From 9255fa9d24087402859a7a93eb3a4c25e96c9fec Mon Sep 17 00:00:00 2001
From: rickyes <ives199511@gmail.com>
Date: Thu, 28 May 2020 23:15:55 +0800
Subject: [PATCH 01/13] http: add maxTotalSockets to agent class

---
 doc/api/http.md                               | 10 +++
 lib/_http_agent.js                            | 74 ++++++++++++++++---
 .../test-http-agent-maxtotalsockets.js        | 65 ++++++++++++++++
 3 files changed, 139 insertions(+), 10 deletions(-)
 create mode 100644 test/parallel/test-http-agent-maxtotalsockets.js

diff --git a/doc/api/http.md b/doc/api/http.md
index 357d8b16928d47..ad3c09df23073a 100644
--- a/doc/api/http.md
+++ b/doc/api/http.md
@@ -300,6 +300,16 @@ added: v0.3.6
 By default set to `Infinity`. Determines how many concurrent sockets the agent
 can have open per origin. Origin is the returned value of [`agent.getName()`][].
 
+### `agent.maxTotalSockets`
+<!-- YAML
+added: REPLACEME
+-->
+
+* {number}
+
+By default set to `undefined`. Determines how many concurrent sockets the agent
+can have open. The `maxSockets` will not take effect when this parameter is set.
+
 ### `agent.requests`
 <!-- YAML
 added: v0.5.9
diff --git a/lib/_http_agent.js b/lib/_http_agent.js
index 91ca52c4e6e52f..3ba62d9516a2b6 100644
--- a/lib/_http_agent.js
+++ b/lib/_http_agent.js
@@ -39,6 +39,7 @@ const {
   },
 } = require('internal/errors');
 const { once } = require('internal/util');
+const { validateNumber } = require('internal/validators');
 
 const kOnKeylog = Symbol('onkeylog');
 // New Agent code.
@@ -93,6 +94,12 @@ function Agent(options) {
     throw new ERR_INVALID_OPT_VALUE('scheduling', this.scheduling);
   }
 
+  if (this.options.maxTotalSockets !== undefined) {
+    validateNumber(this.options.maxTotalSockets, 'maxTotalSockets');
+    this.maxTotalSockets = this.options.maxTotalSockets;
+    this.totalSocketCount = 0;
+  }
+
   this.on('free', (socket, options) => {
     const name = this.getName(options);
     debug('agent.on(free)', name);
@@ -127,12 +134,25 @@ function Agent(options) {
 
     const freeSockets = this.freeSockets[name] || [];
     const freeLen = freeSockets.length;
-    let count = freeLen;
-    if (this.sockets[name])
-      count += this.sockets[name].length;
 
-    if (count > this.maxSockets ||
-        freeLen >= this.maxFreeSockets ||
+    // The maxSockets is invalid when maxTotalSockets is set
+    if (this.maxTotalSockets) {
+      if (this.totalSocketCount > this.maxTotalSockets) {
+        socket.destroy();
+        return;
+      }
+    } else {
+      let count = freeLen;
+      if (this.sockets[name])
+        count += this.sockets[name].length;
+
+      if (count > this.maxSockets) {
+        socket.destroy();
+        return;
+      }
+    }
+
+    if (freeLen >= this.maxFreeSockets ||
         !this.keepSocketAlive(socket)) {
       socket.destroy();
       return;
@@ -231,9 +251,6 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
       delete this.freeSockets[name];
   }
 
-  const freeLen = freeSockets ? freeSockets.length : 0;
-  const sockLen = freeLen + this.sockets[name].length;
-
   if (socket) {
     // Guard against an uninitialized or user supplied Socket.
     const handle = socket._handle;
@@ -246,7 +263,23 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
     this.reuseSocket(socket, req);
     setRequestSocket(this, req, socket);
     this.sockets[name].push(socket);
-  } else if (sockLen < this.maxSockets) {
+    if (this.maxTotalSockets)
+      this.totalSocketCount++;
+    return;
+  }
+
+  const freeLen = freeSockets ? freeSockets.length : 0;
+  const sockLen = freeLen + this.sockets[name].length;
+  let isWait = false;
+
+  // The maxSockets is invalid when maxTotalSockets is set
+  if (this.maxTotalSockets) {
+    this.totalSocketCount >= this.maxTotalSockets && (isWait = true);
+  } else {
+    sockLen >= this.maxSockets && (isWait = true);
+  }
+
+  if (isWait === false) {
     debug('call onSocket', sockLen, freeLen);
     // If we are under maxSockets create a new one.
     this.createSocket(req, options, (err, socket) => {
@@ -261,6 +294,10 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
     if (!this.requests[name]) {
       this.requests[name] = [];
     }
+
+    if (this.maxTotalSockets)
+      req._options = options;
+
     this.requests[name].push(req);
   }
 };
@@ -286,6 +323,8 @@ Agent.prototype.createSocket = function createSocket(req, options, cb) {
       this.sockets[name] = [];
     }
     this.sockets[name].push(s);
+    if (this.maxTotalSockets)
+      this.totalSocketCount++;
     debug('sockets', name, this.sockets[name].length);
     installListeners(this, s, options);
     cb(null, s);
@@ -392,13 +431,27 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
         // Don't leak
         if (sockets[name].length === 0)
           delete sockets[name];
+        if (this.maxTotalSockets)
+          this.totalSocketCount--;
       }
     }
   }
 
+  let req;
   if (this.requests[name] && this.requests[name].length) {
     debug('removeSocket, have a request, make a socket');
-    const req = this.requests[name][0];
+    req = this.requests[name][0];
+  } else if (this.maxTotalSockets) {
+    for (const prop in this.requests) {
+      debug('removeSocket, have a request with different origin, make a socket');
+      req = this.requests[prop][0];
+      options = req._options;
+      delete req._options;
+      break;
+    }
+  }
+
+  if (req && options) {
     // If we have pending requests and a socket gets closed make a new one
     this.createSocket(req, options, (err, socket) => {
       if (err)
@@ -407,6 +460,7 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
         socket.emit('free');
     });
   }
+
 };
 
 Agent.prototype.keepSocketAlive = function keepSocketAlive(socket) {
diff --git a/test/parallel/test-http-agent-maxtotalsockets.js b/test/parallel/test-http-agent-maxtotalsockets.js
new file mode 100644
index 00000000000000..aff4d28c26358d
--- /dev/null
+++ b/test/parallel/test-http-agent-maxtotalsockets.js
@@ -0,0 +1,65 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const http = require('http');
+const Countdown = require('../common/countdown');
+
+const maxTotalSockets = 3;
+
+const agent = new http.Agent({
+  keepAlive: true,
+  keepAliveMsecs: 1000,
+  maxTotalSockets,
+  maxSockets: 100,
+  maxFreeSockets: 3
+});
+
+const server = http.createServer(common.mustCall((req, res) => {
+  res.end('hello world');
+}, 6));
+
+server.keepAliveTimeout = 0;
+
+const countdown = new Countdown(6, () => {
+  agent.destroy();
+  server.close();
+});
+
+function handler() {
+  for (let i = 0; i < 6; i++) {
+    http.get({
+      host: 'localhost',
+      port: server.address().port,
+      agent: agent,
+      path: `/${i}`,
+      // Setting different origins
+      family: i < 3 ? 4 : 6
+    }, common.mustCall(res => {
+      assert.strictEqual(res.statusCode, 200);
+      res.resume();
+      res.on('end', common.mustCall(() => {
+        const count = getTotalSocketsCount();
+        assert(count <= maxTotalSockets);
+        countdown.dec();
+      }));
+    }));
+  }
+}
+
+function getTotalSocketsCount() {
+  let num = 0;
+  for (const key of Object.keys(agent.sockets)) {
+    num += agent.sockets[key].length;
+  }
+  return num;
+}
+
+function getRequestCount() {
+  let num = 0;
+  for (const key of Object.keys(agent.requests)) {
+    num += agent.requests[key].length;
+  }
+  return num;
+}
+
+server.listen(0, common.mustCall(handler));

From 958f2b31f044b1e5a3d6b645778d91d3fce6516c Mon Sep 17 00:00:00 2001
From: rickyes <ives199511@gmail.com>
Date: Fri, 29 May 2020 00:02:55 +0800
Subject: [PATCH 02/13] fixup

---
 lib/_http_agent.js                               | 3 ++-
 test/parallel/test-http-agent-maxtotalsockets.js | 5 +++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/_http_agent.js b/lib/_http_agent.js
index 3ba62d9516a2b6..9fc4833f9a48f4 100644
--- a/lib/_http_agent.js
+++ b/lib/_http_agent.js
@@ -443,7 +443,8 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
     req = this.requests[name][0];
   } else if (this.maxTotalSockets) {
     for (const prop in this.requests) {
-      debug('removeSocket, have a request with different origin, make a socket');
+      debug('removeSocket, have a request with different origin,' +
+        ' make a socket');
       req = this.requests[prop][0];
       options = req._options;
       delete req._options;
diff --git a/test/parallel/test-http-agent-maxtotalsockets.js b/test/parallel/test-http-agent-maxtotalsockets.js
index aff4d28c26358d..2248b4327e5ba7 100644
--- a/test/parallel/test-http-agent-maxtotalsockets.js
+++ b/test/parallel/test-http-agent-maxtotalsockets.js
@@ -21,6 +21,7 @@ const server = http.createServer(common.mustCall((req, res) => {
 server.keepAliveTimeout = 0;
 
 const countdown = new Countdown(6, () => {
+  assert.strictEqual(getRequestCount(), 0);
   agent.destroy();
   server.close();
 });
@@ -33,8 +34,8 @@ function handler() {
       agent: agent,
       path: `/${i}`,
       // Setting different origins
-      family: i < 3 ? 4 : 6
-    }, common.mustCall(res => {
+      family: i < 3 ? 4 : 6,
+    }, common.mustCall((res) => {
       assert.strictEqual(res.statusCode, 200);
       res.resume();
       res.on('end', common.mustCall(() => {

From 53ce024e40a415b380caf1ff9207c131beb8bc0b Mon Sep 17 00:00:00 2001
From: rickyes <ives199511@gmail.com>
Date: Fri, 29 May 2020 00:21:03 +0800
Subject: [PATCH 03/13] fixup

---
 lib/_http_agent.js | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/_http_agent.js b/lib/_http_agent.js
index 9fc4833f9a48f4..87a31d87610d84 100644
--- a/lib/_http_agent.js
+++ b/lib/_http_agent.js
@@ -89,15 +89,15 @@ function Agent(options) {
   this.maxSockets = this.options.maxSockets || Agent.defaultMaxSockets;
   this.maxFreeSockets = this.options.maxFreeSockets || 256;
   this.scheduling = this.options.scheduling || 'fifo';
+  this.maxTotalSockets = this.options.maxTotalSockets;
+  this.totalSocketCount = 0;
 
   if (this.scheduling !== 'fifo' && this.scheduling !== 'lifo') {
     throw new ERR_INVALID_OPT_VALUE('scheduling', this.scheduling);
   }
 
-  if (this.options.maxTotalSockets !== undefined) {
-    validateNumber(this.options.maxTotalSockets, 'maxTotalSockets');
-    this.maxTotalSockets = this.options.maxTotalSockets;
-    this.totalSocketCount = 0;
+  if (this.maxTotalSockets !== undefined) {
+    validateNumber(this.maxTotalSockets, 'maxTotalSockets');
   }
 
   this.on('free', (socket, options) => {

From 773d9f0e042eb3b6b64cb8f4097781d9eb3d11b1 Mon Sep 17 00:00:00 2001
From: rickyes <ives199511@gmail.com>
Date: Fri, 29 May 2020 11:56:29 +0800
Subject: [PATCH 04/13] fixup

---
 doc/api/http.md                               |  4 +-
 lib/_http_agent.js                            | 67 +++++++------------
 .../test-http-agent-maxtotalsockets.js        | 14 +++-
 3 files changed, 37 insertions(+), 48 deletions(-)

diff --git a/doc/api/http.md b/doc/api/http.md
index ad3c09df23073a..70f7ca6d19691c 100644
--- a/doc/api/http.md
+++ b/doc/api/http.md
@@ -307,8 +307,8 @@ added: REPLACEME
 
 * {number}
 
-By default set to `undefined`. Determines how many concurrent sockets the agent
-can have open. The `maxSockets` will not take effect when this parameter is set.
+By default set to `Infinity`. Determines how many concurrent sockets the agent
+can have open.
 
 ### `agent.requests`
 <!-- YAML
diff --git a/lib/_http_agent.js b/lib/_http_agent.js
index 87a31d87610d84..252cc38701d7bc 100644
--- a/lib/_http_agent.js
+++ b/lib/_http_agent.js
@@ -36,6 +36,7 @@ const {
   codes: {
     ERR_INVALID_ARG_TYPE,
     ERR_INVALID_OPT_VALUE,
+    ERR_OUT_OF_RANGE,
   },
 } = require('internal/errors');
 const { once } = require('internal/util');
@@ -98,6 +99,11 @@ function Agent(options) {
 
   if (this.maxTotalSockets !== undefined) {
     validateNumber(this.maxTotalSockets, 'maxTotalSockets');
+    if (this.maxTotalSockets <= 0)
+      throw new ERR_OUT_OF_RANGE('maxTotalSockets', '> 0',
+        this.maxTotalSockets);
+  } else {
+    this.maxTotalSockets = Infinity;
   }
 
   this.on('free', (socket, options) => {
@@ -134,25 +140,13 @@ function Agent(options) {
 
     const freeSockets = this.freeSockets[name] || [];
     const freeLen = freeSockets.length;
+    let count = freeLen;
+    if (this.sockets[name])
+      count += this.sockets[name].length;
 
-    // The maxSockets is invalid when maxTotalSockets is set
-    if (this.maxTotalSockets) {
-      if (this.totalSocketCount > this.maxTotalSockets) {
-        socket.destroy();
-        return;
-      }
-    } else {
-      let count = freeLen;
-      if (this.sockets[name])
-        count += this.sockets[name].length;
-
-      if (count > this.maxSockets) {
-        socket.destroy();
-        return;
-      }
-    }
-
-    if (freeLen >= this.maxFreeSockets ||
+    if (this.totalSocketCount > this.maxTotalSockets ||
+        count > this.maxSockets ||
+        freeLen >= this.maxFreeSockets ||
         !this.keepSocketAlive(socket)) {
       socket.destroy();
       return;
@@ -251,6 +245,9 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
       delete this.freeSockets[name];
   }
 
+  const freeLen = freeSockets ? freeSockets.length : 0;
+  const sockLen = freeLen + this.sockets[name].length;
+
   if (socket) {
     // Guard against an uninitialized or user supplied Socket.
     const handle = socket._handle;
@@ -263,23 +260,9 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
     this.reuseSocket(socket, req);
     setRequestSocket(this, req, socket);
     this.sockets[name].push(socket);
-    if (this.maxTotalSockets)
-      this.totalSocketCount++;
-    return;
-  }
-
-  const freeLen = freeSockets ? freeSockets.length : 0;
-  const sockLen = freeLen + this.sockets[name].length;
-  let isWait = false;
-
-  // The maxSockets is invalid when maxTotalSockets is set
-  if (this.maxTotalSockets) {
-    this.totalSocketCount >= this.maxTotalSockets && (isWait = true);
-  } else {
-    sockLen >= this.maxSockets && (isWait = true);
-  }
-
-  if (isWait === false) {
+    this.totalSocketCount++;
+  } else if (sockLen < this.maxSockets &&
+      this.totalSocketCount < this.maxTotalSockets) {
     debug('call onSocket', sockLen, freeLen);
     // If we are under maxSockets create a new one.
     this.createSocket(req, options, (err, socket) => {
@@ -295,8 +278,8 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
       this.requests[name] = [];
     }
 
-    if (this.maxTotalSockets)
-      req._options = options;
+    // Used to create sockets for pending requests from different origin
+    req._options = options;
 
     this.requests[name].push(req);
   }
@@ -323,8 +306,7 @@ Agent.prototype.createSocket = function createSocket(req, options, cb) {
       this.sockets[name] = [];
     }
     this.sockets[name].push(s);
-    if (this.maxTotalSockets)
-      this.totalSocketCount++;
+    this.totalSocketCount++;
     debug('sockets', name, this.sockets[name].length);
     installListeners(this, s, options);
     cb(null, s);
@@ -431,8 +413,7 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
         // Don't leak
         if (sockets[name].length === 0)
           delete sockets[name];
-        if (this.maxTotalSockets)
-          this.totalSocketCount--;
+        this.totalSocketCount--;
       }
     }
   }
@@ -441,18 +422,18 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
   if (this.requests[name] && this.requests[name].length) {
     debug('removeSocket, have a request, make a socket');
     req = this.requests[name][0];
-  } else if (this.maxTotalSockets) {
+  } else {
     for (const prop in this.requests) {
       debug('removeSocket, have a request with different origin,' +
         ' make a socket');
       req = this.requests[prop][0];
       options = req._options;
-      delete req._options;
       break;
     }
   }
 
   if (req && options) {
+    delete req._options;
     // If we have pending requests and a socket gets closed make a new one
     this.createSocket(req, options, (err, socket) => {
       if (err)
diff --git a/test/parallel/test-http-agent-maxtotalsockets.js b/test/parallel/test-http-agent-maxtotalsockets.js
index 2248b4327e5ba7..3afc5d05ca4370 100644
--- a/test/parallel/test-http-agent-maxtotalsockets.js
+++ b/test/parallel/test-http-agent-maxtotalsockets.js
@@ -1,16 +1,18 @@
 'use strict';
+
 const common = require('../common');
 const assert = require('assert');
 const http = require('http');
 const Countdown = require('../common/countdown');
 
 const maxTotalSockets = 3;
+const maxSockets = 2;
 
 const agent = new http.Agent({
   keepAlive: true,
   keepAliveMsecs: 1000,
   maxTotalSockets,
-  maxSockets: 100,
+  maxSockets,
   maxFreeSockets: 3
 });
 
@@ -39,14 +41,20 @@ function handler() {
       assert.strictEqual(res.statusCode, 200);
       res.resume();
       res.on('end', common.mustCall(() => {
-        const count = getTotalSocketsCount();
-        assert(count <= maxTotalSockets);
+        testMaxSockets();
+        assert(getTotalSocketsCount() <= maxTotalSockets);
         countdown.dec();
       }));
     }));
   }
 }
 
+function testMaxSockets() {
+  for(const key of Object.keys(agent.sockets)) {
+    assert(agent.sockets[key].length <= maxSockets)
+  }
+}
+
 function getTotalSocketsCount() {
   let num = 0;
   for (const key of Object.keys(agent.sockets)) {

From 5dffb12f222cfa1fdb0d5c7ec2060630dd70f894 Mon Sep 17 00:00:00 2001
From: rickyes <ives199511@gmail.com>
Date: Fri, 29 May 2020 12:25:25 +0800
Subject: [PATCH 05/13] fixup

---
 lib/_http_agent.js                            |  2 +-
 .../test-http-agent-maxtotalsockets.js        | 28 ++++++++++++++-----
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/lib/_http_agent.js b/lib/_http_agent.js
index 252cc38701d7bc..0c85d03ec056eb 100644
--- a/lib/_http_agent.js
+++ b/lib/_http_agent.js
@@ -101,7 +101,7 @@ function Agent(options) {
     validateNumber(this.maxTotalSockets, 'maxTotalSockets');
     if (this.maxTotalSockets <= 0)
       throw new ERR_OUT_OF_RANGE('maxTotalSockets', '> 0',
-        this.maxTotalSockets);
+                                 this.maxTotalSockets);
   } else {
     this.maxTotalSockets = Infinity;
   }
diff --git a/test/parallel/test-http-agent-maxtotalsockets.js b/test/parallel/test-http-agent-maxtotalsockets.js
index 3afc5d05ca4370..764ba943793d02 100644
--- a/test/parallel/test-http-agent-maxtotalsockets.js
+++ b/test/parallel/test-http-agent-maxtotalsockets.js
@@ -8,6 +8,24 @@ const Countdown = require('../common/countdown');
 const maxTotalSockets = 3;
 const maxSockets = 2;
 
+assert.throws(() => new http.Agent({
+  maxTotalSockets: 'test',
+}), {
+  code: 'ERR_INVALID_ARG_TYPE',
+  name: 'TypeError',
+  message: 'The "maxTotalSockets" argument must be of type number. ' +
+    "Received type string ('test')",
+});
+
+assert.throws(() => new http.Agent({
+  maxTotalSockets: -1,
+}), {
+  code: 'ERR_OUT_OF_RANGE',
+  name: 'RangeError',
+  message: 'The value of "maxTotalSockets" is out of range. ' +
+    'It must be > 0. Received -1',
+});
+
 const agent = new http.Agent({
   keepAlive: true,
   keepAliveMsecs: 1000,
@@ -41,7 +59,9 @@ function handler() {
       assert.strictEqual(res.statusCode, 200);
       res.resume();
       res.on('end', common.mustCall(() => {
-        testMaxSockets();
+        for (const key of Object.keys(agent.sockets)) {
+          assert(agent.sockets[key].length <= maxSockets);
+        }
         assert(getTotalSocketsCount() <= maxTotalSockets);
         countdown.dec();
       }));
@@ -49,12 +69,6 @@ function handler() {
   }
 }
 
-function testMaxSockets() {
-  for(const key of Object.keys(agent.sockets)) {
-    assert(agent.sockets[key].length <= maxSockets)
-  }
-}
-
 function getTotalSocketsCount() {
   let num = 0;
   for (const key of Object.keys(agent.sockets)) {

From ca965055806772a15f9bc53cb4503abcc227ac22 Mon Sep 17 00:00:00 2001
From: rickyes <ives199511@gmail.com>
Date: Fri, 29 May 2020 15:17:09 +0800
Subject: [PATCH 06/13] fixup

---
 lib/_http_agent.js                            |  2 +-
 .../test-http-agent-maxtotalsockets.js        | 26 ++++++++++++-------
 2 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/lib/_http_agent.js b/lib/_http_agent.js
index 0c85d03ec056eb..19b1e4865121d7 100644
--- a/lib/_http_agent.js
+++ b/lib/_http_agent.js
@@ -307,7 +307,7 @@ Agent.prototype.createSocket = function createSocket(req, options, cb) {
     }
     this.sockets[name].push(s);
     this.totalSocketCount++;
-    debug('sockets', name, this.sockets[name].length);
+    debug('sockets', name, this.sockets[name].length, this.totalSocketCount);
     installListeners(this, s, options);
     cb(null, s);
   });
diff --git a/test/parallel/test-http-agent-maxtotalsockets.js b/test/parallel/test-http-agent-maxtotalsockets.js
index 764ba943793d02..9d2d26a60890b4 100644
--- a/test/parallel/test-http-agent-maxtotalsockets.js
+++ b/test/parallel/test-http-agent-maxtotalsockets.js
@@ -5,9 +5,6 @@ const assert = require('assert');
 const http = require('http');
 const Countdown = require('../common/countdown');
 
-const maxTotalSockets = 3;
-const maxSockets = 2;
-
 assert.throws(() => new http.Agent({
   maxTotalSockets: 'test',
 }), {
@@ -26,6 +23,9 @@ assert.throws(() => new http.Agent({
     'It must be > 0. Received -1',
 });
 
+const maxTotalSockets = 2;
+const maxSockets = 3;
+
 const agent = new http.Agent({
   keepAlive: true,
   keepAliveMsecs: 1000,
@@ -37,24 +37,27 @@ const agent = new http.Agent({
 const server = http.createServer(common.mustCall((req, res) => {
   res.end('hello world');
 }, 6));
+const server2 = http.createServer(common.mustCall((req, res) => {
+  res.end('hello world');
+}, 6));
 
 server.keepAliveTimeout = 0;
+server2.keepAliveTimeout = 0;
 
-const countdown = new Countdown(6, () => {
+const countdown = new Countdown(12, () => {
   assert.strictEqual(getRequestCount(), 0);
   agent.destroy();
   server.close();
+  server2.close();
 });
 
-function handler() {
+function handler(s) {
   for (let i = 0; i < 6; i++) {
     http.get({
       host: 'localhost',
-      port: server.address().port,
+      port: s.address().port,
       agent: agent,
       path: `/${i}`,
-      // Setting different origins
-      family: i < 3 ? 4 : 6,
     }, common.mustCall((res) => {
       assert.strictEqual(res.statusCode, 200);
       res.resume();
@@ -62,7 +65,8 @@ function handler() {
         for (const key of Object.keys(agent.sockets)) {
           assert(agent.sockets[key].length <= maxSockets);
         }
-        assert(getTotalSocketsCount() <= maxTotalSockets);
+        const totalSocketsCount = getTotalSocketsCount();
+        assert(totalSocketsCount <= maxTotalSockets);
         countdown.dec();
       }));
     }));
@@ -85,4 +89,6 @@ function getRequestCount() {
   return num;
 }
 
-server.listen(0, common.mustCall(handler));
+server.listen(0, common.mustCall(() => handler(server)));
+server2.listen(0, common.mustCall(() => handler(server2)));
+

From 154eb28b54978586eded72e7f86138db4cd8f7bb Mon Sep 17 00:00:00 2001
From: rickyes <ives199511@gmail.com>
Date: Fri, 29 May 2020 23:17:16 +0800
Subject: [PATCH 07/13] fixup

---
 lib/_http_agent.js                            |  7 ++++-
 .../test-http-agent-maxtotalsockets.js        | 30 +++++++++++++------
 2 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/lib/_http_agent.js b/lib/_http_agent.js
index 19b1e4865121d7..c2b3b5291813d1 100644
--- a/lib/_http_agent.js
+++ b/lib/_http_agent.js
@@ -22,6 +22,7 @@
 'use strict';
 
 const {
+  NumberIsInteger,
   ObjectKeys,
   ObjectSetPrototypeOf,
   ObjectValues,
@@ -99,6 +100,10 @@ function Agent(options) {
 
   if (this.maxTotalSockets !== undefined) {
     validateNumber(this.maxTotalSockets, 'maxTotalSockets');
+    if (!NumberIsInteger(this.maxTotalSockets)) {
+      throw new ERR_OUT_OF_RANGE('maxTotalSockets', 'an integer',
+                                 this.maxTotalSockets);
+    }
     if (this.maxTotalSockets <= 0)
       throw new ERR_OUT_OF_RANGE('maxTotalSockets', '> 0',
                                  this.maxTotalSockets);
@@ -262,7 +267,7 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
     this.sockets[name].push(socket);
     this.totalSocketCount++;
   } else if (sockLen < this.maxSockets &&
-      this.totalSocketCount < this.maxTotalSockets) {
+             this.totalSocketCount < this.maxTotalSockets) {
     debug('call onSocket', sockLen, freeLen);
     // If we are under maxSockets create a new one.
     this.createSocket(req, options, (err, socket) => {
diff --git a/test/parallel/test-http-agent-maxtotalsockets.js b/test/parallel/test-http-agent-maxtotalsockets.js
index 9d2d26a60890b4..a003a7ced60772 100644
--- a/test/parallel/test-http-agent-maxtotalsockets.js
+++ b/test/parallel/test-http-agent-maxtotalsockets.js
@@ -14,13 +14,26 @@ assert.throws(() => new http.Agent({
     "Received type string ('test')",
 });
 
-assert.throws(() => new http.Agent({
-  maxTotalSockets: -1,
-}), {
-  code: 'ERR_OUT_OF_RANGE',
-  name: 'RangeError',
-  message: 'The value of "maxTotalSockets" is out of range. ' +
-    'It must be > 0. Received -1',
+[NaN, Infinity].forEach((item) => {
+  assert.throws(() => new http.Agent({
+    maxTotalSockets: item,
+  }), {
+    code: 'ERR_OUT_OF_RANGE',
+    name: 'RangeError',
+    message: 'The value of "maxTotalSockets" is out of range. ' +
+      `It must be an integer. Received ${item}`,
+  });
+});
+
+[-1, 0].forEach((item) => {
+  assert.throws(() => new http.Agent({
+    maxTotalSockets: item,
+  }), {
+    code: 'ERR_OUT_OF_RANGE',
+    name: 'RangeError',
+    message: 'The value of "maxTotalSockets" is out of range. ' +
+      `It must be > 0. Received ${item}`,
+  });
 });
 
 const maxTotalSockets = 2;
@@ -56,7 +69,7 @@ function handler(s) {
     http.get({
       host: 'localhost',
       port: s.address().port,
-      agent: agent,
+      agent,
       path: `/${i}`,
     }, common.mustCall((res) => {
       assert.strictEqual(res.statusCode, 200);
@@ -91,4 +104,3 @@ function getRequestCount() {
 
 server.listen(0, common.mustCall(() => handler(server)));
 server2.listen(0, common.mustCall(() => handler(server2)));
-

From 62118aff0bae89ebea33d20dc9407feb47ad98a9 Mon Sep 17 00:00:00 2001
From: rickyes <ives199511@gmail.com>
Date: Sat, 30 May 2020 02:54:25 +0800
Subject: [PATCH 08/13] fixup

---
 doc/api/http.md    |  2 +-
 lib/_http_agent.js | 10 +++++++---
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/doc/api/http.md b/doc/api/http.md
index 70f7ca6d19691c..cc602d83cdfe10 100644
--- a/doc/api/http.md
+++ b/doc/api/http.md
@@ -308,7 +308,7 @@ added: REPLACEME
 * {number}
 
 By default set to `Infinity`. Determines how many concurrent sockets the agent
-can have open.
+can have open. Unlike `maxSockets`, this parameter across all origins.
 
 ### `agent.requests`
 <!-- YAML
diff --git a/lib/_http_agent.js b/lib/_http_agent.js
index c2b3b5291813d1..fed6c2e457d5e4 100644
--- a/lib/_http_agent.js
+++ b/lib/_http_agent.js
@@ -44,6 +44,7 @@ const { once } = require('internal/util');
 const { validateNumber } = require('internal/validators');
 
 const kOnKeylog = Symbol('onkeylog');
+const kRequestOptions = Symbol('requestOptions');
 // New Agent code.
 
 // The largest departure from the previous implementation is that
@@ -284,7 +285,7 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
     }
 
     // Used to create sockets for pending requests from different origin
-    req._options = options;
+    req[kRequestOptions] = options;
 
     this.requests[name].push(req);
   }
@@ -428,17 +429,20 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
     debug('removeSocket, have a request, make a socket');
     req = this.requests[name][0];
   } else {
+    // TODO(rickyes): this logic will not be FIFO across origins. There might be 
+    // older requests in a different origin, but if the origin which releases
+    // the socket has pending requests that will be prioritized.
     for (const prop in this.requests) {
       debug('removeSocket, have a request with different origin,' +
         ' make a socket');
       req = this.requests[prop][0];
-      options = req._options;
+      options = req[kRequestOptions];
       break;
     }
   }
 
   if (req && options) {
-    delete req._options;
+    delete req[kRequestOptions];
     // If we have pending requests and a socket gets closed make a new one
     this.createSocket(req, options, (err, socket) => {
       if (err)

From eabfaee3f2a8b5c3bd216b6c73d69fe875401e4e Mon Sep 17 00:00:00 2001
From: rickyes <ives199511@gmail.com>
Date: Sat, 30 May 2020 03:00:35 +0800
Subject: [PATCH 09/13] fixup

---
 lib/_http_agent.js | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/lib/_http_agent.js b/lib/_http_agent.js
index fed6c2e457d5e4..b6fe585516150f 100644
--- a/lib/_http_agent.js
+++ b/lib/_http_agent.js
@@ -429,9 +429,10 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
     debug('removeSocket, have a request, make a socket');
     req = this.requests[name][0];
   } else {
-    // TODO(rickyes): this logic will not be FIFO across origins. There might be 
-    // older requests in a different origin, but if the origin which releases
-    // the socket has pending requests that will be prioritized.
+    // TODO(rickyes): this logic will not be FIFO across origins.
+    // There might be older requests in a different origin, but
+    // if the origin which releases the socket has pending requests
+    // that will be prioritized.
     for (const prop in this.requests) {
       debug('removeSocket, have a request with different origin,' +
         ' make a socket');

From d7148e3e41b79ed46c3eae6261558bb8ff82c25e Mon Sep 17 00:00:00 2001
From: rickyes <ives199511@gmail.com>
Date: Sat, 30 May 2020 03:04:08 +0800
Subject: [PATCH 10/13] fixup

---
 doc/api/http.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/api/http.md b/doc/api/http.md
index cc602d83cdfe10..8cebfe10bb865a 100644
--- a/doc/api/http.md
+++ b/doc/api/http.md
@@ -308,7 +308,7 @@ added: REPLACEME
 * {number}
 
 By default set to `Infinity`. Determines how many concurrent sockets the agent
-can have open. Unlike `maxSockets`, this parameter across all origins.
+can have open. Unlike `maxSockets`, this parameter applies across all origins.
 
 ### `agent.requests`
 <!-- YAML

From 1eebc864a8b39ebd4751be957c287004b51b44ba Mon Sep 17 00:00:00 2001
From: rickyes <ives199511@gmail.com>
Date: Sat, 30 May 2020 13:36:31 +0800
Subject: [PATCH 11/13] fixup

---
 lib/_http_agent.js                            |  10 +-
 .../test-http-agent-maxtotalsockets.js        | 141 +++++++++---------
 2 files changed, 78 insertions(+), 73 deletions(-)

diff --git a/lib/_http_agent.js b/lib/_http_agent.js
index b6fe585516150f..e236da94a1e125 100644
--- a/lib/_http_agent.js
+++ b/lib/_http_agent.js
@@ -22,7 +22,7 @@
 'use strict';
 
 const {
-  NumberIsInteger,
+  NumberIsNaN,
   ObjectKeys,
   ObjectSetPrototypeOf,
   ObjectValues,
@@ -101,11 +101,7 @@ function Agent(options) {
 
   if (this.maxTotalSockets !== undefined) {
     validateNumber(this.maxTotalSockets, 'maxTotalSockets');
-    if (!NumberIsInteger(this.maxTotalSockets)) {
-      throw new ERR_OUT_OF_RANGE('maxTotalSockets', 'an integer',
-                                 this.maxTotalSockets);
-    }
-    if (this.maxTotalSockets <= 0)
+    if (this.maxTotalSockets <= 0 || NumberIsNaN(this.maxTotalSockets))
       throw new ERR_OUT_OF_RANGE('maxTotalSockets', '> 0',
                                  this.maxTotalSockets);
   } else {
@@ -434,6 +430,8 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
     // if the origin which releases the socket has pending requests
     // that will be prioritized.
     for (const prop in this.requests) {
+      // Check whether this specific origin is already at maxSockets
+      if (this.sockets[prop] && this.sockets[prop].length) break;
       debug('removeSocket, have a request with different origin,' +
         ' make a socket');
       req = this.requests[prop][0];
diff --git a/test/parallel/test-http-agent-maxtotalsockets.js b/test/parallel/test-http-agent-maxtotalsockets.js
index a003a7ced60772..41bb6fd1597d07 100644
--- a/test/parallel/test-http-agent-maxtotalsockets.js
+++ b/test/parallel/test-http-agent-maxtotalsockets.js
@@ -14,18 +14,7 @@ assert.throws(() => new http.Agent({
     "Received type string ('test')",
 });
 
-[NaN, Infinity].forEach((item) => {
-  assert.throws(() => new http.Agent({
-    maxTotalSockets: item,
-  }), {
-    code: 'ERR_OUT_OF_RANGE',
-    name: 'RangeError',
-    message: 'The value of "maxTotalSockets" is out of range. ' +
-      `It must be an integer. Received ${item}`,
-  });
-});
-
-[-1, 0].forEach((item) => {
+[-1, 0, NaN].forEach((item) => {
   assert.throws(() => new http.Agent({
     maxTotalSockets: item,
   }), {
@@ -36,71 +25,89 @@ assert.throws(() => new http.Agent({
   });
 });
 
-const maxTotalSockets = 2;
-const maxSockets = 3;
+assert.ok(new http.Agent({
+  maxTotalSockets: Infinity,
+}));
 
-const agent = new http.Agent({
-  keepAlive: true,
-  keepAliveMsecs: 1000,
-  maxTotalSockets,
-  maxSockets,
-  maxFreeSockets: 3
-});
+function start(param = {}) {
+  const { maxTotalSockets, maxSockets } = param;
+
+  const agent = new http.Agent({
+    keepAlive: true,
+    keepAliveMsecs: 1000,
+    maxTotalSockets,
+    maxSockets,
+    maxFreeSockets: 3
+  });
 
-const server = http.createServer(common.mustCall((req, res) => {
-  res.end('hello world');
-}, 6));
-const server2 = http.createServer(common.mustCall((req, res) => {
-  res.end('hello world');
-}, 6));
+  const server = http.createServer(common.mustCall((req, res) => {
+    res.end('hello world');
+  }, 6));
+  const server2 = http.createServer(common.mustCall((req, res) => {
+    res.end('hello world');
+  }, 6));
 
-server.keepAliveTimeout = 0;
-server2.keepAliveTimeout = 0;
+  server.keepAliveTimeout = 0;
+  server2.keepAliveTimeout = 0;
 
-const countdown = new Countdown(12, () => {
-  assert.strictEqual(getRequestCount(), 0);
-  agent.destroy();
-  server.close();
-  server2.close();
-});
+  const countdown = new Countdown(12, () => {
+    assert.strictEqual(getRequestCount(), 0);
+    agent.destroy();
+    server.close();
+    server2.close();
+  });
 
-function handler(s) {
-  for (let i = 0; i < 6; i++) {
-    http.get({
-      host: 'localhost',
-      port: s.address().port,
-      agent,
-      path: `/${i}`,
-    }, common.mustCall((res) => {
-      assert.strictEqual(res.statusCode, 200);
-      res.resume();
-      res.on('end', common.mustCall(() => {
-        for (const key of Object.keys(agent.sockets)) {
-          assert(agent.sockets[key].length <= maxSockets);
-        }
-        const totalSocketsCount = getTotalSocketsCount();
-        assert(totalSocketsCount <= maxTotalSockets);
-        countdown.dec();
+  function handler(s) {
+    for (let i = 0; i < 6; i++) {
+      http.get({
+        host: 'localhost',
+        port: s.address().port,
+        agent,
+        path: `/${i}`,
+      }, common.mustCall((res) => {
+        assert.strictEqual(res.statusCode, 200);
+        res.resume();
+        res.on('end', common.mustCall(() => {
+          for (const key of Object.keys(agent.sockets)) {
+            assert(agent.sockets[key].length <= maxSockets);
+          }
+          assert(getTotalSocketsCount() <= maxTotalSockets);
+          countdown.dec();
+        }));
       }));
-    }));
+    }
   }
-}
 
-function getTotalSocketsCount() {
-  let num = 0;
-  for (const key of Object.keys(agent.sockets)) {
-    num += agent.sockets[key].length;
+  function getTotalSocketsCount() {
+    let num = 0;
+    for (const key of Object.keys(agent.sockets)) {
+      num += agent.sockets[key].length;
+    }
+    return num;
   }
-  return num;
-}
 
-function getRequestCount() {
-  let num = 0;
-  for (const key of Object.keys(agent.requests)) {
-    num += agent.requests[key].length;
+  function getRequestCount() {
+    let num = 0;
+    for (const key of Object.keys(agent.requests)) {
+      num += agent.requests[key].length;
+    }
+    return num;
   }
-  return num;
+
+  server.listen(0, common.mustCall(() => handler(server)));
+  server2.listen(0, common.mustCall(() => handler(server2)));
 }
 
-server.listen(0, common.mustCall(() => handler(server)));
-server2.listen(0, common.mustCall(() => handler(server2)));
+// If maxTotalSockets is larger than maxSockets,
+// then the origin check will be skipped
+// when the socket is removed.
+[{
+  maxTotalSockets: 2,
+  maxSockets: 3,
+}, {
+  maxTotalSockets: 3,
+  maxSockets: 2,
+}, {
+  maxTotalSockets: 2,
+  maxSockets: 2,
+}].forEach((param) => start(param));

From 25b6fa514c523e52660023ad97f0c524c9283db1 Mon Sep 17 00:00:00 2001
From: rickyes <ives199511@gmail.com>
Date: Sat, 30 May 2020 20:01:07 +0800
Subject: [PATCH 12/13] fixup

---
 test/parallel/test-http-agent-maxtotalsockets.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/parallel/test-http-agent-maxtotalsockets.js b/test/parallel/test-http-agent-maxtotalsockets.js
index 41bb6fd1597d07..c44c8db627d330 100644
--- a/test/parallel/test-http-agent-maxtotalsockets.js
+++ b/test/parallel/test-http-agent-maxtotalsockets.js
@@ -110,4 +110,4 @@ function start(param = {}) {
 }, {
   maxTotalSockets: 2,
   maxSockets: 2,
-}].forEach((param) => start(param));
+}].forEach(start);

From 2931fa9a35dd07de263ffd0bfa262a791fcc2c1b Mon Sep 17 00:00:00 2001
From: rickyes <ives199511@gmail.com>
Date: Sat, 30 May 2020 23:48:30 +0800
Subject: [PATCH 13/13] fixup

---
 lib/_http_agent.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/_http_agent.js b/lib/_http_agent.js
index e236da94a1e125..3401595673ba49 100644
--- a/lib/_http_agent.js
+++ b/lib/_http_agent.js
@@ -441,7 +441,7 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
   }
 
   if (req && options) {
-    delete req[kRequestOptions];
+    req[kRequestOptions] = undefined;
     // If we have pending requests and a socket gets closed make a new one
     this.createSocket(req, options, (err, socket) => {
       if (err)