Package SCons :: Module Taskmaster

Module Taskmaster

Generic Taskmaster module for the SCons build engine.

This module contains the primary interface(s) between a wrapping user interface and the SCons build engine. There are two key classes here:

Taskmaster

This is the main engine for walking the dependency graph and calling things to decide what does or doesn't need to be built.

Task

This is the base class for allowing a wrapping interface to decide what does or doesn't actually need to be done. The intention is for a wrapping interface to subclass this as appropriate for different types of behavior it may need.

The canonical example is the SCons native Python interface, which has Task subclasses that handle its specific behavior, like printing "`foo' is up to date" when a top-level target doesn't need to be built, and handling the -c option by removing targets as its "build" action. There is also a separate subclass for suppressing this output when the -q option is used.

The Taskmaster instantiates a Task object for each (set of) target(s) that it decides need to be evaluated and/or built.

Classes

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Stats
A simple class for holding statistics about the disposition of a Node by the Taskmaster. If we're collecting statistics, each Node processed by the Taskmaster gets one of these attached, in which case the Taskmaster records its decision each time it processes the Node. (Ideally, that's just once per Node.)

Task
Default SCons build engine task.

AlwaysTask

OutOfDateTask

Taskmaster
The Taskmaster for walking the dependency DAG.

Functions

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dump_stats()

source code

find_cycle(stack, visited)

source code

Variables

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__doc__ = ...

__revision__ = 'src/engine/SCons/Taskmaster.py rel_2.4.0:3365:...

StateString = {0: 'no_state', 1: 'pending', 2: 'executing', 3:...

NODE_NO_STATE = 0

NODE_PENDING = 1

NODE_EXECUTING = 2

NODE_UP_TO_DATE = 3

NODE_EXECUTED = 4

NODE_FAILED = 5

print_prepare = 0

CollectStats = None
hash(x)

StatsNodes = []

fmt = '%(considered)3d %(already_handled)3d %(problem)3d %(chi...

__package__ = 'SCons'

Variables Details

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doc

Value:

"""
Generic Taskmaster module for the SCons build engine.

This module contains the primary interface(s) between a wrapping user
interface and the SCons build engine.  There are two key classes here:

    Taskmaster
        This is the main engine for walking the dependency graph and
...

revision

Value:

'src/engine/SCons/Taskmaster.py rel_2.4.0:3365:9259ea1c13d7 2015/09/21
 14:03:43 bdbaddog'

StateString

Value:

{0: 'no_state',
 1: 'pending',
 2: 'executing',
 3: 'up_to_date',
 4: 'executed',
 5: 'failed'}

fmt

Value:

'%(considered)3d %(already_handled)3d %(problem)3d %(child_failed)3d %
(not_built)3d %(side_effects)3d %(build)3d '