I have been researching the Java Memory Model all day today, in order to understand in detail the problems with the JMM pre-Java 5 and the changes made by JSR-133 implemented ... |
In my java project, almost every non-static method I've written is synchronized. I've decided to fix up some code today, by removing most of the synchronized keywords. Right there I created ... |
What could be the understanding of the following?
I have gone through this post at SO but still at a loss to assemble it.
code1:
synchronized(this){
// some code
}
code2:
Object lock = new ...
|
Is there any alternative to synchronize class or method without using 'synchronized' keyword in java ?
Thanks,
Mallikarjun Kokatanur
|
I've heard that choosing to use the word 'synchronized' to describe mutexed statements is simply a mistake (Edit: 'mistake' was a bad choice of words here. Please see edit) in Java, ... |
I was implementing a FIFO queue of requests instances (preallocated request objects for speed) and started with using the "synchronized" keyword on the add method. The method was quite short ... |
I have this code in Java:
public void doSomeThing() {
synchronized (this) {
...
|
|
I'm confused by an issue about reference and synchronized keyword a long time.
I usually see some code like this:
Class someClass {
...
private SomeObject mObject;
...
|
Possible Duplicate:
what synchronized statement used for?
What is use of synchronized keyword?
|
Java 5 introduce the lock method. Any pros and cons using lock compared to synchronized keyword?
|
I tried to make a event dispatcher in Java that will dispatch events as threads. So all the EventListener classes are essentially implemented the Runnable class. Like how firing of events ... |
can you check if this code will be thread safe/ replace synchronization's features? like restricting access to multiple threads?
class CheckSynch{
public static booloean check=true;
public static void func() // ...
|
I need some clarificaton on how the syncronized keyword works in java 6.
Using the following example class.
class Carrier {
private String[] _collection = new String[2];
public Carrier() ...
|
In C#, the lock keyword is nice syntax for a try/catch block and an instance of Monitor.
In Java, what synchronization class is used user the hood of the synchronized keyword?
Edit - ... |
Is there some way how to ensure that java flushes the cache of writes that have been done before the CyclicBarrier or CountDownLatch allows us to continue (as the synchronized keyword ... |
I was reading a threading tutorial that’s originally from (I believe) the IBM developerworks site. In it they talked about the synchronized keyword and how a synchronized block of code ... |
Hi all, Before which of the following can the keyword "synchronized" be placed, without causing a compile error. Choices: 1. class methods 2. instance methods 3. variables 4. classes Answer is 1 and 2 .It's cool. But wht. about ch. 3 I compiled and ran it works. Although choice 3 is not a sensible thing to choose. CAN synchronized KEY WORD ... |
To which of the following can we apply the synchronized keyword Options : a . A top level class b . A static member variable c . A static method d . An instance variable e . An instance method I think the answer is c, d, e, You can apply the synchronized to an instance method class Blair2 extends Thread ... |
|
Hmmmm. English. I'm at a loss for a decent english version, unless you want it to be four paragraphs long. But I'll it the short version a shot...: "Now class, let me introduce you to our new talking stick, Mr. 'object.' If you wish to speak, wait quietly until whoever is using the talking stick currently finishes. Grabbing of the talking ... |
Does this mean a synchronized static method can be run at the same time a regular synchronized method is being run? What happens if they both modify a static variable? I thought no other synchronized method, static or regular, could run while a synchronized static method was running in that same class. Is that true? If not, does that mean that ... |
When a subclass method matches in name and in the number and type of arguments to the method in the super-class (that is, the method signatures match), the subclass is said to override that method. Here synchronized is not part of method signature, so you are not breaking overriding rule .. ok |
Hi I need explanation for the following passage: A synchronized method can be accessed by only one thread at a time. Transient variables cannot be serialized. An abstract method does not have an implementation; it has to be implemented by the first concrete subclass of the containing class. The class containing at least one abstract method has to be declared as ... |
I thought I understood this - turns out perhaps i don't! if I use the synchronized keyword on a thread's run method..i.e. public synchronized void run() {some code} And then create multiple instances of the above thread and start them from another class (person is my thread class - it implements runnable) eg.. Person jeremy = new Person("Jeremy"); Person james = ... |
Hi, In my program a cron job is runing for every five minutes and it calls a method to send an xml message.I am using Application server with two nodes.so when server starts two nodes are invoking the cron job simultaneously so my method is called twice and i am getting some deffects. 1)Due to two server two times methods are ... |
Hi, I am not sure if it belongs here, but it is a Java question, so i am asking here... If we want only one thread to have access to a method, we normally use the synchronized keyword (or enclose it in a synchronized block)... However, if i have multiple servers running(to perform load balancing or anything else), and each has ... |
|
|
class ThreadSafe { protected Thread owner; protected boolean checkOwner(Thread accessor) { boolean allow = false; if(owner==null) { owner = accessor; allow = true; }else if(owner==accessor){allow = true;} return allow; } public void release(Thread requester) // thread that makes the request { if(requester == owner) //we dont want this public method to be called by anyone other than current owner owner = ... |
Hi everyone, I am preparing for the SCJP test and I have trouble understanding the usage of the synchronized keyword. In the following code i am attempting to create three threads and synchronize the run method such that 100 As Bs and Cs will be printed unbroken on one line. But the trouble is that the output is getting all jumbled ... |
synchronized on a static method locks on a class, but that doesn't mean that every member of that class is locked. It just means that other things that can only run if they have a lock on the class (other synchronized static methods) can't run until the lock is released. The same basic thing applied so synchronized non-static methods. They lock ... |
|
Let's say my synchronized method is rather large and for modularity I break parts of it up into smaller methods: do these other methods also need to be declared as synchronized - even if the only method that will call them is the original large synchronized method? I am not sure if the moment my currently holding thread jumps off from ... |
The idea is that running the main methods gives something like A count=13, B count=10: A + B count=23, shared counter=23 (where A and B are writer threads) If I take out the synchronised keyword in the MyThread class, things get much worse...the 'personal' totals of A and B do not equal the total held in the shared counter rather quickly.. ... |
One point about the synchronized keyword is unclear: it places a lock on the object (either the one specified in a synchronized block, or the method's owner in a synchronized method). Does this mean that, while a syncronized block/method is being run, access to ALL the object's methods is prohibited, or only the ones that are also marked as synchronized? |