Check for timeout in wait() loop
up vote
1
down vote
favorite
I want to check for a condition in a guarded wait()
loop with a user-specified total timeout, similar to how LinkedBlockingQueue.poll()
works.
For example collection
can be appended to by different threads, but only when the collection contains a value equating to myItem
within timeout
, should the loop terminate successfully. If the user-specified timeout elapses, it should throw.
This is my current best approach:
long startTime = System.currentTimeMillis();
synchronized (collection) {
while (!collection.contains(myItem)) {
long remaining = System.currentTimeMillis() - startTime - timeout;
if (remaining < 0)
throw new TimeoutException();
collection.wait(remaining);
}
}
The problem here is that System.currentTimeMillis()
(or System.nanoTime()
) is called inside a synchronized context. IntelliJ's warning states:
While not necessarily representing a problem, such calls cause an expensive context switch, and are best kept out of synchronized contexts, if possible.
I wonder how much impact this 'expensive context switch' will have in practice, with Oracle JVM 8?
This is one alternative I came up with, but I don't like this as the actual timeout becomes ⌊timeout/10⌋*10 + delta
. and the error will probably be much worse than the context switch.
synchronized (collection) {
int loops = 0;
while (!collection.contains(myItem)) {
if(loops++ > timeout / 10)
throw new TimeoutException();
collection.wait(10);
}
}
java locking timeout
bumped to the homepage by Community♦ 16 hours ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
add a comment |
up vote
1
down vote
favorite
I want to check for a condition in a guarded wait()
loop with a user-specified total timeout, similar to how LinkedBlockingQueue.poll()
works.
For example collection
can be appended to by different threads, but only when the collection contains a value equating to myItem
within timeout
, should the loop terminate successfully. If the user-specified timeout elapses, it should throw.
This is my current best approach:
long startTime = System.currentTimeMillis();
synchronized (collection) {
while (!collection.contains(myItem)) {
long remaining = System.currentTimeMillis() - startTime - timeout;
if (remaining < 0)
throw new TimeoutException();
collection.wait(remaining);
}
}
The problem here is that System.currentTimeMillis()
(or System.nanoTime()
) is called inside a synchronized context. IntelliJ's warning states:
While not necessarily representing a problem, such calls cause an expensive context switch, and are best kept out of synchronized contexts, if possible.
I wonder how much impact this 'expensive context switch' will have in practice, with Oracle JVM 8?
This is one alternative I came up with, but I don't like this as the actual timeout becomes ⌊timeout/10⌋*10 + delta
. and the error will probably be much worse than the context switch.
synchronized (collection) {
int loops = 0;
while (!collection.contains(myItem)) {
if(loops++ > timeout / 10)
throw new TimeoutException();
collection.wait(10);
}
}
java locking timeout
bumped to the homepage by Community♦ 16 hours ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
add a comment |
up vote
1
down vote
favorite
up vote
1
down vote
favorite
I want to check for a condition in a guarded wait()
loop with a user-specified total timeout, similar to how LinkedBlockingQueue.poll()
works.
For example collection
can be appended to by different threads, but only when the collection contains a value equating to myItem
within timeout
, should the loop terminate successfully. If the user-specified timeout elapses, it should throw.
This is my current best approach:
long startTime = System.currentTimeMillis();
synchronized (collection) {
while (!collection.contains(myItem)) {
long remaining = System.currentTimeMillis() - startTime - timeout;
if (remaining < 0)
throw new TimeoutException();
collection.wait(remaining);
}
}
The problem here is that System.currentTimeMillis()
(or System.nanoTime()
) is called inside a synchronized context. IntelliJ's warning states:
While not necessarily representing a problem, such calls cause an expensive context switch, and are best kept out of synchronized contexts, if possible.
I wonder how much impact this 'expensive context switch' will have in practice, with Oracle JVM 8?
This is one alternative I came up with, but I don't like this as the actual timeout becomes ⌊timeout/10⌋*10 + delta
. and the error will probably be much worse than the context switch.
synchronized (collection) {
int loops = 0;
while (!collection.contains(myItem)) {
if(loops++ > timeout / 10)
throw new TimeoutException();
collection.wait(10);
}
}
java locking timeout
I want to check for a condition in a guarded wait()
loop with a user-specified total timeout, similar to how LinkedBlockingQueue.poll()
works.
For example collection
can be appended to by different threads, but only when the collection contains a value equating to myItem
within timeout
, should the loop terminate successfully. If the user-specified timeout elapses, it should throw.
This is my current best approach:
long startTime = System.currentTimeMillis();
synchronized (collection) {
while (!collection.contains(myItem)) {
long remaining = System.currentTimeMillis() - startTime - timeout;
if (remaining < 0)
throw new TimeoutException();
collection.wait(remaining);
}
}
The problem here is that System.currentTimeMillis()
(or System.nanoTime()
) is called inside a synchronized context. IntelliJ's warning states:
While not necessarily representing a problem, such calls cause an expensive context switch, and are best kept out of synchronized contexts, if possible.
I wonder how much impact this 'expensive context switch' will have in practice, with Oracle JVM 8?
This is one alternative I came up with, but I don't like this as the actual timeout becomes ⌊timeout/10⌋*10 + delta
. and the error will probably be much worse than the context switch.
synchronized (collection) {
int loops = 0;
while (!collection.contains(myItem)) {
if(loops++ > timeout / 10)
throw new TimeoutException();
collection.wait(10);
}
}
java locking timeout
java locking timeout
edited Jun 7 at 9:09
asked Jun 7 at 8:11
Mark Jeronimus
1765
1765
bumped to the homepage by Community♦ 16 hours ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
bumped to the homepage by Community♦ 16 hours ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
up vote
0
down vote
I think you should be fine with System.currentTimeMillis()
. Even though the method itself is not synchronized
, mostly native method call internally would be synchronized
.
Read this old but still useful article about the same thing.
http://www.devx.com/Java/Article/28685
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
I think you should be fine with System.currentTimeMillis()
. Even though the method itself is not synchronized
, mostly native method call internally would be synchronized
.
Read this old but still useful article about the same thing.
http://www.devx.com/Java/Article/28685
add a comment |
up vote
0
down vote
I think you should be fine with System.currentTimeMillis()
. Even though the method itself is not synchronized
, mostly native method call internally would be synchronized
.
Read this old but still useful article about the same thing.
http://www.devx.com/Java/Article/28685
add a comment |
up vote
0
down vote
up vote
0
down vote
I think you should be fine with System.currentTimeMillis()
. Even though the method itself is not synchronized
, mostly native method call internally would be synchronized
.
Read this old but still useful article about the same thing.
http://www.devx.com/Java/Article/28685
I think you should be fine with System.currentTimeMillis()
. Even though the method itself is not synchronized
, mostly native method call internally would be synchronized
.
Read this old but still useful article about the same thing.
http://www.devx.com/Java/Article/28685
answered Jun 14 at 7:43
Jabbar_Jigariyo
22414
22414
add a comment |
add a comment |
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