GENERIC ERLANG PORT [DRIVER] (GEP[D]), VERSION 0.7 (Jan 22 2011)

PURPOSE
-------------------------------------------------
To automatically generate an Erlang port driver or Erlang port
for C/C++ bindings using a single self-contained file.

Files:
test_bindings.h contains the ONLY configuration to support the C functions in
    test_functions.h and test_functions.c

test_bindings.erl provides the gen_server to manage the port or port driver
erlang_functions_hrl.h creates the erlang function interface
port_driver.cpp provides the Erlang port driver implementation
port.cpp and port.hpp provide the Erlang port implementation

Whether PORT_DRIVER_NAME_PREFIX or PORT_NAME_PREFIX is defined determines
if a port driver or port is built, respectively (in test_bindings.h).
If both are defined, a port driver is built.

Features:
- a function binding with only a single line tuple
- efficient passing of function types with no intermediate character buffer
- functionality like the Erlang Driver Tool Kit (EDTK) (no fd handling though)
- macro expansion to avoid code duplication errors
- floating point type handling
- stdout/stderr handling in the generated port code

Caveat:
The generated port driver code can not be used for hot code updating
if it performs an asynchronous call because erts will lock the driver
(making it "permanent") with driver_lock_driver()
(http://erlang.org/doc/man/erl_driver.html#driver_lock_driver).
With the driver locked, there is no possibility that an async
operation would create instability after a hot code update.


BUILDING
-------------------------------------------------

Some of the newer features in port_driver.cpp require erts >= 5.6.
Boost is required for the preprocessor macro expansion code
(http://www.boost.org/).

To build with cmake:
  mkdir build
  cd build
  cmake ..
  make

To build with the make script:
  ./make.sh


RUNNING
-------------------------------------------------

The test_bindings code should generate output similar to:

$ erl +A 16
Erlang R13B02 (erts-5.7.3) [source] [64-bit] [smp:4:4] [rq:4] [async-threads:16] [kernel-poll:false]

Eshell V5.7.3  (abort with ^G)
1> test_bindings:start().
using port driver
{ok,<0.35.0>}
2> test_bindings:test(). 
sync sleep
async sleep
...
ok
3>
async function call returned: {ok,ok}
3>


LICENSE
-------------------------------------------------
BSD license


CONTACT
-------------------------------------------------
Michael Truog <mjtruog at gmail dot com>