com.facebook.buck.core.rules.resolver.impl

Class MultiThreadedActionGraphBuilder

java.lang.Object

com.facebook.buck.core.rules.impl.AbstractBuildRuleResolver

com.facebook.buck.core.rules.resolver.impl.AbstractActionGraphBuilder

com.facebook.buck.core.rules.resolver.impl.MultiThreadedActionGraphBuilder

All Implemented Interfaces:

ActionGraphBuilder, BuildRuleResolver, SourcePathRuleFinder

public class MultiThreadedActionGraphBuilder
extends AbstractActionGraphBuilder

Implementation of BuildRuleResolver that supports build rules being created in parallel.

In order to prevent race-conditions and duplicate work, this implementation imposes additional semantics for concurrent access:

• Rules are stored in futures.
• Accessing incomplete rules from the current thread behaves as if the rule does not exist. Accessing incomplete rules from other threads waits for the rule future to complete.

The implementation parallelizes work via the parallelizer and when it receives a call for multiple things at the same time via requireAllRules or computeAllIfAbsent. For all of these cases, it basically creates a list of Tasks, schedules them, tries to finish them on the current thread and then waiting for them. When a Task is scheduled, we submit a job to the executor service to complete that task.

This means that a task that is doing work will only recursively process tasks that it has directly asked for (i.e. stack traces will look nice). In the case where work is done by another thread, stack traces will be captured on that thread and then re-thrown from the thread that requested the work.

Constructor Summary

Constructors

Constructor and Description
MultiThreadedActionGraphBuilder(com.google.common.util.concurrent.ListeningExecutorService executor, TargetGraph targetGraph, ConfigurationRuleRegistry configurationRuleRegistry, TargetNodeToBuildRuleTransformer buildRuleGenerator, CellProvider cellProvider)

Method Summary

Modifier and Type	Method and Description
<T extends BuildRule> T	addToIndex(T buildRule) Deprecated.
com.google.common.collect.ImmutableSortedMap<BuildTarget,BuildRule>	computeAllIfAbsent(com.google.common.collect.ImmutableMap<BuildTarget,java.util.function.Function<BuildTarget,BuildRule>> mappings)
BuildRule	computeIfAbsent(BuildTarget target, java.util.function.Function<BuildTarget,BuildRule> mappingFunction) Retrieve the BuildRule for the given BuildTarget.
Iterable<BuildRule>	getBuildRules()
Parallelizer	getParallelizer() Returns a parallelizer object that parallelizes if the current BuildRuleResolver supports parallelism.
Optional<BuildRule>	getRuleOptional(BuildTarget buildTarget) Returns the BuildRule associated with the given BuildTarget if it is already present.
Iterable<BuildRule>	getSuccessfullyConstructedBuildRules()
void	invalidate() Invalidates this object.
com.google.common.collect.ImmutableSortedSet<BuildRule>	requireAllRules(Iterable<BuildTarget> buildTargets)
<T> Optional<T>	requireMetadata(BuildTarget target, Class<T> metadataClass) Retrieve a piece of metadata for a target.
BuildRule	requireRule(BuildTarget target) Retrieve the BuildRule for the given BuildTarget.
com.google.common.util.concurrent.ListenableFuture<BuildRule>	requireRuleFuture(BuildTarget target) Requires the rule asynchronously.

Methods inherited from class com.facebook.buck.core.rules.resolver.impl.AbstractActionGraphBuilder

checkRuleIsBuiltForCorrectTarget

Methods inherited from class com.facebook.buck.core.rules.impl.AbstractBuildRuleResolver

filterBuildRuleInputs, filterBuildRuleInputs, filterBuildRuleInputs, filterBuildRuleInputs, getAllRules, getRule, getRule, getRule, getRuleOptionalWithType, getRuleWithType, getSourcePathResolver

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.facebook.buck.core.rules.BuildRuleResolver

getAllRules, getRule, getRuleOptionalWithType, getRuleWithType

Methods inherited from interface com.facebook.buck.core.rules.SourcePathRuleFinder

filterBuildRuleInputs, filterBuildRuleInputs, filterBuildRuleInputs, filterBuildRuleInputs, getRule, getRule, getSourcePathResolver

Constructor Detail

MultiThreadedActionGraphBuilder

public MultiThreadedActionGraphBuilder(com.google.common.util.concurrent.ListeningExecutorService executor,
                                       TargetGraph targetGraph,
                                       ConfigurationRuleRegistry configurationRuleRegistry,
                                       TargetNodeToBuildRuleTransformer buildRuleGenerator,
                                       CellProvider cellProvider)

Method Detail

getBuildRules

public Iterable<BuildRule> getBuildRules()

Returns:

an unmodifiable view of the rules in the index. Throws an exception if construction fails for any rule.

getSuccessfullyConstructedBuildRules

public Iterable<BuildRule> getSuccessfullyConstructedBuildRules()

Returns:

an unmodifiable view of the successfully constructed (i.e. didn't throw an exception during construction) rules in the index. Does not throw an exception if construction failed for any rule.

getRuleOptional

public Optional<BuildRule> getRuleOptional(BuildTarget buildTarget)

Description copied from interface: BuildRuleResolver

Returns the BuildRule associated with the given BuildTarget if it is already present.

computeIfAbsent

public BuildRule computeIfAbsent(BuildTarget target,
                                 java.util.function.Function<BuildTarget,BuildRule> mappingFunction)

Description copied from interface: ActionGraphBuilder

Retrieve the BuildRule for the given BuildTarget. If no rules are associated with the target, compute the rule using the given supplier and update the mapping.

Parameters:

target - target with which the BuildRule is associated.

mappingFunction - function to compute the rule.

Returns:

the current value associated with the rule

requireAllRules

public com.google.common.collect.ImmutableSortedSet<BuildRule> requireAllRules(Iterable<BuildTarget> buildTargets)

Specified by:

requireAllRules in interface ActionGraphBuilder

Overrides:

requireAllRules in class AbstractActionGraphBuilder

computeAllIfAbsent

public com.google.common.collect.ImmutableSortedMap<BuildTarget,BuildRule> computeAllIfAbsent(com.google.common.collect.ImmutableMap<BuildTarget,java.util.function.Function<BuildTarget,BuildRule>> mappings)

Specified by:

computeAllIfAbsent in interface ActionGraphBuilder

Overrides:

computeAllIfAbsent in class AbstractActionGraphBuilder

getParallelizer

public Parallelizer getParallelizer()

Description copied from interface: ActionGraphBuilder

Returns a parallelizer object that parallelizes if the current BuildRuleResolver supports parallelism.

requireRule

public BuildRule requireRule(BuildTarget target)

Description copied from interface: ActionGraphBuilder

Retrieve the BuildRule for the given BuildTarget. If no rules are associated with the target, compute it by transforming the TargetNode associated with this build target using the TargetNodeToBuildRuleTransformer associated with this instance.

requireRuleFuture

public com.google.common.util.concurrent.ListenableFuture<BuildRule> requireRuleFuture(BuildTarget target)

Requires the rule asynchronously. This isn't part of the ActionGraphBuilder interface and so is only used in places where we know we have a multithreaded one.

Specified by:

requireRuleFuture in interface ActionGraphBuilder

Overrides:

requireRuleFuture in class AbstractActionGraphBuilder

addToIndex

@Deprecated
public <T extends BuildRule> T addToIndex(T buildRule)

Deprecated.

Please use computeIfAbsent instead

requireMetadata

public <T> Optional<T> requireMetadata(BuildTarget target,
                                       Class<T> metadataClass)

Description copied from interface: ActionGraphBuilder

Retrieve a piece of metadata for a target. This metadata is computed via MetadataProvidingDescription.createMetadata(com.facebook.buck.core.model.BuildTarget, com.facebook.buck.core.rules.ActionGraphBuilder, com.facebook.buck.core.cell.CellPathResolver, T, java.util.Optional<com.google.common.collect.ImmutableMap<com.facebook.buck.core.model.BuildTarget, com.facebook.buck.versions.Version>>, java.lang.Class<U>).

invalidate

public void invalidate()

Description copied from interface: ActionGraphBuilder

Invalidates this object. All future calls will throw InvalidStateException.