RFR: Remove map synchronization from SignatureAndHashAlgorithm

[Sean Mullan]

Hi Steven,

Thanks, I filed an issue on your behalf for tracking purposes: 
https://bugs.openjdk.java.net/browse/JDK-8179275

Also, have you signed the OCA? See 
http://www.oracle.com/technetwork/community/oca-486395.html for more 
information.

--Sean

On 4/15/17 3:25 PM, Steven Davidovitz wrote:
> 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);
>      }
>  }
>