somewhat working grid

+ Starvation is still an issue, but adding a slight bit of randomness
  seems to help a bit. Also, simulating massive systems like 64x64 is a
  bit too slow, so scale grid example down to 16x16. 256 cores is still
  a fair bit, but I might try to think of some optimization methods.
  I wonder at what point threading becomes faster than just running on a
  single core?

+ Test now also sets processor nodes to sleep to avoid starvation issue,
  seems like an opportunity for a DoS attack if someone can get enough
  cores to bombard a single node with enough traffic.
  The riscv64 processor has an initial control interface, very messy
  code, should probably come up with a more elegant way to deal with
  sleep/wakeups

1 files changed, 3 insertions, 0 deletions

diff --git a/src/grid/node.c b/src/grid/node.c
index 16cce1b..df237c7 100644
--- a/src/grid/node.c
+++ b/src/grid/node.c
@@ -56,6 +56,9 @@ static stat port_receive(struct port *port, struct packet pkt)
 
 static stat grid_receive(struct grid_node *grid, struct component *from, struct packet pkt)
 {
+	if (rand() % 256 == 0)
+		return EBUSY;
+
 	uint16_t x;
 	uint16_t y;
 	uint64_t addr = pkt.to;