Skip to main content

Slides from JMM talk

The slides from the JMM talk are available here for people's perusal. Enjoy!
Labels:

Comments

Anonymous said…
Jeremy, this PDF is no longer accessible. I get a 403 error :(
October 28, 2008 at 12:58 AM
Jeremy Manson said…
Yes. My hosting gave up on me. I'm working on it.
October 28, 2008 at 10:51 PM
jay said…
Hi Jeremy,
Still not accessible.
Any luck with sorting it out yet ?
cheers,
jay
January 9, 2009 at 8:03 AM
Anonymous said…
Jeremy, Can you pls post the slides j1_talk.ppt and Jeremy Manson's dissertation( which is a comprehensive overview of the model) pdf... eagerly waiting for your post
April 26, 2010 at 12:37 PM
Jeremy Manson said…
Sorry about the long latency - I completely forgot.
May 26, 2010 at 10:35 PM
Steve said…
I found nearly identical slides hosted here:
https://slideplayer.com/slide/4264654/
November 7, 2018 at 5:17 PM
Post a Comment

Popular posts from this blog

Double Checked Locking

I still get a lot of questions about whether double-checked locking works in Java, and I should probably post something to clear it up. And I'll plug Josh Bloch's new book, too. Double Checked Locking is this idiom: // Broken -- Do Not Use! class Foo {   private Helper helper = null;   public Helper getHelper() {     if (helper == null) {       synchronized(this) {         if (helper == null) {           helper = new Helper();         }       }     }   return helper; } The point of this code is to avoid synchronization when the object has already been constructed. This code doesn't work in Java. The basic principle is that compiler transformations (this includes the JIT, which is the optimizer that the JVM uses) can change the code around so that the code in the Helper constructor occurs after the write to the helper variable. If it does this, then after the constructing thread writes to helper, but before it actually finishes constructing the object,
107 comments
Read more

What Volatile Means in Java

Today, I'm going to talk about what volatile means in Java. I've sort-of covered this in other posts, such as my posting on the ++ operator , my post on double-checked locking and the like, but I've never really addressed it directly. First, you have to understand a little something about the Java memory model. I've struggled a bit over the years to explain it briefly and well. As of today, the best way I can think of to describe it is if you imagine it this way: Each thread in Java takes place in a separate memory space (this is clearly untrue, so bear with me on this one). You need to use special mechanisms to guarantee that communication happens between these threads, as you would on a message passing system. Memory writes that happen in one thread can "leak through" and be seen by another thread, but this is by no means guaranteed. Without explicit communication, you can't guarantee which writes get seen by other threads, or even the order in whic
176 comments
Read more

Date-Race-Ful Lazy Initialization for Performance

I was asked a question about benign data races in Java this week, so I thought I would take the opportunity to discuss one of the (only) approved patterns for benign races. So, at the risk of encouraging bad behavior (don't use data races in your code!), I will discuss the canonical example of "benign races for performance improvement". Also, I'll put in another plug for Josh Bloch's new revision of Effective Java (lgt amazon) , which I continue to recommend. As a reminder, basically, a data race is when you have one (or more) writes, and potentially some reads; they are all to the same memory location; they can happen at the same time; and that there is nothing in the program to prevent it. This is different from a race condition , which is when you just don't know the order in which two actions are going to occur. I've put more discussion of what a data race actually is at the bottom of this post. A lot of people think that it is okay to have a data
53 comments
Read more