Mixing
How to create handler with callbacks that run on a different thread?
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ height:90px;width:728px;box-sizing:border-box;
}
I am trying to create a Handler that will handle messages on its own thread
What I am currently doing is running during the onCreate part of the activity this code:
lateinit var _handler: Handler
lateinit var hThread: HandlerThread
fun setUpHandler() {
hThread = HandlerThread("HandlerThread")
hThread.start()
_handler = Handler(hThread.looper, this::callback)
}
the problem is that even though I use a different thread's looper the callback runs on the ui thread.
I tested it by running creating this method:
fun callback(msg: Message): Boolean {
Log.d("Handler", "got message ${msg.what} in thread main? ${Looper.myLooper() == Looper.getMainLooper()}")
return true
}
when I call it like this:
_handler.dispatchMessage(Message.obtain(_handler, 1))
I get:
Handler: got message 1 in thread main? true
but when I run it like this:
Handler(hThread.looper).post {
val msg = Message.obtain()
msg.what = 2
callback(msg)
}
I get this message:
Handler: got message 2 in thread main? false
I currently use the second approach, but out of curiosity , is there a way to make the first approach work?
as a side question, is running hThread.quit() in the activity's onDestroy method enough to terminate the extra Thread I started or do I have to do anything else?
android android-handler edited Jan 3 at 15:22
Fantômas
32.9k156491
asked Jan 3 at 14:02
CrucesCruces
787621
add a comment |
I am trying to create a Handler that will handle messages on its own thread
What I am currently doing is running during the onCreate part of the activity this code:
lateinit var _handler: Handler
lateinit var hThread: HandlerThread
fun setUpHandler() {
hThread = HandlerThread("HandlerThread")
hThread.start()
_handler = Handler(hThread.looper, this::callback)
}
the problem is that even though I use a different thread's looper the callback runs on the ui thread.
I tested it by running creating this method:
fun callback(msg: Message): Boolean {
Log.d("Handler", "got message ${msg.what} in thread main? ${Looper.myLooper() == Looper.getMainLooper()}")
return true
}
when I call it like this:
_handler.dispatchMessage(Message.obtain(_handler, 1))
I get:
Handler: got message 1 in thread main? true
but when I run it like this:
Handler(hThread.looper).post {
val msg = Message.obtain()
msg.what = 2
callback(msg)
}
I get this message:
Handler: got message 2 in thread main? false
I currently use the second approach, but out of curiosity , is there a way to make the first approach work?
as a side question, is running hThread.quit() in the activity's onDestroy method enough to terminate the extra Thread I started or do I have to do anything else?
android android-handler edited Jan 3 at 15:22
Fantômas
32.9k156491
asked Jan 3 at 14:02
CrucesCruces
787621
add a comment |
I am trying to create a Handler that will handle messages on its own thread
What I am currently doing is running during the onCreate part of the activity this code:
lateinit var _handler: Handler
lateinit var hThread: HandlerThread
fun setUpHandler() {
hThread = HandlerThread("HandlerThread")
hThread.start()
_handler = Handler(hThread.looper, this::callback)
}
the problem is that even though I use a different thread's looper the callback runs on the ui thread.
I tested it by running creating this method:
fun callback(msg: Message): Boolean {
Log.d("Handler", "got message ${msg.what} in thread main? ${Looper.myLooper() == Looper.getMainLooper()}")
return true
}
when I call it like this:
_handler.dispatchMessage(Message.obtain(_handler, 1))
I get:
Handler: got message 1 in thread main? true
but when I run it like this:
Handler(hThread.looper).post {
val msg = Message.obtain()
msg.what = 2
callback(msg)
}
I get this message:
Handler: got message 2 in thread main? false
I currently use the second approach, but out of curiosity , is there a way to make the first approach work?
as a side question, is running hThread.quit() in the activity's onDestroy method enough to terminate the extra Thread I started or do I have to do anything else?
android android-handler edited Jan 3 at 15:22
Fantômas
32.9k156491
asked Jan 3 at 14:02
CrucesCruces
787621
I am trying to create a Handler that will handle messages on its own thread
What I am currently doing is running during the onCreate part of the activity this code:
lateinit var _handler: Handler
lateinit var hThread: HandlerThread
fun setUpHandler() {
hThread = HandlerThread("HandlerThread")
hThread.start()
_handler = Handler(hThread.looper, this::callback)
}
the problem is that even though I use a different thread's looper the callback runs on the ui thread.
I tested it by running creating this method:
fun callback(msg: Message): Boolean {
Log.d("Handler", "got message ${msg.what} in thread main? ${Looper.myLooper() == Looper.getMainLooper()}")
return true
}
when I call it like this:
_handler.dispatchMessage(Message.obtain(_handler, 1))
I get:
Handler: got message 1 in thread main? true
but when I run it like this:
Handler(hThread.looper).post {
val msg = Message.obtain()
msg.what = 2
callback(msg)
}
I get this message:
Handler: got message 2 in thread main? false
I currently use the second approach, but out of curiosity , is there a way to make the first approach work?
as a side question, is running hThread.quit() in the activity's onDestroy method enough to terminate the extra Thread I started or do I have to do anything else?
android android-handler android android-handler edited Jan 3 at 15:22
Fantômas
32.9k156491
asked Jan 3 at 14:02
CrucesCruces
787621
edited Jan 3 at 15:22
Fantômas
32.9k156491
asked Jan 3 at 14:02
CrucesCruces
787621
edited Jan 3 at 15:22
Fantômas
32.9k156491
edited Jan 3 at 15:22
Fantômas
32.9k156491
edited Jan 3 at 15:22
Fantômas
32.9k156491
32.9k156491
asked Jan 3 at 14:02
CrucesCruces
787621
asked Jan 3 at 14:02
CrucesCruces
787621
asked Jan 3 at 14:02
CrucesCruces
787621
787621
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
As mentioned here the dispatchMessage function runs the Message through the callback on whatever Thread the function is called on... so since your calling it from the UI Thread that's where it appears.
Also FYI dispatchMessage isn't really used as it defeats the purpose of using a Handler and attaching it to a Thread etc as perfectly demonstrated here.
quit() terminates the Looper which essentially terminates the infinite while loop in effect that keeps the HandlerThread "alive" in it's run() method, so yes, it should be enough to kill the Thread itself. However, beware that any Message or Runnable currently already executing will not be stopped, and all other Messages or Runnables in the MessageQueue of the Looper will not be executed.
answered Jan 3 at 14:13
MercatoMercato
414411
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f54023827%2fhow-to-create-handler-with-callbacks-that-run-on-a-different-thread%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
As mentioned here the dispatchMessage function runs the Message through the callback on whatever Thread the function is called on... so since your calling it from the UI Thread that's where it appears.
Also FYI dispatchMessage isn't really used as it defeats the purpose of using a Handler and attaching it to a Thread etc as perfectly demonstrated here.
quit() terminates the Looper which essentially terminates the infinite while loop in effect that keeps the HandlerThread "alive" in it's run() method, so yes, it should be enough to kill the Thread itself. However, beware that any Message or Runnable currently already executing will not be stopped, and all other Messages or Runnables in the MessageQueue of the Looper will not be executed.
answered Jan 3 at 14:13
MercatoMercato
414411
add a comment |
As mentioned here the dispatchMessage function runs the Message through the callback on whatever Thread the function is called on... so since your calling it from the UI Thread that's where it appears.
Also FYI dispatchMessage isn't really used as it defeats the purpose of using a Handler and attaching it to a Thread etc as perfectly demonstrated here.
quit() terminates the Looper which essentially terminates the infinite while loop in effect that keeps the HandlerThread "alive" in it's run() method, so yes, it should be enough to kill the Thread itself. However, beware that any Message or Runnable currently already executing will not be stopped, and all other Messages or Runnables in the MessageQueue of the Looper will not be executed.
answered Jan 3 at 14:13
MercatoMercato
414411
add a comment |
As mentioned here the dispatchMessage function runs the Message through the callback on whatever Thread the function is called on... so since your calling it from the UI Thread that's where it appears.
Also FYI dispatchMessage isn't really used as it defeats the purpose of using a Handler and attaching it to a Thread etc as perfectly demonstrated here.
quit() terminates the Looper which essentially terminates the infinite while loop in effect that keeps the HandlerThread "alive" in it's run() method, so yes, it should be enough to kill the Thread itself. However, beware that any Message or Runnable currently already executing will not be stopped, and all other Messages or Runnables in the MessageQueue of the Looper will not be executed.
answered Jan 3 at 14:13
MercatoMercato
414411
As mentioned here the dispatchMessage function runs the Message through the callback on whatever Thread the function is called on... so since your calling it from the UI Thread that's where it appears.
Also FYI dispatchMessage isn't really used as it defeats the purpose of using a Handler and attaching it to a Thread etc as perfectly demonstrated here.
quit() terminates the Looper which essentially terminates the infinite while loop in effect that keeps the HandlerThread "alive" in it's run() method, so yes, it should be enough to kill the Thread itself. However, beware that any Message or Runnable currently already executing will not be stopped, and all other Messages or Runnables in the MessageQueue of the Looper will not be executed.
answered Jan 3 at 14:13
MercatoMercato
414411
answered Jan 3 at 14:13
MercatoMercato
414411
answered Jan 3 at 14:13
MercatoMercato
414411
answered Jan 3 at 14:13
MercatoMercato
414411
414411
add a comment |
add a comment |
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f54023827%2fhow-to-create-handler-with-callbacks-that-run-on-a-different-thread%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
