On Fri, 4 Dec 2020 06:50:14 GMT, Stuart Marks <sma...@openjdk.org> wrote:
> This rewrites the doc of ArraysSupport.newLength, adds detail to the > exception message, and adds a test. In addition to some renaming and a bit of > refactoring of the actual code, I also made two changes of substance to the > code: > > 1. I fixed a problem with overflow checking. In the original code, if > oldLength and prefGrowth were both very large (say, Integer.MAX_VALUE), this > method could return a negative value. It turns out that writing tests helps > find bugs! > > 2. Under the old policy, if oldLength and minGrowth required a length above > SOFT_MAX_ARRAY_LENGTH but not above Integer.MAX_VALUE, this method would > return Integer.MAX_VALUE. That doesn't make any sense, because attempting to > allocate an array of that length will almost certainly cause the Hotspot to > throw OOME because its implementation limit was exceeded. Instead, if the > required length is in this range, this method returns that required length. > > Separately, I'll work on retrofitting various call sites around the JDK to > use this method. src/java.base/share/classes/jdk/internal/util/ArraysSupport.java line 626: > 624: * attempt an array allocation with that length and encounter an > OutOfMemoryError. > 625: * Of course, regardless of the length value returned from this > method, the caller > 626: * may encounter OutOfMemoryError if there is insufficient heap to > fufill the request. typo in line 626: fufill -> fulfill ------------- PR: https://git.openjdk.java.net/jdk/pull/1617
