waitForReturnCapability: fix logic bug

The check for whether a Capability was free was inverted, which harmed
performance for callbacks.

diff --git a/rts/Capability.c b/rts/Capability.c
index ddaba69..4264f0f 100644 (file)
--- a/rts/Capability.c
+++ b/rts/Capability.c
@@ -500,7 +500,7 @@ waitForReturnCapability (Capability **pCap, Task *task)
     if (cap == NULL) {
        // Try last_free_capability first
        cap = last_free_capability;
-       if (!cap->running_task) {
+       if (cap->running_task) {
            nat i;
            // otherwise, search for a free capability
             cap = NULL;