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digitalmars.D.learn - Malloc in D

reply "Marcin" <m_zap o2.pl> writes:
Hi!
I find code:
[code]
import c.stdlib;
import c.stdlib;
import std.outofmemory;

class Foo{
	static void[] buffer;
	static int bufindex;
	static const int bufsize = 100;
	static this(){
		void *p;
		p = malloc(bufsize);
		if (!p)
		throw new OutOfMemory;
		gc.addRange(p, p + bufsize);
		buffer = p[0 .. bufsize];
	}
	static ~this(){
		if (buffer.length){
			gc.removeRange(buffer);
			free(buffer);
			buffer = null;
		}
	}
	new(uint sz){
		void *p;
		p = &buffer[bufindex];
		bufindex += sz;
		if (bufindex > buffer.length)
		throw new OutOfMemory;
		return p;
	}
	delete(void* p){
		assert(0);
	}
	static int mark(){
		return bufindex;
	}

	static void release(int i){
		bufindex = i;
	}
}
void test(){
	int m = Foo.mark();
	Foo f1 = new Foo; // allocate
	Foo f2 = new Foo; // allocate
	Foo.release(m); // deallocate f1 and f2
}
[/code]
When I try compile i have some error:[code]
vander vander-VirtualBox:~/Pulpit/D$ gdc Memory.d -o Memory
Memory.d:1: Error: module stdlib is in file 'c/stdlib.d' which 
cannot be read
import path[0] = 
/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.4.5/../../../../../include/d/4.4.5/i686-linux-gnu
import path[1] = 
/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.4.5/../../../../../include/d/4.4.5
vander vander-VirtualBox:~/Pulpit/D$[/code]
When i comment import c.stdlib;
I have error
[code]
vander vander-VirtualBox:~/Pulpit/D$ gdc Memory.d -o Memory
Memory.d:11: Error: undefined identifier malloc
Memory.d:11: Error: function expected before (), not __error of 
type _error_
Memory.d:13: Error: identifier 'OutOfMemory' is not defined
Memory.d:13: Error: OutOfMemory is used as a type
Memory.d:13: Error: new can only create structs, dynamic arrays 
or class objects, not void's
Memory.d:13: Error: can only throw class objects, not type void*
Memory.d:14: Error: undefined identifier gc, did you mean static 
import gcc?
Error: no property 'addRange' for type 'TOK149'
Memory.d:14: Error: function expected before (), not __error of 
type TOK149
Memory.d:19: Error: undefined identifier gc, did you mean static 
import gcc?
Error: no property 'removeRange' for type 'TOK149'
Memory.d:19: Error: function expected before (), not __error of 
type TOK149
Memory.d:20: Error: undefined identifier free, did you mean 
function fread?
Memory.d:20: Error: function expected before (), not __error of 
type _error_
Memory.d:29: Error: identifier 'OutOfMemory' is not defined
Memory.d:29: Error: OutOfMemory is used as a type
Memory.d:29: Error: new can only create structs, dynamic arrays 
or class objects, not void's
Memory.d:29: Error: can only throw class objects, not type void*
vander vander-VirtualBox:~/Pulpit/D$
[/code]
What's can be wrong?
Apr 27 2012
parent reply "Dejan Lekic" <dejan.lekic gmail.com> writes:
On Friday, 27 April 2012 at 09:05:12 UTC, Marcin wrote:

 Hi!
 I find code:
 [code]
 import c.stdlib;
 import c.stdlib;
 import std.outofmemory;

 class Foo{
 	static void[] buffer;
 	static int bufindex;
 	static const int bufsize = 100;
 	static this(){
 		void *p;
 		p = malloc(bufsize);
 		if (!p)
 		throw new OutOfMemory;
 		gc.addRange(p, p + bufsize);
 		buffer = p[0 .. bufsize];
 	}
 	static ~this(){
 		if (buffer.length){
 			gc.removeRange(buffer);
 			free(buffer);
 			buffer = null;
 		}
 	}
 	new(uint sz){
 		void *p;
 		p = &buffer[bufindex];
 		bufindex += sz;
 		if (bufindex > buffer.length)
 		throw new OutOfMemory;
 		return p;
 	}
 	delete(void* p){
 		assert(0);
 	}
 	static int mark(){
 		return bufindex;
 	}

 	static void release(int i){
 		bufindex = i;
 	}
 }
 void test(){
 	int m = Foo.mark();
 	Foo f1 = new Foo; // allocate
 	Foo f2 = new Foo; // allocate
 	Foo.release(m); // deallocate f1 and f2
 }
 [/code]
 When I try compile i have some error:[code]
 vander vander-VirtualBox:~/Pulpit/D$ gdc Memory.d -o Memory
 Memory.d:1: Error: module stdlib is in file 'c/stdlib.d' which 
 cannot be read
 import path[0] = 
 /usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.4.5/../../../../../include/d/4.4.5/i686-linux-gnu
 import path[1] = 
 /usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.4.5/../../../../../include/d/4.4.5
 vander vander-VirtualBox:~/Pulpit/D$[/code]
 When i comment import c.stdlib;
 I have error
 [code]
 vander vander-VirtualBox:~/Pulpit/D$ gdc Memory.d -o Memory
 Memory.d:11: Error: undefined identifier malloc
 Memory.d:11: Error: function expected before (), not __error of 
 type _error_
 Memory.d:13: Error: identifier 'OutOfMemory' is not defined
 Memory.d:13: Error: OutOfMemory is used as a type
 Memory.d:13: Error: new can only create structs, dynamic arrays 
 or class objects, not void's
 Memory.d:13: Error: can only throw class objects, not type void*
 Memory.d:14: Error: undefined identifier gc, did you mean 
 static import gcc?
 Error: no property 'addRange' for type 'TOK149'
 Memory.d:14: Error: function expected before (), not __error of 
 type TOK149
 Memory.d:19: Error: undefined identifier gc, did you mean 
 static import gcc?
 Error: no property 'removeRange' for type 'TOK149'
 Memory.d:19: Error: function expected before (), not __error of 
 type TOK149
 Memory.d:20: Error: undefined identifier free, did you mean 
 function fread?
 Memory.d:20: Error: function expected before (), not __error of 
 type _error_
 Memory.d:29: Error: identifier 'OutOfMemory' is not defined
 Memory.d:29: Error: OutOfMemory is used as a type
 Memory.d:29: Error: new can only create structs, dynamic arrays 
 or class objects, not void's
 Memory.d:29: Error: can only throw class objects, not type void*
 vander vander-VirtualBox:~/Pulpit/D$
 [/code]
 What's can be wrong?


You probably have a very old GDC...

1) GC is a Struct inside core.memory so you need a line:

   GC gc;

2) You need to throw OutOfMemoryError which is defined in 
core.exception.

3) You need const(void*) pointers for GC methods.

So I first recommend you install latest GDC, and then modify your 
code to be more up-to-date.

I hope this helps.

Regards :)
Apr 27 2012
parent "Marcin" <m_zap o2.pl> writes:
Thanks for you help:)

On Friday, 27 April 2012 at 09:20:04 UTC, Dejan Lekic wrote:

 On Friday, 27 April 2012 at 09:05:12 UTC, Marcin wrote:

 Hi!
 I find code:
 [code]
 import c.stdlib;
 import c.stdlib;
 import std.outofmemory;

 class Foo{
 	static void[] buffer;
 	static int bufindex;
 	static const int bufsize = 100;
 	static this(){
 		void *p;
 		p = malloc(bufsize);
 		if (!p)
 		throw new OutOfMemory;
 		gc.addRange(p, p + bufsize);
 		buffer = p[0 .. bufsize];
 	}
 	static ~this(){
 		if (buffer.length){
 			gc.removeRange(buffer);
 			free(buffer);
 			buffer = null;
 		}
 	}
 	new(uint sz){
 		void *p;
 		p = &buffer[bufindex];
 		bufindex += sz;
 		if (bufindex > buffer.length)
 		throw new OutOfMemory;
 		return p;
 	}
 	delete(void* p){
 		assert(0);
 	}
 	static int mark(){
 		return bufindex;
 	}

 	static void release(int i){
 		bufindex = i;
 	}
 }
 void test(){
 	int m = Foo.mark();
 	Foo f1 = new Foo; // allocate
 	Foo f2 = new Foo; // allocate
 	Foo.release(m); // deallocate f1 and f2
 }
 [/code]
 When I try compile i have some error:[code]
 vander vander-VirtualBox:~/Pulpit/D$ gdc Memory.d -o Memory
 Memory.d:1: Error: module stdlib is in file 'c/stdlib.d' which 
 cannot be read
 import path[0] = 
 /usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.4.5/../../../../../include/d/4.4.5/i686-linux-gnu
 import path[1] = 
 /usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.4.5/../../../../../include/d/4.4.5
 vander vander-VirtualBox:~/Pulpit/D$[/code]
 When i comment import c.stdlib;
 I have error
 [code]
 vander vander-VirtualBox:~/Pulpit/D$ gdc Memory.d -o Memory
 Memory.d:11: Error: undefined identifier malloc
 Memory.d:11: Error: function expected before (), not __error 
 of type _error_
 Memory.d:13: Error: identifier 'OutOfMemory' is not defined
 Memory.d:13: Error: OutOfMemory is used as a type
 Memory.d:13: Error: new can only create structs, dynamic 
 arrays or class objects, not void's
 Memory.d:13: Error: can only throw class objects, not type 
 void*
 Memory.d:14: Error: undefined identifier gc, did you mean 
 static import gcc?
 Error: no property 'addRange' for type 'TOK149'
 Memory.d:14: Error: function expected before (), not __error 
 of type TOK149
 Memory.d:19: Error: undefined identifier gc, did you mean 
 static import gcc?
 Error: no property 'removeRange' for type 'TOK149'
 Memory.d:19: Error: function expected before (), not __error 
 of type TOK149
 Memory.d:20: Error: undefined identifier free, did you mean 
 function fread?
 Memory.d:20: Error: function expected before (), not __error 
 of type _error_
 Memory.d:29: Error: identifier 'OutOfMemory' is not defined
 Memory.d:29: Error: OutOfMemory is used as a type
 Memory.d:29: Error: new can only create structs, dynamic 
 arrays or class objects, not void's
 Memory.d:29: Error: can only throw class objects, not type 
 void*
 vander vander-VirtualBox:~/Pulpit/D$
 [/code]
 What's can be wrong?


 You probably have a very old GDC...

 1) GC is a Struct inside core.memory so you need a line:

   GC gc;

 2) You need to throw OutOfMemoryError which is defined in 
 core.exception.

 3) You need const(void*) pointers for GC methods.

 So I first recommend you install latest GDC, and then modify 
 your code to be more up-to-date.

 I hope this helps.

 Regards :)
Apr 27 2012