From dd482087edbda396899eb32fa2255b37dd755cfc Mon Sep 17 00:00:00 2001
From: Oliver Blanthorn <freedom4cows@gmail.com>
Date: Sat, 9 May 2020 12:36:03 +0100
Subject: [PATCH] Remove now unused locks

---
 src/background.ts |  2 -
 src/content.ts    |  2 -
 src/lib/config.ts |  1 -
 src/lib/locks.ts  | 94 -----------------------------------------------
 4 files changed, 99 deletions(-)
 delete mode 100644 src/lib/locks.ts

diff --git a/src/background.ts b/src/background.ts
index e415635d..5aebb33f 100644
--- a/src/background.ts
+++ b/src/background.ts
@@ -25,7 +25,6 @@ import { AutoContain } from "@src/lib/autocontainers"
 import * as extension_info from "@src/lib/extension_info"
 import * as omnibox from "@src/background/omnibox"
 import * as R from "ramda"
-import * as locks from "@src/lib/locks"
 
 // Add various useful modules to the window for debugging
 ; (window as any).tri = Object.assign(Object.create(null), {
@@ -46,7 +45,6 @@ import * as locks from "@src/lib/locks"
     contentLocation: window.location,
     R,
     perf,
-    locks,
 })
 
 import { HintingCmds } from "@src/background/hinting"
diff --git a/src/content.ts b/src/content.ts
index 222950f3..39bfed17 100644
--- a/src/content.ts
+++ b/src/content.ts
@@ -143,7 +143,6 @@ import * as updates from "@src/lib/updates"
 import * as urlutils from "@src/lib/url_util"
 import * as scrolling from "@src/content/scrolling"
 import * as R from "ramda"
-import * as locks from "@src/lib/locks"
 import * as visual from "@src/lib/visual"
 /* tslint:disable:import-spacing */
 ; (window as any).tri = Object.assign(Object.create(null), {
@@ -175,7 +174,6 @@ import * as visual from "@src/lib/visual"
     R,
     updates,
     urlutils,
-    locks,
 })
 
 logger.info("Loaded commandline content?", commandline_content)
diff --git a/src/lib/config.ts b/src/lib/config.ts
index 9d192ef9..ab83b72d 100644
--- a/src/lib/config.ts
+++ b/src/lib/config.ts
@@ -803,7 +803,6 @@ export class default_config {
         performance: "warning",
         state: "warning",
         styling: "warning",
-        locks: "warning",
     }
 
     /**
diff --git a/src/lib/locks.ts b/src/lib/locks.ts
deleted file mode 100644
index b4d4a508..00000000
--- a/src/lib/locks.ts
+++ /dev/null
@@ -1,94 +0,0 @@
-// This attempts to implement the Ricart-Agrawala algorithm: https://www.wikipedia.org/wiki/Ricart%E2%80%93Agrawala_algorithm
-import {messageAllTabs} from "@src/lib/messaging"
-
-import {v1 as uuid} from "uuid"
-import * as Logging from "@src/lib/logging"
-
-const logger = new Logging.Logger("locks")
-
-export const OWNED_LOCKS = new Set()
-
-export const DESIRED_LOCKS = {}
-
-export const ID = uuid()
-
-const now = () => (new Date()).getTime() + Math.random() // getTime is accurate only to ms, so fake microseconds with random
-
-export async function acquire(lockname: string, timeout = 2000) {
-    if (OWNED_LOCKS.has(lockname) || DESIRED_LOCKS.hasOwnProperty(lockname)) return;
-    const time = now()
-
-    DESIRED_LOCKS[lockname] = time
-
-    const a = await Promise.race([
-        Promise.all([
-            browser.runtime.sendMessage({type: "lock", command: "acquire", args: [lockname, time, ID]}),
-            messageAllTabs("lock", "acquire", [lockname, time, ID]),
-        ]),
-        new Promise(resolve => setTimeout(
-            () => {
-                resolve("ERROR: LOST THE RACE")
-            },
-        timeout)), // Take the lock anyway after timeout
-    ])
-    if (a === "ERROR: LOST THE RACE") {logger.warning("lock " + lockname + " was taken without confirmation")}
-
-    delete DESIRED_LOCKS[lockname]
-    OWNED_LOCKS.add(lockname)
-}
-
-/**
- * Execute func after acquiring a named lock. If func takes longer than timeout, release the lock early.
- * Returns the value of func.
- */
-export async function withlock(lockname: string, func, timeout = 500) {
-    await acquire(lockname)
-    const p = (async () => func())() // Ensure function is promisified
-    const a = await Promise.race([
-        p,
-        new Promise(resolve => setTimeout(
-            () => {
-                resolve("ERROR: LOST THE RACE")
-            },
-        timeout)), // Release the lock anyway after timeout
-    ])
-    if (a === "ERROR: LOST THE RACE") {logger.warning("lock " + lockname + " was released early")}
-    release(lockname)
-    return p
-}
-
-export async function release(lockname: string) {
-    OWNED_LOCKS.delete(lockname)
-}
-
-function lockhandler(msg, sender, sendResponse) {
-    if (msg.type !== "lock") return false
-    if (msg.command == "acquire") {
-        const lockname = msg.args[0]
-        const their_niceness = msg.args[1]
-        if (ID == msg.args[2]) {return sendResponse("Lock reply: I am you")}
-        (async () => {
-            while (true) {
-                // If we don't have the lock
-                if (!OWNED_LOCKS.has(lockname)) {
-                    // and don't want it
-                    if (!DESIRED_LOCKS.hasOwnProperty(lockname)) {
-                        // Let them know they can have it
-                        return sendResponse([lockname, now()])
-                    }
-                    // or they wanted it before we asked for it
-                    if (DESIRED_LOCKS[lockname] > their_niceness) {
-                        // Let them know they can have it
-                        return sendResponse([lockname, now()])
-                    }
-                }
-
-                // Otherwise wait a bit and then look again
-                await new Promise(resolve => setTimeout(resolve, 100)) // Sleep 100ms
-            }
-        })()
-    }
-    return true // Tell the browser to wait for sendResponse even though it's async
-}
-
-browser.runtime.onMessage.addListener(lockhandler) // Messaging.addListener doesn't allow us to send async responses - is this on purpose?