Overview
The goal of FLY is to provide a portable, scalable and easy-to-use programming environment for scientific computing. Later on, all the concepts here described will be properly studied in deep.
Table of contents
Idea
FLY perceives a cloud computing infrastructure as a parallel computing architecture on which it is possible to execute some parts of its execution flow in parallel. FLY enables the domain developers (i.e., domain experts with limited knowledge about complex parallel and distributed systems) to design their applications exploiting data and task parallelism on any FlS architecture. This is achieved by a rich language that provides domain-specific constructs, that enable the developers to easily interact, using an environment abstraction, with different FaaS back-ends.
Basic concepts
Types
FLY provides two sets of types named basic and domain types. Basic types, inherited by Java, comprises boolean, integer, real (double point precision floats) and string. Moreover, FLY supports one/bi/three-dimensional array definition for basic types. In addition to basic types, FLY provides several domain types that enable the users to interact and communicate with the computing back-ends.
FLY is a strongly typed language since is based on Java backend. Once a variable is defined, can not be assigned a different type value to it.
Variables and Constants
To define a new variable FLY provide the var clause, followed by an assignment operator (=) and it’s initialization right-value.
var <identifier> = <value>
To define a new constant FLY provide instead the val clause, also followed by assignment operator and initialization value.
val <identifier> = <value>
Remember that constants are immutable, and can not change value after the initialization.
Identifiers
Identifiers can be any kind of character either lowercase (a-z), or uppercase (A-Z). Other allowd characters are the underscore ( _ ) and digits (0-9). Any identifier can not starts with a digit.
Each identifier it’s unique in the scope in which is defined, and can’t be defined other variable with the same identifier in the same scope.
Semicolon?
Even if FLY is based on Java, no semicolon are needed at the end of each statement. Each statement just needs a new-line character to be isolated by the others.
Scope
TODO
FLY Environments
FLY provides implicit support for parallel and distributed computing paradigms and memory locality, enabling the users to manage and elaborate data on a cloud environment without the effort of knowing all the details behind cloud providers API. A FLY program is executable either on a SMP or a cloud infrastructure (supporting FaaS) without a deep knowledge of the underlying computing resources. FLY is compiled in native code (Java code) and it is able to automatically exploit the computing resources available that better fit its computation requirements.
var Cloud = [type="azure", client_id="", tenant_id="", secret_key="", subscription_id="", region="West Europe", language="python", nthreads=10, seconds=300]
var Local = [type="smp", nthreads=4]
FLY Functions
The main innovative aspect of FLY is represented by the concept of FLY function. A FLY function can be seen as an independent block of code, that can be executed concurrently. FLY functions can be executed in sequential mode, in parallel on SMP or on a FaaS back-end.
func pi(){
var r = [type="random"]
var x = r.nextDouble()
var y = r.nextDouble()
var msg = 0
if((x * x)+(y * y) < 1.0){msg = 1}
ch!msg on cloud
}
func estimation(){
var sum = 0
var crt = 0
for i in [0:10] {
sum += ch? as Integer
crt += 1
}
println "pi estimation: " + (sum*4.0) / crt
}
fly pi in [0:10] on Cloud thenall estimation
Channels
The language provides programming constructs for functions definition, execution, synchronization and communication. Communication among different environments/back-ends is obtained through some virtual communication path named channels. Along these lines FLY has been designed as an enhanced scripting language and is composed by a sequence of standard instructions integrated with a number of FLY functions invocation, which interact via channels.
var ch = [type="channel"] on Cloud