From 57a1d719e8199efa09569ef3ede9637c1dc394ee Mon Sep 17 00:00:00 2001
From: Kevin Heifner <heifnerk@objectcomputing.com>
Date: Mon, 26 Jun 2023 13:37:28 -0400
Subject: [PATCH] GH-1251 Use multiindex, process in order of last used,
 prioritize eosio.*

---
 .../chain/webassembly/eos-vm-oc/code_cache.hpp | 18 ++++++++++++++----
 .../runtimes/eos-vm-oc/code_cache.cpp          |  8 ++++----
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/libraries/chain/include/eosio/chain/webassembly/eos-vm-oc/code_cache.hpp b/libraries/chain/include/eosio/chain/webassembly/eos-vm-oc/code_cache.hpp
index 29d432ebaf..ec8c13b9ab 100644
--- a/libraries/chain/include/eosio/chain/webassembly/eos-vm-oc/code_cache.hpp
+++ b/libraries/chain/include/eosio/chain/webassembly/eos-vm-oc/code_cache.hpp
@@ -15,7 +15,6 @@
 
 
 #include <thread>
-#include <shared_mutex>
 
 namespace std {
     template<> struct hash<eosio::chain::eosvmoc::code_tuple> {
@@ -78,9 +77,20 @@ class code_cache_base {
       local::datagram_protocol::socket _compile_monitor_write_socket{_ctx};
       local::datagram_protocol::socket _compile_monitor_read_socket{_ctx};
 
-      //these are really only useful to the async code cache, but keep them here so
-      //free_code can be shared
-      deque<code_tuple> _queued_compiles;
+      //these are really only useful to the async code cache, but keep them here so free_code can be shared
+      using queued_compilies_t = boost::multi_index_container<
+         code_tuple,
+         indexed_by<
+            sequenced<>,
+            hashed_unique<tag<by_hash>,
+               composite_key< code_tuple,
+                  member<code_tuple, digest_type, &code_tuple::code_id>,
+                  member<code_tuple, uint8_t,     &code_tuple::vm_version>
+               >
+            >
+         >
+      >;
+      queued_compilies_t _queued_compiles;
       std::unordered_map<code_tuple, bool> _outstanding_compiles_and_poison;
 
       size_t _free_bytes_eviction_threshold;
diff --git a/libraries/chain/webassembly/runtimes/eos-vm-oc/code_cache.cpp b/libraries/chain/webassembly/runtimes/eos-vm-oc/code_cache.cpp
index 62a08756ce..88fe0f3929 100644
--- a/libraries/chain/webassembly/runtimes/eos-vm-oc/code_cache.cpp
+++ b/libraries/chain/webassembly/runtimes/eos-vm-oc/code_cache.cpp
@@ -157,7 +157,8 @@ const code_descriptor* const code_cache_async::get_descriptor_for_code(const acc
       it->second = false;
       return nullptr;
    }
-   if(std::find(_queued_compiles.cbegin(), _queued_compiles.cend(), ct) != _queued_compiles.end()) {
+   if(auto it = _queued_compiles.get<by_hash>().find(boost::make_tuple(std::ref(code_id), vm_version)); it != _queued_compiles.get<by_hash>().end()) {
+      _queued_compiles.relocate(_queued_compiles.begin(), _queued_compiles.project<0>(it));
       failure = get_cd_failure::temporary; // Compile might not be done yet
       return nullptr;
    }
@@ -387,9 +388,8 @@ void code_cache_base::free_code(const digest_type& code_id, const uint8_t& vm_ve
    }
 
    //if it's in the queued list, erase it
-   auto i = std::find(_queued_compiles.cbegin(), _queued_compiles.cend(), code_tuple{code_id, vm_version});
-   if (i != _queued_compiles.cend())
-      _queued_compiles.erase(i);
+   if(auto i = _queued_compiles.get<by_hash>().find(boost::make_tuple(std::ref(code_id), vm_version)); i != _queued_compiles.get<by_hash>().end())
+      _queued_compiles.get<by_hash>().erase(i);
 
    //however, if it's currently being compiled there is no way to cancel the compile,
    //so instead set a poison boolean that indicates not to insert the code in to the cache