Fiber Descriptor
An Avail FiberDescriptor fiber represents an independently schedulable flow of control. Its simplistic description of its behavior is a continuation which is repeatedly replaced with continuations representing successively more advanced states, thereby effecting execution.
Fibers are effectively scheduled via the AvailRuntime's executor, which is a ThreadPoolExecutor. A fiber scheduled in this way runs until it acknowledges being interrupted for some reason or it completes its calculation. If it is interrupted, the L2Chunk machinery ensures the fiber first reaches a state representing a consistent level one continuation before giving up its time-slice.
This fiber pooling model allows a huge number of fibers to efficiently and automatically take advantage of the available CPUs and processing cores, leading to a qualitatively different concurrency model than ones which are mapped directly to operating system threads, such as Java, or extreme lightweight models that cannot support simultaneous execution, such as Smalltalk (e.g., VisualWorks). Clearly, the latter does not scale to a modern (2013) computing environment, and the former leaves one at the mercy of the severe limitations and costs imposed by operating systems.
Author
Todd L Smith
Parameters
The mutability of the new descriptor.
Types
These are the possible execution states of a fiber.
A helper class, one per fiber. It's referenced referenced through a pojo from a field of the fiber, so that the FiberDescriptor can be easily switched from mutable to immutable or shared, without cloning the state.
The interpretation of the FiberHelper's flags.
The general flags. These are flags that are not otherwise grouped for semantic purposes, such as indicating interrupt requests or synchronization.
The advisory interrupt request flags. The flags declared as enumeration values within this enum are the interrupt request flags.
The layout of object slots for my instances.
The synchronization flags. The flags declared as enumeration values within this enum are for synchronization-related conditions.
The trace flags. The flags declared as enumeration values within this Enum are for system tracing modes.
Functions
Ensure that the specified field is writable.
Create a new object whose descriptor is the receiver, and which has the specified number of indexed (variable) slots.
Create a new object whose descriptor is the receiver, and which has the specified number of indexed (variable) slots for objects and ints.
Create a new object whose descriptor is the receiver, and which has the specified number of indexed (variable) slots.
Create a new object whose descriptor is the receiver, and which has the specified number of indexed (variable) slots.
Can an object using this descriptor have more than the minimum number of integer slots?
Can an object using this descriptor have more than the minimum number of object slots?
Answer the immutable version of this descriptor.
Answer how many levels of printing to allow before elision.
Answer whether the argument types supported by the specified FunctionTypeDescriptor are acceptable argument types for invoking a FunctionDescriptor whose type is self.
Answer whether these are acceptable TypeDescriptor for invoking a FunctionDescriptor whose type is self.
Answer whether these are acceptable arguments for invoking a FunctionDescriptor whose type is self.
Answer whether these are acceptable TypeDescriptor for invoking a FunctionDescriptor that is an instance of self. There may be more entries in the TupleDescriptor than are required by the FunctionTypeDescriptor.
Answer whether these are acceptable arguments for invoking a FunctionDescriptor that is an instance of self. There may be more entries in the TupleDescriptor than are required by the FunctionTypeDescriptor.
Record the fact that the given L2Chunk depends on the object not changing in some way peculiar to the kind of object. Most typically, this is applied to A_Methods, triggering invalidation if A_Definitions are added to or removed from the method, but at some point we may also support slowly-changing variables.
Add the operands and answer the result.
Add the operands and answer the result.
Construct a Java string from the given Avail StringDescriptor.
Construct a Java set from the given TupleDescriptor.
Construct a TupleDescriptor from the given SetDescriptor. Element ordering in the tuple will be arbitrary and unstable.
Visit my child phrases with the action.
Map my children through the (destructive) transformation specified by aBlock.
Compare a subrange of the receiver with a subrange of the given TupleDescriptor. The size of the subrange of both objects is determined by the index range supplied for the receiver.
Compare a subrange of the receiver with a subrange of the given ByteStringDescriptor. The size of the subrange of both objects is determined by the index range supplied for the receiver.
Compare a subrange of the receiver with a subrange of the given ByteTupleDescriptor. The size of the subrange of both objects is determined by the index range supplied for the receiver.
Compare a subrange of the receiver with a subrange of the given IntegerIntervalTupleDescriptor. The size of the subrange of both objects is determined by the index range supplied for the receiver.
Compare a subrange of the receiver with a subrange of the given NybbleTupleDescriptor. The size of the subrange of both objects is determined by the index range supplied for the receiver.
Compare a subrange of the receiver with a subrange of the given ObjectTupleDescriptor. The size of the subrange of both objects is determined by the index range supplied for the receiver.
Compare a subrange of the receiver with a subrange of the given RepeatedElementTupleDescriptor. The size of the subrange of both objects is determined by the index range supplied for the receiver.
Compare a subrange of the receiver with a subrange of the given SmallIntegerIntervalTupleDescriptor. The size of the subrange of both objects is determined by the index range supplied for the receiver.
Compare a subrange of the receiver with a subrange of another object. The size of the subrange of both objects is determined by the index range supplied for the receiver.
Compare a subrange of the receiver with a subrange of the given TwoByteStringDescriptor. The size of the subrange of both objects is determined by the index range supplied for the receiver.
Compute this object's TypeTag, having failed to extract it from the descriptor directly in AvailObjectRepresentation.typeTag.
Answer a fiber's internal debug log.
{@inheritDoc}
Divide the operands and answer the result.
Divide the operands and answer the result.
Answer whether the arguments, both objects, are equal in value.
Answer whether the arguments, an object and a TupleDescriptor, are equal in value.
Answer whether the arguments, an object and a ByteStringDescriptor, are equal in value.
Answer whether the arguments, an object, and a ByteTupleDescriptor, are equal in value.
Answer whether the receiver, an object, is a character with a code point equal to the integer argument.
Answer whether the arguments, an object and a CompiledCodeDescriptor, are equal.
Answer whether the arguments, an object and a FiberTypeDescriptor, are equal in value.
Answer whether the arguments, an object and a FunctionDescriptor, are equal in value.
Answer whether the arguments, an object and a FunctionTypeDescriptor, are equal.
Extract a 64-bit signed Java long from the specified Avail integer.
Answer whether the receiver contains the specified element.
Is the specified AvailObject an Avail atom?
Given two objects that are known to be equal, is the first one in a better form (more compact, more efficient, older generation) than the second one?
Sets only use explicit bins for collisions, otherwise they store the element itself. This works because a bin can't be an element of a set.
Is the specified AvailObject an Avail boolean?
Is the specified AvailObject an Avail byte tuple?
Is the specified AvailObject an Avail character?
Is the specified AvailObject an Avail extended integer?
Is the specified AvailObject an Avail function?
Is the specified AvailObject an Avail map?
Is the specified AvailObject an Avail nybble?
Is the specified AvailObject an Avail set?
Is the specified AvailObject an Avail string?
Is the specified AvailObject an Avail tuple?
Is the specified AvailObject an Avail unsigned byte?
Answer a pojo's java object. The type is not statically checkable in Java, but at least making it generic avoids an explicit cast expression at each call site.
Given that the receiver is marked immutable, but its slots have not yet been made immutable, scan them now. For each slot found to be mutable, mark it immutable and add it to the supplied list.
Given that the receiver is marked shared, but its slots have not yet been shared, scan them now. For each slot found to be unshared, mark it and add it to the supplied list.
{@inheritDoc}
{@inheritDoc}
Add a DefinitionDescriptor to the receiver. Causes dependent chunks to be invalidated.
Difference the operands and answer the result.
Add a GrammaticalRestrictionDescriptor to the receiver.
Multiply the operands and answer the result.
Multiply the operands and answer the result.
Answer how many arguments my instances expect. This is applicable to both MethodDescriptor and CompiledCodeDescriptor.
Add the operands and answer the result.
Given two objects that are known to be equal, the second of which is in the form of a tuple type, is the first one in a better form than the second one?
Return the MethodDescriptor's TupleDescriptor of FunctionDescriptor that statically restrict call sites by argument type.
Use a special setter mechanism that allows the continuation to be non-shared, even if the fiber it's to be plugged into is shared.
Difference the operands and answer the result.
Difference the operands and answer the result.
Multiply the operands and answer the result.
Print the object to the StringBuilder. By default show it as the descriptor's name and a line-by-line list of fields. If the indent is beyond the maximumIndent, indicate it's too deep without recursing. If the object is in the specified recursion list, indicate a recursive print and return.
Answer the shared version of this descriptor.
Throw an AvailUnsupportedOperationException suitable to be thrown by the sender.
Properties
A Statistic that records the number and size of each allocation.
Used for quickly checking integer fields when AvailObjectRepresentation.shouldCheckSlots is enabled.
Used for quickly checking object fields when AvailObjectRepresentation.shouldCheckSlots is enabled.
The minimum number of integer slots an AvailObject can have if it uses this descriptor. Does not include indexed slots possibly at the end. Populated automatically by the constructor.
The minimum number of object slots an AvailObject can have if it uses this descriptor. Does not include indexed slots possibly at the end. Populated automatically by the constructor.
This read-only property can be used in place of unsupportedOperation. Using the getter produces almost the same diagnostic stack trace when executed, but is a much shorter expression.