From 4b937de8a690411125ed0e2f7dd9f4868640867a Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Fri, 20 Jan 2017 12:01:54 -0800
Subject: [PATCH] lock: remove nonsense from mutex.

---
 lib/utils/lock.js | 90 +++++------------------------------------------
 1 file changed, 8 insertions(+), 82 deletions(-)

diff --git a/lib/utils/lock.js b/lib/utils/lock.js
index 232a0b96..d9f5d3a6 100644
--- a/lib/utils/lock.js
+++ b/lib/utils/lock.js
@@ -24,12 +24,10 @@ function Lock(named) {
   this.named = named === true;
 
   this.jobs = [];
-  this.waiting = [];
   this.busy = false;
   this.destroyed = false;
 
   this.map = Object.create(null);
-  this.pending = 0;
   this.current = null;
 
   this.unlocker = this.unlock.bind(this);
@@ -76,19 +74,6 @@ Lock.prototype.hasPending = function hasPending(name) {
   return this.map[name] > 0;
 };
 
-/**
- * Test whether the lock is
- * busy with a named job.
- * @returns {Boolean}
- */
-
-Lock.prototype.isBusy = function isBusy() {
-  assert(this.named, 'Must use named jobs.');
-  if (this.current)
-    return true;
-  return this.pending > 0;
-};
-
 /**
  * Lock the parent object and all its methods
  * which use the lock. Begin to queue calls.
@@ -124,7 +109,6 @@ Lock.prototype.lock = function lock(arg1, arg2) {
       if (!this.map[name])
         this.map[name] = 0;
       this.map[name]++;
-      this.pending++;
     }
     return new Promise(function(resolve, reject) {
       self.jobs.push(new Job(resolve, reject, name));
@@ -150,11 +134,8 @@ Lock.prototype.unlock = function unlock() {
   this.busy = false;
   this.current = null;
 
-  if (this.jobs.length === 0) {
-    assert(this.pending === 0);
-    this.drain();
+  if (this.jobs.length === 0)
     return;
-  }
 
   assert(!this.destroyed);
 
@@ -164,10 +145,6 @@ Lock.prototype.unlock = function unlock() {
     assert(this.map[job.name] > 0);
     if (--this.map[job.name] === 0)
       delete this.map[job.name];
-    this.pending--;
-  } else {
-    if (this.pending === 0)
-      this.drain();
   }
 
   this.busy = true;
@@ -176,50 +153,6 @@ Lock.prototype.unlock = function unlock() {
   job.resolve(this.unlocker);
 };
 
-/**
- * Wait for a drain (empty queue).
- * @returns {Promise}
- */
-
-Lock.prototype.wait = function wait() {
-  var self = this;
-
-  assert(this.named, 'Must use named jobs.');
-
-  if (this.destroyed)
-    return Promise.reject(new Error('Lock is destroyed.'));
-
-  if (!this.isBusy()) {
-    assert(this.waiting.length === 0);
-    return Promise.resolve();
-  }
-
-  return new Promise(function(resolve, reject) {
-    self.waiting.push(new Job(resolve, reject, null));
-  });
-};
-
-/**
- * Notify drainers that the queue has emptied.
- * @private
- */
-
-Lock.prototype.drain = function drain() {
-  var i, jobs, job;
-
-  if (this.waiting.length === 0)
-    return;
-
-  jobs = this.waiting.slice();
-
-  this.waiting.length = 0;
-
-  for (i = 0; i < jobs.length; i++) {
-    job = jobs[i];
-    job.resolve();
-  }
-};
-
 /**
  * Destroy the lock. Purge all pending calls.
  */
@@ -237,22 +170,12 @@ Lock.prototype.destroy = function destroy() {
   this.busy = false;
   this.jobs.length = 0;
   this.map = Object.create(null);
-  this.pending = 0;
   this.current = null;
 
   for (i = 0; i < jobs.length; i++) {
     job = jobs[i];
     job.reject(err);
   }
-
-  jobs = this.waiting.slice();
-
-  this.waiting.length = 0;
-
-  for (i = 0; i < jobs.length; i++) {
-    job = jobs[i];
-    job.reject(err);
-  }
 };
 
 /**
@@ -284,7 +207,8 @@ MappedLock.create = function create() {
 };
 
 /**
- * Test whether the lock has a pending job by name.
+ * Test whether the lock has a pending
+ * job or a job in progress (by name).
  * @param {String} name
  * @returns {Boolean}
  */
@@ -294,12 +218,14 @@ MappedLock.prototype.has = function has(name) {
 };
 
 /**
- * Test whether the lock is busy .
+ * Test whether the lock has
+ * a pending job by name.
+ * @param {String} name
  * @returns {Boolean}
  */
 
-MappedLock.prototype.isBusy = function isBusy() {
-  return this.busy;
+MappedLock.prototype.hasPending = function hasPending(name) {
+  return this.jobs[name] != null;
 };
 
 /**