A register-based, parallel virtual machine programmable in custom assembly lookalike language with strong emphasis on reliability, predictability, and concurrency.
]$ ./configure # (1) configure the project ]$ make -j # (2) build it
./configure is not required if you do not want or need to run tests
under Valgirnd. Configuring will create necessary suppresion file for your
version of Valgrind.
Note: the default build is run with
-O0 (without any optimisations).
You can compile Viua VM with higher optimisation leves, but keep in mind that
the compilation might not succeed on machines with less than 4GB RAM if you use
-O3 optimisation level.
This is tracked by issue
7c06177872c3a718510a54e6513820f8fe0fb99b in the
embedded issue repository.
.function: main/0 allocate_registers %3 local text %1 local "Hello World!\n" integer %2 local 1 io_write %2 local %2 local %1 local io_wait void %2 local 1s izero %0 local return .end
README.asm file to see commented version of this sample program.
Viua is a runtime environment focused on reliability, predictability, and concurrency. It is suitable for writing long-running software that runs in the background providing infrastructure services:
The VM is not ready to be used in places where performance matters. It is best to employ it for tasks which do not require human interaction or near real-time responses.
The VM should be able to fully utilise all cores of the CPU it's running on to execute the virtual processes and FFI calls of the software it runs. If configured to do so it may generate high CPU loads, but is relatively light on RAM and should not contain any memory leaks (all runtime tests are run under Valgrind to ensure this).
The virtual machine is covered by more than 500 tests to provide safety, and guard against possible regressions. It ships with an assembler and a static analyser, but does not provide any higher-level language compiler or debugger.
Some features also supported by the VM:
For enhanced reliability, Viua assembler provides a built-in static analyser that is able to detect most common errors related to register manipulation at compile time (type mismatches, invalid register access). It provides traced errors whenever possible, i.e. when it detects an error and is able to trace execution path that would trigger it, a sequence of instructions (with source code locations) leading to the detected error is presented to the user instead of a single offending instruction.
Current limitations include:
Viua VM is an alpha-stage software.
Even though great care is taken not to introduce bugs during development, it is inevitable that some will make their way into the codebase. Viua in its current state is not production ready; bytecode definition and format will be altered, opcodes may be removed and added without deprecation warning, and various external and internal APIs may change without prior notice.
Suitable announcements will be made when the VM reaches beta, RC and release stages.
The way Viua works has mostly been influenced by C++ (static and dynamic method dispatch, move semantics), and Erlang (message passing, indepenedent VM-based lightweight processes as units of concurrency).
Viua can be programmed in an assembly-like language which must be compiled into bytecode. A typical session is shown below (assuming current working directory is the local clone of Viua repository):
]$ vim some_file.asm ]$ ./build/bin/vm/asm -o some_file.bc some_file.asm # static analysis or syntax errors... ]$ vim some_file.asm ]$ ./build/bin/vm/asm -o some_file.bc some_file.asm ]$ ./build/bin/vm/kernel some_file.bc # runtime exceptions... ]$ vim some_file.asm ]$ ./build/bin/vm/asm -o some_file.bc some_file.asm ]$ ./build/bin/vm/kernel some_file.bc
Please read CONTRIBUTING.markdown for details on development setup, and the process for submitting patches, bug reports, and feature suggestions.
Issues are tracked using the Issue tool.
Patches should be submitted via email. See "Contact information" at the bottom of this file.
The code is licensed under GNU GPL v3.
Project website: viuavm.org
Maintainer: <marekjm at ozro dot pw>