          ? right_child
+                          : left_child;
+    if (gpr_time_cmp(t->deadline, first[next_i]->deadline) <= 0) break;
     first[i] = first[next_i];
     first[i]->heap_index = i;
     i = next_i;
@@ -95,7 +93,7 @@ static void maybe_shrink(grpc_timer_heap *heap) {
 static void note_changed_priority(grpc_timer_heap *heap, grpc_timer *timer) {
   uint32_t i = timer->heap_index;
   uint32_t parent = (uint32_t)(((int)i - 1) / 2);
-  if (gpr_time_cmp(heap->timers[parent]->deadline, timer->deadline) < 0) {
+  if (gpr_time_cmp(heap->timers[parent]->deadline, timer->deadline) > 0) {
     adjust_upwards(heap->timers, i, timer);
   } else {
     adjust_downwards(heap->timers, i, heap->timer_count, timer);
diff --git a/src/cpp/README.md b/src/cpp/README.md
index baeba08315..83d37aa2ed 100644
--- a/src/cpp/README.md
+++ b/src/cpp/README.md
@@ -6,3 +6,77 @@ This directory contains source code for C++ implementation of gRPC.
 #Status
 
 Beta
+
+#Pre-requisites
+
+##Linux
+
+```sh
+ $ [sudo] apt-get install build-essential autoconf libtool
+```
+
+##Mac OSX
+
+For a Mac system, git is not available by default. You will first need to
+install Xcode from the Mac AppStore and then run the following command from a
+terminal:
+
+```sh
+ $ [sudo] xcode-select --install
+```
+
+##Protoc
+
+By default gRPC uses [protocol buffers](https://github.com/google/protobuf),
+you will need the `protoc` compiler to generate stub server and client code.
+
+If you compile gRPC from source, as described below, this also installs the
+`protoc` compiler.
+
+If it hasn't been installed, you can run the following commands to install it.
+
+```sh
+$ cd grpc/third_party/protobuf
+$ sudo make install   # 'make' should have been run by core grpc
+```
+
+Alternatively, you can download `protoc` binaries from
+[the protocol buffers Github repository](https://github.com/google/protobuf/releases).
+
+#Installation
+
+Currently to install gRPC for C++, you need to build from source as described
+below.
+
+#Build from Source
+
+```sh
+ $ git clone https://github.com/grpc/grpc.git
+ $ cd grpc
+ $ git submodule update --init
+ $ make
+ $ [sudo] make install
+```
+
+#Documentation
+
+You can find out how to build and run our simplest gRPC C++ example in our
+[C++ quick start](https://github.com/grpc/grpc/tree/{{ site.data.config.grpc_release_branch }}/examples/cpp).
+
+For more detailed documentation on using gRPC in C++ , see our main
+documentation site at [grpc.io](http://grpc.io), specifically:
+
+* [Overview](http://www.grpc.io/docs/): An introduction to gRPC with a simple
+  Hello World example in all our supported languages, including C++.
+* [gRPC Basics - C++](http://www.grpc.io/docs/tutorials/basic/c.html):
+  A tutorial that steps you through creating a simple gRPC C++ example
+  application.
+* [Asynchronous Basics - C++](http://www.grpc.io/docs/tutorials/async/helloasync-cpp.html):
+  A tutorial that shows you how to use gRPC C++'s asynchronous/non-blocking
+  APIs.
+
+
+# Examples
+
+Code examples for gRPC C++ live in this repository's
+[examples/cpp](https://github.com/grpc/grpc/tree/{{ site.data.config.grpc_release_branch }}/examples/cpp) directory.
diff --git a/src/node/README.md b/src/node/README.md
index b46b986243..3501b54a66 100644
--- a/src/node/README.md
+++ b/src/node/README.md
@@ -5,7 +5,7 @@
 Beta
 
 ## PREREQUISITES
-- `node`: This requires `node` to be installed. If you instead have the `nodejs` executable on Debian, you should install the [`nodejs-legacy`](https://packages.debian.org/sid/nodejs-legacy) package.
+- `node`: This requires `node` to be installed, version `0.12` or above. If you instead have the `nodejs` executable on Debian, you should install the [`nodejs-legacy`](https://packages.debian.org/sid/nodejs-legacy) package.
 
 ## INSTALLATION
 
diff --git a/src/node/src/client.js b/src/node/src/client.js
index 81299b337c..2459e28321 100644
--- a/src/node/src/client.js
+++ b/src/node/src/client.js
@@ -411,7 +411,7 @@ function makeUnaryRequestFunction(method, serialize, deserialize) {
         }
       }
       if (status.code !== grpc.status.OK) {
-        error = new Error(response.status.details);
+        error = new Error(status.details);
         error.code = status.code;
         error.metadata = status.metadata;
         callback(error);
diff --git a/src/php/README.md b/src/php/README.md
index b368482f06..cf8f2c11b0 100644
--- a/src/php/README.md
+++ b/src/php/README.md
@@ -9,14 +9,21 @@ Beta
 
 ## Environment
 
-Prerequisite: PHP 5.5 or later, `phpunit`, `pecl`
+Prerequisite: `php` >=5.5, `phpize`, `pecl`, `phpunit`
 
-**Linux:**
+**Linux (Debian):**
 
 ```sh
 $ sudo apt-get install php5 php5-dev php-pear
 ```
 
+**Linux (CentOS):**
+
+```sh
+$ yum install php55w
+$ yum --enablerepo=remi,remi-php55 install php-devel php-pear
+```
+
 **Mac OS X:**
 
 ```sh
@@ -24,11 +31,11 @@ $ curl -O http://pear.php.net/go-pear.phar
 $ sudo php -d detect_unicode=0 go-pear.phar
 ```
 
-**PHPUnit: (Both Linux and Mac OS X)**
+**PHPUnit:**
 ```sh
-$ curl https://phar.phpunit.de/phpunit.phar -o phpunit.phar
-$ chmod +x phpunit.phar
-$ sudo mv phpunit.phar /usr/local/bin/phpunit
+$ wget https://phar.phpunit.de/phpunit-old.phar
+$ chmod +x phpunit-old.phar
+$ sudo mv phpunit-old.phar /usr/bin/phpunit
 ```
 
 ## Quick Install
@@ -39,15 +46,22 @@ Install the gRPC PHP extension
 sudo pecl install grpc-beta
 ```
 
+This will compile and install the gRPC PHP extension into the standard PHP extension directory. You should be able to run the [unit tests](#unit-tests), with the PHP extension installed.
+
+To run tests with generated stub code from `.proto` files, you will also need the `composer`, `protoc` and `protoc-gen-php` binaries. You can find out how to get these [below](#generated-code-tests).
+
 ## Build from Source
 
+
+### gRPC C core library
+
 Clone this repository
 
 ```sh
 $ git clone https://github.com/grpc/grpc.git
 ```
 
-Build and install the gRPC C core libraries
+Build and install the gRPC C core library
 
 ```sh
 $ cd grpc
@@ -56,20 +70,15 @@ $ make
 $ sudo make install
 ```
 
-Note: you may encounter a warning about the Protobuf compiler `protoc` 3.0.0+ not being installed. The following might help, and will be useful later on when we need to compile the `protoc-gen-php` tool.
+### gRPC PHP extension
 
-```sh
-$ cd grpc/third_party/protobuf
-$ sudo make install   # 'make' should have been run by core grpc
-```
-
-Install the gRPC PHP extension
+Install the gRPC PHP extension from PECL
 
 ```sh
 $ sudo pecl install grpc-beta
 ```
 
-OR
+Or, compile from source
 
 ```sh
 $ cd grpc/src/php/ext/grpc
@@ -79,58 +88,98 @@ $ make
 $ sudo make install
 ```
 
+### Update php.ini
+
 Add this line to your `php.ini` file, e.g. `/etc/php5/cli/php.ini`
 
 ```sh
 extension=grpc.so
 ```
 
-Install Composer
+## Unit Tests
+
+You will need the source code to run tests
+
+```sh
+$ git clone https://github.com/grpc/grpc.git
+$ cd grpc
+$ git pull --recurse-submodules && git submodule update --init --recursive
+```
+
+Run unit tests
 
 ```sh
 $ cd grpc/src/php
+$ ./bin/run_tests.sh
+```
+
+## Generated Code Tests
+
+This section specifies the prerequisites for running the generated code tests, as well as how to run the tests themselves.
+
+### Composer
+
+If you don't have it already, install `composer` to pull in some runtime dependencies based on the `composer.json` file.
+
+```sh
 $ curl -sS https://getcomposer.org/installer | php
 $ sudo mv composer.phar /usr/local/bin/composer
+
+$ cd grpc/src/php
 $ composer install
 ```
 
-## Unit Tests
+### Protobuf compiler
 
-Run unit tests
+Again if you don't have it already, you need to install the protobuf compiler `protoc`, version 3.0.0+.
+
+If you compiled the gRPC C core library from source above, the `protoc` binary should have been installed as well. If it hasn't been installed, you can run the following commands to install it.
 
 ```sh
-$ cd grpc/src/php
-$ ./bin/run_tests.sh
+$ cd grpc/third_party/protobuf
+$ sudo make install   # 'make' should have been run by core grpc
 ```
 
-## Generated Code Tests
+Alternatively, you can download `protoc` binaries from [the protocol buffers Github repository](https://github.com/google/protobuf/releases).
 
-Install `protoc-gen-php`
+
+### PHP protobuf compiler
+
+You need to install `protoc-gen-php` to generate stub class `.php` files from service definition `.proto` files.
 
 ```sh
-$ cd grpc/src/php/vendor/datto/protobuf-php
+$ cd grpc/src/php/vendor/datto/protobuf-php # if you had run `composer install` in the previous step
+
+OR
+
+$ git clone https://github.com/stanley-cheung/Protobuf-PHP # clone from github repo
+
 $ gem install rake ronn
 $ rake pear:package version=1.0
 $ sudo pear install Protobuf-1.0.tgz
 ```
 
-Generate client stub code
+### Client Stub
+
+Generate client stub classes from `.proto` files
 
 ```sh
 $ cd grpc/src/php
 $ ./bin/generate_proto_php.sh
 ```
 
-Run a local server serving the math services
+### Run test server
 
- - Please see [Node][] on how to run an example server
+Run a local server serving the math services. Please see [Node][] for how to run an example server.
 
 ```sh
-$ cd grpc/src/node
+$ cd grpc
 $ npm install
-$ nodejs examples/math_server.js
+$ nodejs src/node/test/math/math_server.js
 ```
 
+### Run test client
+
 Run the generated code tests
 
 ```sh
@@ -161,13 +210,15 @@ $ sudo service apache2 restart
 Make sure the Node math server is still running, as above. 
 
 ```sh
-$ cd grpc/src/node
-$ nodejs examples/math_server.js
+$ cd grpc
+$ npm install
+$ nodejs src/node/test/math/math_server.js
 ```
 
 Make sure you have run `composer install` to generate the `vendor/autoload.php` file
 
 ```sh
+$ cd grpc/src/php
 $ composer install
 ```
 
@@ -229,13 +280,15 @@ $ sudo service php5-fpm restart
 Make sure the Node math server is still running, as above. 
 
 ```sh
-$ cd grpc/src/node
-$ nodejs examples/math_server.js
+$ cd grpc
+$ npm install
+$ nodejs src/node/test/math/math_server.js
 ```
 
 Make sure you have run `composer install` to generate the `vendor/autoload.php` file
 
 ```sh
+$ cd grpc/src/php
 $ composer install
 ```
 
diff --git a/src/python/grpcio/README.rst b/src/python/grpcio/README.rst
index f3e962c197..3dfae50b4b 100644
--- a/src/python/grpcio/README.rst
+++ b/src/python/grpcio/README.rst
@@ -6,7 +6,7 @@ Package for gRPC Python.
 Installation
 ------------
 
-gRPC Python is available for Linux and Mac OS X running Python 2.7.
+gRPC Python is available for Linux, Mac OS X, and Windows running Python 2.7.
 
 From PyPI
 ~~~~~~~~~
@@ -23,11 +23,15 @@ Else system wide (on Ubuntu)...
 
   $ sudo pip install grpcio
 
+n.b. On Windows and on Mac OS X one *must* have a recent release of :code:`pip`
+to retrieve the proper wheel from PyPI. Be sure to upgrade to the latest
+version!
+
 From Source
 ~~~~~~~~~~~
 
 Building from source requires that you have the Python headers (usually a
-package named `python-dev`).
+package named :code:`python-dev`).
 
 ::
 
@@ -36,8 +40,8 @@ package named `python-dev`).
   $ cd $REPO_ROOT
   $ pip install .
 
-Note that `$REPO_ROOT` can be assigned to whatever directory name floats your
-fancy.
+Note that :code:`$REPO_ROOT` can be assigned to whatever directory name floats
+your fancy.
 
 Troubleshooting
 ~~~~~~~~~~~~~~~
diff --git a/src/python/grpcio/commands.py b/src/python/grpcio/commands.py
index aa29c728f2..c1f444f6f1 100644
--- a/src/python/grpcio/commands.py
+++ b/src/python/grpcio/commands.py
@@ -119,8 +119,7 @@ class SphinxDocumentation(setuptools.Command):
     import sphinx
     import sphinx.apidoc
     metadata = self.distribution.metadata
-    src_dir = os.path.join(
-        PYTHON_STEM, self.distribution.package_dir[''], 'grpc')
+    src_dir = os.path.join(PYTHON_STEM, 'grpc')
     sys.path.append(src_dir)
     sphinx.apidoc.main([
         '', '--force', '--full', '-H', metadata.name, '-A', metadata.author,
@@ -264,6 +263,42 @@ class Gather(setuptools.Command):
       self.distribution.fetch_build_eggs(self.distribution.tests_require)
 
 
+class TestLite(setuptools.Command):
+  """Command to run tests without fetching or building anything."""
+
+  description = 'run tests without fetching or building anything.'
+  user_options = []
+
+  def initialize_options(self):
+    pass
+
+  def finalize_options(self):
+    # distutils requires this override.
+    pass
+
+  def run(self):
+    self._add_eggs_to_path()
+
+    import tests
+    loader = tests.Loader()
+    loader.loadTestsFromNames(['tests'])
+    runner = tests.Runner()
+    result = runner.run(loader.suite)
+    if not result.wasSuccessful():
+      sys.exit('Test failure')
+
+  def _add_eggs_to_path(self):
+    """Adds all egg files under .eggs to sys.path"""
+    # TODO(jtattemusch): there has to be a cleaner way to do this
+    import pkg_resources
+    eggs_dir = os.path.join(PYTHON_STEM, '../../../.eggs')
+    eggs = [os.path.join(eggs_dir, filename)
+            for filename in os.listdir(eggs_dir)
+            if filename.endswith('.egg')]
+    for egg in eggs:
+      sys.path.insert(0, pkg_resources.normalize_path(egg))
+
+
 class RunInterop(test.test):
 
   description = 'run interop test client/server'
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pyx.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pyx.pxi
index c139147114..e11138b1cd 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pyx.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pyx.pxi
@@ -140,7 +140,8 @@ cdef class CompletionQueue:
         grpc_completion_queue_shutdown(self.c_completion_queue)
       # Pump the queue
       while not self.is_shutdown:
-        event = grpc_completion_queue_next(
-            self.c_completion_queue, c_deadline, NULL)
+        with nogil:
+          event = grpc_completion_queue_next(
+              self.c_completion_queue, c_deadline, NULL)
         self._interpret_event(event)
       grpc_completion_queue_destroy(self.c_completion_queue)
diff --git a/src/python/grpcio/precompiled.py b/src/python/grpcio/precompiled.py
index ae2a0c835a..d34250b02c 100644
--- a/src/python/grpcio/precompiled.py
+++ b/src/python/grpcio/precompiled.py
@@ -31,6 +31,7 @@ import os
 import platform
 import shutil
 import sys
+import sysconfig
 
 import setuptools
 
@@ -51,9 +52,15 @@ USE_PRECOMPILED_BINARIES = bool(int(os.environ.get(
 
 def _tagged_ext_name(base):
   uname = platform.uname()
-  tags = '-'.join((grpc_version.VERSION, uname[0], uname[4]))
-  flavor = 'ucs2' if sys.maxunicode == 65535 else 'ucs4'
-  return '{base}-{tags}-{flavor}'.format(base=base, tags=tags, flavor=flavor)
+  tags = (
+      grpc_version.VERSION,
+      'py{}'.format(sysconfig.get_python_version()),
+      uname[0],
+      uname[4],
+  )
+  ucs = 'ucs{}'.format(sysconfig.get_config_var('Py_UNICODE_SIZE'))
+  return '{base}-{tags}-{ucs}'.format(
+      base=base, tags='-'.join(tags), ucs=ucs)
 
 
 class BuildTaggedExt(setuptools.Command):
diff --git a/src/python/grpcio/tests/_runner.py b/src/python/grpcio/tests/_runner.py
index 38a5432e79..b0dbd92a49 100644
--- a/src/python/grpcio/tests/_runner.py
+++ b/src/python/grpcio/tests/_runner.py
@@ -144,7 +144,7 @@ class Runner(object):
   def run(self, suite):
     """See setuptools' test_runner setup argument for information."""
     # only run test cases with id starting with given prefix
-    testcase_filter = os.getenv('GPRC_PYTHON_TESTRUNNER_FILTER')
+    testcase_filter = os.getenv('GRPC_PYTHON_TESTRUNNER_FILTER')
     filtered_cases = []
     for case in _loader.iterate_suite_cases(suite):
       if not testcase_filter or case.id().startswith(testcase_filter):
diff --git a/src/ruby/.rubocop.yml b/src/ruby/.rubocop.yml
index ff5cf8db83..d13ce42655 100644
--- a/src/ruby/.rubocop.yml
+++ b/src/ruby/.rubocop.yml
@@ -15,3 +15,6 @@ Metrics/CyclomaticComplexity:
 
 Metrics/PerceivedComplexity:
   Max: 8
+
+Metrics/ClassLength:
+  Max: 250
diff --git a/src/ruby/lib/grpc/generic/rpc_server.rb b/src/ruby/lib/grpc/generic/rpc_server.rb
index ef2997c991..b30d19dd2b 100644
--- a/src/ruby/lib/grpc/generic/rpc_server.rb
+++ b/src/ruby/lib/grpc/generic/rpc_server.rb
@@ -107,7 +107,9 @@ module GRPC
 
     # Starts running the jobs in the thread pool.
     def start
-      fail 'already stopped' if @stopped
+      @stop_mutex.synchronize do
+        fail 'already stopped' if @stopped
+      end
       until @workers.size == @size.to_i
         next_thread = Thread.new do
           catch(:exit) do  # allows { throw :exit } to kill a thread
@@ -264,10 +266,10 @@ module GRPC
       @pool = Pool.new(@pool_size)
       @run_cond = ConditionVariable.new
       @run_mutex = Mutex.new
-      @running = false
+      # running_state can take 4 values: :not_started, :running, :stopping, and
+      # :stopped. State transitions can only proceed in that order.
+      @running_state = :not_started
       @server = RpcServer.setup_srv(server_override, @cq, **kw)
-      @stopped = false
-      @stop_mutex = Mutex.new
     end
 
     # stops a running server
@@ -275,27 +277,42 @@ module GRPC
     # the call has no impact if the server is already stopped, otherwise
     # server's current call loop is it's last.
     def stop
-      return unless @running
-      @stop_mutex.synchronize do
-        @stopped = true
+      @run_mutex.synchronize do
+        fail 'Cannot stop before starting' if @running_state == :not_started
+        return if @running_state != :running
+        transition_running_state(:stopping)
       end
       deadline = from_relative_time(@poll_period)
-      return if @server.close(@cq, deadline)
-      deadline = from_relative_time(@poll_period)
       @server.close(@cq, deadline)
       @pool.stop
     end
 
-    # determines if the server has been stopped
-    def stopped?
-      @stop_mutex.synchronize do
-        return @stopped
+    def running_state
+      @run_mutex.synchronize do
+        return @running_state
+      end
+    end
+
+    # Can only be called while holding @run_mutex
+    def transition_running_state(target_state)
+      state_transitions = {
+        not_started: :running,
+        running: :stopping,
+        stopping: :stopped
+      }
+      if state_transitions[@running_state] == target_state
+        @running_state = target_state
+      else
+        fail "Bad server state transition: #{@running_state}->#{target_state}"
       end
     end
 
-    # determines if the server is currently running
     def running?
-      @running
+      running_state == :running
+    end
+
+    def stopped?
+      running_state == :stopped
     end
 
     # Is called from other threads to wait for #run to start up the server.
@@ -304,13 +321,11 @@ module GRPC
     #
     # @param timeout [Numeric] number of seconds to wait
     # @result [true, false] true if the server is running, false otherwise
-    def wait_till_running(timeout = 0.1)
-      end_time, sleep_period = Time.now + timeout, (1.0 * timeout) / 100
-      while Time.now < end_time
-        @run_mutex.synchronize { @run_cond.wait(@run_mutex) } unless running?
-        sleep(sleep_period)
+    def wait_till_running(timeout = nil)
+      @run_mutex.synchronize do
+        @run_cond.wait(@run_mutex, timeout) if @running_state == :not_started
+        return @running_state == :running
       end
-      running?
     end
 
     # Runs the server in its own thread, then waits for signal INT or TERM on
@@ -360,11 +375,14 @@ module GRPC
     # @param service [Object|Class] a service class or object as described
     #        above
     def handle(service)
-      fail 'cannot add services if the server is running' if running?
-      fail 'cannot add services if the server is stopped' if stopped?
-      cls = service.is_a?(Class) ? service : service.class
-      assert_valid_service_class(cls)
-      add_rpc_descs_for(service)
+      @run_mutex.synchronize do
+        unless @running_state == :not_started
+          fail 'cannot add services if the server has been started'
+        end
+        cls = service.is_a?(Class) ? service : service.class
+        assert_valid_service_class(cls)
+        add_rpc_descs_for(service)
+      end
     end
 
     # runs the server
@@ -375,16 +393,13 @@ module GRPC
     # - #running? returns true after this is called, until #stop cause the
     #   the server to stop.
     def run
-      if rpc_descs.size.zero?
-        GRPC.logger.warn('did not run as no services were present')
-        return
-      end
       @run_mutex.synchronize do
-        @running = true
-        @run_cond.signal
+        fail 'cannot run without registering services' if rpc_descs.size.zero?
+        @pool.start
+        @server.start
+        transition_running_state(:running)
+        @run_cond.broadcast
       end
-      @pool.start
-      @server.start
       loop_handle_server_calls
     end
 
@@ -413,9 +428,9 @@ module GRPC
 
     # handles calls to the server
     def loop_handle_server_calls
-      fail 'not running' unless @running
+      fail 'not started' if running_state == :not_started
       loop_tag = Object.new
-      until stopped?
+      while running_state == :running
         begin
           an_rpc = @server.request_call(@cq, loop_tag, INFINITE_FUTURE)
           break if (!an_rpc.nil?) && an_rpc.call.nil?
@@ -430,11 +445,14 @@ module GRPC
         rescue Core::CallError, RuntimeError => e
           # these might happen for various reasonse.  The correct behaviour of
           # the server is to log them and continue, if it's not shutting down.
-          GRPC.logger.warn("server call failed: #{e}") unless stopped?
+          if running_state == :running
+            GRPC.logger.warn("server call failed: #{e}")
+          end
           next
         end
       end
-      @running = false
+      # @running_state should be :stopping here
+      @run_mutex.synchronize { transition_running_state(:stopped) }
       GRPC.logger.info("stopped: #{self}")
     end
 
@@ -484,9 +502,10 @@ module GRPC
       cls.assert_rpc_descs_have_methods
     end
 
+    # This should be called while holding @run_mutex
     def add_rpc_descs_for(service)
       cls = service.is_a?(Class) ? service : service.class
-      specs, handlers = rpc_descs, rpc_handlers
+      specs, handlers = (@rpc_descs ||= {}), (@rpc_handlers ||= {})
       cls.rpc_descs.each_pair do |name, spec|
         route = "/#{cls.service_name}/#{name}".to_sym
         fail "already registered: rpc #{route} from #{spec}" if specs.key? route
diff --git a/src/ruby/spec/generic/rpc_server_spec.rb b/src/ruby/spec/generic/rpc_server_spec.rb
index be6331d68b..dfaec6d6ed 100644
--- a/src/ruby/spec/generic/rpc_server_spec.rb
+++ b/src/ruby/spec/generic/rpc_server_spec.rb
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -220,19 +220,10 @@ describe GRPC::RpcServer do
       @srv = RpcServer.new(**opts)
     end
 
-    after(:each) do
-      @srv.stop
-    end
-
     it 'starts out false' do
       expect(@srv.stopped?).to be(false)
     end
 
-    it 'stays false after a #stop is called before #run' do
-      @srv.stop
-      expect(@srv.stopped?).to be(false)
-    end
-
     it 'stays false after the server starts running', server: true do
       @srv.handle(EchoService)
       t = Thread.new { @srv.run }
@@ -247,8 +238,8 @@ describe GRPC::RpcServer do
       t = Thread.new { @srv.run }
       @srv.wait_till_running
       @srv.stop
-      expect(@srv.stopped?).to be(true)
       t.join
+      expect(@srv.stopped?).to be(true)
     end
   end
 
@@ -266,9 +257,7 @@ describe GRPC::RpcServer do
         server_override: @server
       }
       r = RpcServer.new(**opts)
-      r.run
-      expect(r.running?).to be(false)
-      r.stop
+      expect { r.run }.to raise_error(RuntimeError)
     end
 
     it 'is true after run is called with a registered service' do
@@ -293,10 +282,6 @@ describe GRPC::RpcServer do
       @srv = RpcServer.new(**@opts)
     end
 
-    after(:each) do
-      @srv.stop
-    end
-
     it 'raises if #run has already been called' do
       @srv.handle(EchoService)
       t = Thread.new { @srv.run }
@@ -528,10 +513,6 @@ describe GRPC::RpcServer do
         @srv = RpcServer.new(**server_opts)
       end
 
-      after(:each) do
-        @srv.stop
-      end
-
       it 'should be added to BadStatus when requests fail', server: true do
         service = FailingService.new
         @srv.handle(service)
diff --git a/test/core/iomgr/timer_heap_test.c b/test/core/iomgr/timer_heap_test.c
index 077a9fd6bd..cd34696f7d 100644
--- a/test/core/iomgr/timer_heap_test.c
+++ b/test/core/iomgr/timer_heap_test.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -38,6 +38,8 @@
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
+#include <grpc/support/useful.h>
+
 #include "test/core/util/test_config.h"
 
 static gpr_timespec random_deadline(void) {
@@ -57,79 +59,6 @@ static grpc_timer *create_test_elements(size_t num_elements) {
   return elems;
 }
 
-static int cmp_elem(const void *a, const void *b) {
-  int i = *(const int *)a;
-  int j = *(const int *)b;
-  return i - j;
-}
-
-static size_t *all_top(grpc_timer_heap *pq, size_t *n) {
-  size_t *vec = NULL;
-  size_t *need_to_check_children;
-  size_t num_need_to_check_children = 0;
-
-  *n = 0;
-  if (pq->timer_count == 0) return vec;
-  need_to_check_children =
-      gpr_malloc(pq->timer_count * sizeof(*need_to_check_children));
-  need_to_check_children[num_need_to_check_children++] = 0;
-  vec = gpr_malloc(pq->timer_count * sizeof(*vec));
-  while (num_need_to_check_children > 0) {
-    size_t ind = need_to_check_children[0];
-    size_t leftchild, rightchild;
-    num_need_to_check_children--;
-    memmove(need_to_check_children, need_to_check_children + 1,
-            num_need_to_check_children * sizeof(*need_to_check_children));
-    vec[(*n)++] = ind;
-    leftchild = 1u + 2u * ind;
-    if (leftchild < pq->timer_count) {
-      if (gpr_time_cmp(pq->timers[leftchild]->deadline,
-                       pq->timers[ind]->deadline) >= 0) {
-        need_to_check_children[num_need_to_check_children++] = leftchild;
-      }
-      rightchild = leftchild + 1;
-      if (rightchild < pq->timer_count &&
-          gpr_time_cmp(pq->timers[rightchild]->deadline,
-                       pq->timers[ind]->deadline) >= 0) {
-        need_to_check_children[num_need_to_check_children++] = rightchild;
-      }
-    }
-  }
-
-  gpr_free(need_to_check_children);
-
-  return vec;
-}
-
-static void check_pq_top(grpc_timer *elements, grpc_timer_heap *pq,
-                         uint8_t *inpq, size_t num_elements) {
-  gpr_timespec max_deadline = gpr_inf_past(GPR_CLOCK_REALTIME);
-  size_t *max_deadline_indices =
-      gpr_malloc(num_elements * sizeof(*max_deadline_indices));
-  size_t *top_elements;
-  size_t num_max_deadline_indices = 0;
-  size_t num_top_elements;
-  size_t i;
-  for (i = 0; i < num_elements; ++i) {
-    if (inpq[i] && gpr_time_cmp(elements[i].deadline, max_deadline) >= 0) {
-      if (gpr_time_cmp(elements[i].deadline, max_deadline) > 0) {
-        num_max_deadline_indices = 0;
-        max_deadline = elements[i].deadline;
-      }
-      max_deadline_indices[num_max_deadline_indices++] = elements[i].heap_index;
-    }
-  }
-  qsort(max_deadline_indices, num_max_deadline_indices,
-        sizeof(*max_deadline_indices), cmp_elem);
-  top_elements = all_top(pq, &num_top_elements);
-  GPR_ASSERT(num_top_elements == num_max_deadline_indices);
-  for (i = 0; i < num_top_elements; i++) {
-    GPR_ASSERT(max_deadline_indices[i] == top_elements[i]);
-  }
-  gpr_free(max_deadline_indices);
-  gpr_free(top_elements);
-}
-
 static int contains(grpc_timer_heap *pq, grpc_timer *el) {
   size_t i;
   for (i = 0; i < pq->timer_count; i++) {
@@ -145,15 +74,19 @@ static void check_valid(grpc_timer_heap *pq) {
     size_t right_child = left_child + 1u;
     if (left_child < pq->timer_count) {
       GPR_ASSERT(gpr_time_cmp(pq->timers[i]->deadline,
-                              pq->timers[left_child]->deadline) >= 0);
+                              pq->timers[left_child]->deadline) <= 0);
     }
     if (right_child < pq->timer_count) {
       GPR_ASSERT(gpr_time_cmp(pq->timers[i]->deadline,
-                              pq->timers[right_child]->deadline) >= 0);
+                              pq->timers[right_child]->deadline) <= 0);
     }
   }
 }
 
+/*******************************************************************************
+ * test1
+ */
+
 static void test1(void) {
   grpc_timer_heap pq;
   const size_t num_test_elements = 200;
@@ -162,6 +95,8 @@ static void test1(void) {
   grpc_timer *test_elements = create_test_elements(num_test_elements);
   uint8_t *inpq = gpr_malloc(num_test_elements);
 
+  gpr_log(GPR_INFO, "test1");
+
   grpc_timer_heap_init(&pq);
   memset(inpq, 0, num_test_elements);
   GPR_ASSERT(grpc_timer_heap_is_empty(&pq));
@@ -172,7 +107,6 @@ static void test1(void) {
     check_valid(&pq);
     GPR_ASSERT(contains(&pq, &test_elements[i]));
     inpq[i] = 1;
-    check_pq_top(test_elements, &pq, inpq, num_test_elements);
   }
   for (i = 0; i < num_test_elements; ++i) {
     /* Test that check still succeeds even for element that wasn't just
@@ -182,7 +116,7 @@ static void test1(void) {
 
   GPR_ASSERT(pq.timer_count == num_test_elements);
 
-  check_pq_top(test_elements, &pq, inpq, num_test_elements);
+  check_valid(&pq);
 
   for (i = 0; i < num_test_operations; ++i) {
     size_t elem_num = (size_t)rand() % num_test_elements;
@@ -193,14 +127,12 @@ static void test1(void) {
       grpc_timer_heap_add(&pq, el);
       GPR_ASSERT(contains(&pq, el));
       inpq[elem_num] = 1;
-      check_pq_top(test_elements, &pq, inpq, num_test_elements);
       check_valid(&pq);
     } else {
       GPR_ASSERT(contains(&pq, el));
       grpc_timer_heap_remove(&pq, el);
       GPR_ASSERT(!contains(&pq, el));
       inpq[elem_num] = 0;
-      check_pq_top(test_elements, &pq, inpq, num_test_elements);
       check_valid(&pq);
     }
   }
@@ -210,7 +142,108 @@ static void test1(void) {
   gpr_free(inpq);
 }
 
+/*******************************************************************************
+ * test2
+ */
+
+typedef struct {
+  grpc_timer elem;
+  bool inserted;
+} elem_struct;
+
+static elem_struct *search_elems(elem_struct *elems, size_t count,
+                                 bool inserted) {
+  size_t *search_order = gpr_malloc(count * sizeof(*search_order));
+  for (size_t i = 0; i < count; i++) {
+    search_order[i] = i;
+  }
+  for (size_t i = 0; i < count * 2; i++) {
+    size_t a = (size_t)rand() % count;
+    size_t b = (size_t)rand() % count;
+    GPR_SWAP(size_t, search_order[a], search_order[b]);
+  }
+  elem_struct *out = NULL;
+  for (size_t i = 0; out == NULL && i < count; i++) {
+    if (elems[search_order[i]].inserted == inserted) {
+      out = &elems[search_order[i]];
+    }
+  }
+  gpr_free(search_order);
+  return out;
+}
+
+static void test2(void) {
+  gpr_log(GPR_INFO, "test2");
+
+  grpc_timer_heap pq;
+
+  elem_struct elems[1000];
+  size_t num_inserted = 0;
+
+  grpc_timer_heap_init(&pq);
+  memset(elems, 0, sizeof(elems));
+
+  for (size_t round = 0; round < 10000; round++) {
+    int r = rand() % 1000;
+    if (r <= 550) {
+      /* 55% of the time we try to add something */
+      elem_struct *el = search_elems(elems, GPR_ARRAY_SIZE(elems), false);
+      if (el != NULL) {
+        el->elem.deadline = random_deadline();
+        grpc_timer_heap_add(&pq, &el->elem);
+        el->inserted = true;
+        num_inserted++;
+        check_valid(&pq);
+      }
+    } else if (r <= 650) {
+      /* 10% of the time we try to remove something */
+      elem_struct *el = search_elems(elems, GPR_ARRAY_SIZE(elems), true);
+      if (el != NULL) {
+        grpc_timer_heap_remove(&pq, &el->elem);
+        el->inserted = false;
+        num_inserted--;
+        check_valid(&pq);
+      }
+    } else {
+      /* the remaining times we pop */
+      if (num_inserted > 0) {
+        grpc_timer *top = grpc_timer_heap_top(&pq);
+        grpc_timer_heap_pop(&pq);
+        for (size_t i = 0; i < GPR_ARRAY_SIZE(elems); i++) {
+          if (top == &elems[i].elem) {
+            GPR_ASSERT(elems[i].inserted);
+            elems[i].inserted = false;
+          }
+        }
+        num_inserted--;
+        check_valid(&pq);
+      }
+    }
+
+    if (num_inserted) {
+      gpr_timespec *min_deadline = NULL;
+      for (size_t i = 0; i < GPR_ARRAY_SIZE(elems); i++) {
+        if (elems[i].inserted) {
+          if (min_deadline == NULL) {
+            min_deadline = &elems[i].elem.deadline;
+          } else {
+            if (gpr_time_cmp(elems[i].elem.deadline, *min_deadline) < 0) {
+              min_deadline = &elems[i].elem.deadline;
+            }
+          }
+        }
+      }
+      GPR_ASSERT(
+          0 == gpr_time_cmp(grpc_timer_heap_top(&pq)->deadline, *min_deadline));
+    }
+  }
+
+  grpc_timer_heap_destroy(&pq);
+}
+
 static void shrink_test(void) {
+  gpr_log(GPR_INFO, "shrink_test");
+
   grpc_timer_heap pq;
   size_t i;
   size_t expected_size;
@@ -274,6 +307,7 @@ int main(int argc, char **argv) {
 
   for (i = 0; i < 5; i++) {
     test1();
+    test2();
     shrink_test();
   }
 
diff --git a/test/cpp/qps/qps_worker.cc b/test/cpp/qps/qps_worker.cc
index 9442017ddf..b83e9d1dd7 100644
--- a/test/cpp/qps/qps_worker.cc
+++ b/test/cpp/qps/qps_worker.cc
@@ -101,6 +101,19 @@ static std::unique_ptr<Server> CreateServer(const ServerConfig& config) {
   abort();
 }
 
+class ScopedProfile GRPC_FINAL {
+ public:
+  ScopedProfile(const char* filename, bool enable) : enable_(enable) {
+    if (enable_) grpc_profiler_start(filename);
+  }
+  ~ScopedProfile() {
+    if (enable_) grpc_profiler_stop();
+  }
+
+ private:
+  const bool enable_;
+};
+
 class WorkerServiceImpl GRPC_FINAL : public WorkerService::Service {
  public:
   WorkerServiceImpl(int server_port, QpsWorker* worker)
@@ -114,9 +127,8 @@ class WorkerServiceImpl GRPC_FINAL : public WorkerService::Service {
       return Status(StatusCode::RESOURCE_EXHAUSTED, "");
     }
 
-    grpc_profiler_start("qps_client.prof");
+    ScopedProfile profile("qps_client.prof", false);
     Status ret = RunClientBody(ctx, stream);
-    grpc_profiler_stop();
     return ret;
   }
 
@@ -128,9 +140,8 @@ class WorkerServiceImpl GRPC_FINAL : public WorkerService::Service {
       return Status(StatusCode::RESOURCE_EXHAUSTED, "");
     }
 
-    grpc_profiler_start("qps_server.prof");
+    ScopedProfile profile("qps_server.prof", false);
     Status ret = RunServerBody(ctx, stream);
-    grpc_profiler_stop();
     return ret;
   }
 
diff --git a/tools/distrib/python/docgen.py b/tools/distrib/python/docgen.py
index 4ac8f9c64a..161d83e3b7 100755
--- a/tools/distrib/python/docgen.py
+++ b/tools/distrib/python/docgen.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python2.7
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -51,29 +51,35 @@ SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
 PROJECT_ROOT = os.path.abspath(os.path.join(SCRIPT_DIR, '..', '..', '..'))
 
 CONFIG = args.config
-SETUP_PATH = os.path.join(PROJECT_ROOT, 'src/python/grpcio/setup.py')
-DOC_PATH = os.path.join(PROJECT_ROOT, 'src/python/grpcio/doc/build')
+SETUP_PATH = os.path.join(PROJECT_ROOT, 'setup.py')
+REQUIREMENTS_PATH = os.path.join(PROJECT_ROOT, 'requirements.txt')
+DOC_PATH = os.path.join(PROJECT_ROOT, 'doc/build')
 INCLUDE_PATH = os.path.join(PROJECT_ROOT, 'include')
 LIBRARY_PATH = os.path.join(PROJECT_ROOT, 'libs/{}'.format(CONFIG))
 VIRTUALENV_DIR = os.path.join(SCRIPT_DIR, 'distrib_virtualenv')
 VIRTUALENV_PYTHON_PATH = os.path.join(VIRTUALENV_DIR, 'bin', 'python')
+VIRTUALENV_PIP_PATH = os.path.join(VIRTUALENV_DIR, 'bin', 'pip')
 
 environment = os.environ.copy()
 environment.update({
     'CONFIG': CONFIG,
     'CFLAGS': '-I{}'.format(INCLUDE_PATH),
     'LDFLAGS': '-L{}'.format(LIBRARY_PATH),
-    'LD_LIBRARY_PATH': LIBRARY_PATH
+    'LD_LIBRARY_PATH': LIBRARY_PATH,
+    'GRPC_PYTHON_BUILD_WITH_CYTHON': '1',
 })
 
 subprocess_arguments_list = [
     {'args': ['make'], 'cwd': PROJECT_ROOT},
     {'args': ['virtualenv', VIRTUALENV_DIR], 'env': environment},
+    {'args': [VIRTUALENV_PIP_PATH, 'install', '-r', REQUIREMENTS_PATH],
+     'env': environment},
     {'args': [VIRTUALENV_PYTHON_PATH, SETUP_PATH, 'build'], 'env': environment},
     {'args': [VIRTUALENV_PYTHON_PATH, SETUP_PATH, 'doc'], 'env': environment},
 ]
 
 for subprocess_arguments in subprocess_arguments_list:
+  print('Running command: {}'.format(subprocess_arguments['args']))
   subprocess.check_call(**subprocess_arguments)
 
 if args.submit:
diff --git a/tools/run_tests/artifact_targets.py b/tools/run_tests/artifact_targets.py
index 288a3f0154..e61c46d8b5 100644
--- a/tools/run_tests/artifact_targets.py
+++ b/tools/run_tests/artifact_targets.py
@@ -69,16 +69,6 @@ def create_jobspec(name, cmdline, environ=None, shell=False,
   return jobspec
 
 
-def macos_arch_env(arch):
-  """Returns environ specifying -arch arguments for make."""
-  if arch == 'x86':
-    arch_arg = '-arch i386'
-  elif arch == 'x64':
-    arch_arg = '-arch x86_64'
-  else:
-    raise Exception('Unsupported arch')
-  return {'CFLAGS': arch_arg, 'LDFLAGS': arch_arg}
-
 _MACOS_COMPAT_FLAG = '-mmacosx-version-min=10.7'
 
 _ARCH_FLAG_MAP = {
@@ -191,13 +181,17 @@ class CSharpExtArtifact:
       environ = {'CONFIG': 'opt',
                  'EMBED_OPENSSL': 'true',
                  'EMBED_ZLIB': 'true',
-                 'CFLAGS': '-DGPR_BACKWARDS_COMPATIBILITY_MODE'}
+                 'CFLAGS': '-DGPR_BACKWARDS_COMPATIBILITY_MODE',
+                 'LDFLAGS': ''}
       if self.platform == 'linux':
         return create_docker_jobspec(self.name,
             'tools/dockerfile/grpc_artifact_linux_%s' % self.arch,
-            'tools/run_tests/build_artifact_csharp.sh')
+            'tools/run_tests/build_artifact_csharp.sh',
+            environ=environ)
       else:
-        environ.update(macos_arch_env(self.arch))
+        archflag = _ARCH_FLAG_MAP[self.arch]
+        environ['CFLAGS'] += ' %s %s' % (archflag, _MACOS_COMPAT_FLAG)
+        environ['LDFLAGS'] += ' %s' % archflag
         return create_jobspec(self.name,
                               ['tools/run_tests/build_artifact_csharp.sh'],
                               environ=environ)
diff --git a/tools/run_tests/build_python.sh b/tools/run_tests/build_python.sh
index f120fc7ed6..79a148faf1 100755
--- a/tools/run_tests/build_python.sh
+++ b/tools/run_tests/build_python.sh
@@ -40,7 +40,11 @@ export PATH=$ROOT/bins/$CONFIG:$ROOT/bins/$CONFIG/protobuf:$PATH
 export CFLAGS="-I$ROOT/include -std=gnu99"
 export LDFLAGS="-L$ROOT/libs/$CONFIG"
 export GRPC_PYTHON_BUILD_WITH_CYTHON=1
-export GRPC_PYTHON_ENABLE_CYTHON_TRACING=1
+
+if [ "$CONFIG" = "gcov" ]
+then
+  export GRPC_PYTHON_ENABLE_CYTHON_TRACING=1
+fi
 
 tox --notest
 
diff --git a/tools/run_tests/run_python.sh b/tools/run_tests/run_python.sh
index beb747a616..d4b7250cbb 100755
--- a/tools/run_tests/run_python.sh
+++ b/tools/run_tests/run_python.sh
@@ -40,13 +40,13 @@ export PATH=$ROOT/bins/$CONFIG:$ROOT/bins/$CONFIG/protobuf:$PATH
 export CFLAGS="-I$ROOT/include -std=c89"
 export LDFLAGS="-L$ROOT/libs/$CONFIG"
 export GRPC_PYTHON_BUILD_WITH_CYTHON=1
-export GRPC_PYTHON_ENABLE_CYTHON_TRACING=1
 
 if [ "$CONFIG" = "gcov" ]
 then
+  export GRPC_PYTHON_ENABLE_CYTHON_TRACING=1
   tox
 else
-  $ROOT/.tox/py27/bin/python $ROOT/setup.py test
+  $ROOT/.tox/py27/bin/python $ROOT/setup.py test_lite
 fi
 
 mkdir -p $ROOT/reports
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index cc004f38d7..2df82adf0a 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -360,7 +360,7 @@ class PythonLanguage(object):
           ['tools/run_tests/run_python.sh'],
           None,
           environ=dict(environment.items() +
-                       [('GPRC_PYTHON_TESTRUNNER_FILTER', suite_name)]),
+                       [('GRPC_PYTHON_TESTRUNNER_FILTER', suite_name)]),
           shortname='py.test.%s' % suite_name,
           timeout_seconds=5*60)
           for suite_name in tests_json]