Is GC.setAttr(p, GC.BlkAttr.NO_MOVE) guaranteed to work?
There is an example in GC.addRoot() documentation where the programmer is trying to mark a memory block as NO_MOVE: http://dlang.org/phobos/core_memory.html#.GC.addRoot auto context = new Object; GC.addRoot(cast(void*)context); GC.setAttr(cast(void*)context, GC.BlkAttr.NO_MOVE); If I understand it correctly, as soon as addRoot() succeeds, the block may have already been moved perhaps due to the needs of another thread. Will setAttr() still work if that happened? Perhaps the GC is supposed to track any previously used memory block reference like 'context' so that the call will succeed? (I doubt it.) If the example can indeed fail, will swapping the last two statements work as in the following code? auto context = new Object; GC.setAttr(cast(void*)context, GC.BlkAttr.NO_MOVE); GC.addRoot(cast(void*)context); How about the reverse operations: Can I still use 'ctx' to refer to potentially moved memory block in the following code? GC.removeRoot(ctx); GC.clrAttr(ctx, GC.BlkAttr.NO_MOVE); It seems to me that as a general rule, one cannot trust setting NO_MOVE on a GC-managed block at all. If that's true, addRoot() must have an overload that takes attributes as well and work atomically in that regard, right? Ali
Re: Is GC.setAttr(p, GC.BlkAttr.NO_MOVE) guaranteed to work?
On 02.07.2014 08:17, Ali Çehreli wrote: There is an example in GC.addRoot() documentation where the programmer is trying to mark a memory block as NO_MOVE: http://dlang.org/phobos/core_memory.html#.GC.addRoot auto context = new Object; GC.addRoot(cast(void*)context); GC.setAttr(cast(void*)context, GC.BlkAttr.NO_MOVE); If I understand it correctly, as soon as addRoot() succeeds, the block may have already been moved perhaps due to the needs of another thread. Yes, but the local variable context also has been changed to the new location by a moving GC (also any temporaries on the stack). Will setAttr() still work if that happened? Perhaps the GC is supposed to track any previously used memory block reference like 'context' so that the call will succeed? (I doubt it.) If the example can indeed fail, will swapping the last two statements work as in the following code? auto context = new Object; GC.setAttr(cast(void*)context, GC.BlkAttr.NO_MOVE); GC.addRoot(cast(void*)context); How about the reverse operations: Can I still use 'ctx' to refer to potentially moved memory block in the following code? GC.removeRoot(ctx); GC.clrAttr(ctx, GC.BlkAttr.NO_MOVE); It seems to me that as a general rule, one cannot trust setting NO_MOVE on a GC-managed block at all. If that's true, addRoot() must have an overload that takes attributes as well and work atomically in that regard, right? Ali addRoot tells the GC that there are external references into GC managed memory. These references are not visible to the GC, so it cannot modify them when moving the referenced memory. As a consequence, addRoot implies NO_MOVE. I think the example is flawed. The issue raised does show a rule to follow, though: do not store a GC pointer to external memory before calling addRoot() or setAttr(NO_MOVE), it might get moved after the assignment, but before being fixed. BTW: The current GC has no support for moving, and the NO_MOVE flag isn't even stored anywhere (getAttr after setAttr will not report it being set).
Integer max value
Is there a way to get the max size of an integer?
Re: Integer max value
On Wednesday, 2 July 2014 at 08:39:06 UTC, pgtkda wrote: Is there a way to get the max size of an integer? int.max The same exists for other built-ins and enums.
Re: Integer max value
On Wednesday, 2 July 2014 at 08:58:46 UTC, Rene Zwanenburg wrote: On Wednesday, 2 July 2014 at 08:39:06 UTC, pgtkda wrote: Is there a way to get the max size of an integer? int.max The same exists for other built-ins and enums. thank you very much
similar method as Math.Ceiling in c#
Is there a similar method as Math.Ceiling in D? http://msdn.microsoft.com/en-US/en-en/library/zx4t0t48(v=vs.110).aspx
Re: similar method as Math.Ceiling in c#
On Wednesday, 2 July 2014 at 13:36:17 UTC, pgtkda wrote: Is there a similar method as Math.Ceiling in D? http://msdn.microsoft.com/en-US/en-en/library/zx4t0t48(v=vs.110).aspx http://dlang.org/phobos/std_math.html#.ceil
overloading InExpression
Is this possible? The documentation for std.container lists in as an operator in the container API but only associative arrays actually seem to support it.
Re: overloading InExpression
struct S
{
int opIn_r(int key)
{
return key*2;
}
}
void main()
{
assert((42 in S.init) == 84);
}
Re: Can't modify this
On Saturday, 28 June 2014 at 20:40:21 UTC, Ary Borenszweig wrote:
This doesn't work:
class Foo {
this() {
this = new Foo;
}
}
Error: Cannot modify 'this'
However you can do this:
class Foo {
this() {
auto p = this;
*p = new Foo();
}
}
It even changes the value of this!
Should that compile? I mean, it's the same as modifying
'this'...
D language was not aimed toward preventing any attepmt to
circumvent some hypothetical limitations (it does not even cope
with things which it should definetely prevent). There are holes
much - much worse. And changing value of this parameter is not a
problem anyway, since it is possible to have typeid(this) !=
typeid of type of current method which is bigger problem than
pointing to different value of same type.
Re: overloading InExpression
On Wednesday, 2 July 2014 at 14:14:57 UTC, Dicebot wrote:
struct S
{
int opIn_r(int key)
{
return key*2;
}
}
void main()
{
assert((42 in S.init) == 84);
}
Thanks! I wonder, why the _r and lack of documentation?
Re: overloading InExpression
On 07/02/2014 07:35 AM, Vlad Levenfeld wrote:
On Wednesday, 2 July 2014 at 14:14:57 UTC, Dicebot wrote:
struct S
{
int opIn_r(int key)
{
return key*2;
}
}
void main()
{
assert((42 in S.init) == 84);
}
Thanks! I wonder, why the _r
I think it is the old syntax, meaning this is the overload for when an
S object is on the right-hand side.
and lack of documentation?
It appears in the binary operator table:
http://dlang.org/operatoroverloading.html#Binary
Also see the section 'Inclusion query by opBinaryRight!in' here:
http://ddili.org/ders/d.en/operator_overloading.html
Ali
Re: overloading InExpression
On Wednesday, 2 July 2014 at 15:36:23 UTC, Kozzi11 wrote: Thanks! I wonder, why the _r and lack of documentation? Maybe something from old days? But in current a href=http://dlang.org/operatoroverloading.html#Binary; target=_blankdoc/a there is a opBinary: Yep, I think it is D1 legacy approach. opBinary should be more appropriate.
Re: overloading InExpression
On Wednesday, 2 July 2014 at 14:35:55 UTC, Vlad Levenfeld wrote:
On Wednesday, 2 July 2014 at 14:14:57 UTC, Dicebot wrote:
struct S
{
int opIn_r(int key)
{
return key*2;
}
}
void main()
{
assert((42 in S.init) == 84);
}
Thanks! I wonder, why the _r and lack of documentation?
Maybe something from old days? But in current a
href=http://dlang.org/operatoroverloading.html#Binary;
target=_blankdoc/a there is a opBinary:
struct S
{
int opBinaryRight(string op : in)(int key)
{
return key*2;
}
}
void main()
{
assert((42 in S.init) == 84);
}
Re: overloading InExpression
Dicebot: Yep, I think it is D1 legacy approach. opBinary should be more appropriate. I hope the usage of the old operator overloading functions will generate deprecation messages soon. Bye, bearophile
Building D on windows
Hi, I was able to build dmd on my windows machine using VS2013 (using the vs2010 sln file). However, I am not sure how to proceed with building the druntime and phobos. Could someone please point me to instructions for the same? I tried the following 1. Downloaded make and shell (digital mars) 2. created a shell file script.sh that contains the following make -f posix.mak DMD=../dmd/src/vcbuild/Win32/Release/dmd_msc.exe\ 3. Executed the sh file shell script.sh I got the following error - C:\Users\labuser\dlang\druntimedir ..\dmd\src\vcbuild\Win32\Release\dmd_msc.exe C:\Users\labuser\dlang\druntimeshell script.sh shell 1.01 make -f posix.mak DMD=../dmd/src/vcbuild/Win32/Release/dmd_msc.exe Error on line 10: '=' is not a valid filename char --- errorlevel 1 Regards, Kashyap
Re: Building D on windows
On Wednesday, 2 July 2014 at 16:06:08 UTC, Kashyap wrote: I got the following error - C:\Users\labuser\dlang\druntimedir ..\dmd\src\vcbuild\Win32\Release\dmd_msc.exe C:\Users\labuser\dlang\druntimeshell script.sh shell 1.01 make -f posix.mak DMD=../dmd/src/vcbuild/Win32/Release/dmd_msc.exe Error on line 10: '=' is not a valid filename char --- errorlevel 1 Hi, It looks like you are trying to use the posix makefile with Digital Mars make. posix.mak uses GNU make syntax - the makefile for DigitalMars make is win32.mak. So you will need to either make sure GNU make comes first in your PATH, or simply use win32.mak instead. There is a wiki page with instructions for building D from source: http://wiki.dlang.org/Building_DMD
Re: Why is the Win32 boilerplate the way it is?
On Sunday, 29 June 2014 at 15:06:25 UTC, Jeremy Sorensen wrote: The only question I have is what happens when you use SUBSYSTEM:WINDOWS:4.0 (Which I understand means XP or higher) and the program runs on something older? Windows XP is version 5.1. 4.0 was Windows NT 4 (which I believe was the NT-family Windows version preceding Windows 2000).
Re: overloading InExpression
On Wed, Jul 02, 2014 at 02:35:54PM +, Vlad Levenfeld via
Digitalmars-d-learn wrote:
On Wednesday, 2 July 2014 at 14:14:57 UTC, Dicebot wrote:
struct S
{
int opIn_r(int key)
{
return key*2;
}
}
void main()
{
assert((42 in S.init) == 84);
}
Thanks! I wonder, why the _r and lack of documentation?
Don't use opIn_r, that's a relic from D1. Instead, use this:
struct S {
int opBinaryRight(string op)(int key)
if (op == in)
{
return key*2;
}
}
T
--
I think Debian's doing something wrong, `apt-get install pesticide', doesn't
seem to remove the bugs on my system! -- Mike Dresser
Re: overloading InExpression
Ah yes I never noticed that in was in the binary op table. In my defense, searching for in usually yields too many results to be useful. Thanks to everyone for your help!
CTFE bug or enhancement?
Everything compiles fine except for function qux2: http://dpaste.dzfl.pl/9d9187e0b450 Is this a bug or an enhancement for CTFE? It would be really nice to have this feature because core.simd has functions such as: void16 __simd(XMM opcode, void16 op1, void16 op2, ubyte imm8); Where all the arguments must be compile time constants. It would be nice to be able to push some parameters out from the type list and into the argument list in user code too.
Re: CTFE bug or enhancement?
Actually, this is an enhancement because adding: enum b = blah Makes them fail. :(
Re: CTFE bug or enhancement?
On Thursday, 3 July 2014 at 01:55:14 UTC, safety0ff wrote: Actually, this is an enhancement because adding: enum b = blah Makes them fail. :( The question is now: how can the delegate be evaluated for the return value but not for the enum?
Re: CTFE bug or enhancement?
On Thursday, 3 July 2014 at 02:02:19 UTC, safety0ff wrote: On Thursday, 3 July 2014 at 01:55:14 UTC, safety0ff wrote: Actually, this is an enhancement because adding: enum b = blah Makes them fail. :( The question is now: how can the delegate be evaluated for the return value but not for the enum? Looks like an ICE: https://github.com/D-Programming-Language/dmd/blob/master/src/interpret.c#L5169
spawn and wait
Hi,
I want to spawn several similar tasks and then wait for all of
them to complete to go on do some other things, like:
```d
void task(int id)
{
// do the stuff
}
void main()
{
foreach (i; 0..10) {
spawn(task, i);
}
wait(?); // wait for all task to complete
doSomeOtherThings();
}
```
But I don't see a `wait` method for Tid, similar to Pid in
std.process.
What is the idiomatic way to do these things?
My current workaround is using messages:
```d
#!/usr/bin/rdmd
import std.stdio;
import std.concurrency;
void child(int id)
{
writeln(Starting child: , id);
ownerTid.send(id);
}
void main()
{
foreach (i; 0..10)
{
spawn(child, i);
}
for (int n = 0; n 10; ++n) {
receive((int i) {
writeln(Received:, i);
});
}
}
```
But it is verbose and seems error prone.
DUB help plz
I've been trying to figure DUB out and have been having a bit of
trouble. I'm trying to make a simple program that uses Derelict
GL3 and SDL2. I keep getting this error though:
derelict.util.exception.SharedLibLoadException@C:\Users\Kyoji\AppData\Roaming\dub\packages\derelict-util-1.0.1\source\derelict\util\exception.d(35):
Failed to load one or more shared libraries:
SDL2.dll - The specified module could not be found.
I'm not sure how to get that .dll, I tried doing 'dub upgrade'
but that didn't do much.
Here's what some of my files look like:
app.d :
import std.stdio;
import derelict.opengl3.gl3;
import derelict.sdl2.sdl;
void main()
{
writeln(Edit source/app.d to start your project.);
DerelictGL3.load();
DerelictSDL2.load();
DerelictGL3.reload();
}
---
dub.json :
---
{
name: testbuild,
description: A minimal D application.,
copyright: Copyright © 2014, Kyoji,
authors: [Kyoji],
importPaths: [lib/],
dependencies: {
derelict-gl3: =1.0.2,
derelict-sdl2: =1.2.1,
}
}
--
I setup a lib folder from the project root, and I have the source
files for the packages under 'import'.
Is the only thing I'm missing the .dll's?
Thanks!
Re: spawn and wait
On 07/02/2014 08:29 PM, Puming wrote:
I want to spawn several similar tasks and then wait for all of them to
complete to go on do some other things
If you don't care about account for each of them individually,
core.thread.thread_joinAll would work. The following program starts two
waves of threads and waits for both of the waves to complete:
import std.stdio;
import std.concurrency;
import core.thread;
void foo(Duration duration)
{
writefln(Working for %s, duration);
Thread.sleep(duration);
}
void spawnThreads(size_t count)
{
foreach (i; 0 .. count) {
spawn(foo, (i + 1).seconds);
}
writefln(Started %s workers, count);
}
void main()
{
spawnThreads(2);
writefln(Waiting for all to finish);
thread_joinAll();
spawnThreads(3);
writefln(Waiting for all to finish);
thread_joinAll();
}
Ali
