chore(3p/nix): unvendor tvix 0.1 r/4098

Nothing is using this now, and we'll likely never pick this up again,
but we learned a lot in the process.

Every now and then this breaks in some bizarre way on channel bumps
and it's just a waste of time to maintain that.

Change-Id: Idcf2f5acd4ca7070ce18d7149cbfc0d967dc0a44
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5632
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: lukegb <lukegb@tvl.fyi>
Autosubmit: tazjin <tazjin@tvl.su>

1 files changed, 0 insertions, 140 deletions

diff --git a/third_party/nix/src/libutil/thread-pool.hh b/third_party/nix/src/libutil/thread-pool.hh
deleted file mode 100644
index 0efc4c1bfc67..000000000000
--- a/third_party/nix/src/libutil/thread-pool.hh
+++ /dev/null
@@ -1,140 +0,0 @@
-#pragma once
-
-#include <atomic>
-#include <functional>
-#include <map>
-#include <queue>
-#include <thread>
-
-#include "libutil/sync.hh"
-#include "libutil/util.hh"
-
-namespace nix {
-
-MakeError(ThreadPoolShutDown, Error);
-
-/* A simple thread pool that executes a queue of work items
-   (lambdas). */
-class ThreadPool {
- public:
-  explicit ThreadPool(size_t maxThreads = 0);
-
-  ~ThreadPool();
-
-  // FIXME: use std::packaged_task?
-  typedef std::function<void()> work_t;
-
-  /* Enqueue a function to be executed by the thread pool. */
-  void enqueue(const work_t& t);
-
-  /* Execute work items until the queue is empty. Note that work
-     items are allowed to add new items to the queue; this is
-     handled correctly. Queue processing stops prematurely if any
-     work item throws an exception. This exception is propagated to
-     the calling thread. If multiple work items throw an exception
-     concurrently, only one item is propagated; the others are
-     printed on stderr and otherwise ignored. */
-  void process();
-
- private:
-  size_t maxThreads;
-
-  struct State {
-    std::queue<work_t> pending;
-    size_t active = 0;
-    std::exception_ptr exception;
-    std::vector<std::thread> workers;
-    bool draining = false;
-  };
-
-  std::atomic_bool quit{false};
-
-  Sync<State> state_;
-
-  std::condition_variable work;
-
-  void doWork(bool mainThread);
-
-  void shutdown();
-};
-
-/* Process in parallel a set of items of type T that have a partial
-   ordering between them. Thus, any item is only processed after all
-   its dependencies have been processed. */
-template <typename T>
-void processGraph(ThreadPool& pool, const std::set<T>& nodes,
-                  std::function<std::set<T>(const T&)> getEdges,
-                  std::function<void(const T&)> processNode) {
-  struct Graph {
-    std::set<T> left;
-    std::map<T, std::set<T>> refs, rrefs;
-  };
-
-  Sync<Graph> graph_(Graph{nodes, {}, {}});
-
-  std::function<void(const T&)> worker;
-
-  worker = [&](const T& node) {
-    {
-      auto graph(graph_.lock());
-      auto i = graph->refs.find(node);
-      if (i == graph->refs.end()) {
-        goto getRefs;
-      }
-      goto doWork;
-    }
-
-  getRefs : {
-    auto refs = getEdges(node);
-    refs.erase(node);
-
-    {
-      auto graph(graph_.lock());
-      for (auto& ref : refs) {
-        if (graph->left.count(ref)) {
-          graph->refs[node].insert(ref);
-          graph->rrefs[ref].insert(node);
-        }
-      }
-      if (graph->refs[node].empty()) {
-        goto doWork;
-      }
-    }
-  }
-
-    return;
-
-  doWork:
-    processNode(node);
-
-    /* Enqueue work for all nodes that were waiting on this one
-       and have no unprocessed dependencies. */
-    {
-      auto graph(graph_.lock());
-      for (auto& rref : graph->rrefs[node]) {
-        auto& refs(graph->refs[rref]);
-        auto i = refs.find(node);
-        assert(i != refs.end());
-        refs.erase(i);
-        if (refs.empty()) {
-          pool.enqueue(std::bind(worker, rref));
-        }
-      }
-      graph->left.erase(node);
-      graph->refs.erase(node);
-      graph->rrefs.erase(node);
-    }
-  };
-
-  for (auto& node : nodes) {
-    pool.enqueue(std::bind(worker, std::ref(node)));
-  }
-
-  pool.process();
-
-  if (!graph_.lock()->left.empty()) {
-    throw Error("graph processing incomplete (cyclic reference?)");
-  }
-}
-
-}  // namespace nix