Qpid Dispatch
=============

Qpid Dispatch is a high-performance, lightweight AMQP 1.0 message router.
It provides flexible and scalable interconnect between any AMQP endpoints,
whether they be clients, brokers or other AMQP-enabled services.

Dependencies
============

To build dispatch on a yum-based Linux system, you will need the following
packages installed:

- qpid-proton-c-devel
- python-qpid-proton
- cmake
- make
- gcc
- python-devel
- cyrus-sasl-plain
- cyrus-sasl-devel
- libnghttp2-devel
- asciidoc (for building docs)
- asciidoctor (for building docs)

The unit tests are implemented using Python's unittest library.

Dispatch will not build on Windows.

To build formatted documentation (man pages, HTML, PDF) see the requirements in doc/README

Building and testing
====================

From the dispatch directory:

$ mkdir my_build    # or directory of your choice.
$ cd my_build
$ cmake ..
$ make


Running The Tests
=================

From the <build> directory you can run all the system and tests with:
$ ctest -VV

ctest uses the script <build>/test/run.py to set up the correct environment for
tests. You can use it to run tests individually from the <build>/tests
directory, for example:

$ ./run.py unit_tests_size 3
$ ./run.py -m unittest system_tests_qdstat

Run it without arguments to get a summary of how it can be used:
$ ./run.py

The HTTP2 system tests (tests/system_tests_http2.py) use the Python Quart framework to start a HTTP2 server. 
The HTTP2 system tests will run only if
   1. Python version >= 3.7
   2. Python Web Microframework Quart version >= 0.13
   3. curl is available

The TCP system tests (tests/system_tests_tcp_adaptor.py) use the
Python selectors module when running echo clients and servers.
The TCP system tests run only if Python selectors is available.

To install pip, Quart, and selectors
 - curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
 - python3 get-pip.py
 - pip3 install --user quart
 - pip3 install --user selectors

The gRPC system tests (tests/system_tests_grpc.py) use grpcio and protobuf modules.
To install them use:
  - pip3 install --user grpcio protobuf
In order to regenerate the auto generated pb2 files used by system_tests_grpc.py,
you must also install the following dependency:
  - pip3 install --user grpcio-tools
And run the following command to generate grpc code:
  - python -m grpc_tools.protoc -I. --python_out=. --grpc_python_out=. ./friendship.proto


Test Suite Code Coverage (GNU tools only)
=========================================

Use coverage analysis to ensure that all code paths are exercised by
the test suite. To run the tests and perform code coverage analysis:

# install the lcov package
$ yum install lcov

# configure and build for the Coverage build type (from the <build> directory):
$ cmake -DCMAKE_BUILD_TYPE=Coverage .. && make

# run the test suite and generate the coverage html output
$ ctest && make coverage

# Then point your browser at:
  <build>/coverage_results/html/index.html


Clean build, install and test
=============================

$ source config.sh; test.sh

This does the following:
- NOTE: delete any existing directories 'build' and 'install'
- Do a fresh cmake and make in directory 'build'
- Run unit tests (not system tests) in 'build'
- Do 'make install' into the directory 'install'
- Run system tests on the installation in 'install'.


Run Time Validation
===================

The CTest test suite can be configured to enable extra run time
validation checks against the dispatch router.

Since run time validation slows down qdrouter considerably it is
disabled by default.  It can be enabled by setting the RUNTIME_CHECK
build flag via the cmake command.

Note well: Depending on your environment the ctest suite may time out
if validation is enabled due to the additional run time overhead it
adds.  You can extend the default test time via the ctest "--timeout"
option.  Example:

ctest --timeout 1500 -VV

The Qpid Dispatch Router test suite supports the following run time
validation tools:

Valgrind Memcheck
-----------------
Runs qdrouterd under Valgrind's memcheck leak checker during the CTest
suite.  This will cause tests to fail if a memory error is
encountered.  Use the grinder tool (in the bin directory) to create a
summary of the errors found during the test run.

The valgrind toolset must be installed in order to use memcheck.

To enable memcheck set the RUNTIME_CHECK build flag to "memcheck":

cmake .. -DRUNTIME_CHECK=memcheck

If valgrind detects errors the qdrouterd process will exit with an
exit code of 42. This will be displayed in the CTest output. For
example:

RuntimeError: Errors during teardown:
Process XXXX error: exit code 42, expected 0

GCC/Clang Thread Sanitizer (TSAN)
---------------------------------
This option turns on extra run time threading verification.

Applicable only to GCC versions >= 7.4 and Clang versions >= 6.0.

To enable the thread sanitizer set the RUNTIME_CHECK build flag to "tsan":

cmake .. -DRUNTIME_CHECK=tsan

The TSAN library (libtsan) must be installed in order to use this
option.

If threading violations are detected during the CTest suite the
qdrouterd process will exit with an exit code of 66. This will be
displayed in the CTest output. For example:

RuntimeError: Errors during teardown:
Process XXXX error: exit code 66, expected 0

False positives can be suppressed via the tsan.supp file in the tests
directory.

GCC/Clang Address Sanitizer (ASAN)
----------------------------------
This option turns on extra run time memory verification, including
leak checks.

Applicable only to GCC versions >= 5.4 and Clang versions >= 6.0.

To enable the address sanitizer set the RUNTIME_CHECK build flag to "asan":

cmake .. -DCMAKE_C_FLAGS=-DQD_MEMORY_DEBUG -DRUNTIME_CHECK=asan

On Aarch64, a hardware-assisted address sanitizer is enabled with "hwasan":

cmake .. -DCMAKE_C_FLAGS=-DQD_MEMORY_DEBUG -DRUNTIME_CHECK=hwasan

The ASAN (libasan) and UBSAN (libubsan) libraries must be installed in
order to use this option.

Memory pool will produce false leak reports unless QD_MEMORY_DEBUG
is also defined.

False positive leak errors can be suppressed via the lsan.supp file in
the tests directory.


CMake Build Options
===================

Use `cmake-gui` to explore the CMake build options available.
Existing build directory can be opened with `cmake-gui -S .. -B .`

-DCMAKE_BUILD_TYPE=
-------------------

Dispatch defaults to building with the `RelWithDebInfo` CMake preset.
Other options include `Debug` (disables optimizations) and `Coverage`.

-DQD_ENABLE_ASSERTIONS=
-----------------------

Seting this to `ON` enables asserts irrespective of `CMAKE_BUILD_TYPE`.

-DQD_MEMORY_STATS=
------------------

Dispatch will track memory pool usage statistics if this is enabled.

-DCONSOLE_INSTALL=
------------------

Web console will not be built if this is set to `OFF`.

-DRUNTIME_CHECK=
----------------

Enables C/C++ runtime checkers. See "Run Time Validation" chapter above.