[manoelcampos]

Moves ProcessorBenchmark (added with the API before cloudsimplus/cloudsimplus#595 in #12) to the current single Processor API, and adds the results before and after #595 to the README.

Changes

• ProcessorScenario.newHost()/newVm() create Hosts and VMs with a CoreCapacity. They're the only methods that create machines, so the benchmark logic didn't change.
• MemoryFootprintBenchmark uses HeapMeter (from Add ProcessorBenchmark to measure simulation time and memory footprint for cloudsimplus#595 (before) #12), which reads the live heap from a class histogram. So it no longer needs -XX:+UseSerialGC.
• CI builds with the published 9.0.0-SNAPSHOT again. This removes the step from Add ProcessorBenchmark to measure simulation time and memory footprint for cloudsimplus#595 (before) #12 that built CloudSim Plus from before #595.

Results

• Before: CloudSim Plus 9bb9de25c, running the benchmark from Add ProcessorBenchmark to measure simulation time and memory footprint for cloudsimplus#595 (before) #12.
• After: CloudSim Plus with #595.
• JDK 25.0.4, default GC, -Xmx4g. Each value is the median of 5 rounds. The simulation time is measured after 2 warmup runs.

Heap retained by each machine (bytes)

Cores	Host before	Host after	Reduction	VM before	VM after	Reduction
1	940.6	812.6	14%	883.3	795.3	10%
8	1,807.1	808.1	55%	891.9	795.5	11%
32	4,804.7	821.4	83%	883.6	795.6	10%
128	16,722.2	811.2	95%	883.1	804.5	9%

Before #595, a Host grew about 123 bytes per core. Now its size doesn't depend on the number of cores. VMs were already using a single Processor before #595, so their size didn't depend on the number of cores either.

Whole simulation

Scenario: 1,000 Hosts with 32 cores, 4,000 VMs with 8 cores and 8,000 Cloudlets with 4 cores.

Measure	Before	After	Reduction
Heap retained before running	9.6 MB	5.5 MB	43%
Heap retained after running	12.2 MB	8.6 MB	30%
Simulation time	1.691 s	0.776 s	54%

At scale

Using the per-object savings above, a simulation with 1M Cloudlets, 100K VMs and 10K Hosts uses this much less heap (Cloudlets keep 216 B each, so they don't change the result):

Host cores	Saved per Host	Saved by 10K Hosts	Saved by 100K VMs (88 B each)	Total saved
1	128 B	1.3 MB	8.8 MB	10.1 MB
8	999 B	10.0 MB	8.8 MB	18.8 MB
32	3,983 B	39.8 MB	8.8 MB	48.6 MB
128	15,911 B	159.1 MB	8.8 MB	167.9 MB

The bigger the Hosts (in number of cores), the bigger the saving, since each core was an object before #595.

Note about master

master now has #11 (the move to the new API) restored on top of #12. Until this PR is merged, the master build fails: the benchmark from #12 still uses the old API, while CI still builds CloudSim Plus from before #595.

🤖 Generated with Claude Code