RFR: JDK-8277822: Remove debug-only heap overrun checks in os::malloc and friends [v3]

[Coleen Phillimore]

On Fri, 14 Jan 2022 17:20:27 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> Thomas Stuefe has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:
>> 
>>  - Merge branch 'master' into JDK-8277822-Remove-debug-only-heap-overrun-checks-in-os-malloc-and-friends
>>  - Merge branch 'master' into JDK-8277822-Remove-debug-only-heap-overrun-checks-in-os-malloc-and-friends
>>  - initialize newly malloced memory
>>  - JDK-8277822-Remove-debug-only-heap-overrun-checks-in-os-malloc-and-friends
>
> src/hotspot/share/runtime/os.cpp line 41:
> 
>> 39: #include "logging/logStream.hpp"
>> 40: #include "memory/allocation.inline.hpp"
>> 41: #include "memory/guardedMemory.hpp"
> 
> Should this file now be deleted if not used?

I see it's used in jniCheck.cpp - was it double-guarded ?  It's ok to leave this maybe to investigate for another time.

> src/hotspot/share/runtime/os.cpp line 622:
> 
>> 620: static void break_if_ptr_caught(void* ptr) {
>> 621:   if (p2i(ptr) == (intptr_t)MallocCatchPtr) {
>> 622:     log_warning(malloc, free)("ptr caught: " PTR_FORMAT, p2i(ptr));
> 
> If this is the same as MallocCatchPtr, doesn't this output simply print MallocCatchPtr?

I don't understand what this does. ie. please tell what it does in a comment.

-------------

PR: https://git.openjdk.java.net/jdk/pull/6554