Questions tagged [synchronized-block]
85 questions
60
votes
2 answers
In java, return value within synchronized block seems like bad style. Does it really matter?
I have a Collections.synchronizedList of WeakReference, _components;
I wrote something like the following, expecting the complier to complain:
public boolean addComponent2(Component e) {
synchronized (_components) {
return…
Charlweed
- 1,517
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56
votes
5 answers
What is the difference between synchronized on lockObject and using this as the lock?
I know the difference between synchronized method and synchronized block but I am not sure about the synchronized block part.
Assuming I have this code
class Test {
private int x=0;
private Object lockObject = new Object();
public void…
GantengX
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38
votes
6 answers
What is the difference between a synchronized method and synchronized block in Java?
What is the difference between a synchronized method and synchronized block in Java ?
I have been searching the answer on the Net, people seem to be so unsure about this one :-(
My take would be there is no difference between the two, except that…
Geek
- 23,089
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- 85
32
votes
3 answers
What is the purpose of passing parameter to synchronized block?
I know that
When you synchronize a block of code, you specify which object's lock
you want to use as the lock, so you could, for example, use some
third-party object as the lock for this piece of code. That gives you
the ability to have more…
John Rambo
- 906
- 1
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21
votes
7 answers
It is better to have a synchronized block inside a try block or a try block inside a synchronized block?
For example, is this better?
try {
synchronized (bean) {
// Write something
}
} catch (InterruptedException e) {
// Write something
}
Or it's better this:
synchronized (bean) {
try {
// Write…
user1883212
- 7,539
- 11
- 46
- 82
13
votes
8 answers
Synchronized block not working
This exercise is straight out of SCJP by Kathy Seirra and Bert Bates
Synchronizing a Block of Code
In this exercise we will attempt to synchronize a block of code. Within that block of code we will get the lock on an object, so that other threads…
atsurti
- 294
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9
votes
2 answers
AtomicBoolean vs synchronized block
I was trying to cut thread contention in my code by replacing some synchronized blocks with AtomicBoolean.
Here's an example with synchronized:
public void toggleCondition() {
synchronized (this.mutex) {
if (this.toggled) {
…
biasedbit
- 2,860
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- 47
9
votes
5 answers
Rejecting class because it failed compile-time verification Android
One of my application suddenly fails on startup, with the following error message :
java.lang.VerifyError: Rejecting class
com.sample.BufferManagerImpl because it failed
compile-time verification (declaration of
…
XGouchet
- 10,002
- 10
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- 83
5
votes
0 answers
RxJava - synchronized block - inner Source
I want to use synchronized block for source of flatMap. But I need to use this construct for processing (method processItem), not only when inner source is created.
This Observable is called each 5 minutes (for example…
elnino
- 235
- 3
- 12
5
votes
5 answers
Is this ok? Synchronized( thread ), then thread=null in the synch block
I see this:
// thread is a member of this class
synchronized( this.thread )
{
this.thread.running = false;
this.thread.notifyAll(); // Wake up anything that was .waiting() on
// the thread
this.thread = null; // kill this thread…
bobobobo
- 64,917
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5
votes
1 answer
Concurrency in Java using synchronized blocks not giving expected results
Below is a trivial java program. It has a counter called "cnt" that is incremented and then added to a List called "monitor". "cnt" is incremented by multiple threads, and values are added to "monitor" by multiple threads.
At the end of the method…
StvnBrkdll
- 3,924
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5
votes
4 answers
Does synchronized (this) lock only the synchronized block or all the "this" code?
public class ObjectCounter {
private static long numOfInstances = 0;
public ObjectCounter(){
synchronized(this){
numOfInstances++;
}
}
**public static synchronized long getCount(){
return…
Oriel Cochavi
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5
votes
2 answers
How do I exit a monitor in bytecode properly?
I was reading the JVM specification to try to figure out how to properly handle monitors. The example they give in the relevant section looks like this:
0 aload_1 // Push f
1 dup // Duplicate it on the stack
2 …
user11171
- 3,821
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4
votes
2 answers
using this keyword with synchronized block in java
I have two thread that have access to an object. with synchronized(a), i supply lock on object a so now in each time on thread can access to object "a" and modify that.if execute this code we have 1 2. without synchronized block some times we get 2…
kankan256
- 210
- 1
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4
votes
2 answers
Does Java `synchronized` block lock on Object reference, or value?
Given the output shown below:
Path path1 = Paths.get("/Users/someone/foo");
Path path2 = Paths.get("/Users/someone/foo");
System.out.println(path1.toString() == path2.toString()); // outputs false
…
albusshin
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