How to release-store in qnx

Greetings again,

sorry to bother you, but is there a QNX-way of storing a variable with release memory semantics (that is a partial memory fence) without using boost or any additional library?

Might, using g++ 4.3.x, declaring the variable volatile be enough for an implicit release store (and will it be like that when the new C++0x standard is released)?

Thanks again for help,

Solved problem via locked atomic test and set (in assembler: xchg) operation, which should imply the store release barrier.