Hi Chris
Point well taken, but being unable to create a native thread is
definitely a VirtualMachineError, and personally I don't care whether
the JVM throws an OOME or any other kind of VirtualMachineError in that
case.
My point was that I don't see how being unable to return a result
because of a language limitation (i.e. arrays being indexed by integers,
and thus limited to 2G for byte[]), has anything to do with
OutOfMemoryError. I believe it would be much more logical to throw a
recoverable RuntimeException in this case (e.g.
java.lang.ArrayOverflowException, as an analog of
java.nio.BufferOverflowException).
Anthony
On 12/03/2017 15:53, Christoph Engelbert wrote:
Hey Anthony,
The meaning is already overloaded, as "Cannot create native thread"
is also an OutOfMemoryError and in like 99% of the cases means
"Linux ran out of filehandles". The chance the OS really couldn't
allocate a thread for the reason of no main memory available is very
narrow :)
Chris
Am 3/12/2017 um 3:24 PM schrieb Anthony Vanelverdinghe:
Files::readAllBytes is specified to throw an OutOfMemoryError "if
an array of the required size cannot be allocated, for example the
file is larger that 2G". Now in Java 9, InputStream::readAllBytes
does the same.
However, this overloads the meaning of OutOfMemoryError: either
"the JVM is out of memory" or "the resultant array would require
long-based indices".
In my opinion, this overloading is problematic, because:
- OutOfMemoryError has very clear semantics, and I don't see the
link between OOME and the fact that a resultant byte[] would need
to be >2G. If I have 5G of free heap space, and try to read a 3G
file, I'd expect something like an UnsupportedOperationException,
but definitely not an OutOfMemoryError.
- the former meaning is an actual Error, whereas the latter is an
Exception from which the application can recover.
- developers might be tempted to catch the OOME and retry to read
the file/input stream in chunks, no matter the cause of the OOME.
What was the rationale for using OutOfMemory here? And would it
still be possible to change this before Rampdown Phase 2?
Kind regards,
Anthony
