diff options
| -rw-r--r-- | coroutine-win32.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/coroutine-win32.c b/coroutine-win32.c index edc1f72c18..17ace37dee 100644 --- a/coroutine-win32.c +++ b/coroutine-win32.c @@ -36,8 +36,17 @@ typedef struct static __thread CoroutineWin32 leader; static __thread Coroutine *current; -CoroutineAction qemu_coroutine_switch(Coroutine *from_, Coroutine *to_, - CoroutineAction action) +/* This function is marked noinline to prevent GCC from inlining it + * into coroutine_trampoline(). If we allow it to do that then it + * hoists the code to get the address of the TLS variable "current" + * out of the while() loop. This is an invalid transformation because + * the SwitchToFiber() call may be called when running thread A but + * return in thread B, and so we might be in a different thread + * context each time round the loop. + */ +CoroutineAction __attribute__((noinline)) +qemu_coroutine_switch(Coroutine *from_, Coroutine *to_, + CoroutineAction action) { CoroutineWin32 *from = DO_UPCAST(CoroutineWin32, base, from_); CoroutineWin32 *to = DO_UPCAST(CoroutineWin32, base, to_); |