tcg: signal-free qemu_cpu_kick

Signals are slow and do not exist on Win32.  The previous patches
have done most of the legwork to introduce memory barriers (some
of them were even there already for the sake of Windows!) and
we can now set the flags directly in the iothread.

qemu_cpu_kick_thread is not used anymore on TCG, since the TCG thread is
never outside usermode while the CPU is running (not halted).  Instead run
the content of the signal handler (now in qemu_cpu_kick_no_halt) directly.
qemu_cpu_kick_no_halt is also used in qemu_mutex_lock_iothread to avoid
the overhead of qemu_cond_broadcast.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/cpu-exec.c b/cpu-exec.c
index ef9d745..6a30261 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -341,7 +341,7 @@ static void cpu_handle_debug_exception(CPUState *cpu)
 
 /* main execution loop */
 
-volatile sig_atomic_t exit_request;
+bool exit_request;
 CPUState *tcg_current_cpu;
 
 int cpu_exec(CPUState *cpu)