From e163f41850bd09a17d3102a3af0af2e3cd831ab0 Mon Sep 17 00:00:00 2001 From: Robert Kanter Date: Fri, 13 Oct 2017 13:52:58 -0700 Subject: [PATCH] HADOOP-14938. Configuration.updatingResource map should be initialized lazily (misha@cloudera.com via rkanter) --- .../org/apache/hadoop/conf/Configuration.java | 93 +++++++++++-------- 1 file changed, 55 insertions(+), 38 deletions(-) diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java index 9d5bb1bb0de..f94eba6f629 100644 --- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java +++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java @@ -290,9 +290,9 @@ public class Configuration implements Iterable>, /** * Stores the mapping of key to the resource which modifies or loads - * the key most recently + * the key most recently. Created lazily to avoid wasting memory. */ - private Map updatingResource; + private volatile Map updatingResource; /** * Specify exact input factory to avoid time finding correct one. @@ -749,7 +749,6 @@ public class Configuration implements Iterable>, */ public Configuration(boolean loadDefaults) { this.loadDefaults = loadDefaults; - updatingResource = new ConcurrentHashMap(); // Register all classes holding property tags with REGISTERED_TAG_CLASS.put("core", CorePropertyTag.class); @@ -768,25 +767,27 @@ public class Configuration implements Iterable>, */ @SuppressWarnings("unchecked") public Configuration(Configuration other) { - this.resources = (ArrayList) other.resources.clone(); - synchronized(other) { - if (other.properties != null) { - this.properties = (Properties)other.properties.clone(); - } + this.resources = (ArrayList) other.resources.clone(); + synchronized(other) { + if (other.properties != null) { + this.properties = (Properties)other.properties.clone(); + } - if (other.overlay!=null) { - this.overlay = (Properties)other.overlay.clone(); - } + if (other.overlay!=null) { + this.overlay = (Properties)other.overlay.clone(); + } + + if (other.updatingResource != null) { + this.updatingResource = new ConcurrentHashMap( + other.updatingResource); + } + this.finalParameters = Collections.newSetFromMap( + new ConcurrentHashMap()); + this.finalParameters.addAll(other.finalParameters); + this.REGISTERED_TAG_CLASS.putAll(other.REGISTERED_TAG_CLASS); + this.propertyTagsMap.putAll(other.propertyTagsMap); + } - this.updatingResource = new ConcurrentHashMap( - other.updatingResource); - this.finalParameters = Collections.newSetFromMap( - new ConcurrentHashMap()); - this.finalParameters.addAll(other.finalParameters); - this.REGISTERED_TAG_CLASS.putAll(other.REGISTERED_TAG_CLASS); - this.propertyTagsMap.putAll(other.propertyTagsMap); - } - synchronized(Configuration.class) { REGISTRY.put(this, null); } @@ -1277,14 +1278,14 @@ public class Configuration implements Iterable>, String newSource = (source == null ? "programmatically" : source); if (!isDeprecated(name)) { - updatingResource.put(name, new String[] {newSource}); + putIntoUpdatingResource(name, new String[] {newSource}); String[] altNames = getAlternativeNames(name); if(altNames != null) { for(String n: altNames) { if(!n.equals(name)) { getOverlay().setProperty(n, value); getProps().setProperty(n, value); - updatingResource.put(n, new String[] {newSource}); + putIntoUpdatingResource(n, new String[] {newSource}); } } } @@ -1295,7 +1296,7 @@ public class Configuration implements Iterable>, for(String n : names) { getOverlay().setProperty(n, value); getProps().setProperty(n, value); - updatingResource.put(n, new String[] {altSource}); + putIntoUpdatingResource(n, new String[] {altSource}); } } } @@ -2634,17 +2635,19 @@ public class Configuration implements Iterable>, protected synchronized Properties getProps() { if (properties == null) { properties = new Properties(); - Map backup = - new ConcurrentHashMap(updatingResource); + Map backup = updatingResource != null ? + new ConcurrentHashMap(updatingResource) : null; loadResources(properties, resources, quietmode); if (overlay != null) { properties.putAll(overlay); - for (Map.Entry item: overlay.entrySet()) { - String key = (String)item.getKey(); - String[] source = backup.get(key); - if(source != null) { - updatingResource.put(key, source); + if (backup != null) { + for (Map.Entry item : overlay.entrySet()) { + String key = (String) item.getKey(); + String[] source = backup.get(key); + if (source != null) { + updatingResource.put(key, source); + } } } } @@ -3060,8 +3063,8 @@ public class Configuration implements Iterable>, } if (!finalParameters.contains(attr)) { properties.setProperty(attr, value); - if(source != null) { - updatingResource.put(attr, source); + if (source != null) { + putIntoUpdatingResource(attr, source); } } else { // This is a final parameter so check for overrides. @@ -3366,9 +3369,10 @@ public class Configuration implements Iterable>, redactor.redact(name, config.get(name))); jsonGen.writeBooleanField("isFinal", config.finalParameters.contains(name)); - String[] resources = config.updatingResource.get(name); + String[] resources = config.updatingResource != null ? + config.updatingResource.get(name) : null; String resource = UNKNOWN_RESOURCE; - if(resources != null && resources.length > 0) { + if (resources != null && resources.length > 0) { resource = resources[0]; } jsonGen.writeStringField("resource", resource); @@ -3448,8 +3452,8 @@ public class Configuration implements Iterable>, String value = org.apache.hadoop.io.Text.readString(in); set(key, value); String sources[] = WritableUtils.readCompressedStringArray(in); - if(sources != null) { - updatingResource.put(key, sources); + if (sources != null) { + putIntoUpdatingResource(key, sources); } } } @@ -3462,8 +3466,8 @@ public class Configuration implements Iterable>, for(Map.Entry item: props.entrySet()) { org.apache.hadoop.io.Text.writeString(out, (String) item.getKey()); org.apache.hadoop.io.Text.writeString(out, (String) item.getValue()); - WritableUtils.writeCompressedStringArray(out, - updatingResource.get(item.getKey())); + WritableUtils.writeCompressedStringArray(out, updatingResource != null ? + updatingResource.get(item.getKey()) : null); } } @@ -3563,4 +3567,17 @@ public class Configuration implements Iterable>, } return tag; } + + private void putIntoUpdatingResource(String key, String[] value) { + Map localUR = updatingResource; + if (localUR == null) { + synchronized (this) { + localUR = updatingResource; + if (localUR == null) { + updatingResource = localUR = new ConcurrentHashMap<>(8); + } + } + } + localUR.put(key, value); + } }