In function run_thread() the function check_irqs() gets called after the thread switch for atomic handoff reasons. In yield() it's the other way round.
If check_irqs() is called after run_thread() and check_irqs() is called before switch_next() in yield(), it can happen in a constructed case that a background thread runs twice without a check_irqs() call in between. Call check_irqs() after switch_next() in yield() to prevent this.
Signed-off-by: Volker Rümelin vr_qemu@t-online.de --- src/stacks.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/src/stacks.c b/src/stacks.c index df32325..4c8e5df 100644 --- a/src/stacks.c +++ b/src/stacks.c @@ -629,12 +629,11 @@ yield(void) return; } struct thread_info *cur = getCurThread(); + // Switch to the next thread + switch_next(cur); if (cur == &MainThread) // Permit irqs to fire check_irqs(); - - // Switch to the next thread - switch_next(cur); }
void VISIBLE16