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digitalmars.D.learn - How to retrieve total amount of system RAM?

reply Benji Smith <dlanguage benjismith.net> writes:
I've been looking through Tango documentation for a function that'll 
tell me the total amount of RAM installed on the system, bu I can't find 
anything that looks helpful. Anyone have any suggestions?

Thanks!

--benji
Aug 13 2008
parent reply "Steven Schveighoffer" <schveiguy yahoo.com> writes:
"Benji Smith" wrote

 I've been looking through Tango documentation for a function that'll tell 
 me the total amount of RAM installed on the system, bu I can't find 
 anything that looks helpful. Anyone have any suggestions?

 Thanks!



This is something that is highly OS-dependant (and even different versions 
of the same OS do it differently).  It's not something that Tango is likely 
to provide an abstract interface for.

-Steve
Aug 13 2008
next sibling parent Benji Smith <dlanguage benjismith.net> writes:
Steven Schveighoffer wrote:

 "Benji Smith" wrote

 I've been looking through Tango documentation for a function that'll tell 
 me the total amount of RAM installed on the system, bu I can't find 
 anything that looks helpful. Anyone have any suggestions?

 Thanks!



 This is something that is highly OS-dependant (and even different versions 
 of the same OS do it differently).  It's not something that Tango is likely 
 to provide an abstract interface for.
 
 -Steve 



Okay. I suppose I'll have to find the win32 & linux functions and write 
the wrappers myself.

Thanks!

--benji
Aug 13 2008
prev sibling parent reply "Denis Koroskin" <2korden gmail.com> writes:
On Wed, 13 Aug 2008 22:39:36 +0400, Steven Schveighoffer  
<schveiguy yahoo.com> wrote:


 "Benji Smith" wrote

 I've been looking through Tango documentation for a function that'll  
 tell
 me the total amount of RAM installed on the system, bu I can't find
 anything that looks helpful. Anyone have any suggestions?

 Thanks!



 This is something that is highly OS-dependant (and even different  
 versions
 of the same OS do it differently).  It's not something that Tango is  
 likely
 to provide an abstract interface for.

 -Steve



The same goes for IO (console I/O, file I/O, socket etc). Despite that it  
is present in Tango.

I see a huge benefit of having (at least basic) OS statistics (like OS  
name, version, type, device presence and capabilities - RAM, CPU, etc) in  
the standard library. Isn't is supposed to eliminate custom  
platform-specific code?
Aug 13 2008
parent reply "Steven Schveighoffer" <schveiguy yahoo.com> writes:
"Denis Koroskin" wrote

 On Wed, 13 Aug 2008 22:39:36 +0400, Steven Schveighoffer

 "Benji Smith" wrote

 I've been looking through Tango documentation for a function that'll 
 tell
 me the total amount of RAM installed on the system, bu I can't find
 anything that looks helpful. Anyone have any suggestions?

 Thanks!



 This is something that is highly OS-dependant (and even different 
 versions
 of the same OS do it differently).  It's not something that Tango is 
 likely
 to provide an abstract interface for.

 -Steve



 The same goes for IO (console I/O, file I/O, socket etc). Despite that it 
 is present in Tango.

 I see a huge benefit of having (at least basic) OS statistics (like OS 
 name, version, type, device presence and capabilities - RAM, CPU, etc) in 
 the standard library. Isn't is supposed to eliminate custom 
 platform-specific code?



Getting system memory isn't part of any standard that I know of (at least on 
the posix side), and there's not a large demand for it.  The API for getting 
memory is decided on by OS implementors.  What you would end up with is a 
list of versions for not only different OSes, but different versions of the 
OS.  It's along the same lines as getting/setting network interface 
addresses.

From experience (I have written a program to get system memory size), it is 
not trivial.  And not always accurate.

This is not to say that it couldn't be added.  If you come up with something 
that looks reasonable, Tango might accept it.

-Steve
Aug 13 2008
parent reply Benji Smith <dlanguage benjismith.net> writes:
Steven Schveighoffer wrote:

 Getting system memory isn't part of any standard that I know of (at least on 
 the posix side), and there's not a large demand for it.  The API for getting 
 memory is decided on by OS implementors.  What you would end up with is a 
 list of versions for not only different OSes, but different versions of the 
 OS.  It's along the same lines as getting/setting network interface 
 addresses.
 
 From experience (I have written a program to get system memory size), it is 
 not trivial.  And not always accurate.
 
 This is not to say that it couldn't be added.  If you come up with something 
 that looks reasonable, Tango might accept it.
 
 -Steve 




In win32, it looks like the GlobalMemoryStatus (for all non-NT versions) 
and GlobalMemoryStatusEx (for all NT-based versions), from kernel32.dll, 
would do the trick.

http://msdn.microsoft.com/en-us/library/aa366586.aspx
http://msdn.microsoft.com/en-us/library/aa366589(VS.85).aspx

In linux, a bare-minimum solution would be to read from /proc/meminfo, 
even if there's no POSIX function.

Of course, I'm talking out of my ass here, because my experience with 
C/C++ programming is very thin. I don't know, for example, how you'd 
check for the existence of the GlobalMemoryStatusEx function and fall 
back to GlobalMemoryStatus when it doesn't exist.

It seems doable, though my own systems programming experience is 
probably too lacking for me to make it happen myself.

--benji
Aug 13 2008
parent reply Wyverex <wyverex.cypher gmail.com> writes:
Benji Smith wrote:

 Steven Schveighoffer wrote:

 Getting system memory isn't part of any standard that I know of (at 
 least on the posix side), and there's not a large demand for it.  The 
 API for getting memory is decided on by OS implementors.  What you 
 would end up with is a list of versions for not only different OSes, 
 but different versions of the OS.  It's along the same lines as 
 getting/setting network interface addresses.

 From experience (I have written a program to get system memory size), 
 it is not trivial.  And not always accurate.

 This is not to say that it couldn't be added.  If you come up with 
 something that looks reasonable, Tango might accept it.

 -Steve 



 
 In win32, it looks like the GlobalMemoryStatus (for all non-NT versions) 
 and GlobalMemoryStatusEx (for all NT-based versions), from kernel32.dll, 
 would do the trick.
 
 http://msdn.microsoft.com/en-us/library/aa366586.aspx
 http://msdn.microsoft.com/en-us/library/aa366589(VS.85).aspx
 
 In linux, a bare-minimum solution would be to read from /proc/meminfo, 
 even if there's no POSIX function.
 
 Of course, I'm talking out of my ass here, because my experience with 
 C/C++ programming is very thin. I don't know, for example, how you'd 
 check for the existence of the GlobalMemoryStatusEx function and fall 
 back to GlobalMemoryStatus when it doesn't exist.
 
 It seems doable, though my own systems programming experience is 
 probably too lacking for me to make it happen myself.
 
 --benji



Id default to NT version since its Win 2000+,
Then force version flag for non-NT,  or dont support 95, 98, ME

version(WIN_NO_NT)
   alias GlobalMemoryStatus GlobalMemoryStat;
else
   alias GlobalMemoryStatusEx GlobalMemoryStat;
Aug 13 2008
parent reply Benji Smith <dlanguage benjismith.net> writes:
Wyverex wrote:

 Id default to NT version since its Win 2000+,
 Then force version flag for non-NT,  or dont support 95, 98, ME
 
 version(WIN_NO_NT)
   alias GlobalMemoryStatus GlobalMemoryStat;
 else
   alias GlobalMemoryStatusEx GlobalMemoryStat;



For this project, I'm trying to support all versions of windows, even 
those old beasties 95, 98, and ME.

(The project is a library for reporting anonymous statistics about user 
behavior. Failing to support the older operating systems would create a 
bias in the reporting that I'd rather avoid.)

And, if at all possible, I'd rather just compile a single binary, even 
if it means jumping through some weird hoops in writing my code. Is 
there any feasible solution?

--benji
Aug 13 2008
next sibling parent reply Wyverex <wyverex.cypher gmail.com> writes:
Benji Smith wrote:

 Wyverex wrote:

 Id default to NT version since its Win 2000+,
 Then force version flag for non-NT,  or dont support 95, 98, ME

 version(WIN_NO_NT)
   alias GlobalMemoryStatus GlobalMemoryStat;
 else
   alias GlobalMemoryStatusEx GlobalMemoryStat;



 For this project, I'm trying to support all versions of windows, even 
 those old beasties 95, 98, and ME.
 
 (The project is a library for reporting anonymous statistics about user 
 behavior. Failing to support the older operating systems would create a 
 bias in the reporting that I'd rather avoid.)
 
 And, if at all possible, I'd rather just compile a single binary, even 
 if it means jumping through some weird hoops in writing my code. Is 
 there any feasible solution?
 
 --benji



Looks like you'd have to try to get the function address from the DLL..

http://msdn.microsoft.com/en-us/library/ms724832(VS.85).aspx
Aug 13 2008
parent reply Benji Smith <dlanguage benjismith.net> writes:
Wyverex wrote:

 Looks like you'd have to try to get the function address from the DLL..
 
 http://msdn.microsoft.com/en-us/library/ms724832(VS.85).aspx



Cool. Is there a D library that already provides basic DLL 
functionality, (wrapping the LoadLibrary and GetProcAddress functions)?

Thanks again,

--benji
Aug 13 2008
next sibling parent reply Wyverex <wyverex.cypher gmail.com> writes:
Benji Smith wrote:

 Wyverex wrote:

 Looks like you'd have to try to get the function address from the DLL..

 http://msdn.microsoft.com/en-us/library/ms724832(VS.85).aspx



 Cool. Is there a D library that already provides basic DLL 
 functionality, (wrapping the LoadLibrary and GetProcAddress functions)?
 
 Thanks again,
 
 --benji





//tango
tango.sys.win32.UserGdi

//winapi bindings
win32.core

//Phobos
std.c.windows.windows
Aug 13 2008
parent Benji Smith <dlanguage benjismith.net> writes:
Wyverex wrote:

 //tango
 tango.sys.win32.UserGdi
 
 //winapi bindings
 win32.core
 
 //Phobos
 std.c.windows.windows



Very nice! Lots of useful stuff in there!

--benji
Aug 13 2008
prev sibling parent Lars Ivar Igesund <larsivar igesund.net> writes:
Benji Smith wrote:


 Wyverex wrote:

 Looks like you'd have to try to get the function address from the DLL..
 
 http://msdn.microsoft.com/en-us/library/ms724832(VS.85).aspx



 Cool. Is there a D library that already provides basic DLL
 functionality, (wrapping the LoadLibrary and GetProcAddress functions)?



tango.sys.SharedLib

-- 
Lars Ivar Igesund
blog at http://larsivi.net
DSource, #d.tango & #D: larsivi
Dancing the Tango
Aug 14 2008
prev sibling parent reply "Steven Schveighoffer" <schveiguy yahoo.com> writes:
"Benji Smith" wrote

 Wyverex wrote:

 Id default to NT version since its Win 2000+,
 Then force version flag for non-NT,  or dont support 95, 98, ME

 version(WIN_NO_NT)
   alias GlobalMemoryStatus GlobalMemoryStat;
 else
   alias GlobalMemoryStatusEx GlobalMemoryStat;



 For this project, I'm trying to support all versions of windows, even 
 those old beasties 95, 98, and ME.

 (The project is a library for reporting anonymous statistics about user 
 behavior. Failing to support the older operating systems would create a 
 bias in the reporting that I'd rather avoid.)

 And, if at all possible, I'd rather just compile a single binary, even if 
 it means jumping through some weird hoops in writing my code. Is there any 
 feasible solution?



Usually, the non-EX versions of MS functions work fine on the newer 
platforms, they are just not preferred.

Unless, of course, there is some resolution issue :)

In that case, you can call the GetVersion function. 
http://msdn.microsoft.com/en-us/library/ms724439.aspx

-Steve
Aug 13 2008
parent Benji Smith <dlanguage benjismith.net> writes:
Steven Schveighoffer wrote:

 Usually, the non-EX versions of MS functions work fine on the newer 
 platforms, they are just not preferred.
 
 Unless, of course, there is some resolution issue :)
 
 In that case, you can call the GetVersion function. 
 http://msdn.microsoft.com/en-us/library/ms724439.aspx
 
 -Steve 



Well, there's this litle tidbit:

"On computers with more than 4 GB of memory, the MEMORYSTATUS structure 
can return incorrect information, reporting a value of –1 to indicate an 
overflow. If your application is at risk for this behavior, use the 
GlobalMemoryStatusEx function instead of the GlobalMemoryStatus function."

http://msdn.microsoft.com/en-us/library/aa366772(VS.85).aspx

--benji
Aug 13 2008