Javascript engine

• US 6,892,200 B2
• Filed: 10/30/2002
• Issued: 05/10/2005
• Est. Priority Date: 11/13/2001
• Status: Expired due to Term

• Current Assignee: Meta Platforms, Inc. (f/k/a Facebook, Inc.)
• Original Assignee: America Online Inc. (Warner Bros. Discovery, Inc.)
• Inventors: Eich, Brendan
• Primary Examiner(s): MOFIZ, APU M
• Application Number:
  US10/285,043
• Publication Number:
  US 20030110160A1
• Time in Patent Office: 923 Days
• Field of Search: 707/1, 707/8, 707/10, 707/103.R, 707/104.1, 707/203, 706/45, 708/250, 709/203, 709/204, 709/223, 709/229, 710/200, 712/23, 717/101, 717/104, 717/108, 717/115, 717/127, 717/139, 717/141, 718/100, 718/102, 718/107
• US Class Current: 707/704
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

A JavaScript enhancement is provided that increases performance of the JavaScript by avoiding the use of locking mechanisms in multi-threaded sessions. To do so, an object is deemed owned by a thread exclusively until the script is ended or suspended. Because scripts are typically short and complete quickly, the overhead to start and end a request containing a script is much less than the overhead of locking each and every object access done by the script, on average.

Claims

1. A computer implemented method for avoiding using a locking mechanism when a thread having a context requests to use an object having a scope and having an owner of said scope, said method comprising:

determining if said owner is the same as said context;

if said owner is the same as said context, then avoiding using locking mechanism;

if said owner is not the same as said context, then promoting a lock on said object'"'"'s scope;

initially setting said object'"'"'s scope'"'"'s owner to a current context of a current thread when said object'"'"'s scope is created;

resetting said object'"'"'s scope'"'"'s owner to a second thread'"'"'s context when said second thread claims exclusive ownership of said scope; and

setting said object'"'"'s scope'"'"'s owner to null when said ownership is shaped.

2. A computer implemented method for locking an object having an ownership attribute, wherein a first thread having a first context makes a first request to a JavaScript engine at a first time, said first request comprising using said object, and a second thread having a second context makes a second request to the JavaScript engine at a second and later time, said second request comprising using said object, said method comprising:

said JavaScript engine determining if said first request is finished with said object;

if said first request is not finished with said object, then;

said JavaScript engine comparing said second context of said second thread with said ownership attribute of said object;

if said comparison is different, then suspending said second request until said first request is finished with said object;

said JavaScript engine setting said ownership attribute of said object to null;

said JavaScript engine resuming said second request;

otherwise, said JavaScript engine setting said ownership attribute of said object to said second context and processing said second request.

3. An computer implemented apparatus for avoiding using a locking mechanism when a thread having a context requests to use an object having a scope and having an owner of said scope, said apparatus comprising:

means for determining if said owner is the same as said context;

if said owner is the same as said context, then means for avoiding using locking mechanism;

if said owner is not the same as said context, then means for promoting a lock on said object'"'"'s scope;

means for initially setting said object'"'"'s scope'"'"'s owner to a current context of a current thread when said object'"'"'s scope is created;

means for resetting said object'"'"'s scope'"'"'s owner to a second thread'"'"'s context when said second thread claims exclusive ownership of said scope; and

means for setting said object'"'"'s scope'"'"'s owner to null when said ownership is shared.

4. An computer implemented apparatus for locking an object having an ownership attribute, wherein a first thread having a first context makes a first request to a JavaScript engine at a first time, said first request comprising using said object, and a second thread having a second context makes a second request to the JavaScript engine at a second and later time, said second request comprising using said object, said apparatus comprising:

means for said JavaScript engine determining if said first request is finished with said object;

if said first request is not finished with said object, then;

means for said JavaScript engine comparing said second context of said second thread with said ownership attribute of said object;

if said comparison is different, then means for suspending said second request until said first request is finished with said object;

means for said JavaScript engine setting said ownership attribute of said object to null;

means for said JavaScript engine resuming said second request;

otherwise, means for said JavaScript engine setting said ownership attribute of said object to said second context and processing said second request.

5. A computer implemented method for locking an object having an ownership attribute, wherein a first thread having a first context makes a first request to a scripting service thread (all cases) engine at a first time, said first request comprising using said object, and a second thread having a second context makes a second request to the scripting engine at a second and later time, said second request comprising using said object, said method comprising:

said scripting engine determining if said first request is finished with said object;

if said first request is not finished with said object, then;

said scripting engine comparing said second context of said second thread with said ownership attribute of said object;

if said comparison is different, then suspending said second request until said first request is finished with said object;

said scripting engine setting said ownership attribute of said object to null;

said scripting engine resuming said second request;

otherwise, said scripting engine setting said ownership attribute of said object to said second context and processing said second request.

6. A computer implemented apparatus for locking an object having an ownership attribute, wherein a first thread having a first context makes a first request to a scripting engine at a first time, said first request comprising using said object, and a second thread having a second context makes a second request to the scripting engine at a second and later time, said second request comprising using said object, said apparatus comprising:

means for said scripting engine determining if said first request is finished with said object;

if said first request is not finished with said object, then;

means for said scripting t engine comparing said second context of said second thread with said ownership attribute of said object;

if said comparison is different, then means for suspending said second request until said first request is finished with said object;

means for said scripting engine setting said ownership attribute of said object to null;

means for said scripting engine resuming said second request; and

otherwise, means for said scripting engine setting said ownership attribute of said object to said second context and processing said second request.