Re: parallelism with delegate
On Friday, 22 September 2023 at 04:24:19 UTC, Vitaliy Fadeev
wrote:
able ?
how to use correctly?
```d
import std.parallelism;
auto async_task = task!fn( args ); // error
// Error: no property
`opCall` for type `app.A`, did you mean `new A`?
async_task.executeInNewThread();
```
where
```d
auto a = new A();
auto fn =
class A
{
void fn( string url )
{
// DO
}
}
```
Playground:
https://run.dlang.io/is/HvhtoP
gist:
https://gist.github.com/run-dlang/218b69e1afd79e5944ea10aa7ca61e1b
Also check out std.concurrency
Re: parallelism with delegate
On Thursday, September 21, 2023 10:33:44 PM MDT Vitaliy Fadeev via Digitalmars-d-learn wrote: > On Friday, 22 September 2023 at 04:24:19 UTC, Vitaliy Fadeev > > wrote: > > ... > > Skip this thread. I see solution. > > How to delete missed posts on this forum ? This forum is esentially just a web client for some D-specific newsgroups (and a number of folks access it via either the newsgroup interface or its associated mailing list rather than through the web interface). So, you can't edit or remove posts. Admins can remove spam from the newsgroup (and thus the forum), but that's pretty much it, and even then, that doesn't remove it from the mailing list, because you can't get an e-mail back once it's been sent. So, once you send something to the forum, it's out there forever. - Jonathan M Davis
Re: parallelism with delegate
On Friday, 22 September 2023 at 04:33:44 UTC, Vitaliy Fadeev wrote: On Friday, 22 September 2023 at 04:24:19 UTC, Vitaliy Fadeev wrote: ... Skip this thread. I see solution. How to delete missed posts on this forum ? It's there forever, you have to live with that error ;) See https://forum.dlang.org/help#about
Re: parallelism with delegate
On Friday, 22 September 2023 at 04:24:19 UTC, Vitaliy Fadeev wrote: ... Skip this thread. I see solution. How to delete missed posts on this forum ?
Re: parallelism
On Sunday, 28 January 2018 at 04:44:23 UTC, thedeemon wrote: On Saturday, 27 January 2018 at 20:49:43 UTC, Arun Chandrasekaran wrote: But really I'm not sure why you want static foreach here I was just trying to see if static foreach can be used here, but well, you showed that it's not required. I just got intrigued to see the error on labeled break. Thanks anyway.
Re: parallelism
On Saturday, 27 January 2018 at 20:49:43 UTC, Arun Chandrasekaran
wrote:
Error: must use labeled break within static foreach
Just follow the compiler suggestion:
void main(string[] args) {
auto op = Operation.a;
foreach (_; 0 .. args.length) {
ops: final switch (op) {
static foreach(e; EnumMembers!Operation) {
case e:
mixin(e.to!string ~ "();");
break ops;
}
}
}
}
Here 'ops' is a label that we use to tell break what exactly it
breaks.
But really I'm not sure why you want static foreach here, a
simple foreach is fine, it gets unrolled statically here just
like static one.
Re: parallelism
On Saturday, 27 January 2018 at 17:54:53 UTC, thedeemon wrote:
On Saturday, 27 January 2018 at 11:19:37 UTC, Arun
Chandrasekaran wrote:
Simplified test case that still errors:
You got really close here. Here's a working version:
enum Operation {
a,
b
}
import std.traits, std.conv, std.stdio;
void main(string[] args) {
auto op = Operation.a;
foreach (_; 0 .. args.length) {
final switch (op) {
foreach(e; EnumMembers!Operation) {
case e:
mixin(e.to!string ~ "();");
break;
}
}
}
}
void a() { writeln("A!"); }
void b() { writeln("B!"); }
Thanks, that did the trick.
How to use break inside a static foreach? Changing the above
foreach each to static gives the following error:
Error: must use labeled break within static foreach
Re: parallelism
On Saturday, 27 January 2018 at 11:19:37 UTC, Arun Chandrasekaran
wrote:
Simplified test case that still errors:
You got really close here. Here's a working version:
enum Operation {
a,
b
}
import std.traits, std.conv, std.stdio;
void main(string[] args) {
auto op = Operation.a;
foreach (_; 0 .. args.length) {
final switch (op) {
foreach(e; EnumMembers!Operation) {
case e:
mixin(e.to!string ~ "();");
break;
}
}
}
}
void a() { writeln("A!"); }
void b() { writeln("B!"); }
Re: parallelism
On Saturday, 27 January 2018 at 10:49:45 UTC, Arun Chandrasekaran
wrote:
On Saturday, 27 January 2018 at 10:38:25 UTC, Nicholas Wilson
wrote:
...
[snip]
Simplified test case that still errors:
```
enum Operation {
a,
b
}
import std.traits;
import std.conv;
void main(string[] args) {
foreach (_; 0 .. args.length) {
Operation operation;
switch (operation) {
static foreach(e; EnumMembers!Operation) {
case e:
mixin(to!string(e))();
break;
}
}
}
}
void a() {}
void b() {}
```
Re: parallelism
On Saturday, 27 January 2018 at 10:38:25 UTC, Nicholas Wilson
wrote:
On Saturday, 27 January 2018 at 10:28:10 UTC, Arun
Chandrasekaran wrote:
```
import std.parallelism;
auto pool = new TaskPool(options.threadCount);
foreach (_; 0 .. options.iterationCount) {
switch (options.operation) {
static foreach(e; EnumMembers!Operation) {
case e:
pool.put(task!e(options));
break;
}
pool.finish();
```
Does that do the trick?
No it doesn't.
```
/usr/include/dmd/phobos/std/parallelism.d(507,34): Error:
function expected before (), not cast(Operation)0 of type
Operation
/usr/include/dmd/phobos/std/parallelism.d(835,16): Error:
template instance std.parallelism.Task!(cast(Operation)0,
Options) error instantiating
src/app.d(159,32):instantiated from here:
task!(cast(Operation)0, Options)
src/app.d(160,17): Error: must use labeled break within static
foreach
### and so on till the end of enum
```
Re: parallelism
On Saturday, 27 January 2018 at 10:28:10 UTC, Arun Chandrasekaran
wrote:
```
import std.parallelism;
auto pool = new TaskPool(options.threadCount);
foreach (_; 0 .. options.iterationCount) {
switch (options.operation) {
static foreach(e; EnumMembers!Operation) {
case e:
pool.put(task!e(options));
break;
}
pool.finish();
```
Does that do the trick?
Re: parallelism
On Saturday, 27 January 2018 at 10:28:10 UTC, Arun Chandrasekaran wrote: Hi All, Is there a way to rewrite this [...] Damn! The subject should've been something else.. naming is surely hard..
Re: Parallelism Map and Reduce
On Tuesday, 11 December 2012 at 17:50:31 UTC, Ali Çehreli wrote:
On 12/11/2012 08:12 AM, Zardoz wrote:
Could you please move MapIntegrator() to module-level. Then it
should work.
Ali
I try it and now even with normal Map function give me errors
with dmd !
public Entity MapIntegrator ( Entity me) {
me.Integrador3Orden ();
return me;
}
void main() {
Entity[] objects;
...
objects = array( map!MapIntegrator(objects) );
...
}
With this error :
dmd -w -wi -version=SReduction simulator.d entity.d vector.d
-ofreduceSim
simulator.d(194): Error: template
std.algorithm.map!(MapIntegrator).map does not match any function
template declaration
/usr/include/dmd/phobos/std/algorithm.d(369): Error: template
std.algorithm.map!(MapIntegrator).map(Range) if
(isInputRange!(Unqual!(Range))) cannot deduce template function
from argument types !()(Entity[])
Re: Parallelism Map and Reduce
On 12/12/2012 05:47 AM, Zardoz wrote:
On Tuesday, 11 December 2012 at 17:50:31 UTC, Ali Çehreli wrote:
On 12/11/2012 08:12 AM, Zardoz wrote:
Could you please move MapIntegrator() to module-level. Then it should
work.
Ali
I try it and now even with normal Map function give me errors with dmd !
public Entity MapIntegrator ( Entity me) {
me.Integrador3Orden ();
return me;
}
void main() {
Entity[] objects;
...
objects = array( map!MapIntegrator(objects) );
...
}
With this error :
dmd -w -wi -version=SReduction simulator.d entity.d vector.d -ofreduceSim
simulator.d(194): Error: template std.algorithm.map!(MapIntegrator).map
does not match any function template declaration
/usr/include/dmd/phobos/std/algorithm.d(369): Error: template
std.algorithm.map!(MapIntegrator).map(Range) if
(isInputRange!(Unqual!(Range))) cannot deduce template function from
argument types !()(Entity[])
Strange. The following program works for me with dmd 2.060. It uses both
the regular and parallel versions of map and reduce:
import std.array;
import std.algorithm;
import std.parallelism;
struct Entity
{
void Integrador3Orden()
{}
}
public Entity MapIntegrator ( Entity me) {
me.Integrador3Orden ();
return me;
}
void main() {
Entity[] objects;
objects = array( map!MapIntegrator(objects) );
objects = array(taskPool.map!MapIntegrator(objects));
int[] acelByObjs;
int reduced = reduce!a + b(0, acelByObjs);
reduced = taskPool.reduce!a + b(0, acelByObjs);
}
Ali
Re: Parallelism Map and Reduce
On 12/11/2012 02:53 AM, Zardoz wrote:
auto acelByObjs = map!( (Entity o) {
Vector3 r = o.pos[0] - pos[0];
return r * (o.mass / pow((r.sq_length + epsilon2), 1.5));
} )(objects);
newAcel = reduce!(a + b)(acelByObjs);
It works very well with the std.algorithm Map and Reduce but when I try
to use std.parallelism versions of it, parallel Map give me this
compilataion errors :
entity.d(63): Error: template instance map!(delegate @system
Vector3(Entity o)
{
Vector3 r = o.pos[0LU].opBinary(this.pos[0LU]);
return r.opBinary(o.mass / pow(r.sq_length() + epsilon2,1.5));
}
) cannot use local '__lambda3' as parameter to non-global template
map(functions...)
That used to work a couple of dmd versions ago. I think it was a bug
that it worked, so it stopped working after bug fixes.
If I'm not mistaken this is actually related to a compiler
implementation issue: Lambda's have a single pointer to store the
context that they have been started in.
When a lambda is a free-standing function (aka module function or
global function) then there is only the context to deal with. When the
template is a member function (taskPool.map is) then there is also the
object that the function is started on.
The single pointer of the lambda is not sufficient to store both without
big changes in the compiler.
(I may be off with that description above. e.g. there may be two
pointers when three are actually needed, etc.)
I had to change following chapter after dmd's behavior had changed:
http://ddili.org/ders/d.en/parallelism.html
--- Quoting ---
import std.parallelism;
// ...
double averageGrade(Student student)
{
return student.averageGrade;
}
// ...
auto results = taskPool.map!averageGrade(students, 3);
Note: The free-standing averageGrade() function above is needed due to a
limitation that involves using local delegates with member function
templates like TaskPool.map:
auto results = taskPool.map!(a = a.averageGrade)(students, 3);
// ← compilation ERROR
--
As you see above, the solution is to use a function with taskPool.map,
not a lambda.
Ali
Re: Parallelism Map and Reduce
Ali Çehreli: The single pointer of the lambda is not sufficient to store both without big changes in the compiler. I think adding a heavier 3-word delegate is not too much hard to do. But it makes the language more complex, so so far Walter is not willing to introduce them. But in the end introducing them may become inevitable :-) I think such hypothetical 3-word delegates need to be discussed in the main D newsgroup. Bye, bearophile
Re: Parallelism Map and Reduce
On Tuesday, 11 December 2012 at 15:22:49 UTC, Ali Çehreli wrote:
That used to work a couple of dmd versions ago. I think it was
a bug that it worked, so it stopped working after bug fixes.
If I'm not mistaken this is actually related to a compiler
implementation issue: Lambda's have a single pointer to store
the context that they have been started in.
When a lambda is a free-standing function (aka module
function or global function) then there is only the context
to deal with. When the template is a member function
(taskPool.map is) then there is also the object that the
function is started on.
The single pointer of the lambda is not sufficient to store
both without big changes in the compiler.
(I may be off with that description above. e.g. there may be
two pointers when three are actually needed, etc.)
I had to change following chapter after dmd's behavior had
changed:
http://ddili.org/ders/d.en/parallelism.html
--- Quoting ---
import std.parallelism;
// ...
double averageGrade(Student student)
{
return student.averageGrade;
}
// ...
auto results = taskPool.map!averageGrade(students, 3);
Note: The free-standing averageGrade() function above is needed
due to a limitation that involves using local delegates with
member function templates like TaskPool.map:
auto results = taskPool.map!(a = a.averageGrade)(students,
3); // ← compilation ERROR
--
As you see above, the solution is to use a function with
taskPool.map, not a lambda.
Ali
I try to use a function instead of a lambda function I'm keep
getting compiler errors. Code :
Entity MapIntegrator (ref Entity me) {
me.Integrador3Orden (iDeltaT);
return me;
}
objects = array( taskPool.map!MapIntegrator(objects) );
With taskPool.Map I get this errors :
simulator.d(196): Error: template instance map!(MapIntegrator)
cannot use local 'MapIntegrator' as parameter to non-global
template map(functions...)
/usr/include/dmd/phobos/std/parallelism.d(1969): Error: function
std.parallelism.TaskPool.map!(MapIntegrator).map!(Entity[]).map.Map.fillBuf
cannot access frame of function D main
/usr/include/dmd/phobos/std/parallelism.d(1974): Error: template
instance amap!(MapIntegrator) cannot use local 'MapIntegrator' as
parameter to non-global template amap(functions...)
/usr/include/dmd/phobos/std/parallelism.d(1675): Error: function
std.parallelism.TaskPool.amap!(MapIntegrator).amap!(Entity[],ulong,Entity[]).amap
cannot access frame of function D main
/usr/include/dmd/phobos/std/parallelism.d(1706): Error: function
std.parallelism.TaskPool.amap!(MapIntegrator).amap!(Entity[],ulong,Entity[]).amap.doIt
cannot access frame of function D main
/usr/include/dmd/phobos/std/parallelism.d(1974): Error: template
instance
std.parallelism.TaskPool.amap!(MapIntegrator).amap!(Entity[],ulong,Entity[])
error instantiating
simulator.d(196):instantiated from here: map!(Entity[])
simulator.d(196): Error: template instance
std.parallelism.TaskPool.map!(MapIntegrator).map!(Entity[]) error
instantiating
make: *** [predSim] Error 1
But again, with std.algorthim Map it don give any error and works
fine.
