With the removal of the synchronization on priorityMap inside 'SignatureAndHashAlgorithm.getSupportedAlgorithms' in rev daaace32c979 [1], it seems unnecessary to use a synchronizedSortedMap. Benchmarking, I see a 2x performance increase by using the bare TreeMap.
measureModified sample 11336330 11949.506 ± 1775.776 ns/op measureOriginal sample 10855026 23003.654 ± 2286.571 ns/op Thanks, Steven Davidovitz 1: http://hg.openjdk.java.net/jdk9/dev/jdk/rev/daaace32c979 diff --git a/src/java.base/share/classes/sun/security/ssl/SignatureAndHashAlgorithm.java b/src/java.base/share/classes/sun/security/ssl/SignatureAndHashAlgorithm.java --- a/src/java.base/share/classes/sun/security/ssl/SignatureAndHashAlgorithm.java +++ b/src/java.base/share/classes/sun/security/ssl/SignatureAndHashAlgorithm.java @@ -396,46 +396,42 @@ } static { - supportedMap = Collections.synchronizedSortedMap( - new TreeMap<Integer, SignatureAndHashAlgorithm>()); - priorityMap = Collections.synchronizedSortedMap( - new TreeMap<Integer, SignatureAndHashAlgorithm>()); - - synchronized (supportedMap) { - int p = SUPPORTED_ALG_PRIORITY_MAX_NUM; - supports(HashAlgorithm.MD5, SignatureAlgorithm.RSA, - "MD5withRSA", --p); - supports(HashAlgorithm.SHA1, SignatureAlgorithm.DSA, - "SHA1withDSA", --p); - supports(HashAlgorithm.SHA1, SignatureAlgorithm.RSA, - "SHA1withRSA", --p); - supports(HashAlgorithm.SHA1, SignatureAlgorithm.ECDSA, - "SHA1withECDSA", --p); + supportedMap = new TreeMap<Integer, SignatureAndHashAlgorithm>(); + priorityMap = new TreeMap<Integer, SignatureAndHashAlgorithm>(); - if (Security.getProvider("SunMSCAPI") == null) { - supports(HashAlgorithm.SHA224, SignatureAlgorithm.DSA, - "SHA224withDSA", --p); - supports(HashAlgorithm.SHA224, SignatureAlgorithm.RSA, - "SHA224withRSA", --p); - supports(HashAlgorithm.SHA224, SignatureAlgorithm.ECDSA, - "SHA224withECDSA", --p); - } + int p = SUPPORTED_ALG_PRIORITY_MAX_NUM; + supports(HashAlgorithm.MD5, SignatureAlgorithm.RSA, + "MD5withRSA", --p); + supports(HashAlgorithm.SHA1, SignatureAlgorithm.DSA, + "SHA1withDSA", --p); + supports(HashAlgorithm.SHA1, SignatureAlgorithm.RSA, + "SHA1withRSA", --p); + supports(HashAlgorithm.SHA1, SignatureAlgorithm.ECDSA, + "SHA1withECDSA", --p); - supports(HashAlgorithm.SHA256, SignatureAlgorithm.DSA, - "SHA256withDSA", --p); - supports(HashAlgorithm.SHA256, SignatureAlgorithm.RSA, - "SHA256withRSA", --p); - supports(HashAlgorithm.SHA256, SignatureAlgorithm.ECDSA, - "SHA256withECDSA", --p); - supports(HashAlgorithm.SHA384, SignatureAlgorithm.RSA, - "SHA384withRSA", --p); - supports(HashAlgorithm.SHA384, SignatureAlgorithm.ECDSA, - "SHA384withECDSA", --p); - supports(HashAlgorithm.SHA512, SignatureAlgorithm.RSA, - "SHA512withRSA", --p); - supports(HashAlgorithm.SHA512, SignatureAlgorithm.ECDSA, - "SHA512withECDSA", --p); + if (Security.getProvider("SunMSCAPI") == null) { + supports(HashAlgorithm.SHA224, SignatureAlgorithm.DSA, + "SHA224withDSA", --p); + supports(HashAlgorithm.SHA224, SignatureAlgorithm.RSA, + "SHA224withRSA", --p); + supports(HashAlgorithm.SHA224, SignatureAlgorithm.ECDSA, + "SHA224withECDSA", --p); } + + supports(HashAlgorithm.SHA256, SignatureAlgorithm.DSA, + "SHA256withDSA", --p); + supports(HashAlgorithm.SHA256, SignatureAlgorithm.RSA, + "SHA256withRSA", --p); + supports(HashAlgorithm.SHA256, SignatureAlgorithm.ECDSA, + "SHA256withECDSA", --p); + supports(HashAlgorithm.SHA384, SignatureAlgorithm.RSA, + "SHA384withRSA", --p); + supports(HashAlgorithm.SHA384, SignatureAlgorithm.ECDSA, + "SHA384withECDSA", --p); + supports(HashAlgorithm.SHA512, SignatureAlgorithm.RSA, + "SHA512withRSA", --p); + supports(HashAlgorithm.SHA512, SignatureAlgorithm.ECDSA, + "SHA512withECDSA", --p); } }
