From 754a785ee15915c4d8d81dbd55d7005e07c6407e Mon Sep 17 00:00:00 2001 From: smooth Date: Wed, 4 Mar 2015 23:35:04 -0800 Subject: [PATCH 1/2] minimum subsidy for mining incentives, remove unused LEGACY_FEE define --- src/cryptonote_config.h | 4 +--- src/cryptonote_core/blockchain_storage.cpp | 3 ++- src/cryptonote_core/cryptonote_basic_impl.cpp | 4 ++++ 3 files changed, 7 insertions(+), 4 deletions(-) diff --git a/src/cryptonote_config.h b/src/cryptonote_config.h index e26945086..e5df844e7 100644 --- a/src/cryptonote_config.h +++ b/src/cryptonote_config.h @@ -51,6 +51,7 @@ // MONEY_SUPPLY - total number coins to be generated #define MONEY_SUPPLY ((uint64_t)(-1)) #define EMISSION_SPEED_FACTOR (20) +#define FINAL_SUBSIDY_PER_MINUTE ((uint64_t)300000000000) // 3 * pow(10, 11) #define CRYPTONOTE_REWARD_BLOCKS_WINDOW 100 #define CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE 20000 //size of block (bytes) after which reward for block calculated using block size @@ -61,9 +62,6 @@ #define FEE_PER_KB ((uint64_t)10000000000) // pow(10, 10) -// temporarily to allow backward compatibility during the switch to per-kb -//#define MINING_ALLOWED_LEGACY_FEE ((uint64_t)100000000000) // pow(10, 11) - #define ORPHANED_BLOCKS_MAX_COUNT 100 diff --git a/src/cryptonote_core/blockchain_storage.cpp b/src/cryptonote_core/blockchain_storage.cpp index e2b6f2326..1f35e6a5b 100644 --- a/src/cryptonote_core/blockchain_storage.cpp +++ b/src/cryptonote_core/blockchain_storage.cpp @@ -1709,7 +1709,8 @@ bool blockchain_storage::handle_block_to_main_chain(const block& bl, const crypt bei.bl = bl; bei.block_cumulative_size = cumulative_block_size; bei.cumulative_difficulty = current_diffic; - bei.already_generated_coins = already_generated_coins + base_reward; + bei.already_generated_coins = base_reward < (MONEY_SUPPLY-already_generated_coins) ? already_generated_coins + base_reward : MONEY_SUPPLY; + if(m_blocks.size()) bei.cumulative_difficulty += m_blocks.back().cumulative_difficulty; diff --git a/src/cryptonote_core/cryptonote_basic_impl.cpp b/src/cryptonote_core/cryptonote_basic_impl.cpp index a7416a7e4..f2d862e57 100644 --- a/src/cryptonote_core/cryptonote_basic_impl.cpp +++ b/src/cryptonote_core/cryptonote_basic_impl.cpp @@ -60,6 +60,10 @@ namespace cryptonote { //----------------------------------------------------------------------------------------------- bool get_block_reward(size_t median_size, size_t current_block_size, uint64_t already_generated_coins, uint64_t &reward) { uint64_t base_reward = (MONEY_SUPPLY - already_generated_coins) >> EMISSION_SPEED_FACTOR; + if (base_reward < FINAL_SUBSIDY_PER_MINUTE) + { + base_reward = FINAL_SUBSIDY_PER_MINUTE; + } //make it soft if (median_size < CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE) { From 41a95e7b11ba9eb7ef94e1708f2407608148b8ed Mon Sep 17 00:00:00 2001 From: smooth Date: Thu, 5 Mar 2015 00:45:54 -0800 Subject: [PATCH 2/2] add comment about avoiding overflow --- src/cryptonote_core/blockchain_storage.cpp | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/src/cryptonote_core/blockchain_storage.cpp b/src/cryptonote_core/blockchain_storage.cpp index 1f35e6a5b..42269e05c 100644 --- a/src/cryptonote_core/blockchain_storage.cpp +++ b/src/cryptonote_core/blockchain_storage.cpp @@ -1709,6 +1709,12 @@ bool blockchain_storage::handle_block_to_main_chain(const block& bl, const crypt bei.bl = bl; bei.block_cumulative_size = cumulative_block_size; bei.cumulative_difficulty = current_diffic; + + // In the "tail" state when the minimum subsidy (implemented in get_block_reward) is in effect, the number of + // coins will eventually exceed MONEY_SUPPLY and overflow a uint64. To prevent overflow, cap already_generated_coins + // at MONEY_SUPPLY. already_generated_coins is only used to compute the block subsidy and MONEY_SUPPLY yields a + // subsidy of 0 under the base formula and therefore the minimum subsidy >0 in the tail state. + bei.already_generated_coins = base_reward < (MONEY_SUPPLY-already_generated_coins) ? already_generated_coins + base_reward : MONEY_SUPPLY; if(m_blocks.size())