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ASF GitHub Bot commented on MRESOLVER-346: ------------------------------------------ michael-o commented on code in PR #272: URL: https://github.com/apache/maven-resolver/pull/272#discussion_r1157625854 ########## maven-resolver-impl/src/main/java/org/eclipse/aether/internal/impl/DefaultDeployer.java: ########## @@ -197,7 +197,7 @@ public DeployResult deploy(RepositorySystemSession session, DeployRequest reques e); } - try (SyncContext syncContext = syncContextFactory.newInstance(session, false)) { + try (SyncContext syncContext = syncContextFactory.newInstance(session, true)) { Review Comment: Checksums and stuff are generated on the fly and never persisted on disk, as far as I remember?! ########## maven-resolver-impl/src/main/java/org/eclipse/aether/internal/impl/DefaultArtifactResolver.java: ########## @@ -256,207 +257,226 @@ public List<ArtifactResult> resolveArtifacts( artifacts.add(request.getArtifact()); } - syncContext.acquire(artifacts, null); - - return resolve(session, requests); + return resolve(shared, exclusive, artifacts, session, requests); } } @SuppressWarnings("checkstyle:methodlength") private List<ArtifactResult> resolve( - RepositorySystemSession session, Collection<? extends ArtifactRequest> requests) + SyncContext shared, + SyncContext exclusive, + Collection<Artifact> subjects, + RepositorySystemSession session, + Collection<? extends ArtifactRequest> requests) throws ArtifactResolutionException { - List<ArtifactResult> results = new ArrayList<>(requests.size()); - boolean failures = false; - final boolean simpleLrmInterop = ConfigUtils.getBoolean(session, false, CONFIG_PROP_SIMPLE_LRM_INTEROP); + SyncContext current = shared; + try { + while (true) { Review Comment: Can we end up in an endless loop here? Whould a do while loop with a condition make more sense here? We need at least one iteration. ########## maven-resolver-impl/src/main/java/org/eclipse/aether/internal/impl/DefaultArtifactResolver.java: ########## @@ -256,207 +257,226 @@ public List<ArtifactResult> resolveArtifacts( artifacts.add(request.getArtifact()); } - syncContext.acquire(artifacts, null); - - return resolve(session, requests); + return resolve(shared, exclusive, artifacts, session, requests); } } @SuppressWarnings("checkstyle:methodlength") private List<ArtifactResult> resolve( - RepositorySystemSession session, Collection<? extends ArtifactRequest> requests) + SyncContext shared, + SyncContext exclusive, + Collection<Artifact> subjects, + RepositorySystemSession session, + Collection<? extends ArtifactRequest> requests) throws ArtifactResolutionException { - List<ArtifactResult> results = new ArrayList<>(requests.size()); - boolean failures = false; - final boolean simpleLrmInterop = ConfigUtils.getBoolean(session, false, CONFIG_PROP_SIMPLE_LRM_INTEROP); + SyncContext current = shared; + try { + while (true) { + current.acquire(subjects, null); - LocalRepositoryManager lrm = session.getLocalRepositoryManager(); - WorkspaceReader workspace = session.getWorkspaceReader(); + boolean failures = false; + final List<ArtifactResult> results = new ArrayList<>(requests.size()); + final boolean simpleLrmInterop = ConfigUtils.getBoolean(session, false, CONFIG_PROP_SIMPLE_LRM_INTEROP); + final LocalRepositoryManager lrm = session.getLocalRepositoryManager(); + final WorkspaceReader workspace = session.getWorkspaceReader(); + final List<ResolutionGroup> groups = new ArrayList<>(); + // filter != null: means "filtering applied", if null no filtering applied (behave as before) + final RemoteRepositoryFilter filter = remoteRepositoryFilterManager.getRemoteRepositoryFilter(session); - List<ResolutionGroup> groups = new ArrayList<>(); - // filter != null: means "filtering applied", if null no filtering applied (behave as before) - RemoteRepositoryFilter filter = remoteRepositoryFilterManager.getRemoteRepositoryFilter(session); + for (ArtifactRequest request : requests) { + RequestTrace trace = RequestTrace.newChild(request.getTrace(), request); - for (ArtifactRequest request : requests) { - RequestTrace trace = RequestTrace.newChild(request.getTrace(), request); + ArtifactResult result = new ArtifactResult(request); + results.add(result); - ArtifactResult result = new ArtifactResult(request); - results.add(result); + Artifact artifact = request.getArtifact(); - Artifact artifact = request.getArtifact(); + if (current == shared) { + artifactResolving(session, trace, artifact); + } - artifactResolving(session, trace, artifact); + String localPath = artifact.getProperty(ArtifactProperties.LOCAL_PATH, null); + if (localPath != null) { + // unhosted artifact, just validate file + File file = new File(localPath); + if (!file.isFile()) { + failures = true; + result.addException(new ArtifactNotFoundException(artifact, null)); + } else { + artifact = artifact.setFile(file); + result.setArtifact(artifact); + artifactResolved(session, trace, artifact, null, result.getExceptions()); + } + continue; + } - String localPath = artifact.getProperty(ArtifactProperties.LOCAL_PATH, null); - if (localPath != null) { - // unhosted artifact, just validate file - File file = new File(localPath); - if (!file.isFile()) { - failures = true; - result.addException(new ArtifactNotFoundException(artifact, null)); - } else { - artifact = artifact.setFile(file); - result.setArtifact(artifact); - artifactResolved(session, trace, artifact, null, result.getExceptions()); - } - continue; - } + List<RemoteRepository> remoteRepositories = request.getRepositories(); + List<RemoteRepository> filteredRemoteRepositories = new ArrayList<>(remoteRepositories); + if (filter != null) { + for (RemoteRepository repository : remoteRepositories) { + RemoteRepositoryFilter.Result filterResult = filter.acceptArtifact(repository, artifact); + if (!filterResult.isAccepted()) { + result.addException(new ArtifactFilteredOutException( + artifact, repository, filterResult.reasoning())); + filteredRemoteRepositories.remove(repository); + } + } + } - List<RemoteRepository> remoteRepositories = request.getRepositories(); - List<RemoteRepository> filteredRemoteRepositories = new ArrayList<>(remoteRepositories); - if (filter != null) { - for (RemoteRepository repository : remoteRepositories) { - RemoteRepositoryFilter.Result filterResult = filter.acceptArtifact(repository, artifact); - if (!filterResult.isAccepted()) { - result.addException( - new ArtifactFilteredOutException(artifact, repository, filterResult.reasoning())); - filteredRemoteRepositories.remove(repository); + VersionResult versionResult; + try { + VersionRequest versionRequest = + new VersionRequest(artifact, filteredRemoteRepositories, request.getRequestContext()); + versionRequest.setTrace(trace); + versionResult = versionResolver.resolveVersion(session, versionRequest); + } catch (VersionResolutionException e) { + result.addException(e); + continue; } - } - } - VersionResult versionResult; - try { - VersionRequest versionRequest = - new VersionRequest(artifact, filteredRemoteRepositories, request.getRequestContext()); - versionRequest.setTrace(trace); - versionResult = versionResolver.resolveVersion(session, versionRequest); - } catch (VersionResolutionException e) { - result.addException(e); - continue; - } + artifact = artifact.setVersion(versionResult.getVersion()); - artifact = artifact.setVersion(versionResult.getVersion()); + if (versionResult.getRepository() != null) { + if (versionResult.getRepository() instanceof RemoteRepository) { + filteredRemoteRepositories = + Collections.singletonList((RemoteRepository) versionResult.getRepository()); + } else { + filteredRemoteRepositories = Collections.emptyList(); + } + } - if (versionResult.getRepository() != null) { - if (versionResult.getRepository() instanceof RemoteRepository) { - filteredRemoteRepositories = - Collections.singletonList((RemoteRepository) versionResult.getRepository()); - } else { - filteredRemoteRepositories = Collections.emptyList(); - } - } + if (workspace != null) { + File file = workspace.findArtifact(artifact); + if (file != null) { + artifact = artifact.setFile(file); + result.setArtifact(artifact); + result.setRepository(workspace.getRepository()); + artifactResolved(session, trace, artifact, result.getRepository(), null); + continue; + } + } - if (workspace != null) { - File file = workspace.findArtifact(artifact); - if (file != null) { - artifact = artifact.setFile(file); - result.setArtifact(artifact); - result.setRepository(workspace.getRepository()); - artifactResolved(session, trace, artifact, result.getRepository(), null); - continue; - } - } + LocalArtifactResult local = lrm.find( + session, + new LocalArtifactRequest( + artifact, filteredRemoteRepositories, request.getRequestContext())); + result.setLocalArtifactResult(local); + boolean found = (filter != null && local.isAvailable()) || isLocallyInstalled(local, versionResult); + // with filtering it is availability that drives logic + // without filtering it is simply presence of file that drives the logic + // "interop" logic with simple LRM leads to RRF breakage: hence is ignored when filtering in effect + if (found) { + if (local.getRepository() != null) { + result.setRepository(local.getRepository()); + } else { + result.setRepository(lrm.getRepository()); + } + + try { + artifact = artifact.setFile(getFile(session, artifact, local.getFile())); + result.setArtifact(artifact); + artifactResolved(session, trace, artifact, result.getRepository(), null); + } catch (ArtifactTransferException e) { + result.addException(e); + } + if (filter == null && simpleLrmInterop && !local.isAvailable()) { + /* + * NOTE: Interop with simple local repository: An artifact installed by a simple local repo + * manager will not show up in the repository tracking file of the enhanced local repository. + * If however the maven-metadata-local.xml tells us the artifact was installed locally, we + * sync the repository tracking file. + */ + lrm.add(session, new LocalArtifactRegistration(artifact)); + } + + continue; + } - LocalArtifactResult local = lrm.find( - session, - new LocalArtifactRequest(artifact, filteredRemoteRepositories, request.getRequestContext())); - result.setLocalArtifactResult(local); - boolean found = (filter != null && local.isAvailable()) || isLocallyInstalled(local, versionResult); - // with filtering it is availability that drives logic - // without filtering it is simply presence of file that drives the logic - // "interop" logic with simple LRM leads to RRF breakage: hence is ignored when filtering in effect - if (found) { - if (local.getRepository() != null) { - result.setRepository(local.getRepository()); - } else { - result.setRepository(lrm.getRepository()); - } + if (local.getFile() != null) { + LOGGER.info( + "Artifact {} is present in the local repository, but cached from a remote repository ID that is unavailable in current build context, verifying that is downloadable from {}", + artifact, + remoteRepositories); + } - try { - artifact = artifact.setFile(getFile(session, artifact, local.getFile())); - result.setArtifact(artifact); - artifactResolved(session, trace, artifact, result.getRepository(), null); - } catch (ArtifactTransferException e) { - result.addException(e); - } - if (filter == null && simpleLrmInterop && !local.isAvailable()) { - /* - * NOTE: Interop with simple local repository: An artifact installed by a simple local repo - * manager will not show up in the repository tracking file of the enhanced local repository. - * If however the maven-metadata-local.xml tells us the artifact was installed locally, we - * sync the repository tracking file. - */ - lrm.add(session, new LocalArtifactRegistration(artifact)); + LOGGER.debug("Resolving artifact {} from {}", artifact, remoteRepositories); + AtomicBoolean resolved = new AtomicBoolean(false); + Iterator<ResolutionGroup> groupIt = groups.iterator(); + for (RemoteRepository repo : filteredRemoteRepositories) { + if (!repo.getPolicy(artifact.isSnapshot()).isEnabled()) { + continue; + } + + try { + Utils.checkOffline(session, offlineController, repo); + } catch (RepositoryOfflineException e) { + Exception exception = new ArtifactNotFoundException( + artifact, + repo, + "Cannot access " + repo.getId() + " (" + + repo.getUrl() + ") in offline mode and the artifact " + artifact + + " has not been downloaded from it before.", + e); + result.addException(exception); + continue; + } + + ResolutionGroup group = null; + while (groupIt.hasNext()) { + ResolutionGroup t = groupIt.next(); + if (t.matches(repo)) { + group = t; + break; + } + } + if (group == null) { + group = new ResolutionGroup(repo); + groups.add(group); + groupIt = Collections.emptyIterator(); + } + group.items.add(new ResolutionItem(trace, artifact, resolved, result, local, repo)); + } } - continue; - } - - if (local.getFile() != null) { - LOGGER.info( - "Artifact {} is present in the local repository, but cached from a remote repository ID that is unavailable in current build context, verifying that is downloadable from {}", - artifact, - remoteRepositories); - } - - LOGGER.debug("Resolving artifact {} from {}", artifact, remoteRepositories); - AtomicBoolean resolved = new AtomicBoolean(false); - Iterator<ResolutionGroup> groupIt = groups.iterator(); - for (RemoteRepository repo : filteredRemoteRepositories) { - if (!repo.getPolicy(artifact.isSnapshot()).isEnabled()) { + if (!groups.isEmpty() && current == shared) { Review Comment: The not empty implies that resolution is not complete? ########## maven-resolver-impl/src/main/java/org/eclipse/aether/internal/impl/synccontext/named/NamedLockFactoryAdapter.java: ########## @@ -48,6 +49,14 @@ public final class NamedLockFactoryAdapter { public static final TimeUnit DEFAULT_TIME_UNIT = TimeUnit.SECONDS; + public static final String RETRIES_KEY = "aether.syncContext.named.retries"; Review Comment: This change is for me is not related and shoud be a separate ticket and PR. > Too eager locking > ----------------- > > Key: MRESOLVER-346 > URL: https://issues.apache.org/jira/browse/MRESOLVER-346 > Project: Maven Resolver > Issue Type: Bug > Components: Resolver > Reporter: Tamas Cservenak > Assignee: Tamas Cservenak > Priority: Major > Fix For: 1.9.8 > > > The locking that is present in Resolver since 1.8.0 is too eager: > * there are no shared locks used at all > * this implies that local repository access is heavily serialized by locking > * there is no "upgrade" of locking due that above > * consequence is that "hot" artifacts in bigger multi module build run in > parallel become bottleneck as all threads will wait for their moment to grab > exclusive lock. > * another consequence: our "wait time" (def 30s) becomes problem, as due that > above, if build grows, the plausible "wait time" (as all lock is exclusive, > but requester count grows) grows as well. Also, this means we have threads > there doing nothing, just sitting as they wait for exclusive lock one after > another. > We can do it better: there are 4 main areas where locking is used: > * ArtifactInstaller: it is about to install (write) artifact files to local > repository, it needs exclusive lock, *no change needed*. > * ArtifactDeployer: it is about to upload present files to remote, it does > not modifies anything on local. *Change its lock to shared*. The exclusive > lock also meant that if no DeployAtEnd used, other modules during resolution > had to wait while this module uploaded. > * ArtifactResolver and MetadataResolver: two very similar beasts, they > attempt to resolve locally (from local repo) w/o any content modification > (read only), and if not successful, they will reach remote to download what > is needed (write). Here we *could do something similar to > [DCL|https://en.wikipedia.org/wiki/Double-checked_locking] is*: try with > shared lock first, and if local content is not fulfilling, release shared, > acquire exclusive and REDO all (as meanwhile someone else may downloaded > files already). -- This message was sent by Atlassian Jira (v8.20.10#820010)