Nsryjdtyk

I'm looking into JIT behavior on a very simple block of code:

public class PlayWithAssembly {



    public static void main(String args) {

        Random random = new Random();

        random.nextInt();

    }

}

Actually, for the purpose of my question the content of the main method is completely irrelevant. I'm running the following code using OpenJDK 10.0.1 on Ubuntu 16.04.5 and with the following command
java -Xbatch -XX:+PrintCompilation -XX:CompileThreshold=1000000 -cp target/classes com.xxx.playground.internal.bytecode.PlayWithAssembly

Since CompileThreshold is set to a very high value I wouldn't expect JIT to compile anything, I would rather expect JVM to operate fully in interpreted mode in practice for this example. But when running the above command, I'm getting a following list of methods that have been compiled (all of them are part of JDK):

 47    1    b  3       java.lang.StringLatin1::hashCode (42 bytes)

 50    2    b  3       java.util.concurrent.ConcurrentHashMap::tabAt (22 bytes)

 51    3     n 0       jdk.internal.misc.Unsafe::getObjectVolatile (native)   

 55    4    b  3       java.lang.Object::<init> (1 bytes)

 56    5    b  3       java.lang.String::isLatin1 (19 bytes)

 56    6    b  3       java.lang.String::hashCode (49 bytes)

 57    7    b  3       java.lang.String::coder (15 bytes)

 58    8    b  3       java.lang.Math::floorMod (10 bytes)

 59    9    b  3       java.util.ImmutableCollections$SetN::probe (60 bytes)

 62   10    b  1       java.util.ImmutableCollections$Set0::hashCode (2 bytes)

 62   11    b  3       java.lang.String::equals (65 bytes)

 64   12    b  1       java.util.Collections$EmptySet::hashCode (2 bytes)

 65   13    b  3       java.lang.StringLatin1::equals (36 bytes)

 66   14    b  3       java.util.Collections::emptySet (4 bytes)

 66   15    b  3       java.lang.module.ModuleDescriptor$Exports::<init> (10 bytes)

 67   16    b  4       java.lang.StringLatin1::hashCode (42 bytes)

 71    1       3       java.lang.StringLatin1::hashCode (42 bytes)   made not entrant

 72   17    b  3       java.lang.module.ModuleDescriptor$Exports::hashCode (38 bytes)

 73   18    b  3       java.util.Objects::equals (23 bytes)

 73   19    b  3       java.util.Objects::requireNonNull (14 bytes)

 74   20    b  3       java.util.AbstractCollection::<init> (5 bytes)

 76   21    b  3       java.util.AbstractSet::<init> (5 bytes)

 76   22    b  3       java.util.ImmutableCollections$AbstractImmutableSet::<init> (5 bytes)

 77   23    b  1       java.lang.Object::<init> (1 bytes)

 77    4       3       java.lang.Object::<init> (1 bytes)   made not entrant

 81   24    b  1       java.lang.module.ModuleDescriptor::name (5 bytes)

 82   25    b  1       java.lang.module.ModuleReference::descriptor (5 bytes)

 88   26    b  3       java.lang.String::charAt (25 bytes)

 93   27    b  3       java.util.concurrent.ConcurrentHashMap::spread (10 bytes)

 94   28    b  3       java.util.ImmutableCollections$SetN$1::hasNext (47 bytes)

 95   29    b  3       java.util.ImmutableCollections$SetN$1::next (35 bytes)

 96   30    b  3       java.util.Set::of (66 bytes)

 98   31    b  1       java.util.KeyValueHolder::getKey (5 bytes)

 99   32    b  1       java.util.KeyValueHolder::getValue (5 bytes)

100   33    b  3       java.util.ImmutableCollections$MapN::probe (64 bytes)

101   34    b  3       java.util.KeyValueHolder::<init> (21 bytes)

102   35    b  3       java.util.ImmutableCollections$MapN::get (21 bytes)

103   36     n 0       java.lang.Object::hashCode (native)   

103   37    b  3       jdk.internal.module.ModuleReferenceImpl::hashCode (56 bytes)

105   38    b  3       java.util.HashMap::hash (20 bytes)

106   39   !b  3       java.util.concurrent.ConcurrentHashMap::putVal (432 bytes)

112   40     n 0       jdk.internal.misc.Unsafe::compareAndSetLong (native)   

112   41    b  3       java.util.concurrent.ConcurrentHashMap::putIfAbsent (8 bytes)

112   42    b  1       java.lang.module.ResolvedModule::reference (5 bytes)

113   43    b  3       java.util.concurrent.ConcurrentHashMap::addCount (289 bytes)

115    2       3       java.util.concurrent.ConcurrentHashMap::tabAt (22 bytes)   made not entrant

115   39   !   3       java.util.concurrent.ConcurrentHashMap::putVal (432 bytes)   made not entrant

115   44    b  3       jdk.internal.misc.Unsafe::getObjectAcquire (7 bytes)

116   45    b  3       java.util.concurrent.ConcurrentHashMap::tabAt (22 bytes)

116   46     n 0       jdk.internal.misc.Unsafe::compareAndSetObject (native)   

117   47    b  3       java.util.concurrent.ConcurrentHashMap$Node::<init> (20 bytes)

117   48   !b  3       java.util.concurrent.ConcurrentHashMap::putVal (432 bytes)

120   49    b  3       java.util.concurrent.ConcurrentHashMap::casTabAt (21 bytes)

122   50    b  3       java.util.HashMap::getNode (148 bytes)

124   51    b  3       java.lang.String::length (11 bytes)

125   52    b  3       java.lang.StringLatin1::canEncode (13 bytes)

126   53    b  3       java.util.HashMap::put (13 bytes)

127   54     n 0       java.lang.System::arraycopy (native)   (static)

128   55    b  3       java.util.HashMap$Node::<init> (26 bytes)

128   56    b  3       java.util.HashMap::newNode (13 bytes)

129   57    b  3       java.util.HashMap::afterNodeInsertion (1 bytes)

129   58    b  3       java.util.Optional::ofNullable (15 bytes)

131   59    b  3       java.util.HashMap::get (23 bytes)

132   60    b  3       java.util.HashMap::putVal (300 bytes)

135   61    b  1       java.lang.module.ModuleDescriptor$Exports::source (5 bytes)

135   62    b  1       java.util.Collections$1::hasNext (5 bytes)

136   63    b  3       java.lang.module.ResolvedModule::name (11 bytes)

137   64    b  3       java.util.HashSet::add (20 bytes)

137   65    b  1       java.util.Collections$EmptySet::isEmpty (2 bytes)

138   66    b  3       java.lang.module.ResolvedModule::hashCode (16 bytes)

139   67    b  3       java.lang.module.ModuleDescriptor$Exports::isQualified (18 bytes)

140   68    b  1       java.lang.module.ModuleDescriptor::isAutomatic (5 bytes)

140   69    b  3       java.util.AbstractMap::<init> (5 bytes)

141   70    b  1       java.lang.module.ModuleDescriptor$Exports::targets (5 bytes)

141   71    b  1       java.lang.module.ResolvedModule::configuration (5 bytes)

142   72    b  3       java.util.HashMap::<init> (11 bytes)

142   73    b  3       java.util.ImmutableCollections$Set2$1::hasNext (14 bytes)

143   74    b  4       java.util.ImmutableCollections$SetN$1::hasNext (47 bytes)

148   28       3       java.util.ImmutableCollections$SetN$1::hasNext (47 bytes)   made not entrant

149   75    b  1       java.util.ImmutableCollections$Set1::size (2 bytes)

150   76    b  3       java.lang.Math::min (11 bytes)

152   77    b  3       java.util.AbstractCollection::isEmpty (13 bytes)

153   78    b  4       java.lang.String::hashCode (49 bytes)

160    6       3       java.lang.String::hashCode (49 bytes)   made not entrant

162   79    b  3       java.util.Map::entry (10 bytes)

165   80    b  1       java.lang.module.ModuleDescriptor::isOpen (5 bytes)

167   81    b  1       java.util.HashMap::afterNodeInsertion (1 bytes)

167   57       3       java.util.HashMap::afterNodeInsertion (1 bytes)   made not entrant

168   82    b  3       jdk.internal.module.ModuleBootstrap$2::hasNext (30 bytes)

169   83    b  3       java.util.HashMap::resize (356 bytes)

171   84    b  3       java.util.Collections$UnmodifiableCollection$1::hasNext (10 bytes)

172   85    b  3       jdk.internal.module.ModuleBootstrap$2::next (52 bytes)

173   86    b  3       java.util.HashMap::putIfAbsent (13 bytes)

174   87     n 0       java.lang.Module::addExportsToAllUnnamed0 (native)   (static)

175   88    b  1       java.lang.Module::getDescriptor (5 bytes)

182   78       4       java.lang.String::hashCode (49 bytes)   made not entrant

185   89    b  3       java.lang.StringLatin1::indexOf (61 bytes)

187   23       1       java.lang.Object::<init> (1 bytes)   made not entrant

195   90    b  1       java.lang.Object::<init> (1 bytes)

197   91    b  3       java.lang.String::hashCode (49 bytes) 

I was trying to match these methods with the list of intrinsics but it does not match, so my questions are: why these methods are compiled (and others are not), and do I have any control over it?

From the documentation of -XX:CompileThreshold:

This option is ignored when tiered compilation is enabled;

see the option -XX:-TieredCompilation.

So when specifying -XX:-TieredCompilation, most of these entries will go away, however, some entries may still be exempted from the counter based compilation decision.