update docs

fairmq/README.md

@@ -1,80 +1,16 @@
 # FairMQ
 
-The standard FairRoot is running all the different analysis tasks within one process. The FairMQ ([Message Queue](http://en.wikipedia.org/wiki/Message_queue)) allows starting tasks on different processes and provides the communication layer between these processes.
+Standard FairRoot is running all the different analysis tasks within one process. FairMQ ([Message Queue](http://en.wikipedia.org/wiki/Message_queue)) allows starting tasks on different processes and provides the communication layer between these processes.
 
-## Devices
-
-The components encapsulating the tasks are called **devices** and derive from the common base class `FairMQDevice`. FairMQ provides ready to use devices to organize the dataflow between the components (without touching the contents of a message), providing functionality like merging and splitting of the data stream (see subdirectory `devices`).
-
-## Topology
-
-Devices are arranged into **topologies** where each device has a defined number of data inputs and outputs.
-
-Example of a simple FairMQ topology:
-
-![example of FairMQ topology](../docs/images/fairmq-example-topology.png?raw=true "Example of possible FairMQ topology")
-
-Within a topology each device needs a unique id (given to it via required command line option `--id`).
-
-Topology configuration is currently happening via setup scripts. This is very rudimentary and a much more flexible system is now in development. For now, example setup scripts can be found in directory `FairRoot/example/Tutorial3/` along with some additional documentation.
-
-## Communication Patterns
-
-FairMQ devices communicate via the communication patterns offered by ZeroMQ (or nanomsg): PUSH-PULL, PUB-SUB, REQ-REP, PAIR, [more info here](http://api.zeromq.org/4-0:zmq-socket). Each transport may provide further patterns.
-
-## Messages
-
-Devices transport data between each other in form of `FairMQMessage`s. These can be filled with arbitrary content. Message can be initialized in three different ways:
-- **with no parameters**: Initializes an empty message (typically used for receiving).
-- **given message size**: Initializes message body with a given size. Fill the created contents via buffer pointer.
-- **given existing buffer and a size**: Initialize the message from an existing buffer. In case of ZeroMQ this is a zero-copy operation.
-
-After sending the message, the transport takes over control over the message body and will free it with `free()` after it is no longer used. A callback can be given to the message object, to be called instead of the destruction with `free()` (for initialization via buffer+size).
-
-## Transport Interface
-
-The communication layer is available through an interface. Three interface implementations are currently available. Main implementation uses the [ZeroMQ](http://zeromq.org) library. Alternative implementation relies on the [nanomsg](http://nanomsg.org) library. Third transport implementation is using shared memory via boost::interprocess & ZeroMQ combination.
-
-Here is an overview to give an idea how interface is implemented:
-
-![FairMQ transport interface](../docs/images/fairmq-transport-interface.png?raw=true "FairMQ transport interface")
-
-Currently, the transports have been tested to work with these communication patterns:
-
-|               | ZeroMQ | nanomsg | Shared Memory |
-| ------------- |--------| ------- | ------------- |
-| PAIR          | yes    | yes     | yes           |
-| PUSH/PULL     | yes    | yes     | yes           |
-| PUB/SUB       | yes    | yes     | no            |
-| REQ/REP       | yes    | yes     | yes           |
-
-## State Machine
-
-Each FairMQ device has an internal state machine:
-
-![FairMQ state machine](../docs/images/fairmq-states.png?raw=true "FairMQ state machine")
-
-The state machine can be querried and controlled via `GetCurrentStateName()` and `ChangeState("<state name>")` methods. Only legal state transitions are allowed (see image above). Illegal transitions will fail with an error.
-
-If the device is running in interactive mode (default), states can be changed via keyboard input:
-
- - `'h'` - help
- - `'p'` - pause
- - `'r'` - run
- - `'s'` - stop
- - `'t'` - reset task
- - `'d'` - reset device
- - `'q'` - end
- - `'j'` - init task
- - `'i'` - init device
-
-Without the interactive mode, for example for a run in background, two other control mechanisms are available:
-
- - static (`--control static`) - device goes through a simple init -> run -> reset -> exit chain.
- - dds (`--control dds`) - device is controled by external command, in this case using dds commands (fairmq-dds-command-ui).
-
-## Examples
-
-A collection of simple examples in `FairRoot/examples/MQ` directory demonstrates some common usage patterns of FairMQ.
-
-A number of devices to handle the data from the Tutorial3 FairTestDetector of FairRoot are provided as an example and can be found in `FairRoot/base/MQ` directory. The implementation of the tasks run by these devices can be found `FairRoot/examples/advanced/Tutorial3`. The implementation includes sending raw binary data as well as serializing the data with either [Boost Serialization](http://www.boost.org/doc/libs/release/libs/serialization/), [Google Protocol Buffers](https://developers.google.com/protocol-buffers/) or [Root TMessage](http://root.cern.ch/root/html/TMessage.html). Following the examples you can implement your own devices to transport arbitrary data.
+1. [Device](docs/Device.md#1-device)
+   1. [Topology](docs/Device.md#11-topology)
+   2. [Communication Patterns](docs/Device.md#12-communication-patterns)
+   3. [State Machine](docs/Device.md#13-state-machine)
+2. [Transport Interface](docs/Transport.md#2-transport-interface)
+   1. [Message](docs/Transport.md#21-message)
+      1. [Ownership](docs/Transport.md#211-ownership)
+   2. [Channel](docs/Transport.md#22-channel)
+   3. [Poller](docs/Transport.md#23-poller)
+3. [Development](docs/Development.md#3-development)
+   1. [Testing](docs/Development.md#31-testing)
+4. [Examples](docs/Examples.md#4-examples)

fairmq/docs/Development.md

@@ -0,0 +1,9 @@
+← [Back](../README.md)
+
+# 3. Development
+
+# 3.1 Testing
+
+TODO
+
+← [Back](../README.md)

fairmq/docs/Device.md

@@ -0,0 +1,48 @@
+← [Back](../README.md)
+
+# 1. Device
+
+The components encapsulating the tasks are called **devices** and derive from the common base class `FairMQDevice`. FairMQ provides ready to use devices to organize the dataflow between the components (without touching the contents of a message), providing functionality like merging and splitting of the data stream (see subdirectory `devices`).
+
+## 1.1 Topology
+
+Devices are arranged into **topologies** where each device has a defined number of data inputs and outputs.
+
+Example of a simple FairMQ topology:
+
+![example of FairMQ topology](images/example_topology.png?raw=true "Example of possible FairMQ topology")
+
+Within a topology each device needs a unique id (given to it via required command line option `--id`).
+
+Topology configuration is currently happening via setup scripts. This is very rudimentary and a much more flexible system is now in development. For now, example setup scripts can be found in directory `FairRoot/example/Tutorial3/` along with some additional documentation.
+
+## 1.2 Communication Patterns
+
+FairMQ devices communicate via the communication patterns offered by ZeroMQ (or nanomsg): PUSH-PULL, PUB-SUB, REQ-REP, PAIR, [more info here](http://api.zeromq.org/4-0:zmq-socket). Each transport may provide further patterns.
+
+## 1.3 State Machine
+
+Each FairMQ device has an internal state machine:
+
+![FairMQ state machine](images/device_states.png?raw=true "FairMQ state machine")
+
+The state machine can be querried and controlled via `GetCurrentStateName()` and `ChangeState("<state name>")` methods. Only legal state transitions are allowed (see image above). Illegal transitions will fail with an error.
+
+If the device is running in interactive mode (default), states can be changed via keyboard input:
+
+ - `'h'` - help
+ - `'p'` - pause
+ - `'r'` - run
+ - `'s'` - stop
+ - `'t'` - reset task
+ - `'d'` - reset device
+ - `'q'` - end
+ - `'j'` - init task
+ - `'i'` - init device
+
+Without the interactive mode, for example for a run in background, two other control mechanisms are available:
+
+ - static (`--control static`) - device goes through a simple init -> run -> reset -> exit chain.
+ - dds (`--control dds`) - device is controled by external command, in this case using dds commands (fairmq-dds-command-ui).
+
+← [Back](../README.md)

fairmq/docs/Examples.md

@@ -0,0 +1,9 @@
+← [Back](../README.md)
+
+# 4. Examples
+
+A collection of simple examples in `FairRoot/examples/MQ` directory demonstrates some common usage patterns of FairMQ.
+
+A number of devices to handle the data from the Tutorial3 FairTestDetector of FairRoot are provided as an example and can be found in `FairRoot/base/MQ` directory. The implementation of the tasks run by these devices can be found `FairRoot/examples/advanced/Tutorial3`. The implementation includes sending raw binary data as well as serializing the data with either [Boost Serialization](http://www.boost.org/doc/libs/release/libs/serialization/), [Google Protocol Buffers](https://developers.google.com/protocol-buffers/) or [Root TMessage](http://root.cern.ch/root/html/TMessage.html). Following the examples you can implement your own devices to transport arbitrary data.
+
+← [Back](../README.md)

fairmq/docs/Transport.md

@@ -0,0 +1,83 @@
+← [Back](../README.md)
+
+# 2. Transport Interface
+
+The communication layer is available through the transport interface. Three interface implementations are currently available. Main implementation uses the [ZeroMQ](http://zeromq.org) library. Alternative implementation relies on the [nanomsg](http://nanomsg.org) library. Third transport implementation is using shared memory via boost::interprocess & ZeroMQ combination.
+
+Here is an overview to give an idea how the interface is implemented:
+
+![FairMQ transport interface](images/transport_interface.png?raw=true "FairMQ transport interface")
+
+Currently, the transports have been tested to work with these communication patterns:
+
+|               | zeromq | nanomsg | shmem |
+| ------------- |--------| ------- | ----- |
+| PAIR          | yes    | yes     | yes   |
+| PUSH/PULL     | yes    | yes     | yes   |
+| PUB/SUB       | yes    | yes     | no    |
+| REQ/REP       | yes    | yes     | yes   |
+
+The next table shows the supported address types for each transport implementation:
+
+|             | zeromq | nanomsg | shmem | comment                                       |
+| ----------- | ------ | ------- | ----- | --------------------------------------------- |
+| `inproc://` | yes    | yes     | yes   | in process: useful for unit testing           |
+| `ipc://`    | yes    | yes     | yes   | inter process comm: useful on single machin   |
+| `tcp://`    | yes    | yes     | yes   | useful for any communication, local or remote |
+
+## 2.1 Message
+
+Devices transport data between each other in form of `FairMQMessage`s. These can be filled with arbitrary content. Message can be initialized in three different ways by calling `NewMessage()`:
+
+```cpp
+FairMQMessagePtr NewMessage() const;
+```
+**with no parameters**: Initializes an empty message (typically used for receiving).
+
+```cpp
+FairMQMessagePtr NewMessage(const size_t size) const;
+```
+**given message size**: Initializes message body with a given size. Fill the created contents via buffer pointer.
+
+```cpp
+using fairmq_free_fn = void(void* data, void* hint);
+FairMQMessagePtr NewMessage(void* data, const size_t size, fairmq_free_fn* ffn, void* hint = nullptr) const;
+```
+**given existing buffer and a size**: Initialize the message from an existing buffer. In case of ZeroMQ this is a zero-copy operation.
+
+Additionally, FairMQ provides two more message factories for convenience:
+```cpp
+template<typename T>
+FairMQMessagePtr NewSimpleMessage(const T& data) const
+```
+**copy and own**: Copy the `data` argument into the returned message and take ownership (free memory after message is sent). This interface is useful for small, [trivially copyable](http://en.cppreference.com/w/cpp/concept/TriviallyCopyable) data.
+
+```cpp
+template<typename T>
+FairMQMessagePtr NewStaticMessage(const T& data) const
+```
+**point to existing memory**: The returned message will point to the `data` argument, but not take ownership (someone else must destruct this variable). Make sure that `data` lives long enough to be successfully sent. This interface is most useful for third party managed, contiguous memory (Be aware of shallow types with internal pointer references! These will not be sent.)
+
+## 2.1.1 Ownership
+
+The component of a program, that is reponsible for the allocation or destruction of data in memory, is taking ownership over this data. Ownership may be passed along to another component. It is also possible that multiple components share ownership of data. In this case, some strategy must be in place to determine the last user of the data and assign her the responsibility of destruction.
+
+After queuing a message for sending in FairMQ, the transport takes ownership over the message body and will free it with `free()` after it is no longer used. A callback can be passed to the message object, to be called instead of the destruction with `free()` (for initialization via buffer+size).
+
+```cpp
+static void FairMQNoCleanup(void* /*data*/, void* /*obj*/) {}
+
+template<typename T>
+static void FairMQSimpleMsgCleanup(void* /*data*/, void* obj) { delete static_cast<T*>(obj); }
+```
+For convenience, two common deleter callbacks are already defined in the `FairMQTransportFactory` class to aid the user in controlling ownership of the data.
+
+## 2.2 Channel
+
+TODO
+
+## 2.3 Poller
+
+TODO
+
+← [Back](../README.md)