From 6ddafafa7292f6f6716d6683579bf1ce3287e1d5 Mon Sep 17 00:00:00 2001
From: Julian Blake Kongslie
Date: Sat, 15 Oct 2022 14:01:38 -0700
Subject: Initial commit (copied from biggolf)

---
 arbiter.h | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 arbiter.h

(limited to 'arbiter.h')

diff --git a/arbiter.h b/arbiter.h
new file mode 100644
index 0000000..79a9920
--- /dev/null
+++ b/arbiter.h
@@ -0,0 +1,55 @@
+#pragma once
+
+#include <array>
+#include <cassert>
+
+#include "infra/sim.h"
+
+namespace infra {
+    template<typename T, unsigned int peers> struct priority_arbiter : public sim {
+        std::array<port<T>, peers> peerp;
+        port<T> *outp = nullptr;
+
+        void clock() {
+            for (unsigned int i = 0; i < peers; ++i) {
+                if (outp->can_write() && peerp[i].can_read())
+                    outp->write(peerp[i].read());
+            }
+        }
+    };
+
+    template<typename T, unsigned int peers> struct round_robin_arbiter : public sim {
+        std::array<port<T>, peers> peerp;
+        port<T> *outp = nullptr;
+        unsigned int initial = 0;
+
+        void clock() {
+            bool initially_empty = outp->can_write();
+            for (unsigned int i = initial; i < peers; ++i) {
+                if (outp->can_write() && peerp[i].can_read())
+                    outp->write(peerp[i].read());
+            }
+            for (unsigned int i = 0; i < initial; ++i) {
+                if (outp->can_write() && peerp[i].can_read())
+                    outp->write(peerp[i].read());
+            }
+            if (initially_empty && !outp->can_write())
+                if (++initial == peers)
+                    initial = 0;
+        }
+    };
+
+    template<typename T, unsigned int peers> struct shared_bus : public sim {
+        std::array<port<T>, peers> peerp;
+        port<T> *outp = nullptr;
+
+        void clock() {
+            for (unsigned int i = 0; i < peers; ++i) {
+                if (peerp[i].can_read()) {
+                    assert(outp->can_write());
+                    outp->write(peerp[i].read());
+                }
+            }
+        }
+    };
+}
-- 
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