9 files changed, 361 insertions, 0 deletions

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());
+                }
+            }
+        }
+    };
+}
diff --git a/pipetrace.cpp b/pipetrace.cpp
new file mode 100644
index 0000000..e6642ef
--- /dev/null
+++ b/pipetrace.cpp
@@ -0,0 +1,9 @@
+#include <cstdint>
+#include <ostream>
+
+#include "infra/pipetrace.h"
+
+namespace infra {
+    std::ostream *pt::ptfile = nullptr;
+    std::uint64_t pt::next_record = 0;
+}
diff --git a/pipetrace.h b/pipetrace.h
new file mode 100644
index 0000000..656b9b9
--- /dev/null
+++ b/pipetrace.h
@@ -0,0 +1,37 @@
+#pragma once
+
+#include <cstdint>
+#include <fmt/format.h>
+#include <ostream>
+#include <string>
+
+namespace infra {
+    struct transaction {
+        std::uint64_t record = ~(std::uint64_t)0;
+    };
+
+    struct pt {
+        static std::ostream *ptfile;
+
+        static std::uint64_t next_record;
+
+        static transaction toplevel() {
+            transaction t;
+            t.record = next_record++;
+            return t;
+        }
+
+        static transaction child(const transaction &p) {
+            transaction t;
+            t.record = next_record++;
+            if (ptfile)
+                *ptfile << fmt::format("{} parent {}\n", t.record, p.record);
+            return t;
+        }
+
+        static void event(const transaction &t, const char *event, std::uint64_t time, const std::string &data) {
+            if (ptfile)
+                *ptfile << fmt::format("@{} {} {} {}\n", time, t.record, event, data);
+        }
+    };
+}
diff --git a/port.h b/port.h
new file mode 100644
index 0000000..06a3aa5
--- /dev/null
+++ b/port.h
@@ -0,0 +1,45 @@
+#pragma once
+
+#include <cassert>
+#include <optional>
+#include <utility>
+
+#include "infra/sim.h"
+
+namespace infra {
+    template<typename T> struct port : public sim {
+        std::optional<T> consumer_side;
+        std::optional<T> producer_side;
+
+        bool can_read() { return consumer_side.has_value(); }
+        bool can_write() { return !producer_side.has_value(); }
+
+        T read() {
+            assert(can_read());
+            auto x = std::move(*consumer_side);
+            consumer_side.reset();
+            return x;
+        }
+
+        const T & peek() {
+            assert(can_read());
+            return *consumer_side;
+        }
+
+        void discard() {
+            consumer_side.reset();
+        }
+
+        void write(T &&x) {
+            assert(can_write());
+            producer_side = std::move(x);
+        }
+
+        void unclock() {
+            if (!consumer_side && producer_side) {
+                consumer_side = std::move(*producer_side);
+                producer_side.reset();
+            }
+        }
+    };
+}
diff --git a/pt b/pt
new file mode 100755
index 0000000..206795f
--- /dev/null
+++ b/pt
@@ -0,0 +1,104 @@
+#!/usr/bin/ruby
+
+$filter = ARGV
+
+$parents = {}
+$events = {}
+$has = {}
+$data = {}
+$horiz = {}
+$maxtime = -1
+
+$stats = false
+
+$stdin.each_line do | line |
+  case line
+
+    when /^(\d+) parent (\d+)$/
+      child = $1.to_i
+      parent = $2.to_i
+      $parents[child] = parent
+
+    when /^@(\d+) (\d+) (\S*) (.*)$/
+      time = $1.to_i
+      rec = $2.to_i
+      event = $3
+      data = $4
+      if event.size > 0
+        $events[rec] ||= {}
+        $events[rec][time] = event
+        $has[rec] ||= {}
+        $has[rec][event] = true
+        $horiz[event] ||= ""
+        $horiz[event] = $horiz[event].ljust(time)
+        $horiz[event][time] = event
+      end
+      if data.size > 0
+        $data[rec] ||= ""
+        $data[rec] += " #{event}@#{time}:" if event.size > 0
+        $data[rec] += " #{data}"
+      end
+      $maxtime = [$maxtime, time+1].max
+
+    when /^#\s*(.*)$/
+      $stats = true
+      $stdout.write("#{$1}\n")
+
+    else
+      raise "Unexpected line: #{line}"
+  end
+end
+
+$stdout.write("\n") if $stats
+
+$hier = {}
+$hier_direct = {}
+
+$events.each_key do | rec |
+  subhier = {}
+  $hier_direct[rec] = subhier
+  if $parents.key?(rec)
+    $hier_direct[$parents[rec]][rec] = subhier
+  else
+    $hier[rec] = subhier
+  end
+end
+
+$order = []
+
+def flatten(hier)
+  hier.each do | rec, subhier |
+    $order << rec
+    flatten(subhier)
+  end
+end
+flatten($hier)
+
+rwidth = $order.map { | x | x.to_s.size }.max
+
+$horiz.keys.sort.each do | occ |
+  $stdout.write(" " * rwidth + "  #{$horiz[occ].ljust($maxtime)}")
+  count = $horiz[occ].delete(" ").size
+  $stdout.write(" #{($maxtime.to_f / count.to_f).round(2).to_s.rjust(5)} cyc/evt\n")
+end
+$stdout.write("\n")
+
+mwidth = 0
+
+$order.each do | rec |
+  estr = ""
+  filter_match = $filter.empty?
+  $has[rec].each_key do | event |
+    filter_match ||= $filter.include?(event)
+  end
+  next unless filter_match
+  $events[rec].keys.sort.each do | time |
+    estr = estr.ljust(time + 1, estr.size == 0 ? " " : "-")
+    estr[time] = $events[rec][time] if $events[rec][time].size > 0
+  end
+  estr += " " * 5
+  estr = estr.ljust(mwidth - 1)
+  estr = estr.ljust(estr.size + 20 - estr.size % 20)
+  mwidth = [mwidth, estr.size].max
+  $stdout.write(rec.to_s.rjust(rwidth) + ": #{estr}#{$data[rec]}\n")
+end
diff --git a/queue.h b/queue.h
new file mode 100644
index 0000000..1e490bc
--- /dev/null
+++ b/queue.h
@@ -0,0 +1,29 @@
+#pragma once
+
+#include <cassert>
+#include <deque>
+#include <optional>
+#include <utility>
+
+#include "infra/port.h"
+#include "infra/sim.h"
+
+namespace infra {
+    template<typename T, unsigned int size> struct queue : public sim {
+        port<T> input;
+        port<T> *output = nullptr;
+        std::deque<T> elements;
+
+        void clock() {
+            if (input.can_read() && elements.size() < size) {
+                auto x = input.read();
+                elements.emplace_back(std::move(x));
+            }
+            if (output->can_write() && !elements.empty()) {
+                auto &x = elements.front();
+                output->write(std::move(x));
+                elements.pop_front();
+            }
+        }
+    };
+}
diff --git a/sim.cpp b/sim.cpp
new file mode 100644
index 0000000..21acc8c
--- /dev/null
+++ b/sim.cpp
@@ -0,0 +1,9 @@
+#include <cstdint>
+#include <vector>
+
+#include "infra/sim.h"
+
+namespace infra {
+    std::vector<sim *> sim::sims;
+    std::uint64_t sim::now = 0;
+}
diff --git a/sim.h b/sim.h
new file mode 100644
index 0000000..185916a
--- /dev/null
+++ b/sim.h
@@ -0,0 +1,38 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+#include "infra/pipetrace.h"
+
+namespace infra {
+    struct sim {
+        virtual void clock() {}
+        virtual void unclock() {}
+
+        static std::vector<sim *> sims;
+
+        static std::uint64_t now;
+
+        sim() {
+            sims.emplace_back(this);
+        }
+
+        virtual ~sim() {
+            std::erase(sims, this);
+        }
+
+        static void advance() {
+            for (auto &s : sims)
+                s->clock();
+            for (auto &s : sims)
+                s->unclock();
+            ++now;
+        }
+
+        void pte(const transaction &t, const char *event, const std::string &data) {
+            pt::event(t, event, now, data);
+        }
+    };
+}
diff --git a/stat.h b/stat.h
new file mode 100644
index 0000000..f1ca75a
--- /dev/null
+++ b/stat.h
@@ -0,0 +1,35 @@
+#pragma once
+
+#include <fmt/format.h>
+#include <utility>
+
+#include "infra/sim.h"
+
+namespace infra {
+    struct stat : public sim {
+        std::string name;
+        std::uint64_t numerator = 0;
+        std::uint64_t denominator = 0;
+
+        stat(std::string name)
+            : name(std::move(name))
+        { }
+
+        ~stat() {
+            fmt::print("# {} {}\n", name, (double)numerator/(double)denominator);
+        }
+
+        void unclock() {
+            ++denominator;
+        }
+
+        stat & operator++() {
+            ++numerator;
+            return *this;
+        }
+
+        stat & operator++(int) {
+            return operator++();
+        }
+    };
+}