Package uk.ac.man.cs.rainbow.simulator.rasm

RASM instructions.

See:
Description

Class Summary

Abs	Absolute value (negation if less than zero).
Add	Addition.
And	Bitwise/logical and.
BranchFalse	Jumps to the given location (addr) if the value boolean is false.
BranchTrue	Jumps to the given location (addr) if the value boolean is true.
BuildList	Make a list of length n where each element of the list is a copy of value.
Call	Call a function or procedure.
Comment	Comment.
Concat	String concatenation.
Connect	Connect two channels together.
DeclareDeviceWithState	Associate a register with an integer value.
Delay	Delay the executing thread for dt time units.
Div	Division.
Dup	Duplicate the top stack element.
Eql	Equality.
Error	Signal a runtime error.
Exch	Exchange the top two stack elements.
Exit	Terminate the executing thread.
Geq	Greater than or equal to.
Get	Peek a value from a channel.
GetArg	Push a copy of the i'th value (based at 0) of the stack frame onto the top of the stack.
GetType	Get the type of value.
Gt	Greater than.
Index	Duplicate the j'th element on the stack at the top of the stack.
Insert	Assign to a list value.
IsAvailable	Test channel for availability.
Jump	Jump to the location given by the label popped off the stack.
KillStackRange	Delete all the values from the current stack frame apart from the m bottom-most items and the n top-most items.
LabelChannel	Label a channel according to an external specification.
LabelDevice	Label a thread according to an external specification.
Length	Get the length of the list.
Leq	Less than or equal to.
Line	Line identification directive.
Load	Read from register.
Lt	Less than.
MakeChannel	Create a new communications channel.
MakeList	Make a list.
MakeRegister	Create a new register.
MakeUnion	For making unions.
Mod	Remainder.
Mult	Multiplication.
NDChoice	Non-deterministic jump.
NDValue	Non-deterministic random number generator.
Neg	Negation.
Neq	Inverted equality.
Noop	No operation.
Not	Bitwise/logical inversion.
OpenUnion	For unmaking unions (the reverse of makeUnion).
Or	Bitwise/logical (inclusive) or.
Parallel	Execute in parallel.
Pop	Remove one item from the top of the stack.
PopAll	Clears the current stack frame.
Project	Get the index'th item of list.
Push	Pushes the argument onto the stack.
Put	Poke a value to a channel.
PutArg	Reverse of getArg which assigns value to the i'th position in the stack frame.
PutForward	First half of a channel write.
Read	A complete read from a channel.
Release	Sends an acknowledgement on an input channel, chanId.
Return	Return from function or procedure.
Roll	Roll the stack contents like the PostScript roll operator.
SetType	Type casting.
Shl	Shift left without check for overflow.
Shr	Shift right with sign extension and no check for underflow.
Shrz	Shift right with zero extension and no check for underflow.
SignalForward	Sends a request on an output channel, chanId.
Sleep	Cause the thread to become descheduled until something happens.
Split	Split a list up into its elements and length.
StatelessDevice	Mark thread as stateless.
StaticStackBase	Mark stack contents as static.
Store	Write to register.
Sub	Subtraction.
TclExec	Execute an external command.
WaitFor	Wait for channel to become readable.
WaitGet	Wait for channel to become readable, and then read it.
WaitRelease	Waits for an output channel, chanId, to be released.
Write	A complete write to a channel.
Xor	Bitwise/logical exclusive or.

Package uk.ac.man.cs.rainbow.simulator.rasm Description

RASM instructions. Used to control the behaviour of Rainbow threads (indeed, currently the only implementation of Rainbow threads is based on RASM.)

RASM (which is short for Rainbow ASseMler) is based on a threaded, simple stack model of computation. Each thread contains a stack of objects, most of which are immutable values, but which can also consist of types (which are first-class values in RASM, though there aren't all that many operations that you can perform on them), channel referencess (which are the only approved way of communicating between threads) and register references (which are used to provide state that is monitorable by the outside world, like variables in Yellow.)

All RASM instructions are defined in terms of the transformation they perform to their executing thread's stack. Thus, the instruction Exch whose stack transformation is:

x y y x

can be seen as popping the two top elements off the stack and pushing them back on in reverse order. (The rest of the stack is unmodified.)

Some RASM instructions perform their actions relative to the bottom of the current stack frame (no instructions can access anywhere on the stack outside the current stack frame except for Call and Return whose purpose is, in part, to create and destroy stack frames), and the special symbol is used to indicate this. An example is the instruction GetArg which is mainly used to retrieve parameters passed by the current stack frame's caller or local values placed at the bottom of the stack frame below the working area.

Some instructions are actually implemented as macros in terms of others. This only matters in practise if you are looking at the assembler output from a code block; from a programming and code generation point-of-view (i.e. so long as you are using the mandated interface based on RASMCode and RASMList) there is no difference between an instruction that is implemented directly and an instruction that is implemented as a macro. It just makes it far easier to enforce consistency and correctness of implementation...

Since:

Rainbow Server v1.0b4

See Also:

RASMThread, Rainbow Implementors Guide