AbstractExecutionContext (Protelis unspecified Javadoc API)

java.lang.Object
- org.protelis.vm.impl.AbstractExecutionContext<S>

Type Parameters:

S - self-type. Subclasses must parameterize AbstractExecutionContext with themselves, and return themselves in instance(). This forces a compiler check on the type of instanced contexts, ensuring (if no foolish cast is used) that restricted contexts have all the methods available in the main ExecutionContext. For instance, if your class is MyContext, it should be written as MyContext extends AbstractExecutionContext<MyContext>.

All Implemented Interfaces:

ExecutionContext
```
public abstract class AbstractExecutionContext<S extends AbstractExecutionContext<S>>
extends java.lang.Object
implements ExecutionContext
```
Partial implementation of ExecutionContext, containing functionality expected to be shared between most implementations. Instantiations of Protelis should generally extend this class.

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`AbstractExecutionContext(ExecutionEnvironment execenv, NetworkManager netmgr)` Create a new AbstractExecutionContext with a default, time-efficient code path factory.
`protected`	`AbstractExecutionContext(ExecutionEnvironment executionEnvironment, NetworkManager networkManager, CodePathFactory codePathFactory)` Create a new AbstractExecutionContext with the specified `CodePathFactory`.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`<T,R> Field<R>`	`buildField(java.util.function.Function<T,R> computeValue, T localValue)` Builds a new `Field`, fetching data from all the aligned neighbors.
`<T,R> Field<R>`	`buildFieldDeferred(java.util.function.Function<T,R> computeValue, T currentLocal, java.util.function.Supplier<T> toBeSent)` Builds a new `Field`, fetching data from all the aligned neighbors.
`void`	`commit()` Called just after the VM is executed, to finalize information of the execution for the environment.
`protected void`	`commitRecursively()` recursively commits on restricted contexts.
`java.lang.Number`	`getDeltaTime()`
`ExecutionEnvironment`	`getExecutionEnvironment()`
`protected java.util.Map<Reference,?>`	`getFunctions()` Support for first-class functions by returning the set of currently accessible functions.
`protected NetworkManager`	`getNetworkManager()` Accessor for abstract network interface.
`<P> P`	`getPersistent(java.util.function.Supplier<P> ifAbsent)` Gets a value that survives across rounds.
`java.util.Map<CodePath,java.lang.Object>`	`getStoredState()`
`java.lang.Object`	`getVariable(Reference name)` Look up the value of a variable from the local environment.
`protected abstract S`	`instance()` Produce a child execution context, for encapsulated evaluation of sub-programs.
`void`	`newCallStackFrame(byte... id)`
`void`	`newCallStackFrame(int... id)`
`void`	`putMultipleVariables(java.util.Map<Reference,?> map)` Pushes multiple variables.
`void`	`putVariable(Reference name, java.lang.Object value)` Puts a variable value, overwriting the previous one, if any.
`S`	`restrictDomain(Field<?> f)` Give a field, returns a new `ExecutionContext` whose domain is the same of the field one.
`void`	`returnFromCallFrame()` returns from the last frame.
`<T> T`	`runInNewStackFrame(int id, java.util.function.Function<ExecutionContext,T> operation)`
`void`	`setGloballyAvailableReferences(java.util.Map<Reference,?> knownFunctions)` Used internally to support first-class functions by make the functions of a program accessible for reflection at runtime.
`void`	`setPersistent(java.lang.Object o)` Stores a value to be used in future rounds via getPersistent.
`void`	`setup()` Called just before the VM is executed, to enable and preparations needed in the environment.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.protelis.vm.ExecutionContext
getCurrentTime, getDeviceUID, nextRandomDouble

- Constructor Detail
  - AbstractExecutionContext
```
protected AbstractExecutionContext(ExecutionEnvironment execenv,
                                   NetworkManager netmgr)
```
    Create a new AbstractExecutionContext with a default, time-efficient code path factory.
    
    Parameters:
    
    execenv - The execution environment
    
    netmgr - Abstract network interface to be used
  - AbstractExecutionContext
```
protected AbstractExecutionContext(ExecutionEnvironment executionEnvironment,
                                   NetworkManager networkManager,
                                   CodePathFactory codePathFactory)
```
    Create a new AbstractExecutionContext with the specified CodePathFactory. Subclasses which want to use hashing or other means to encode CodePaths can call this constructor, e.g.:
```
 super(executionEnvironment, networkManager, new HashingCodePathFactory(Hashing.sha256()));
 
```
    Parameters:
    
    executionEnvironment - The execution environment
    
    networkManager - Abstract network interface to be used
    
    codePathFactory - The code path factory to use
- Method Detail
  - buildField
```
public final <T,R> Field<R> buildField(java.util.function.Function<T,R> computeValue,
                                       T localValue)
```
    Description copied from interface: ExecutionContext
    
    Builds a new Field, fetching data from all the aligned neighbors. A neighbor is considered to be aligned it it has reached the exact same DefaultTimeEfficientCodePath. The field will always contain at least one value, namely the value of the local device.
    
    Specified by:
    
    buildField in interface ExecutionContext
    
    Type Parameters:
    
    T - the type of the input
    
    R - the type of the output
    
    Parameters:
    
    computeValue - a function that will be applied to localValue and the equivalents shared from neighbors in the process of constructing this field: the field consists of the values returned from applying computeValue to each of device's value
    
    localValue - the local value for this field
    
    Returns:
    
    a new Field containing the local device value and the values for any of the aligned neighbors
  - buildFieldDeferred
```
public final <T,R> Field<R> buildFieldDeferred(java.util.function.Function<T,R> computeValue,
                                               T currentLocal,
                                               java.util.function.Supplier<T> toBeSent)
```
    Description copied from interface: ExecutionContext
    
    Builds a new Field, fetching data from all the aligned neighbors. A neighbor is considered to be aligned it it has reached the exact same DefaultTimeEfficientCodePath. The field will always contain at least one value, namely the value of the local device. The deferred version does not immediately schedule the local value for being sent away. Rather, it schedules the provided Supplier to be executed at the end of the round for obtaining the value to be shared. This function is the base upon which the ShareCall is built.
    
    Specified by:
    
    buildFieldDeferred in interface ExecutionContext
    
    Type Parameters:
    
    T - the type of the input
    
    R - the type of the output
    
    Parameters:
    
    computeValue - a function that will be applied to localValue and the equivalents shared from neighbors in the process of constructing this field: the field consists of the values returned from applying computeValue to each of device's value
    
    currentLocal - the value to be used as local for this field
    
    toBeSent - a Supplier which will be used to compute the local value for this field that will get exported at the end of the round
    
    Returns:
    
    a new Field containing the local device value and the values for any of the aligned neighbors
  - commit
```
public final void commit()
```
    Description copied from interface: ExecutionContext
    
    Called just after the VM is executed, to finalize information of the execution for the environment.
    
    Specified by:
    
    commit in interface ExecutionContext
  - commitRecursively
```
protected final void commitRecursively()
```
    recursively commits on restricted contexts.
  - getDeltaTime
```
public java.lang.Number getDeltaTime()
```
    Specified by:
    
    getDeltaTime in interface ExecutionContext
    
    Returns:
    
    the current time, relative to last round
  - getExecutionEnvironment
```
public final ExecutionEnvironment getExecutionEnvironment()
```
    Specified by:
    
    getExecutionEnvironment in interface ExecutionContext
    
    Returns:
    
    The current ExecutionEnvironment
  - getFunctions
```
protected final java.util.Map<Reference,?> getFunctions()
```
    Support for first-class functions by returning the set of currently accessible functions.
    
    Returns:
    
    Map from function name to function objects
  - getNetworkManager
```
protected final NetworkManager getNetworkManager()
```
    Accessor for abstract network interface.
    
    Returns:
    
    Current abstract network interface
  - getPersistent
```
public final <P> P getPersistent(java.util.function.Supplier<P> ifAbsent)
```
    Description copied from interface: ExecutionContext
    
    Gets a value that survives across rounds. If a value was stored at the previous iteration, then the previous value is returned. Otherwise, the alternative value is computed via isAbsent and stored for the future.
    
    Specified by:
    
    getPersistent in interface ExecutionContext
    
    Type Parameters:
    
    P - type of the value
    
    Parameters:
    
    ifAbsent - replacement
    
    Returns:
    
    the value
  - getVariable
```
public final java.lang.Object getVariable(Reference name)
```
    Description copied from interface: ExecutionContext
    
    Look up the value of a variable from the local environment.
    
    Specified by:
    
    getVariable in interface ExecutionContext
    
    Parameters:
    
    name - The variable to be looked up
    
    Returns:
    
    Value of the variable, or null if it cannot be found.
  - getStoredState
```
public final java.util.Map<CodePath,java.lang.Object> getStoredState()
```
    Returns:
    
    a view on the state stored in this context.
  - instance
```
protected abstract S instance()
```
    Produce a child execution context, for encapsulated evaluation of sub-programs.
    
    Returns:
    
    Child execution context
  - newCallStackFrame
```
public final void newCallStackFrame(byte... id)
```
    Specified by:
    
    newCallStackFrame in interface ExecutionContext
    
    Parameters:
    
    id - stack frame type
  - newCallStackFrame
```
public final void newCallStackFrame(int... id)
```
    Specified by:
    
    newCallStackFrame in interface ExecutionContext
    
    Parameters:
    
    id - stack frame type
  - putMultipleVariables
```
public final void putMultipleVariables(java.util.Map<Reference,?> map)
```
    Description copied from interface: ExecutionContext
    
    Pushes multiple variables.
    
    Specified by:
    
    putMultipleVariables in interface ExecutionContext
    
    Parameters:
    
    map - the variables to push
  - putVariable
```
public final void putVariable(Reference name,
                              java.lang.Object value)
```
    Description copied from interface: ExecutionContext
    
    Puts a variable value, overwriting the previous one, if any.
    
    Specified by:
    
    putVariable in interface ExecutionContext
    
    Parameters:
    
    name - variable reference
    
    value - variable value
  - restrictDomain
```
public final S restrictDomain(@Nonnull
                              Field<?> f)
```
    Description copied from interface: ExecutionContext
    
    Give a field, returns a new ExecutionContext whose domain is the same of the field one.
    
    Specified by:
    
    restrictDomain in interface ExecutionContext
    
    Parameters:
    
    f - the field
    
    Returns:
    
    the restricted domain
  - returnFromCallFrame
```
public final void returnFromCallFrame()
```
    Description copied from interface: ExecutionContext
    
    returns from the last frame.
    
    Specified by:
    
    returnFromCallFrame in interface ExecutionContext
  - runInNewStackFrame
```
public final <T> T runInNewStackFrame(int id,
                                      java.util.function.Function<ExecutionContext,T> operation)
```
    Specified by:
    
    runInNewStackFrame in interface ExecutionContext
    
    Type Parameters:
    
    T - the return type
    
    Parameters:
    
    id - stack frame type
    
    operation - the operation to run in the new context
    
    Returns:
    
    the result of the evaluation
  - setGloballyAvailableReferences
```
public final void setGloballyAvailableReferences(java.util.Map<Reference,?> knownFunctions)
```
    Description copied from interface: ExecutionContext
    
    Used internally to support first-class functions by make the functions of a program accessible for reflection at runtime.
    
    Specified by:
    
    setGloballyAvailableReferences in interface ExecutionContext
    
    Parameters:
    
    knownFunctions - Collection of accessible functions, associating function name and value.
  - setPersistent
```
public final void setPersistent(java.lang.Object o)
```
    Description copied from interface: ExecutionContext
    
    Stores a value to be used in future rounds via getPersistent.
    
    Specified by:
    
    setPersistent in interface ExecutionContext
    
    Parameters:
    
    o - the value to store
  - setup
```
public final void setup()
```
    Description copied from interface: ExecutionContext
    
    Called just before the VM is executed, to enable and preparations needed in the environment.
    
    Specified by:
    
    setup in interface ExecutionContext

Class AbstractExecutionContext<S extends AbstractExecutionContext<S>>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface org.protelis.vm.ExecutionContext

Constructor Detail

AbstractExecutionContext

AbstractExecutionContext

Method Detail

buildField

buildFieldDeferred

commit

commitRecursively

getDeltaTime

getExecutionEnvironment

getFunctions

getNetworkManager

getPersistent

getVariable

getStoredState

instance

newCallStackFrame

newCallStackFrame

putMultipleVariables

putVariable

restrictDomain

returnFromCallFrame

runInNewStackFrame

setGloballyAvailableReferences

setPersistent

setup