Zlib level in JDK7

[Damjan Jovanovic]

On Tue, Feb 15, 2011 at 5:40 PM, Florian Weimer <fweimer at bfk.de> wrote:
> * Andrew John Hughes:
>
>> So yes, that means we use the system zlib (currently 1.2.5 here), jpeg
>> (8c) and png (1.4.5).  1.10 will also finally remove the static
>> linking of libstdc++ and libgcc.  This was done back in the early days
>> of IcedTea as part of preparing OpenJDK for distro packaging, allowing
>> these libraries to receive timely security updates and bug fixes.
>
> It also increases compatibility with systems which use a different
> zlib version.  The symbols of the version in OpenJDK haven't been
> mangled, and the VM crashes if the wrong routines are called due to a
> symbol clash.
>

Such symbol clashes are ultimately caused by the fact that ELF is
probably the only binary file format left today to use the moronic
idea of process-scoped symbol lookup.

The JVM could work around it by using the RTLD_DEEPBIND flag to
dlopen() on Linux, and by linking libraries with "-Bdirect" on
Solaris. Other ELF-using operating systems (BSD?) are probably out of
luck.

Damjan Jovanovic