Re: Using closure causes GC allocation
On Monday, 4 September 2017 at 14:42:45 UTC, Azi Hassan wrote:
On Monday, 4 September 2017 at 05:45:18 UTC, Vino.B wrote:
In order to resolve the issue "Using closure causes GC
allocation" it was stated that we need to use delegates
Alternatively you can drop the functional style and use a
foreach loop that doesn't require delegates, but you'd still
need the GC to store the result in an array. And even then you
could still use Array (from std.container).
Hi All,
Was able to resolve this issue, thank you for your help, below
is the changes that i did to resolve the issue.
import std.stdio: File,writeln;
import std.datetime.systime: Clock, days, SysTime;
import std.file: SpanMode, dirEntries, exists, isFile, mkdir,
remove;
import std.typecons: tuple, Tuple;
import std.algorithm: filter, map, each;
import std.array: array;
Tuple!(string)[] logClean (string[] Lglst, int LogAge) {
if (!Lglst[0].exists) { mkdir(Lglst[0]); }
auto dFiles = dirEntries(Lglst[0], SpanMode.shallow).filter!(a
=a.exists && a.isFile && a.timeCreated < dtLogAge).map!(a
=tuple(a.name)).array;
dFiles.each!(a =a[0].remove);
return dFiles;
}
SysTime dtLogAge () {
int LogAge = mParams[1];
auto ct2 = Clock.currTime();
auto st2 = ct2 + days(-LogAge);
return st2;
}
void main () {
string[] LogDir =
["C:\\Users\\admin\\Desktop\\Current\\Script\\D\\Logs"];
logClean(LogDir);
}
"mParams" is another function that reads the value from the
configuration file and returns the value for the LogAge as
defined in the configuration file.
From,
Vino.B
Re: Using closure causes GC allocation
On Monday, 4 September 2017 at 05:45:18 UTC, Vino.B wrote: In order to resolve the issue "Using closure causes GC allocation" it was stated that we need to use delegates Alternatively you can drop the functional style and use a foreach loop that doesn't require delegates, but you'd still need the GC to store the result in an array. And even then you could still use Array (from std.container).
Re: Using closure causes GC allocation
On Monday, 4 September 2017 at 05:45:18 UTC, Vino.B wrote:
On Saturday, 2 September 2017 at 20:54:03 UTC, Vino.B wrote:
On Saturday, 2 September 2017 at 20:10:58 UTC, Moritz Maxeiner
wrote:
On Saturday, 2 September 2017 at 18:59:30 UTC, Vino.B wrote:
[...]
Cannot reproduce under Linux with dmd 2.076.0 (with commented
out Windows-only check). I'll try to see what happens on
Windows once I have a VM setup.
[...]
You changed the type of dFiles, which you return from
cleanFiles, without changing the return type of cleanFiles.
Change the return type of cleanFiles to the type the compiler
error above tells you it should be (`Tuple!(string,
string)[]` instead of `string[][]`), or let the compiler
infer it via auto (`auto cleanFiles(...`).
Hi,
Thank you very much, was able to resolve the second code
issue by changing the return type of the function.
Hi,
In order to resolve the issue "Using closure causes GC
allocation" it was stated that we need to use delegates, can
you please help me on how to as i have not gone that much far
in D programming.
import std.stdio: File,writeln;
import std.datetime.systime: Clock, days, SysTime;
import std.file: SpanMode, dirEntries, exists, isFile, mkdir,
remove;
import std.typecons: tuple, Tuple;
import std.algorithm: filter, map, each;
import std.array: array;
Tuple!(string)[] logClean (string[] Lglst, int LogAge) {
if (!Lglst[0].exists) { mkdir(Lglst[0]); }
auto ct1 = Clock.currTime();
auto st1 = ct1 + days(-LogAge);
auto dFiles = dirEntries(Lglst[0], SpanMode.shallow).filter!(a
=> a.exists && a.isFile && a.timeCreated < st1).map!(a =>
tuple(a.name)).array;
dFiles.each!(a => a[0].remove);
return dFiles;
}
void main () {
string[] LogDir =
["C:\\Users\\bheev1\\Desktop\\Current\\Script\\D\\Logs"];
int LogAge = 1;
logClean(LogDir,LogAge);
}
From,
Vino.B
If you are getting Using closure causes GC allocation from the
above, it will be because you reference a local in the template
delegate argument to filter:
filter!(a => a.exists &&
a.isFile &&
a.timeCreated < st1)
^^^
because of the local (st1) it needs a closure. I can't remember
how to transform delegates to take parameters and then call with
the parameter set to the local, someone else will have to fill
you in on that one.
Re: Using closure causes GC allocation
On Saturday, 2 September 2017 at 20:54:03 UTC, Vino.B wrote:
On Saturday, 2 September 2017 at 20:10:58 UTC, Moritz Maxeiner
wrote:
On Saturday, 2 September 2017 at 18:59:30 UTC, Vino.B wrote:
[...]
Cannot reproduce under Linux with dmd 2.076.0 (with commented
out Windows-only check). I'll try to see what happens on
Windows once I have a VM setup.
[...]
You changed the type of dFiles, which you return from
cleanFiles, without changing the return type of cleanFiles.
Change the return type of cleanFiles to the type the compiler
error above tells you it should be (`Tuple!(string, string)[]`
instead of `string[][]`), or let the compiler infer it via
auto (`auto cleanFiles(...`).
Hi,
Thank you very much, was able to resolve the second code issue
by changing the return type of the function.
Hi,
In order to resolve the issue "Using closure causes GC
allocation" it was stated that we need to use delegates, can you
please help me on how to as i have not gone that much far in D
programming.
import std.stdio: File,writeln;
import std.datetime.systime: Clock, days, SysTime;
import std.file: SpanMode, dirEntries, exists, isFile, mkdir,
remove;
import std.typecons: tuple, Tuple;
import std.algorithm: filter, map, each;
import std.array: array;
Tuple!(string)[] logClean (string[] Lglst, int LogAge) {
if (!Lglst[0].exists) { mkdir(Lglst[0]); }
auto ct1 = Clock.currTime();
auto st1 = ct1 + days(-LogAge);
auto dFiles = dirEntries(Lglst[0], SpanMode.shallow).filter!(a
=> a.exists && a.isFile && a.timeCreated < st1).map!(a =>
tuple(a.name)).array;
dFiles.each!(a => a[0].remove);
return dFiles;
}
void main () {
string[] LogDir =
["C:\\Users\\bheev1\\Desktop\\Current\\Script\\D\\Logs"];
int LogAge = 1;
logClean(LogDir,LogAge);
}
From,
Vino.B
Re: Using closure causes GC allocation
On Saturday, 2 September 2017 at 20:10:58 UTC, Moritz Maxeiner wrote: On Saturday, 2 September 2017 at 18:59:30 UTC, Vino.B wrote: [...] Cannot reproduce under Linux with dmd 2.076.0 (with commented out Windows-only check). I'll try to see what happens on Windows once I have a VM setup. [...] You changed the type of dFiles, which you return from cleanFiles, without changing the return type of cleanFiles. Change the return type of cleanFiles to the type the compiler error above tells you it should be (`Tuple!(string, string)[]` instead of `string[][]`), or let the compiler infer it via auto (`auto cleanFiles(...`). Hi, Thank you very much, was able to resolve the second code issue by changing the return type of the function.
Re: Using closure causes GC allocation
On Saturday, 2 September 2017 at 18:59:30 UTC, Vino.B wrote:
On Saturday, 2 September 2017 at 18:32:55 UTC, Moritz Maxeiner
wrote:
On Saturday, 2 September 2017 at 18:08:19 UTC, vino.b wrote:
On Saturday, 2 September 2017 at 18:02:06 UTC, Moritz
Maxeiner wrote:
On Saturday, 2 September 2017 at 17:43:08 UTC, Vino.B wrote:
[...]
Line 25 happens because of `[a.name]`. You request a new
array: the memory for this has to be allocated (the reason
why the compiler says "may" is because sometimes, e.g. if
the array literal itself contains only literals, the
allocations needn't happen at runtime and no GC call is
necessary). Since you don't actually use the array, get rid
of it:
[...]
Hi,
Thank you for your help and the DMD version that i am using
is DMD 2.076.0 and yes I am on windows.
Please post a compilable, minimal example including how that
function gets called that yields you that compiler output.
Hi,
Please find the example code below,
[...]
Cannot reproduce under Linux with dmd 2.076.0 (with commented out
Windows-only check). I'll try to see what happens on Windows once
I have a VM setup.
Another similar issue :
I removed the [a.name] and the issue in line 25 has resolved,
but for another function i am getting the same error
string[][] cleanFiles(string FFs, string Step) {
auto dFiles = dirEntries(FFs, SpanMode.shallow).filter!(a =>
a.isFile).map!(a =>[a.name , a.timeCreated.toSimpleString[0 ..
20]]).array; -> Issue in this line
if (Step == "run")
dFiles.each!(a => a[0].remove);
return dFiles;
}
if the replace the line in error as below then i am getting the
error "Error: cannot implicitly convert expression dFiles of
type Tuple!(string, string)[] to string[][]"
auto dFiles = dirEntries(FFs, SpanMode.shallow).filter!(a =>
a.isFile).map!(a => tuple(a.name,
a.timeCreated.toSimpleString[0 .. 20])).array;
You changed the type of dFiles, which you return from cleanFiles,
without changing the return type of cleanFiles. Change the return
type of cleanFiles to the type the compiler error above tells you
it should be (`Tuple!(string, string)[]` instead of
`string[][]`), or let the compiler infer it via auto (`auto
cleanFiles(...`).
Re: Using closure causes GC allocation
On Saturday, 2 September 2017 at 18:32:55 UTC, Moritz Maxeiner
wrote:
On Saturday, 2 September 2017 at 18:08:19 UTC, vino.b wrote:
On Saturday, 2 September 2017 at 18:02:06 UTC, Moritz Maxeiner
wrote:
On Saturday, 2 September 2017 at 17:43:08 UTC, Vino.B wrote:
[...]
Line 25 happens because of `[a.name]`. You request a new
array: the memory for this has to be allocated (the reason
why the compiler says "may" is because sometimes, e.g. if the
array literal itself contains only literals, the allocations
needn't happen at runtime and no GC call is necessary). Since
you don't actually use the array, get rid of it:
[...]
Hi,
Thank you for your help and the DMD version that i am using
is DMD 2.076.0 and yes I am on windows.
Please post a compilable, minimal example including how that
function gets called that yields you that compiler output.
Hi,
Please find the example code below,
import std.stdio: File,writeln;
import std.datetime.systime: Clock, days, SysTime;
import std.file: SpanMode, dirEntries, exists, isFile, mkdir,
remove;
import std.typecons: tuple;
import std.algorithm: filter, map, each;
import std.array: array;
void logClean (string[] Lglst, int LogAge) {
if (!Lglst[0].exists) { mkdir(Lglst[0]); }
auto ct1 = Clock.currTime();
auto st1 = ct1 + days(-LogAge);
auto dFiles = dirEntries(Lglst[0], SpanMode.shallow).filter!(a
=> a.exists && a.isFile && a.timeCreated < st1).map!(a =>
tuple(a.name)).array;
dFiles.each!(a => a[0].remove);
}
void main () {
string[] LogDir =
["C:\\Users\\bheev1\\Desktop\\Current\\Script\\D\\Logs"];
int LogAge = 1;
logClean(LogDir,LogAge);
}
Another similar issue :
I removed the [a.name] and the issue in line 25 has resolved,
but for another function i am getting the same error
string[][] cleanFiles(string FFs, string Step) {
auto dFiles = dirEntries(FFs, SpanMode.shallow).filter!(a =>
a.isFile).map!(a =>[a.name , a.timeCreated.toSimpleString[0 ..
20]]).array; -> Issue in this line
if (Step == "run")
dFiles.each!(a => a[0].remove);
return dFiles;
}
if the replace the line in error as below then i am getting the
error "Error: cannot implicitly convert expression dFiles of type
Tuple!(string, string)[] to string[][]"
auto dFiles = dirEntries(FFs, SpanMode.shallow).filter!(a =>
a.isFile).map!(a => tuple(a.name, a.timeCreated.toSimpleString[0
.. 20])).array;
Re: Using closure causes GC allocation
On Saturday, 2 September 2017 at 18:08:19 UTC, vino.b wrote: On Saturday, 2 September 2017 at 18:02:06 UTC, Moritz Maxeiner wrote: On Saturday, 2 September 2017 at 17:43:08 UTC, Vino.B wrote: [...] Line 25 happens because of `[a.name]`. You request a new array: the memory for this has to be allocated (the reason why the compiler says "may" is because sometimes, e.g. if the array literal itself contains only literals, the allocations needn't happen at runtime and no GC call is necessary). Since you don't actually use the array, get rid of it: [...] Hi, Thank you for your help and the DMD version that i am using is DMD 2.076.0 and yes I am on windows. Please post a compilable, minimal example including how that function gets called that yields you that compiler output.
Re: Using closure causes GC allocation
On Saturday, 2 September 2017 at 18:02:06 UTC, Moritz Maxeiner wrote: On Saturday, 2 September 2017 at 17:43:08 UTC, Vino.B wrote: [...] Line 25 happens because of `[a.name]`. You request a new array: the memory for this has to be allocated (the reason why the compiler says "may" is because sometimes, e.g. if the array literal itself contains only literals, the allocations needn't happen at runtime and no GC call is necessary). Since you don't actually use the array, get rid of it: [...] Hi, Thank you for your help and the DMD version that i am using is DMD 2.076.0 and yes I am on windows. From, Vino.B
Re: Using closure causes GC allocation
On Saturday, 2 September 2017 at 17:43:08 UTC, Vino.B wrote:
Hi All,
Request your help on how to solve the issue in the below
code as when i execute the program with -vgc it state as below:
NewTD.d(21): vgc: using closure causes GC allocation
NewTD.d(25): vgc: array literal may cause GC allocation
void logClean (string[] Lglst, int LogAge) { //Line 21
if (!Lglst[0].exists) { mkdir(Lglst[0]); }
auto ct1 = Clock.currTime();
auto st1 = ct1 + days(-LogAge);
auto dFiles = dirEntries(Lglst[0], SpanMode.shallow).filter!(a
=> a.exists && a.isFile && a.timeCreated < st1).map!(a
=>[a.name]).array; // Line 25
dFiles.each!(f => f[0].remove);
}
Line 25 happens because of `[a.name]`. You request a new array:
the memory for this has to be allocated (the reason why the
compiler says "may" is because sometimes, e.g. if the array
literal itself contains only literals, the allocations needn't
happen at runtime and no GC call is necessary). Since you don't
actually use the array, get rid of it:
---
void logClean (string[] Lglst, int LogAge) { //Line 21
if (!Lglst[0].exists) { mkdir(Lglst[0]); }
auto ct1 = Clock.currTime();
auto st1 = ct1 + days(-LogAge);
auto dFiles = dirEntries(Lglst[0], SpanMode.shallow).filter!(a
=> a.exists && a.isFile && a.timeCreated < st1).array; // Line 25
dFiles.each!(f => f.remove);
}
---
I cannot reproduce the line 21 report, though.
Since you use `timeCreated` I assume you're on Windows, but
what's your D compiler, which D frontend version are you using,
etc. (all the things needed to attempt to reproduce the error).
Using closure causes GC allocation
Hi All,
Request your help on how to solve the issue in the below code
as when i execute the program with -vgc it state as below:
NewTD.d(21): vgc: using closure causes GC allocation
NewTD.d(25): vgc: array literal may cause GC allocation
void logClean (string[] Lglst, int LogAge) { //Line 21
if (!Lglst[0].exists) { mkdir(Lglst[0]); }
auto ct1 = Clock.currTime();
auto st1 = ct1 + days(-LogAge);
auto dFiles = dirEntries(Lglst[0], SpanMode.shallow).filter!(a
=> a.exists && a.isFile && a.timeCreated < st1).map!(a
=>[a.name]).array; // Line 25
dFiles.each!(f => f[0].remove);
}
From,
Vino.B
