从EOS 2.0发布到现在有段时间了，今天单独研究下EOS VM的改进，以及相关的参数配置

引用官方介绍

借助EOSIO 2，我们将发布一个名为EOS VM的新WASM引擎，该引擎由三个组件组成，每个组件都有自己的功能并提供特定的性能增强。
区块链WebAssembly执行的强大组件三重奏

EOS VM Interpreter (eos-vm)

EOS VM解释器是一个WebAssembly解释器，提供了极快的解析/加载，确定性和高效的时限执行。从头开始设计解释器，使我们能够为将来对智能合约的调试支持腾出空间。

EOS VM Just In Time Compiler (JIT) (eos-vm-jit)

EOS VM即时（JIT）编译器是一种WebAssembly编译器，它采用WASM并即时生成本机代码。与WABT，Binaryen和EOS VM解释器之类的解释器相比，该体系结构能够非常快速地执行WASM智能合约，并提供显着的性能优势。这种JIT解决方案的绝对速度使我们能够在区块链上使用它，而无需其他解决方案进行较长的块编译时间。

EOS VM Optimized Compiler (eos-vm-oc-enable)

EOS VM Optimized编译器是EOS VM的第三个组件，它使用了利用多遍编译架构的专用编译器框架（LLVM）。通过优化编译器生成的本机代码通常比在WABT，Binaryen，EOS VM解释器和EOS VM JIT中执行的相同代码快一个数量级。最重要的是，它甚至比现有的WAVM引擎还要快，但是与WAVM不同，它可以利用我们的分层设计在区块链上安全使用。

参数配置

开启eos-vm-jit

wasm-runtime = eos-vm-jit

对于wasm-runtime还支持以下选项

• wabt
• eos_vm
• eos_vm_jit
• eos_vm_oc //EOS VM OC is a tier-up compiler and works in conjunction with the configured base WASM runtime. Enable EOS VM OC via 'eos-vm-oc-enable' option

开启 eos-vm-oc-enable

eos-vm-oc-enable = true

还可修改其他参数

• eos-vm-oc-cache-size-mb // Maximum size (in MiB) of the EOS VM OC code cache
• eos-vm-oc-compile-threads // eos-vm-oc-compile-threads must be set to a non-zero value

对于出块节点来说，官方意思是EOS VM Optimized编译器还没有足够的实际场景测试，防止各BP节点部分开启与未开启的行为之间可能存在差异的风险，官方建议是在生产节点上不使用eos-vm-oc-enable = true 只单独使用eos-vm-jit，
并且由于节点开启后处理会更快，也就是TPS会增加很多，将导致每个块的数据猛增，会导致查询慢，以及可能的稳定因素影响。官方建议先不要使用，等待官方更新支持。
可看此贴 https://github.com/EOSIO/eos/issues/8620

参考

https://eos.io/news/introducing-eosio-2/

为了实际项目中，解决相对有限资源，异步动态价格交换的问题，测试下Bancor 算法

从EOS系统合约中，抽离出测试代码如下

#include <iostream>
#include <cmath>
#include <list>

typedef double real_type;
int64_t supply_amount = 10000000000000ll;                         // RAMCORE

struct connector {
    int64_t balance;
    double weight = .5;
};

int64_t convert_from_exchange( connector& reserve, const int64_t& tokens_amount )
{
    const double R0 = reserve.balance;
    const double S0 = supply_amount;
    const double dS = -tokens_amount; // dS < 0, tokens are subtracted from supply
    const double Fi = double(1) / reserve.weight;

    double dR = R0 * ( std::pow(1. + dS / S0, Fi) - 1. ); // dR < 0 since dS < 0
    if ( dR > 0 ) dR = 0; // rounding errors
    reserve.balance -= int64_t(-dR);
    supply_amount   -= tokens_amount;
    return int64_t(-dR);
}

int64_t convert_to_exchange( connector& reserve, const int64_t& tokens_amount )
{
    const double S0 = supply_amount;
    const double R0 = reserve.balance;
    const double dR = tokens_amount; // dS < 0, tokens are subtracted from supply
    const double F =  reserve.weight;

    double dS = S0 * ( std::pow(1. + dR / R0, F) - 1. );
    if ( dS < 0 ) dS = 0; // rounding errors
    reserve.balance += tokens_amount;
    supply_amount   += int64_t(dS);
    return int64_t(dS);
}

// RAM / EOS
int main() {
    struct connector base;           // RAM
    base.balance = 90091267903;
    struct connector quote;
    quote.balance = 56842445020ll;   // EOS

    int64_t ram_byte = 0;
    int64_t tokens_amount = 10000000000;
    int64_t total_tokens_amount = 0;
    int64_t total_ram_byte = 0;
    int total_num = 10;                 // 测试循环次数
    std::list <int64_t > list_ram_byte;
    // Buy EOS->RAM
    int64_t tmp = 0;
    for (int i = 0; i < total_num; ++i) {
        tmp = convert_to_exchange( quote, tokens_amount );
        ram_byte = convert_from_exchange( base, tmp );
        total_ram_byte += ram_byte;
        list_ram_byte.push_back(ram_byte);
        total_tokens_amount += tokens_amount;
        std::cout << "Buy EOS->RAM " << ram_byte << std::endl;
    }

    for (int i = 0; i < total_num; ++i) {
        tmp = convert_to_exchange( base, list_ram_byte.back() );
        list_ram_byte.pop_back();
        tokens_amount = convert_from_exchange( quote, tmp );
        std::cout << "One Sell RAM->EOS " << tokens_amount << std::endl;
    }
    // Sell RAM->EOS
    //tmp = convert_to_exchange( base, total_ram_byte );
    //tokens_amount = convert_from_exchange( quote, tmp );
    //std::cout << "One Sell RAM->EOS " << tokens_amount << std::endl;

    return 0;
}

测试结果如下

Buy EOS->RAM 13478152673
Buy EOS->RAM 9970155844
Buy EOS->RAM 7674007724
Buy EOS->RAM 6089163862
Buy EOS->RAM 4949324006
Buy EOS->RAM 4102144882
Buy EOS->RAM 3455335389
Buy EOS->RAM 2950326086
Buy EOS->RAM 2548490488
Buy EOS->RAM 2223515894


Sell RAM->EOS 9999999996
Sell RAM->EOS 10000000000
Sell RAM->EOS 9999999999
Sell RAM->EOS 10000000000
Sell RAM->EOS 9999999998
Sell RAM->EOS 10000000000
Sell RAM->EOS 9999999999
Sell RAM->EOS 10000000000
Sell RAM->EOS 10000000000
Sell RAM->EOS 10000000001

符合预期，剩余资源越少，价格越高的需求

参考

https://zhuanlan.zhihu.com/p/40162089

由于Linux代码调试需要，如果当前开发系统是windows的话，可以选择使用CLion 远程链接 WSL。
所以需要子系统开启ssh

安装 ssh

sudo apt-get install openssh-server

Linux 开启密码登录

sudo vim /etc/ssh/sshd_config

找到passwordAuthentication项，修改成yes
重启ssh服务

sudo service sshd restart

查看服务状态

service ssh status
# * sshd is running  显示此内容则表示启动正常

如果提示 sshd error: could not load host key 则需要重新生成 key

dpkg-reconfigure openssh-server

如需密码设置

sudo passwd user-name

如果启动sshd时，报“Could not load host key”

Could not load host key: /etc/ssh/ssh_host_rsa_key
Could not load host key: /etc/ssh/ssh_host_ecdsa_key
Could not load host key: /etc/ssh/ssh_host_ed25519_key

查看下文件是否存在

ll /etc/ssh/

解决方法，重新生成密钥文件

ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key
ssh-keygen -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key
ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key

Clion中子系统配置请参考《Clion Windows Linux子系统》

如果启动报 ssh:unrecognized service

sudo /etc/init.d/ssh restart
sudo /etc/init.d/ssh start

ubuntu 安装 gdb

sudo apt update
sudo apt install gdb

参考

https://www.jetbrains.com/help/clion/quick-tutorial-on-configuring-clion-on-windows.html#WSL
https://www.cnblogs.com/netonline/p/7410586.html
https://blog.csdn.net/zhouzme/article/details/81087837
http://www.gdbtutorial.com/tutorial/how-install-gdb

测试环境

OS: Ubuntu 18.04 server
EOS: v2.0.1
合约：v1.9.1

部署系统合约时出现以下错误

error 2020-02-07T03:05:55.178 cleos     main.cpp:4042                 main                 ] Failed with error: deadline 2020-02-07T03:05:55.175 exceeded by 43us  (2)
deadline 2020-02-07T03:05:55.175 exceeded by 43us

跟下代码（跳转github）

#define FC_CHECK_DEADLINE( DEADLINE, ... ) \
  FC_MULTILINE_MACRO_BEGIN \
    if( DEADLINE < fc::time_point::maximum() && DEADLINE < fc::time_point::now() ) { \
       auto log_mgs = FC_LOG_MESSAGE( error, "deadline ${d} exceeded by ${t}us ", \
             FC_FORMAT_ARG_PARAMS(__VA_ARGS__)("d", DEADLINE)("t", fc::time_point::now() - DEADLINE) ); \
       auto msg = log_mgs.get_limited_message(); \
       throw timeout_exception( std::move( log_mgs ), timeout_exception_code, "timeout_exception", std::move( msg ) ); \
    } \
  FC_MULTILINE_MACRO_END

跟踪宏的调用 （跳转github）

string exception::to_string( log_level ll   )const
   {
      const auto deadline = fc::time_point::now() + format_time_limit;
      std::stringstream ss;
      try {
         ss << my->_what;
         try {
            ss << " (" << variant( my->_code ).as_string() << ")\n";
         } catch( std::bad_alloc& ) {
            throw;
         } catch( ... ) {
            ss << "<- exception in to_string.\n";
         }
         for( auto itr = my->_elog.begin(); itr != my->_elog.end(); ++itr ) {
            try {
               FC_CHECK_DEADLINE(deadline);

查看 main.cpp:4042 （跳转github）

if (!print_recognized_errors(e, verbose)) {
         // Error is not recognized
         if (!print_help_text(e) || verbose) {
            elog("Failed with error: ${e}", ("e", verbose ? e.to_detail_string() : e.to_string()));
         }
      }

发现该异常，为解析异常错误导致的解析超时错误，并非当时真实的错误。
继续查找 https://github.com/EOSIO/eos/issues/8443

2.0和1.8.9包括新的选项http-max-response-time-ms，该选项有助于减轻api节点的滥用。它允许您指定处理请求的时间限制。当前，这意味着将响应转换为json所需的时间受到限制，这是大多数api请求中最耗时的部分。我们将默认值设为30毫秒，以匹配默认的max-transaction-time。对于大块，30ms可能不足以让您的节点转换为json。当然取决于硬件等。随时随地将它放置在任何级别，您可以满足任何一个处理请求的要求。

解决方法

将http-max-response-time-ms参数修改为30毫秒

http-max-response-time-ms = 30

参考

https://github.com/EOSIO/eos/issues/8443
https://github.com/EOSIO/eos/releases/tag/v1.8.9

问题

按v1.8.x部署的方式，启动链部署eosio.bios时报env.set_proposed_producers_ex unresolveable

$ cleos set contract eosio contracts/eosio.bios
Reading WASM from /mnt/d/github/contracts/eosio.bios/eosio.bios.wasm...
Publishing contract...
Error 3070000: WASM Exception
Error Details:
env.set_proposed_producers_ex unresolveable
pending console output:

测试环境

OS：Ubuntu 18.04 server
EOS: v2.0.1
合约：v1.9.1

刚启动时可以看到目前支持了以下新共识

info  2020-02-06T01:42:48.853 nodeos    chain_plugin.cpp:421          operator()           ] Support for builtin protocol feature 'PREACTIVATE_FEATURE' (with digest of '0ec7e080177b2c02b278d5088611686b49d739925a92d9bfcacd7fc6b74053bd') is enabled without activation restrictions
info  2020-02-06T01:42:48.854 nodeos    chain_plugin.cpp:408          operator()           ] Support for builtin protocol feature 'ONLY_LINK_TO_EXISTING_PERMISSION' (with digest of '1a99a59d87e06e09ec5b028a9cbb7749b4a5ad8819004365d02dc4379a8b7241') is enabled with preactivation required
info  2020-02-06T01:42:48.856 nodeos    chain_plugin.cpp:408          operator()           ] Support for builtin protocol feature 'FORWARD_SETCODE' (with digest of '2652f5f96006294109b3dd0bbde63693f55324af452b799ee137a81a905eed25') is enabled with preactivation required
info  2020-02-06T01:42:48.857 nodeos    chain_plugin.cpp:408          operator()           ] Support for builtin protocol feature 'WTMSIG_BLOCK_SIGNATURES' (with digest of '299dcb6af692324b899b39f16d5a530a33062804e41f09dc97e9f156b4476707') is enabled with preactivation required
info  2020-02-06T01:42:48.857 nodeos    chain_plugin.cpp:408          operator()           ] Support for builtin protocol feature 'REPLACE_DEFERRED' (with digest of 'ef43112c6543b88db2283a2e077278c315ae2c84719a8b25f25cc88565fbea99') is enabled with preactivation required
info  2020-02-06T01:42:48.858 nodeos    chain_plugin.cpp:408          operator()           ] Support for builtin protocol feature 'NO_DUPLICATE_DEFERRED_ID' (with digest of '4a90c00d55454dc5b059055ca213579c6ea856967712a56017487886a4d4cc0f') is enabled with preactivation required
info  2020-02-06T01:42:48.860 nodeos    chain_plugin.cpp:408          operator()           ] Support for builtin protocol feature 'RAM_RESTRICTIONS' (with digest of '4e7bf348da00a945489b2a681749eb56f5de00b900014e137ddae39f48f69d67') is enabled with preactivation required
info  2020-02-06T01:42:48.861 nodeos    chain_plugin.cpp:408          operator()           ] Support for builtin protocol feature 'WEBAUTHN_KEY' (with digest of '4fca8bd82bbd181e714e283f83e1b45d95ca5af40fb89ad3977b653c448f78c2') is enabled with preactivation required
info  2020-02-06T01:42:48.862 nodeos    chain_plugin.cpp:408          operator()           ] Support for builtin protocol feature 'DISALLOW_EMPTY_PRODUCER_SCHEDULE' (with digest of '68dcaa34c0517d19666e6b33add67351d8c5f69e999ca1e37931bc410a297428') is enabled with preactivation required
info  2020-02-06T01:42:48.863 nodeos    chain_plugin.cpp:408          operator()           ] Support for builtin protocol feature 'ONLY_BILL_FIRST_AUTHORIZER' (with digest of '8ba52fe7a3956c5cd3a656a3174b931d3bb2abb45578befc59f283ecd816a405') is enabled with preactivation required
info  2020-02-06T01:42:48.864 nodeos    chain_plugin.cpp:408          operator()           ] Support for builtin protocol feature 'RESTRICT_ACTION_TO_SELF' (with digest of 'ad9e3d8f650687709fd68f4b90b41f7d825a365b02c23a636cef88ac2ac00c43') is enabled with preactivation required
info  2020-02-06T01:42:48.864 nodeos    chain_plugin.cpp:408          operator()           ] Support for builtin protocol feature 'FIX_LINKAUTH_RESTRICTION' (with digest of 'e0fb64b1085cc5538970158d05a009c24e276fb94e1a0bf6a528b48fbc4ff526') is enabled with preactivation required
info  2020-02-06T01:42:48.865 nodeos    chain_plugin.cpp:408          operator()           ] Support for builtin protocol feature 'GET_SENDER' (with digest of 'f0af56d2c5a48d60a4a5b5c903edfb7db3a736a94ed589d0b797df33ff9d3e1d') is enabled with preactivation required

查询当前已激活共识

curl -X POST http://127.0.0.1:8888/v1/chain/get_activated_protocol_features -d '{}' | jq

查看代码 （github）
https://github.com/EOSIO/eos/blob/e73a43be09478ed3fe5d48071156e1b7caa0e3e1/libraries/chain/controller.cpp#L3330

template<>
void controller_impl::on_activation<builtin_protocol_feature_t::wtmsig_block_signatures>() {
   db.modify( db.get<protocol_state_object>(), [&]( auto& ps ) {
      add_intrinsic_to_whitelist( ps.whitelisted_intrinsics, "set_proposed_producers_ex" );
   } );
}

报错信息提示WTMSIG_BLOCK_SIGNATURES
查看合约更新日志
https://github.com/EOSIO/eosio.contracts/releases/tag/v1.9.1

The eosio.system and eosio.bios contracts contained in this release can only be deployed on an EOSIO blockchain after the activation of the WTMSIG_BLOCK_SIGNATURES consensus protocol upgrade.

只有开启WTMSIG_BLOCK_SIGNATURES共识才能使用此合约。
根据查看 https://github.com/EOSIO/eos/pull/7404

开启WTMSIG_BLOCK_SIGNATURES共识

目前开启WTMSIG_BLOCK_SIGNATURES共识，需要系统账户先部署eosio.boot，并且此合约在单独的合约分支（吐槽下EOSIO代码版本管理...）
先获取下add-boot-contract分支合约

git clone --branch add-boot-contract https://github.com/EOSIO/eosio.contracts.git
./[path]/eosio.contracts/build.sh

和之前部署一样先激活PREACTIVATE_FEATURE

curl -X POST http://127.0.0.1:8888/v1/producer/schedule_protocol_feature_activations -d '{"protocol_features_to_activate": ["0ec7e080177b2c02b278d5088611686b49d739925a92d9bfcacd7fc6b74053bd"]}' | jq

然后部署下eosio.boot合约

cleos set contract eosio [path]/eosio.contracts/build/contracts/eosio.boot -p eosio@active

激活WTMSIG_BLOCK_SIGNATURES协议

cleos -u http://127.0.0.1:8888 push transaction '{"delay_sec":0,"max_cpu_usage_ms":0,"actions":[{"account":"eosio","name":"activate","data":{"feature_digest":"299dcb6af692324b899b39f16d5a530a33062804e41f09dc97e9f156b4476707"},"authorization":[{"actor":"eosio","permission":"active"}]}]}'

最后查询下PREACTIVATE_FEATURE和WTMSIG_BLOCK_SIGNATURES是否已成功激活

curl -X POST http://127.0.0.1:8888/v1/chain/get_activated_protocol_features -d '{}' | jq

{
  "activated_protocol_features": [
    {
      "feature_digest": "0ec7e080177b2c02b278d5088611686b49d739925a92d9bfcacd7fc6b74053bd",
      "activation_ordinal": 0,
      "activation_block_num": 1176,
      "description_digest": "64fe7df32e9b86be2b296b3f81dfd527f84e82b98e363bc97e40bc7a83733310",
      "dependencies": [],
      "protocol_feature_type": "builtin",
      "specification": [
        {
          "name": "builtin_feature_codename",
          "value": "PREACTIVATE_FEATURE"
        }
      ]
    },
    {
      "feature_digest": "299dcb6af692324b899b39f16d5a530a33062804e41f09dc97e9f156b4476707",
      "activation_ordinal": 1,
      "activation_block_num": 12770,
      "description_digest": "ab76031cad7a457f4fd5f5fca97a3f03b8a635278e0416f77dcc91eb99a48e10",
      "dependencies": [],
      "protocol_feature_type": "builtin",
      "specification": [
        {
          "name": "builtin_feature_codename",
          "value": "WTMSIG_BLOCK_SIGNATURES"
        }
      ]
    }
  ]
}

然后继续之前的步骤，继续部署eosio.bios合约，以及后面的步骤

cleos set contract eosio contracts/eosio.bios

参考
https://developers.eos.io/manuals/eos/latest/nodeos/upgrade-guides/1.8-upgrade-guide
https://eosio.stackexchange.com/questions/5241/how-to-activate-the-wtmsig-block-signatures-protocol-feature
https://eosio.stackexchange.com/questions/5235/error-while-deploying-eosio-system-contract-to-eosio-account-while-setting-up-a