We have:

./os/solaris/vm/jvm_solaris.h:#define ASYNC_SIGNAL SIGUSR2 /* Watcher & async err support. */

and then

./os/solaris/vm/os_solaris.cpp:int os::Solaris::_SIGasync = ASYNC_SIGNAL;
./os/solaris/vm/os_solaris.cpp: print_signal_handler(st, ASYNC_SIGNAL, buf, buflen);

but SIGUSR2 is not used on Solaris, we use SIGJVM2 and override the initialization of _SIGasync:

./os/solaris/vm/os_solaris.cpp: os::Solaris::set_SIGasync(SIGJVM2);

This should be cleaned up.