[Mono-dev] Cross Platform on Linux/Windows with Mono.Posix reference on Linux

[Greg Young]

"I thought Greg's reply would be useful to tell MonoDevelop on Linux
not to even reference the nuget package, but I didn't get that
working."

Mine was for VS / msbuild / xbuild. I don't know about MonoDevelop.

On Wed, Apr 6, 2016 at 9:01 PM, Jason Curl <jcurlnews at arcor.de> wrote:
> Thanks all for your ideas.
>
> My project (github.com/jcurl/serialportstream) ended up including Mono.Posix
> via nuget to allow it to compile on Windows. I found an option that doesn't
> copy the assembly to the target path. I thought Greg's reply would be useful
> to tell MonoDevelop on Linux not to even reference the nuget package, but I
> didn't get that working. The IDE would still parse the entries and download
> from NuGet. So i assume when I compile on Linux, it's linking against the
> nuget version and not the OS version, but when running, it must be using the
> OS version and the library isn't copied to the destination.
>
> I had already implemented a factory OO model, which I use to instantiate
> either WinNativeSerial or UnixNativeSerial on knowing the environment
> platform ID that's in use.
>
> If "the JIT compiler can or will or might in the future, eagerly link
> assemblies at runtime" were sometime to become true, then I've got a problem
> - I certainly don't want to distribute Mono.Posix.
>
> Could I expect problems when compiling against a different version (nuget)
> that is being used at run-time (os)?
>
> Thankyou!
>
>
> On 29/03/2016 17:58, Chris Swiedler wrote:
>>
>> Why not just include references to Mono.Posix.dll in the Windows build?
>> You don't have to install the full framework. We have a similar issue with
>> server apps that are developed on Windows and run on Linux. We just put a
>> win32 build of Mono into our source tree and added Mono.Posix as a
>> reference. Everywhere we invoke any Posix code, we just wrap the statements
>> in something like "if  (Environment.OSVersion.Platform == PlatformID.Unix)".
>>
>> chris
>>
>> -----Original Message-----
>> From: mono-devel-list-bounces at lists.ximian.com
>> [mailto:mono-devel-list-bounces at lists.ximian.com] On Behalf Of Edward Ned
>> Harvey (mono)
>> Sent: Tuesday, March 29, 2016 5:49 AM
>> To: Greg Young <gregoryyoung1 at gmail.com>; Jason Curl <jcurlnews at arcor.de>
>> Cc: mono-devel-list at lists.ximian.com
>> Subject: Re: [Mono-dev] Cross Platform on Linux/Windows with Mono.Posix
>> reference on Linux
>>
>>> From: mono-devel-list-bounces at lists.ximian.com
>>> [mailto:mono-devel-list- bounces at lists.ximian.com] On Behalf Of Greg
>>> Young
>>>
>>> <Reference Include="Mono.Posix" Condition=" '$(OS)' != 'Windows_NT' "
>>> />
>>
>> (for clarification of my previous response, because I was asked for
>> clarification off-list)
>>
>> If you have some code that calls Mono.Posix.Something(), and you have a
>> conditional reference to Mono.Posix in the project, then you're able to
>> build on Mono, but on windows, without the reference, your call to
>> Mono.Posix.Something() will not compile, which prevents you from building,
>> even though at runtime you might never make that call. In order to compile
>> on windows, you'll need to comment-out your Mono.Posix.Something() line, via
>> #if or [Conditional], which means you need a compiler symbol to indicate
>> whether you're building on mono or windows. This could be either separate
>> project files, or multiple build configurations. (Or dynamically generated
>> project files).
>>
>> Maybe you can have a conditional reference to Mono.Posix on mono, and have
>> a separate conditional reference to ../../ExtraClassLibraries/Mono.Posix.dll
>> on windows, with copy-to-destination, so you can get the same code to build
>> on both mono and windows, resulting in an effectively identical
>> cross-platform binary... But I'm almost certain I recall somebody on this
>> list telling me, that the JIT compiler can or will or might in the future,
>> eagerly link assemblies at runtime (or just before runtime), so the
>> Mono.Posix.dll file must be present on windows at runtime in order to avoid
>> runtime exceptions, even though the runtime code execution will never
>> execute that path.
>>
>> You avoid all these problems by abstracting the functionality you want
>> into an interface or abstract class, and using a factory to perform a
>> runtime dynamic load of a mono-specific or windows-specific assembly with a
>> derivative class. You can build the mono-specific assembly on mono, or maybe
>> you can use the double-conditional described above and get the mono-specific
>> assembly to also be buildable on windows. No need to copy Mono.Posix.dll to
>> the destination, because Mono.Posix will only be called at runtime when run
>> on mono.
>> _______________________________________________
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>> Mono-devel-list at lists.ximian.com
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>>
>



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