From 0ab57c48c3c3948e68d2b4443a99fc7497d859cd Mon Sep 17 00:00:00 2001
From: Gav Wood <gavin@ethcore.io>
Date: Thu, 24 Mar 2016 13:51:51 +0000
Subject: [PATCH] Add tracing.

---
 miner/src/miner.rs      | 33 ++++++++++++++++++++-------------
 rpc/src/v1/impls/eth.rs |  3 ++-
 2 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/miner/src/miner.rs b/miner/src/miner.rs
index d4f6c8a00..4e0f4a5c5 100644
--- a/miner/src/miner.rs
+++ b/miner/src/miner.rs
@@ -166,28 +166,35 @@ impl MinerService for Miner {
 	}
 
 	fn update_sealing(&self, chain: &BlockChainClient) {
-		let should_disable_sealing = {
-			let current_no = chain.chain_info().best_block_number;
-			let last_request = self.sealing_block_last_request.lock().unwrap();
-			let is_greater = current_no > *last_request;
-			is_greater && current_no - *last_request > SEALING_TIMEOUT_IN_BLOCKS
-		};
+		if self.sealing_enabled.load(atomic::Ordering::Relaxed) {
+			let should_disable_sealing = {
+				let current_no = chain.chain_info().best_block_number;
+				let last_request = self.sealing_block_last_request.lock().unwrap();
+				let is_greater = current_no > *last_request;
+				is_greater && current_no - *last_request > SEALING_TIMEOUT_IN_BLOCKS
+			};
 
-		if should_disable_sealing {
-			self.sealing_enabled.store(false, atomic::Ordering::Relaxed);
-			*self.sealing_block.lock().unwrap() = None;
-		} else if self.sealing_enabled.load(atomic::Ordering::Relaxed) {
-			self.prepare_sealing(chain);
+			if should_disable_sealing {
+				trace!(target: "miner", "Miner sleeping (current {}, last {})", current_no, last_request);
+				self.sealing_enabled.store(false, atomic::Ordering::Relaxed);
+				*self.sealing_block.lock().unwrap() = None;
+			} else {
+				self.prepare_sealing(chain);
+			}
 		}
 	}
 
 	fn sealing_block(&self, chain: &BlockChainClient) -> &Mutex<Option<ClosedBlock>> {
 		if self.sealing_block.lock().unwrap().is_none() {
 			self.sealing_enabled.store(true, atomic::Ordering::Relaxed);
-
 			self.prepare_sealing(chain);
 		}
-		*self.sealing_block_last_request.lock().unwrap() = chain.chain_info().best_block_number;
+		let sealing_block_last_request = self.sealing_block_last_request.lock().unwrap();
+		let best_number = chain.chain_info().best_block_number;
+		if *sealing_block_last_request != best_number {
+			trace!(target: "miner", "Miner received request (was {}, now {}) - waking up.", sealing_block_last_request, best_number);
+			*sealing_block_last_request = best_number;
+		}
 		&self.sealing_block
 	}
 
diff --git a/rpc/src/v1/impls/eth.rs b/rpc/src/v1/impls/eth.rs
index a065392d5..638403c7d 100644
--- a/rpc/src/v1/impls/eth.rs
+++ b/rpc/src/v1/impls/eth.rs
@@ -398,10 +398,11 @@ impl<C, S, A, M, EM> Eth for EthClient<C, S, A, M, EM>
 		match params {
 			Params::None => {
 				let client = take_weak!(self.client);
-				// check if we're still syncing and return empty strings int that case
+				// check if we're still syncing and return empty strings in that case
 				{
 					let sync = take_weak!(self.sync);
 					if sync.status().state != SyncState::Idle && client.queue_info().is_empty() {
+						trace!(target: "miner", "Syncing. Cannot give any work.");
 						return to_value(&(String::new(), String::new(), String::new()));
 					}
 				}