Re: [Qemu-devel] Race condition between signal handler and cpu_exec()

[Jamie Lokier]

Aurelien Jarno wrote:
> I am currently too tired to find a proper solution (which should only
> use read/write to a variable to keep the operations atomic), I'll look
> at that tomorrow, but patches are welcome in the meanwhile.

The theoretically right thing in C is read/write a "volatile
sig_atomic_t".  The GNU/Linux libc manual has a section "Atomic Data
Access and Signal Handling", where it says you can assume read/writing
an "int" and a pointer are also atomic in this respect on all machines
which matter.

Note that writing to a "char" is not atomic on old Alphas.

-- Jamie