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Posted to users@groovy.apache.org by Blake McBride <bl...@gmail.com> on 2018/04/20 09:21:30 UTC
Re-entrant and multi-entrant Groovy calls
Greetings,
Does Groovy safely support re-entrant and multi-entrant calls? What I mean
by that is the following:
Re-entrant: on a single OS thread - my Java program calls into Groovy,
then Groovy calls into my Java application, and then the Java application
calls back into Groovy. So the stack has Java, Groovy, JAVA, and then
Groovy again.
Multi-entrant: my Java application has many threads. One of my threads
calls into Groovy. Then, while one thread is still in Groovy, another
thread evokes Groovy. So now we have two calls into Groovy by two
independent Java/OS threads running at the same time.
I understand the typical problems associated with application-level shared
variables. This is expected. The question revolves around Groovy's
internals. I presume Groovy may have some shared data that is internal to
Groovy. That's what I am unclear about. Groovy would have had to be
designed for these scenarios from the ground up.
This is a little hard to test because if it can't always correctly handle
these situations, it may not become clear until certain scenarios arrive.
It may be hard for any "test" program I write to cause those scenarios, so
I thought this may be a known answer.
Thanks!
Blake McBride
Re: Re-entrant and multi-entrant Groovy calls
Posted by "Kerridge, Jon" <J....@napier.ac.uk>.
I have intermixed Groovy and JCSP easily and reliably, but not at the low-level thread level.
I use two libraries JCSP (CSP for Java) which provides a process based interface that enables the construction of multiprocess applications, either on a multi-core machine or on a cluster of multi-core machines.
In addition I have created a set of Groovy helper classes, groovyJCSP, that create a much simpler user enviroment to the underlying JCSP library. These libraries have been used for more than 10 years, mostly in teaching but also to undertake large scale application development.
My github account has these libraries available (https://github.com/JonKerridge), which has examples of the use of the library including much higher level management of access to shared variables, including access to partitioned data structures such that two processes can read all the data but only one can write to a specific partition.
Jon
Professor Jon Kerridge
School of Computing
Edinburgh Napier University
Merchiston Campus
Edinburgh EH10 5DT
0131 455 2777
j.kerridge@napier.ac.uk<ma...@napier.ac.uk>
<http://www.soc.napier.ac.uk/~cs10/>
________________________________
From: Blake McBride <bl...@gmail.com>
Sent: 20 April 2018 12:45:31
To: users@groovy.apache.org
Subject: Re: Re-entrant and multi-entrant Groovy calls
Thanks. Speaking of Java alone, I understand that many Java API's are not thread safe. That's fine. However, with respect to Java alone, I can have any number of threads and so long as no thread touches the same (application) variables at the same time, I'm always safe.
I understand that I must take this into account when using Groovy too. My problem is that I don't know if Groovy has some internal stuff that will break even if I have no application variable problems.
Thanks.
Blake McBride
On Fri, Apr 20, 2018 at 6:34 AM, Jochen Theodorou <bl...@gmx.org>> wrote:
Am 20.04.2018 um 11:21 schrieb Blake McBride:
Greetings,
Does Groovy safely support re-entrant and multi-entrant calls? What I mean by that is the following:
Re-entrant: on a single OS thread - my Java program calls into Groovy, then Groovy calls into my Java application, and then the Java application calls back into Groovy. So the stack has Java, Groovy, JAVA, and then Groovy again.
Multi-entrant: my Java application has many threads. One of my threads calls into Groovy. Then, while one thread is still in Groovy, another thread evokes Groovy. So now we have two calls into Groovy by two independent Java/OS threads running at the same time.
this is actually difficult to answer. The runtime system is designed to be safe for multi entrant usages (minus bugs of course). But just like in Java that does not mean all parts of the API are safe for this usage, not even groovy.lang
bye Jochen
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Re: Re-entrant and multi-entrant Groovy calls
Posted by Blake McBride <bl...@gmail.com>.
Thanks. Speaking of Java alone, I understand that many Java API's are not
thread safe. That's fine. However, with respect to Java alone, I can have
any number of threads and so long as no thread touches the same
(application) variables at the same time, I'm always safe.
I understand that I must take this into account when using Groovy too. My
problem is that I don't know if Groovy has some internal stuff that will
break even if I have no application variable problems.
Thanks.
Blake McBride
On Fri, Apr 20, 2018 at 6:34 AM, Jochen Theodorou <bl...@gmx.org> wrote:
>
>
> Am 20.04.2018 um 11:21 schrieb Blake McBride:
>
>> Greetings,
>>
>> Does Groovy safely support re-entrant and multi-entrant calls? What I
>> mean by that is the following:
>>
>> Re-entrant: on a single OS thread - my Java program calls into Groovy,
>> then Groovy calls into my Java application, and then the Java application
>> calls back into Groovy. So the stack has Java, Groovy, JAVA, and then
>> Groovy again.
>>
>> Multi-entrant: my Java application has many threads. One of my threads
>> calls into Groovy. Then, while one thread is still in Groovy, another
>> thread evokes Groovy. So now we have two calls into Groovy by two
>> independent Java/OS threads running at the same time.
>>
>
> this is actually difficult to answer. The runtime system is designed to be
> safe for multi entrant usages (minus bugs of course). But just like in Java
> that does not mean all parts of the API are safe for this usage, not even
> groovy.lang
>
> bye Jochen
>
Re: Re-entrant and multi-entrant Groovy calls
Posted by Jochen Theodorou <bl...@gmx.org>.
Am 20.04.2018 um 11:21 schrieb Blake McBride:
> Greetings,
>
> Does Groovy safely support re-entrant and multi-entrant calls? What I
> mean by that is the following:
>
> Re-entrant: on a single OS thread - my Java program calls into Groovy,
> then Groovy calls into my Java application, and then the Java
> application calls back into Groovy. So the stack has Java, Groovy,
> JAVA, and then Groovy again.
>
> Multi-entrant: my Java application has many threads. One of my threads
> calls into Groovy. Then, while one thread is still in Groovy, another
> thread evokes Groovy. So now we have two calls into Groovy by two
> independent Java/OS threads running at the same time.
this is actually difficult to answer. The runtime system is designed to
be safe for multi entrant usages (minus bugs of course). But just like
in Java that does not mean all parts of the API are safe for this usage,
not even groovy.lang
bye Jochen
Re: Re-entrant and multi-entrant Groovy calls
Posted by "Kerridge, Jon" <J....@napier.ac.uk>.
Hi,
Not really, becasue you have just specified the groovy the crucial bit is how this is called and how data is shared / passed between between the Java and Groovy
Jon
Professor Jon Kerridge
School of Computing
Edinburgh Napier University
Merchiston Campus
Edinburgh EH10 5DT
0131 455 2777
j.kerridge@napier.ac.uk<ma...@napier.ac.uk>
http://www.soc.napier.ac.uk/~cs10/
________________________________
From: Blake McBride <bl...@gmail.com>
Sent: 20 April 2018 13:32:17
To: users@groovy.apache.org
Subject: Re: Re-entrant and multi-entrant Groovy calls
Every time I call Groovy from Java I do the following code snippets. Does this have the problem you are referring to?
public void runGroovy(String fileName) {
JSONObject injson = ...
JSONObject outjson = ...
HibernateSessionUtil hsu = ...
GroovyClass gclass = loadClass(fileName, true);
if (gclass != null) {
Class[] ca = {
JSONObject.class,
JSONObject.class,
HibernateSessionUtil.class,
HTMLFlex.class
};
try {
@SuppressWarnings("unchecked")
Method methp = gclass.getMethod(_method, ca);
if (methp == null) {
errorReturn(response, "Method " + _method + " not found in class " + this.getClass().getName(), null);
return;
}
methp.invoke(null, injson, outjson, hsu, this);
} catch (Exception e) {
errorReturn(response, "Error running method " + _method + " in class " + this.getClass().getName(), e);
return;
}
} else {
errorReturn(response, "Error loading " + fileName, null);
return;
}
}
public synchronized static GroovyClass loadClass(String fileName, boolean report) {
GroovyClass gclass;
[some class cacheing code]
try {
gclass = new GroovyClass(false, fileName);
classCache.put(fileName, new ClassInfo(gclass, (new File(fileName)).lastModified()));
} catch (FileNotFoundException e) {
if (report)
logger.error("File " + fileName + " not found", e);
return null;
} catch (Exception e) {
if (report)
logger.error("Error loading " + fileName, e);
return null;
}
return gclass;
}
On Fri, Apr 20, 2018 at 7:15 AM, Wolfgang Pedot <wo...@finkzeit.at>> wrote:
For Groovy-scripts you need to know that each instance of a script has a Binding to store variables in it and that may cause re-entrance or concurrency issues if you dont create a new script instance for each call.
Wolfgang
Am 20.04.2018 um 11:21 schrieb Blake McBride:
Greetings,
Does Groovy safely support re-entrant and multi-entrant calls? What I mean by that is the following:
Re-entrant: on a single OS thread - my Java program calls into Groovy, then Groovy calls into my Java application, and then the Java application calls back into Groovy. So the stack has Java, Groovy, JAVA, and then Groovy again.
Multi-entrant: my Java application has many threads. One of my threads calls into Groovy. Then, while one thread is still in Groovy, another thread evokes Groovy. So now we have two calls into Groovy by two independent Java/OS threads running at the same time.
I understand the typical problems associated with application-level shared variables. This is expected. The question revolves around Groovy's internals. I presume Groovy may have some shared data that is internal to Groovy. That's what I am unclear about. Groovy would have had to be designed for these scenarios from the ground up.
This is a little hard to test because if it can't always correctly handle these situations, it may not become clear until certain scenarios arrive. It may be hard for any "test" program I write to cause those scenarios, so I thought this may be a known answer.
Thanks!
Blake McBride
This message and its attachment(s) are intended for the addressee(s) only and should not be read, copied, disclosed, forwarded or relied upon by any person other than the intended addressee(s) without the permission of the sender. If you are not the intended addressee you must not take any action based on this message and its attachment(s) nor must you copy or show them to anyone. Please respond to the sender and ensure that this message and its attachment(s) are deleted.
It is your responsibility to ensure that this message and its attachment(s) are scanned for viruses or other defects. Edinburgh Napier University does not accept liability for any loss or damage which may result from this message or its attachment(s), or for errors or omissions arising after it was sent. Email is not a secure medium. Emails entering Edinburgh Napier University's system are subject to routine monitoring and filtering by Edinburgh Napier University.
Edinburgh Napier University is a registered Scottish charity. Registration number SC018373
Re: Re-entrant and multi-entrant Groovy calls
Posted by Wolfgang Pedot <wo...@finkzeit.at>.
I would not expect any problems because of Groovy here, so far
Groovy-Classes have behaved like Java-Classes in my projects
Wolfgang
Am 20.04.2018 um 17:03 schrieb Blake McBride:
> Yes, it is calling a static method on a Groovy class. Is there a
> problem with what I am doing in term of re-entrant or multi-entrant
> interference?
>
> Thanks.
>
> Blake
>
>
> On Fri, Apr 20, 2018 at 8:16 AM, Wolfgang Pedot
> <wolfgang.pedot@finkzeit.at <ma...@finkzeit.at>> wrote:
>
> I dont know, your code looks like it is calling a static method on
> a class.
>
> What I was referring to was using something like
> GroovyScriptEngine.createScript and reusing the returned
> Script-Object.
>
> Wolfgang
>
> Am 20.04.2018 um 14:32 schrieb Blake McBride:
>
> Every time I call Groovy from Java I do the following code
> snippets. Does this have the problem you are referring to?
>
> public void runGroovy(String fileName) {
> JSONObject injson = ...
> JSONObject outjson = ...
> HibernateSessionUtil hsu = ...
>
> GroovyClass gclass =loadClass(fileName,true);
> if (gclass !=null) {
> Class[] ca = {
> JSONObject.class,
> JSONObject.class,
> HibernateSessionUtil.class,
> HTMLFlex.class };
>
> try {
> @SuppressWarnings("unchecked")
> Method methp = gclass.getMethod(_method, ca);
> if (methp ==null) {
> errorReturn(response,"Method " + _method +"
> not found in class " +this.getClass().getName(),null);
> return;
> }
> methp.invoke(null, injson, outjson, hsu,this);
> }catch (Exception e) {
> errorReturn(response,"Error running method " +
> _method +" in class " +this.getClass().getName(), e);
> return;
> }
> }else {
> errorReturn(response,"Error loading " + fileName,null);
> return;
> }
> }
> public synchronized static GroovyClass loadClass(String
> fileName, boolean report) { GroovyClass gclass; *[some class
> cacheing code]*try { gclass = new GroovyClass(false,
> fileName); classCache.put(fileName, new ClassInfo(gclass, (new
> File(fileName)).lastModified())); } catch
> (FileNotFoundException e) { if (report) logger.error("File " +
> fileName + " not found", e); return null; } catch (Exception
> e) { if (report) logger.error("Error loading " + fileName, e);
> return null; } return gclass; }
>
>
>
> On Fri, Apr 20, 2018 at 7:15 AM, Wolfgang Pedot
> <wolfgang.pedot@finkzeit.at
> <ma...@finkzeit.at>
> <mailto:wolfgang.pedot@finkzeit.at
> <ma...@finkzeit.at>>> wrote:
>
> For Groovy-scripts you need to know that each instance of
> a script
> has a Binding to store variables in it and that may cause
> re-entrance or concurrency issues if you dont create a new
> script
> instance for each call.
>
> Wolfgang
>
> Am 20.04.2018 um 11:21 schrieb Blake McBride:
>
> Greetings,
>
> Does Groovy safely support re-entrant and
> multi-entrant calls?
> What I mean by that is the following:
>
> Re-entrant: on a single OS thread - my Java program
> calls into
> Groovy, then Groovy calls into my Java application,
> and then
> the Java application calls back into Groovy. So the
> stack has
> Java, Groovy, JAVA, and then Groovy again.
>
> Multi-entrant: my Java application has many threads.
> One of
> my threads calls into Groovy. Then, while one thread
> is still
> in Groovy, another thread evokes Groovy. So now we
> have two
> calls into Groovy by two independent Java/OS threads
> running
> at the same time.
>
> I understand the typical problems associated with
> application-level shared variables. This is expected. The
> question revolves around Groovy's internals. I
> presume Groovy
> may have some shared data that is internal to Groovy.
> That's
> what I am unclear about. Groovy would have had to be
> designed
> for these scenarios from the ground up.
>
> This is a little hard to test because if it can't always
> correctly handle these situations, it may not become clear
> until certain scenarios arrive. It may be hard for
> any "test"
> program I write to cause those scenarios, so I thought
> this
> may be a known answer.
>
> Thanks!
>
> Blake McBride
>
Re: Re-entrant and multi-entrant Groovy calls
Posted by Blake McBride <bl...@gmail.com>.
Yes, it is calling a static method on a Groovy class. Is there a problem
with what I am doing in term of re-entrant or multi-entrant interference?
Thanks.
Blake
On Fri, Apr 20, 2018 at 8:16 AM, Wolfgang Pedot <wo...@finkzeit.at>
wrote:
> I dont know, your code looks like it is calling a static method on a class.
>
> What I was referring to was using something like
> GroovyScriptEngine.createScript and reusing the returned Script-Object.
>
> Wolfgang
>
> Am 20.04.2018 um 14:32 schrieb Blake McBride:
>
>> Every time I call Groovy from Java I do the following code snippets.
>> Does this have the problem you are referring to?
>>
>> public void runGroovy(String fileName) {
>> JSONObject injson = ...
>> JSONObject outjson = ...
>> HibernateSessionUtil hsu = ...
>>
>> GroovyClass gclass =loadClass(fileName,true);
>> if (gclass !=null) {
>> Class[] ca = {
>> JSONObject.class,
>> JSONObject.class,
>> HibernateSessionUtil.class,
>> HTMLFlex.class };
>>
>> try {
>> @SuppressWarnings("unchecked")
>> Method methp = gclass.getMethod(_method, ca);
>> if (methp ==null) {
>> errorReturn(response,"Method " + _method +" not found in
>> class " +this.getClass().getName(),null);
>> return;
>> }
>> methp.invoke(null, injson, outjson, hsu,this);
>> }catch (Exception e) {
>> errorReturn(response,"Error running method " + _method +" in
>> class " +this.getClass().getName(), e);
>> return;
>> }
>> }else {
>> errorReturn(response,"Error loading " + fileName,null);
>> return;
>> }
>> }
>> public synchronized static GroovyClass loadClass(String fileName, boolean
>> report) { GroovyClass gclass; *[some class cacheing code]*try { gclass =
>> new GroovyClass(false, fileName); classCache.put(fileName, new
>> ClassInfo(gclass, (new File(fileName)).lastModified())); } catch
>> (FileNotFoundException e) { if (report) logger.error("File " + fileName + "
>> not found", e); return null; } catch (Exception e) { if (report)
>> logger.error("Error loading " + fileName, e); return null; } return gclass;
>> }
>>
>>
>>
>> On Fri, Apr 20, 2018 at 7:15 AM, Wolfgang Pedot <
>> wolfgang.pedot@finkzeit.at <ma...@finkzeit.at>> wrote:
>>
>> For Groovy-scripts you need to know that each instance of a script
>> has a Binding to store variables in it and that may cause
>> re-entrance or concurrency issues if you dont create a new script
>> instance for each call.
>>
>> Wolfgang
>>
>> Am 20.04.2018 um 11:21 schrieb Blake McBride:
>>
>> Greetings,
>>
>> Does Groovy safely support re-entrant and multi-entrant calls?
>> What I mean by that is the following:
>>
>> Re-entrant: on a single OS thread - my Java program calls into
>> Groovy, then Groovy calls into my Java application, and then
>> the Java application calls back into Groovy. So the stack has
>> Java, Groovy, JAVA, and then Groovy again.
>>
>> Multi-entrant: my Java application has many threads. One of
>> my threads calls into Groovy. Then, while one thread is still
>> in Groovy, another thread evokes Groovy. So now we have two
>> calls into Groovy by two independent Java/OS threads running
>> at the same time.
>>
>> I understand the typical problems associated with
>> application-level shared variables. This is expected. The
>> question revolves around Groovy's internals. I presume Groovy
>> may have some shared data that is internal to Groovy. That's
>> what I am unclear about. Groovy would have had to be designed
>> for these scenarios from the ground up.
>>
>> This is a little hard to test because if it can't always
>> correctly handle these situations, it may not become clear
>> until certain scenarios arrive. It may be hard for any "test"
>> program I write to cause those scenarios, so I thought this
>> may be a known answer.
>>
>> Thanks!
>>
>> Blake McBride
>>
>>
>
Re: Re-entrant and multi-entrant Groovy calls
Posted by Wolfgang Pedot <wo...@finkzeit.at>.
I dont know, your code looks like it is calling a static method on a class.
What I was referring to was using something like
GroovyScriptEngine.createScript and reusing the returned Script-Object.
Wolfgang
Am 20.04.2018 um 14:32 schrieb Blake McBride:
> Every time I call Groovy from Java I do the following code snippets.
> Does this have the problem you are referring to?
>
> public void runGroovy(String fileName) {
> JSONObject injson = ...
> JSONObject outjson = ...
> HibernateSessionUtil hsu = ...
>
> GroovyClass gclass =loadClass(fileName,true);
> if (gclass !=null) {
> Class[] ca = {
> JSONObject.class,
> JSONObject.class,
> HibernateSessionUtil.class,
> HTMLFlex.class };
>
> try {
> @SuppressWarnings("unchecked")
> Method methp = gclass.getMethod(_method, ca);
> if (methp ==null) {
> errorReturn(response,"Method " + _method +" not found in class " +this.getClass().getName(),null);
> return;
> }
> methp.invoke(null, injson, outjson, hsu,this);
> }catch (Exception e) {
> errorReturn(response,"Error running method " + _method +" in class " +this.getClass().getName(), e);
> return;
> }
> }else {
> errorReturn(response,"Error loading " + fileName,null);
> return;
> }
> }
> public synchronized static GroovyClass loadClass(String fileName,
> boolean report) { GroovyClass gclass; *[some class cacheing code]*try
> { gclass = new GroovyClass(false, fileName); classCache.put(fileName,
> new ClassInfo(gclass, (new File(fileName)).lastModified())); } catch
> (FileNotFoundException e) { if (report) logger.error("File " +
> fileName + " not found", e); return null; } catch (Exception e) { if
> (report) logger.error("Error loading " + fileName, e); return null; }
> return gclass; }
>
>
> On Fri, Apr 20, 2018 at 7:15 AM, Wolfgang Pedot
> <wolfgang.pedot@finkzeit.at <ma...@finkzeit.at>> wrote:
>
> For Groovy-scripts you need to know that each instance of a script
> has a Binding to store variables in it and that may cause
> re-entrance or concurrency issues if you dont create a new script
> instance for each call.
>
> Wolfgang
>
> Am 20.04.2018 um 11:21 schrieb Blake McBride:
>
> Greetings,
>
> Does Groovy safely support re-entrant and multi-entrant calls?
> What I mean by that is the following:
>
> Re-entrant: on a single OS thread - my Java program calls into
> Groovy, then Groovy calls into my Java application, and then
> the Java application calls back into Groovy. So the stack has
> Java, Groovy, JAVA, and then Groovy again.
>
> Multi-entrant: my Java application has many threads. One of
> my threads calls into Groovy. Then, while one thread is still
> in Groovy, another thread evokes Groovy. So now we have two
> calls into Groovy by two independent Java/OS threads running
> at the same time.
>
> I understand the typical problems associated with
> application-level shared variables. This is expected. The
> question revolves around Groovy's internals. I presume Groovy
> may have some shared data that is internal to Groovy. That's
> what I am unclear about. Groovy would have had to be designed
> for these scenarios from the ground up.
>
> This is a little hard to test because if it can't always
> correctly handle these situations, it may not become clear
> until certain scenarios arrive. It may be hard for any "test"
> program I write to cause those scenarios, so I thought this
> may be a known answer.
>
> Thanks!
>
> Blake McBride
>
Re: Re-entrant and multi-entrant Groovy calls
Posted by Blake McBride <bl...@gmail.com>.
Every time I call Groovy from Java I do the following code snippets. Does
this have the problem you are referring to?
public void runGroovy(String fileName) {
JSONObject injson = ...
JSONObject outjson = ...
HibernateSessionUtil hsu = ...
GroovyClass gclass = loadClass(fileName, true);
if (gclass != null) {
Class[] ca = {
JSONObject.class,
JSONObject.class,
HibernateSessionUtil.class,
HTMLFlex.class
};
try {
@SuppressWarnings("unchecked")
Method methp = gclass.getMethod(_method, ca);
if (methp == null) {
errorReturn(response, "Method " + _method + " not found in class " +
this.getClass().getName(),
null);
return;
}
methp.invoke(null, injson, outjson, hsu, this);
} catch (Exception e) {
errorReturn(response, "Error running method " + _method + " in class " +
this.getClass().getName(), e);
return;
}
} else {
errorReturn(response, "Error loading " + fileName, null);
return;
}
}
public synchronized static GroovyClass loadClass(String fileName,
boolean report) {
GroovyClass gclass;
*[some class cacheing code]*
try {
gclass = new GroovyClass(false, fileName);
classCache.put(fileName, new ClassInfo(gclass, (new
File(fileName)).lastModified()));
} catch (FileNotFoundException e) {
if (report)
logger.error("File " + fileName + " not found", e);
return null;
} catch (Exception e) {
if (report)
logger.error("Error loading " + fileName, e);
return null;
}
return gclass;
}
On Fri, Apr 20, 2018 at 7:15 AM, Wolfgang Pedot <wo...@finkzeit.at>
wrote:
> For Groovy-scripts you need to know that each instance of a script has a
> Binding to store variables in it and that may cause re-entrance or
> concurrency issues if you dont create a new script instance for each call.
>
> Wolfgang
>
> Am 20.04.2018 um 11:21 schrieb Blake McBride:
>
>> Greetings,
>>
>> Does Groovy safely support re-entrant and multi-entrant calls? What I
>> mean by that is the following:
>>
>> Re-entrant: on a single OS thread - my Java program calls into Groovy,
>> then Groovy calls into my Java application, and then the Java application
>> calls back into Groovy. So the stack has Java, Groovy, JAVA, and then
>> Groovy again.
>>
>> Multi-entrant: my Java application has many threads. One of my threads
>> calls into Groovy. Then, while one thread is still in Groovy, another
>> thread evokes Groovy. So now we have two calls into Groovy by two
>> independent Java/OS threads running at the same time.
>>
>> I understand the typical problems associated with application-level
>> shared variables. This is expected. The question revolves around Groovy's
>> internals. I presume Groovy may have some shared data that is internal to
>> Groovy. That's what I am unclear about. Groovy would have had to be
>> designed for these scenarios from the ground up.
>>
>> This is a little hard to test because if it can't always correctly handle
>> these situations, it may not become clear until certain scenarios arrive.
>> It may be hard for any "test" program I write to cause those scenarios, so
>> I thought this may be a known answer.
>>
>> Thanks!
>>
>> Blake McBride
>>
>>
>
Re: Re-entrant and multi-entrant Groovy calls
Posted by Wolfgang Pedot <wo...@finkzeit.at>.
For Groovy-scripts you need to know that each instance of a script has a
Binding to store variables in it and that may cause re-entrance or
concurrency issues if you dont create a new script instance for each call.
Wolfgang
Am 20.04.2018 um 11:21 schrieb Blake McBride:
> Greetings,
>
> Does Groovy safely support re-entrant and multi-entrant calls? What I
> mean by that is the following:
>
> Re-entrant: on a single OS thread - my Java program calls into Groovy,
> then Groovy calls into my Java application, and then the Java
> application calls back into Groovy. So the stack has Java, Groovy,
> JAVA, and then Groovy again.
>
> Multi-entrant: my Java application has many threads. One of my
> threads calls into Groovy. Then, while one thread is still in Groovy,
> another thread evokes Groovy. So now we have two calls into Groovy by
> two independent Java/OS threads running at the same time.
>
> I understand the typical problems associated with application-level
> shared variables. This is expected. The question revolves around
> Groovy's internals. I presume Groovy may have some shared data that
> is internal to Groovy. That's what I am unclear about. Groovy would
> have had to be designed for these scenarios from the ground up.
>
> This is a little hard to test because if it can't always correctly
> handle these situations, it may not become clear until certain
> scenarios arrive. It may be hard for any "test" program I write to
> cause those scenarios, so I thought this may be a known answer.
>
> Thanks!
>
> Blake McBride
>