xnu-7195.60.75.tar.gz

[apple/xnu.git] / osfmk / kern / mpsc_queue.c

diff --git a/osfmk/kern/mpsc_queue.c b/osfmk/kern/mpsc_queue.c
index 4784b0dc17286d325670e675c54f5a7af50a2d74..1b47d8b4e68d5db0e873be456a80fe779d2877ba 100644 (file)
--- a/osfmk/kern/mpsc_queue.c
+++ b/osfmk/kern/mpsc_queue.c
@@ -125,9 +125,22 @@ static void
 _mpsc_queue_thread_continue(void *param, wait_result_t wr __unused)
 {
        mpsc_daemon_queue_t dq = param;
+       mpsc_daemon_queue_kind_t kind = dq->mpd_kind;
+       thread_t self = dq->mpd_thread;
+
+       __builtin_assume(self != THREAD_NULL);
+
+       if (kind == MPSC_QUEUE_KIND_THREAD_CRITICAL) {
+               self->options |= TH_OPT_SYSTEM_CRITICAL;
+       }
 
        assert(dq->mpd_thread == current_thread());
-       _mpsc_daemon_queue_drain(dq, dq->mpd_thread);
+       _mpsc_daemon_queue_drain(dq, self);
+
+       if (kind == MPSC_QUEUE_KIND_THREAD_CRITICAL) {
+               self->options &= ~TH_OPT_SYSTEM_CRITICAL;
+       }
+
        thread_block_parameter(_mpsc_queue_thread_continue, dq);
 }
 
@@ -234,14 +247,9 @@ static void
 _mpsc_daemon_queue_drain(mpsc_daemon_queue_t dq, thread_t self)
 {
        mpsc_daemon_invoke_fn_t invoke = dq->mpd_invoke;
-       mpsc_daemon_queue_kind_t kind = dq->mpd_kind;
        mpsc_queue_chain_t head, cur, tail;
        mpsc_daemon_queue_state_t st;
 
-       if (kind == MPSC_QUEUE_KIND_THREAD_CRITICAL) {
-               self->options |= TH_OPT_SYSTEM_CRITICAL;
-       }
-
 again:
        /*
         * Most of the time we're woken up because we're dirty,
@@ -308,10 +316,6 @@ again:
 
        /* dereferencing `dq` past this point is unsafe */
 
-       if (kind == MPSC_QUEUE_KIND_THREAD_CRITICAL) {
-               self->options &= ~TH_OPT_SYSTEM_CRITICAL;
-       }
-
        if (__improbable(st & MPSC_QUEUE_STATE_CANCELED)) {
                thread_wakeup(&dq->mpd_state);
                if (self) {