• Timo Gransch (43/43) Jan 01 2015 Hi,
• Daniel Kozak via Digitalmars-d-learn (6/67) Jan 01 2015 You shoud not use destructor for this operation. In D there is no
• thedeemon (7/13) Jan 01 2015 Destructors are usually called by GC, during a GC cycle, so
• Timo Gransch (5/6) Jan 01 2015 Thanks (also to Daniel Kozak) for the information. I moved the functiona...

Timo Gransch <timo.gransch web.de> writes:

Hi,

I have a class which unzips an archive into a temporary directory below the
system temp folder. I want to delete this temporary directory in the class's
destructor, but when I call rmdir there, I get an

core.exception.InvalidMemoryOperationError (0)

The effect is not limited to this special case. Whenever I call rmdir in the
destructor, no matter for which directory, I get the same error.

Environment: DMD v2.066.1 (from D-Apt) on Ubuntu 14.10 (32 and 64 bit).

Sample code:

// -------------------------------------------
module main;

import std.stdio;
import std.file;
import std.path;

class RmdirTest
{
	private string sTempDir;

	this(string sInstanceName)
	{
		writeln("Constructor called");
		sTempDir=tempDir() ~ dirSeparator ~ sInstanceName;
		mkdir (sTempDir);
	}

	~this()
	{
		writeln("Destructor called");

		if (sTempDir !is null)
		{
			rmdir(sTempDir);
		}
	}
}

void main(string[] args)
{
	RmdirTest rmDirTest=new RmdirTest("123");
}
// -------------------------------------------

Console output is:

Constructor called
Destructor called
core.exception.InvalidMemoryOperationError (0)

The directory "/tmp/123" is created, but not deleted.

When I change the line "(sTempDir !is null)" to "((sTempDir !is null) &&
(exists(sTempDir)) && (isDir(sTempDir)))", the exception is thrown already on
this line, so obviously  the problem also applies to other file functions like
exists and isDir.

Is there any solution for this?

Thanks and best regards,
Timo

Daniel Kozak via Digitalmars-d-learn <digitalmars-d-learn puremagic.com> writes:

Timo Gransch via Digitalmars-d-learn píše v Čt 01. 01. 2015 v 16:14
+0100:
 Hi,
 
 I have a class which unzips an archive into a temporary directory below the
system temp folder. I want to delete this temporary directory in the class's
destructor, but when I call rmdir there, I get an
 
 core.exception.InvalidMemoryOperationError (0)
 
 The effect is not limited to this special case. Whenever I call rmdir in the
destructor, no matter for which directory, I get the same error.
 
 Environment: DMD v2.066.1 (from D-Apt) on Ubuntu 14.10 (32 and 64 bit).
 
 Sample code:
 
 // -------------------------------------------
 module main;
 
 import std.stdio;
 import std.file;
 import std.path;
 
 class RmdirTest
 {
 	private string sTempDir;
 
 	this(string sInstanceName)
 	{
 		writeln("Constructor called");
 		sTempDir=tempDir() ~ dirSeparator ~ sInstanceName;
 		mkdir (sTempDir);
 	}
 
 	~this()
 	{
 		writeln("Destructor called");
 
 		if (sTempDir !is null)
 		{
 			rmdir(sTempDir);
 		}
 	}
 }
 
 void main(string[] args)
 {
 	RmdirTest rmDirTest=new RmdirTest("123");
 }
 // -------------------------------------------
 
 Console output is:
 
 Constructor called
 Destructor called
 core.exception.InvalidMemoryOperationError (0)
 
 The directory "/tmp/123" is created, but not deleted.
 
 When I change the line "(sTempDir !is null)" to "((sTempDir !is null) &&
(exists(sTempDir)) && (isDir(sTempDir)))", the exception is thrown already on
this line, so obviously  the problem also applies to other file functions like
exists and isDir.
 
 Is there any solution for this?
 
 Thanks and best regards,
 Timo

You shoud not use destructor for this operation. In D there is no
guarantee that class destructor will be called. So you can probablly use
struct instead of class or add some method and called it explicitly when
needed

"thedeemon" <dlang thedeemon.com> writes:

On Thursday, 1 January 2015 at 15:14:41 UTC, Timo Gransch wrote:
 Hi,

 I have a class which unzips an archive into a temporary 
 directory below the system temp folder. I want to delete this 
 temporary directory in the class's destructor, but when I call 
 rmdir there, I get an

 core.exception.InvalidMemoryOperationError (0)

Destructors are usually called by GC, during a GC cycle, so 
allocating and deallocating memory is not allowed there. If some 
function allocates, reallocates or deallocates, it will cause 
this very error. This means you shouldn't use any functions in a 
destructor that are not  nogc.

Solution in this case: call rmdir not from destructor.

Timo Gransch <timo.gransch web.de> writes:

Am Thu, 01 Jan 2015 16:07:06 +0000
schrieb "thedeemon" <dlang thedeemon.com>:

 Solution in this case: call rmdir not from destructor.

Thanks (also to Daniel Kozak) for the information. I moved the functionality to
an explicitly called method.

Best regards,
Timo