Streamline large synch blocks in list/TMCH CA loading

[gbrodman]

For reserved/premium lists:
Use double-check locking so that subsequent calls to get the entire map of entries don't need to even check the locking object. This makes things quicker and removes lock-tracking overhead.

For TMCH CA:
we can just remove the synchronization block entirely. Everything inside of it is either constants (e.g. ROOT_CERTS) or a Guava loading cache (CRL_CACHE) which takes care of synchronization for us anyway.

this is taken from our self-scan D.4 14

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This change is 

[weiminyu]

@weiminyu made 1 comment.
Reviewable status: 0 of 3 files reviewed, 1 unresolved discussion (waiting on gbrodman).

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core/src/main/java/google/registry/model/tld/label/ReservedList.java line 196 at r1 (raw file):

  public ImmutableMap<String, ReservedListEntry> getReservedListEntries() {
    if (reservedListMap == null) {
      synchronized (reservedListMapLoadLock) {

We can use synchronized(this) and save an extra field, unless it violates some best practice?

Code quote:

synchronized (reservedListMapLoadLock)

[gbrodman]

@gbrodman made 1 comment.
Reviewable status: 0 of 3 files reviewed, 1 unresolved discussion (waiting on weiminyu).

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core/src/main/java/google/registry/model/tld/label/ReservedList.java line 196 at r1 (raw file):

Previously, weiminyu (Weimin Yu) wrote…

We can use synchronized(this) and save an extra field, unless it violates some best practice?

eh yeah i think that only matters if we start having multiple synchronization blocks, and we're not gonna be doing any other synchronization on this object