Lazarus

Programming => Operating Systems => Android => Topic started by: roeug on October 22, 2012, 12:55:00 pm

Title: CopyMemory, MoveMemory, ZeroMemory
Post by: roeug on October 22, 2012, 12:55:00 pm

How make CopyMemory, MoveMemory, ZeroMemory available in porting from Win?

Title: Re: CopyMemory, MoveMemory, ZeroMemory
Post by: Leledumbo on October 22, 2012, 01:18:29 pm

Use the respective Pascal (platform independent ones):

• CopyMemory -> Move(<source>,<dest>,<size>);
• MoveMemory -> doesn't really exist, do you really need to?
• ZeroMemory -> FillByte(<a variable>,<the variable size>,0);

Title: Re: CopyMemory, MoveMemory, ZeroMemory
Post by: Laksen on October 22, 2012, 03:20:17 pm

Quote from: Leledumbo on October 22, 2012, 01:18:29 pm

Use the respective Pascal (platform independent ones):

• CopyMemory -> Move(<source>,<dest>,<size>);
• MoveMemory -> doesn't really exist, do you really need to?
• ZeroMemory -> FillByte(<a variable>,<the variable size>,0);

It's the other way around. MoveMemory is the equivalent of the Pascal Move function. CopyMemory has no equivalent and is inherently unsafe, and should be replaced with Move

Title: Re: CopyMemory, MoveMemory, ZeroMemory
Post by: roeug on October 24, 2012, 08:25:32 am

Thanks (Could find myself -  was in hurry)

Another question: File routines?

In windows they were
CreateFile
GetFileSize
CreateFileMapping
MapViewOfFile
UnmapViewOfFile
CloseHandle( THandle from CreateFileMapping)
SetFilePointer
+AccessMode

Where can I find analogs in lazarus ?
 TMemoryStream - ok

Title: Re: CopyMemory, MoveMemory, ZeroMemory
Post by: Leledumbo on October 24, 2012, 02:14:11 pm

Quote

Another question: File routines?

Classic: http://www.freepascal.org/docs-html/rtl/system/filefunctions.html
Modern: http://www.freepascal.org/docs-html/rtl/sysutils/ioroutines.html
OOP: http://www.freepascal.org/docs-html/rtl/classes/tfilestream.html

Title: Re: CopyMemory, MoveMemory, ZeroMemory
Post by: Laksen on October 24, 2012, 03:25:34 pm

File mapping is very platform specific. On windows you have MapViewOfFile, while on a POSIX system you can use mmap.

I don't know if anyone has made a crossplatform unit for that, but it should be possible. Otherwise you can fall back on streams