VM Maker: VMMaker-oscog-dtl.59.mcz

>
>
> Am 2011-04-18 um 10:56 schrieb Bert Freudenberg:
>
>>
>> On 18.04.2011, at 07:23, [hidden email] wrote:
>>
>>> Add primitiveImageFormatVersion, an optional named primitive answering the image format number of the current image. This is the value stored in the first word of an image file header when the image is saved, and possibly modified on image load if the VM adds or removes capabilities for the running image. This primitive was added to VMMaker trunk in VMMaker-dtl.169. Rationale: supports float word order handing for image segments, reference http://lists.squeakfoundation.org/pipermail/vm-dev/2011-April/007712.html
>>
>> Is there a way to detect if an image will be saved in a different format than it was loaded?
>>
>> In some images I want to avoid saving them accidentally as a Cog image. I have been doing this by adding a preference "warnAboutSavingAsCog" and checking the VM version string for "cog". With this new primitive I could more reliably detect Cog, but I guess no information about the loaded image is retained?
>
> And: wasn't there a plan to make
> Cog-saved images loadable in non-cogs?

> On Mon, 18 Apr 2011, Tobias Pape wrote:
>
>>
>>
>> Am 2011-04-18 um 10:56 schrieb Bert Freudenberg:
>>
>>>
>>> On 18.04.2011, at 07:23, [hidden email] wrote:
>>>
>>>> Add primitiveImageFormatVersion, an optional named primitive answering the image format number of the current image. This is the value stored in the first word of an image file header when the image is saved, and possibly modified on image load if the VM adds or removes capabilities for the running image. This primitive was added to VMMaker trunk in VMMaker-dtl.169. Rationale: supports float word order handing for image segments, reference http://lists.squeakfoundation.org/pipermail/vm-dev/2011-April/007712.html
>>>
>>> Is there a way to detect if an image will be saved in a different format than it was loaded?
>>>
>>> In some images I want to avoid saving them accidentally as a Cog image. I have been doing this by adding a preference "warnAboutSavingAsCog" and checking the VM version string for "cog". With this new primitive I could more reliably detect Cog, but I guess no information about the loaded image is retained?
>>
>> And: wasn't there a plan to make
>> Cog-saved images loadable in non-cogs?
>
> The last official unix VM can do that and probably the 5.7.4 mac VM can do it too, but there's no official windows VM with this feature. Also this doesn't help much if your users have an older VM installed.

> Am 2011-04-18 um 12:26 schrieb Levente Uzonyi:
>
>> On Mon, 18 Apr 2011, Tobias Pape wrote:
>>
>>> Is there any problem in "backconverting"
>>> an image when saving it in Cog ?
>>
>> For most use cases, there's none. However Cog has to read the whole non-cog image into memory to swap the floats, which increases startup time.
>
> Yes, but consider LittleEndian vs BigEndian
> -Images and -VMs.
> They have to do the same, all the time.

>
> Dave Lewis uploaded a new version of VMMaker to project VM Maker:
> http://www.squeaksource.com/VMMaker/VMMaker-oscog-dtl.59.mcz
>
> ==================== Summary ====================
>
> Name: VMMaker-oscog-dtl.59
> Author: dtl
> Time: 17 April 2011, 10:32:55 am
> UUID: c1d30608-042d-4bb7-20ca-2bf7a46c1508
> Ancestors: VMMaker-oscog-dtl.58
>
> Merge VMMaker-oscog.dtl.58, and add #primitiveImageFormatVersion
>
> Add primitiveMillisecondClockMask, an optional named primitive used in conjunction with primitiveMillisecondClock for duration calculations. The image assumes a value for this constant that is assumed to correspond to the actual value used in the VM. This primitive permits the VM to report the actual value being used.
>
> Add primitiveImageFormatVersion, an optional named primitive answering the image format number of the current image. This is the value stored in the first word of an image file header when the image is saved, and possibly modified on image load if the VM adds or removes capabilities for the running image. This primitive was added to VMMaker trunk in VMMaker-dtl.169. Rationale: supports float word order handing for image segments, reference http://lists.squeakfoundation.org/pipermail/vm-dev/2011-April/007712.html
>
>

> On 18.04.2011, at 13:01, Igor Stasenko wrote:
>
>> What are corresponding image-side changes? Is there a code which using
>> new prims?
>> I will create a Cog issue tracker entry for this.
>
> http://source.squeak.org/trunk/System-dtl.315.diff
>
> http://source.squeak.org/trunk/changes/System-dtl.315(ar.314).cs
>
> - Bert -

> On Mon, 18 Apr 2011, Bert Freudenberg wrote:
>
>>
>> On 18.04.2011, at 07:23, [hidden email] wrote:
>>
>>> Add primitiveImageFormatVersion, an optional named primitive answering the image format number of the current image. This is the value stored in the first word of an image file header when the image is saved, and possibly modified on image load if the VM adds or removes capabilities for the running image. This primitive was added to VMMaker trunk in VMMaker-dtl.169. Rationale: supports float word order handing for image segments, reference http://lists.squeakfoundation.org/pipermail/vm-dev/2011-April/007712.html
>>
>> Is there a way to detect if an image will be saved in a different format than it was loaded?
>>
>> In some images I want to avoid saving them accidentally as a Cog image. I have been doing this by adding a preference "warnAboutSavingAsCog" and checking the VM version string for "cog". With this new primitive I could more reliably detect Cog, but I guess no information about the loaded image is retained?
>
> Why don't you read the first four bytes from the image file to get the image version?

>
> On Mon, 18 Apr 2011, Bert Freudenberg wrote:
>
> >
> >On 18.04.2011, at 07:23, [hidden email]
> >wrote:
> >
> >>Add primitiveImageFormatVersion, an optional named primitive answering
> >>the image format number of the current image. This is the value stored in
> >>the first word of an image file header when the image is saved, and
> >>possibly modified on image load if the VM adds or removes capabilities
> >>for the running image. This primitive was added to VMMaker trunk in
> >>VMMaker-dtl.169. Rationale: supports float word order handing for image
> >>segments, reference
> >>http://lists.squeakfoundation.org/pipermail/vm-dev/2011-April/007712.html
> >
> >Is there a way to detect if an image will be saved in a different format
> >than it was loaded?
> >
> >In some images I want to avoid saving them accidentally as a Cog image. I
> >have been doing this by adding a preference "warnAboutSavingAsCog" and
> >checking the VM version string for "cog". With this new primitive I could
> >more reliably detect Cog, but I guess no information about the loaded
> >image is retained?
>
> Why don't you read the first four bytes from the image file to get the
> image version? Also, there's SmalltalkImage >> #isRunningCog to check if
> the current VM is a CogVM.
>
> imageFormat := (FileStream fileNamed: Smalltalk imageName do: [ :file |
> file binary; next: 4 ]) unsignedLongAt: 1 bigEndian: false.
> isCogVM := Smalltalk isRunningCog.

>
> On Mon, Apr 18, 2011 at 12:12:22PM +0200, Levente Uzonyi wrote:
>>
>> On Mon, 18 Apr 2011, Bert Freudenberg wrote:
>>
>>>
>>> On 18.04.2011, at 07:23, [hidden email]
>>> wrote:
>>>
>>>> Add primitiveImageFormatVersion, an optional named primitive answering
>>>> the image format number of the current image. This is the value stored in
>>>> the first word of an image file header when the image is saved, and
>>>> possibly modified on image load if the VM adds or removes capabilities
>>>> for the running image. This primitive was added to VMMaker trunk in
>>>> VMMaker-dtl.169. Rationale: supports float word order handing for image
>>>> segments, reference
>>>> http://lists.squeakfoundation.org/pipermail/vm-dev/2011-April/007712.html
>>>
>>> Is there a way to detect if an image will be saved in a different format
>>> than it was loaded?
>>>
>>> In some images I want to avoid saving them accidentally as a Cog image. I
>>> have been doing this by adding a preference "warnAboutSavingAsCog" and
>>> checking the VM version string for "cog". With this new primitive I could
>>> more reliably detect Cog, but I guess no information about the loaded
>>> image is retained?
>>
>> Why don't you read the first four bytes from the image file to get the
>> image version? Also, there's SmalltalkImage >> #isRunningCog to check if
>> the current VM is a CogVM.
>>
>> imageFormat := (FileStream fileNamed: Smalltalk imageName do: [ :file |
>> file binary; next: 4 ]) unsignedLongAt: 1 bigEndian: false.
>> isCogVM := Smalltalk isRunningCog.
>
> The image format number in the file is not necessarily the same as the
> image format currently being used. For example, when an interpreter VM
> reads an image saved from Cog (i.e. format 6505), it converts the image
> to format 6504 prior to entering the interpreter. So the disk file will
> tell you that you are using a 6505 image, but the VM knows better and
> will report the current image format version as 6504.