From 26ce1d27d727475a34bccc70f053b23c5e452447 Mon Sep 17 00:00:00 2001
From: Yeastplume <mcordner@gmail.com>
Date: Wed, 19 Jul 2017 16:40:57 +0000
Subject: [PATCH] Updates to ensure multithreaded CI tests don't fail (#81)

Locks loading of miner plugins so it only ever happens once.
---
 grin.toml          |  3 ++-
 grin/Cargo.toml    |  3 ++-
 grin/src/lib.rs    |  2 ++
 grin/src/plugin.rs | 31 +++++++++++++++++++++++++++++--
 4 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/grin.toml b/grin.toml
index b5b9fb98f..f9e304b92 100644
--- a/grin.toml
+++ b/grin.toml
@@ -70,7 +70,8 @@ use_cuckoo_miner = true
 #directory
 #Plugins currently included are:
 #"simple" : the basic cuckoo algorithm
-#"edgetrim" : an algorithm trading speed for a much lower memory footpring
+#"edgetrim" : an algorithm trading speed for a much lower memory footprint
+#"tomato" : Time memory-tradeoff... low memory but very slow
 #Not included but verified working:
 #"cuda" a gpu miner - which currently needs to bebuilt and installed 
 #separately from#the cuckoo-miner repository. Instructions found there
diff --git a/grin/Cargo.toml b/grin/Cargo.toml
index ef4546eb3..2373e4114 100644
--- a/grin/Cargo.toml
+++ b/grin/Cargo.toml
@@ -15,7 +15,7 @@ grin_util = { path = "../util" }
 grin_wallet = { path = "../wallet" }
 secp256k1zkp = { path = "../secp256k1zkp" }
 
-cuckoo_miner = { git = "https://github.com/mimblewimble/cuckoo-miner", tag="grin_integration"}
+cuckoo_miner = { git = "https://github.com/mimblewimble/cuckoo-miner", tag="grin_integration_2"}
 
 env_logger="^0.3.5"
 futures = "^0.1.9"
@@ -29,3 +29,4 @@ tokio-core="^0.1.1"
 tokio-timer="^0.1.0"
 rand = "^0.3"
 tiny-keccak = "1.1"
+lazy_static = "0.2.8"
diff --git a/grin/src/lib.rs b/grin/src/lib.rs
index 190aed30d..038fdbc49 100644
--- a/grin/src/lib.rs
+++ b/grin/src/lib.rs
@@ -34,6 +34,8 @@ extern crate serde_derive;
 extern crate time;
 extern crate tokio_core;
 extern crate tokio_timer;
+#[macro_use]
+extern crate lazy_static;
 
 extern crate grin_api as api;
 extern crate grin_chain as chain;
diff --git a/grin/src/plugin.rs b/grin/src/plugin.rs
index 06f843f6f..c28555799 100644
--- a/grin/src/plugin.rs
+++ b/grin/src/plugin.rs
@@ -29,6 +29,8 @@ use std::collections::HashMap;
 use core::core::Proof;
 use types::{MinerConfig, ServerConfig};
 
+use std::sync::{Mutex};
+
 use cuckoo_miner::{
 	CuckooMiner,
 	CuckooPluginManager,
@@ -37,6 +39,15 @@ use cuckoo_miner::{
 	CuckooMinerSolution,
 	CuckooPluginCapabilities};
 
+//For now, we're just going to keep a static reference around to the loaded config
+//And not allow querying the plugin directory twice once a plugin has been selected
+//This is to keep compatibility with multi-threaded testing, so that spawned
+//testing threads don't try to load/unload the library while another thread is
+//using it.
+lazy_static!{
+    static ref LOADED_CONFIG: Mutex<Option<CuckooMinerConfig>> = Mutex::new(None);
+}
+
 pub struct PluginMiner {
 	miner:Option<CuckooMiner>,
 	last_solution: CuckooMinerSolution,
@@ -73,6 +84,17 @@ impl PluginMiner {
 		//to the executable path, though they should appear somewhere else 
 		//when packaging is more//thought out 
 
+		let mut loaded_config_ref = LOADED_CONFIG.lock().unwrap();
+
+		//Load from here instead
+		if let Some(ref c) = *loaded_config_ref {
+			debug!("Not re-loading plugin or directory.");
+			//this will load the associated plugin
+			let result=CuckooMiner::new(c.clone());
+			self.miner=Some(result.unwrap());
+			return;
+		}
+
     	let mut plugin_manager = CuckooPluginManager::new().unwrap();
     	let result=plugin_manager.load_plugin_dir(plugin_install_path);
 
@@ -96,15 +118,18 @@ impl PluginMiner {
     	let caps = plugin_manager.get_available_plugins(&filter).unwrap();
 		//insert it into the miner configuration being created below
 
-    
     	let mut config = CuckooMinerConfig::new();
-
+	
         info!("Mining using plugin: {}", caps[0].full_path.clone());
     	config.plugin_full_path = caps[0].full_path.clone();
 		if let Some(l) = miner_config.cuckoo_miner_parameter_list {
 			config.parameter_list = l.clone();
 		}
 
+		//Store this config now, because we just want one instance
+		//of the plugin lib per invocation now
+		*loaded_config_ref=Some(config.clone());
+
 		//this will load the associated plugin
 		let result=CuckooMiner::new(config);
 		if let Err(e) = result {
@@ -112,6 +137,8 @@ impl PluginMiner {
 			error!("Accepted values are: {:?}", caps[0].parameters);
 			panic!("Unable to init mining plugin.");
 		}
+
+		
 		self.miner=Some(result.unwrap());
 	} 
 }