RFR: 8320826: call allocate_shared_strings_array after all strings are interned

[Matias Saavedra Silva]

On Tue, 28 Nov 2023 04:09:52 GMT, Ioi Lam <iklam at openjdk.org> wrote:

> `StringTable::allocate_shared_strings_array()` creates a Java object array that has the exact same size as the number of currently interned strings. Therefore, we need to move it to just before we enter the safepoint, where we know no more Java code would be execute.
> 
> I also had to change the assert in `StringTable::allocate_shared_strings_array()` to a condition check:  it's possible for `HeapShared::init_for_dumping()` to disable heap dumping when a Java agent transforms classes like jdk.internal.math.FDBigInteger.

Looks good! I just have one concern below:

src/hotspot/share/classfile/stringTable.cpp line 809:

> 807: // to guarantee because CDS runs with a single Java thread. See JDK-8253495.)
> 808: void StringTable::allocate_shared_strings_array(TRAPS) {
> 809:   if (!CDSConfig::is_dumping_heap()) {

This seems to be redundant considering that `allocate_shared_strings_array()` is only called by `preload_and_dump_impl`. Unless you expect this method to be called elsewhere eventually?

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PR Review: https://git.openjdk.org/jdk/pull/16839#pullrequestreview-1756034818
PR Review Comment: https://git.openjdk.org/jdk/pull/16839#discussion_r1409758719