Mark,
I use a handly little utility called 'shmemmon' to show me the size of available shared memory. I took a quick look on Hobbes for this, but did not find it. I've attached to the post for your use, or if you reluctant to run this search for the shmemmon.zip out there.
It actually seems to be a little utility which Jan van Wijk (of DFSee) created in 2002, hence the reason it was not posted to Hobbes, I suspect.
I created a program object and used SHMEMMON this evening to test shared memory both available and used. For the test I only used Seamonkey and VirtualBox, although a number of system related programs were also running in the background.
The numbers below are the available shared memory reported by SHMEMMON, after various actions were undertaken:
Opening VirtualBox first (without starting Seamonkey):
Initial original shared memory report - no additional load - 253.5 Mb
Virtualbox Program started - 231,2 Mb
Windows XP VM start 175.3 Mb
Seamonkey Program started with VirtualBox and VM start-up 85.5 Mb
Windows XP VM open and active (Seamonkey running) 74.3 Mb
VirtualBox VM shutdown (Seamonkey running) 129.8 Mb
VirtualBox Program Shutdown (Seamonkey running) 150.3 Mb
Start VirtualBox Program again (Seamonkey running) 129.5 Mb
Windows XP VM start (Seamonkey running) 85.5 Mb
Windows XP VM open and active (Seamonkey running) 74.3 Mb
Windows XP VM closed (Seamonkey Active) 129.5 MB
VM start 84.3 Mb
VM open 74.3 Mb
VM closed 130.0 Mb
VirtualBox Shutdown 143.3 Mb
Seamonkey closed 243.2 Mb
I rebooted and also undertook the rest starting Seamonkey first, then VirtualBox:
Initial shared memory report - no additional load 252.5 Mb
No startup of either program, but reported a minute later by SHMEMMON 244.0 Mb (background start-up of something in ArcaOS?)
Seamonkey started 152.8 Mb
VirtualBox started 122.5 Mb
Windows XP VM started and active (Seamonkey running) 69.5 Mb
Windows XP VM stopped 122.5 Mb
VirtualBox Program stopped 152.5 Mb
Seamonkey Program stopped 243.5 Mb
As Dave Yeo has said, the program results may be misleading but it shows what seemed to be happening with shared memory at least for this test, using only two programs. Not being a developer, and having no basis of comparison, I don't know if the shared memory initially reported is low, high, or about normal based on the physical memory installed, other parameters set, or the various apps loaded by the ArcaOS system in the background. I also don't know if anyone has used Theseus or some other program to measure how much shared memory either program requires to initialize.
I still found during the test, though, that I needed the 15 second delay prior to starting a VM in VirtualBox to get it to consistently open normally (the reason I tested the VM opening and closing three times in the first test). I have no idea why that works, but it seems to be consistent for me, although for others your YMMV it seems.
Thought you all might be interested and Best of the evening!
Mark