hub resource limits (#900)

- Feature: Hub dashboard now shows a Resources tile with disk and memory usage against configured limits
- Feature: Hub module listing now shows state-change timestamps and duration for each instance
- Improvement: Hub provisioning rejects new instances when disk or memory usage exceeds configurable thresholds; limits are disabled by default (0 = no limit)
  - `--hub-provision-disk-limit-bytes` - Reject provisioning when used disk exceeds this many bytes
  - `--hub-provision-disk-limit-percent` - Reject provisioning when used disk exceeds this percentage of total disk
  - `--hub-provision-memory-limit-bytes` - Reject provisioning when used memory exceeds this many bytes
  - `--hub-provision-memory-limit-percent` - Reject provisioning when used memory exceeds this percentage of total RAM
- Improvement: Hub process metrics are now tracked atomically per active instance slot, eliminating per-query process handle lookups
- Improvement: Hub, Build Store, and Workspaces service stats sections in the dashboard are now collapsible
- Bugfix: Hub watchdog loop did not check `m_ShutdownFlag`, causing it to spin indefinitely on shutdown

1 files changed, 8 insertions, 28 deletions

diff --git a/src/zenserver/hub/storageserverinstance.cpp b/src/zenserver/hub/storageserverinstance.cpp
index 6b139dbf1..802606f6a 100644
--- a/src/zenserver/hub/storageserverinstance.cpp
+++ b/src/zenserver/hub/storageserverinstance.cpp
@@ -57,16 +57,15 @@ StorageServerInstance::SpawnServerProcess()
 	m_ServerInstance.EnableShutdownOnDestroy();
 }
 
-void
-StorageServerInstance::GetProcessMetrics(ProcessMetrics& OutMetrics) const
+ProcessMetrics
+StorageServerInstance::GetProcessMetrics() const
 {
-	OutMetrics.MemoryBytes		  = m_MemoryBytes.load();
-	OutMetrics.KernelTimeMs		  = m_KernelTimeMs.load();
-	OutMetrics.UserTimeMs		  = m_UserTimeMs.load();
-	OutMetrics.WorkingSetSize	  = m_WorkingSetSize.load();
-	OutMetrics.PeakWorkingSetSize = m_PeakWorkingSetSize.load();
-	OutMetrics.PagefileUsage	  = m_PagefileUsage.load();
-	OutMetrics.PeakPagefileUsage  = m_PeakPagefileUsage.load();
+	ProcessMetrics Metrics;
+	if (m_ServerInstance.IsRunning())
+	{
+		zen::GetProcessMetrics(m_ServerInstance.GetProcessHandle(), Metrics);
+	}
+	return Metrics;
 }
 
 void
@@ -249,25 +248,6 @@ StorageServerInstance::SharedLockedPtr::IsRunning() const
 	return m_Instance->m_ServerInstance.IsRunning();
 }
 
-void
-StorageServerInstance::UpdateMetricsLocked()
-{
-	if (m_ServerInstance.IsRunning())
-	{
-		ProcessMetrics Metrics;
-		zen::GetProcessMetrics(m_ServerInstance.GetProcessHandle(), Metrics);
-
-		m_MemoryBytes.store(Metrics.MemoryBytes);
-		m_KernelTimeMs.store(Metrics.KernelTimeMs);
-		m_UserTimeMs.store(Metrics.UserTimeMs);
-		m_WorkingSetSize.store(Metrics.WorkingSetSize);
-		m_PeakWorkingSetSize.store(Metrics.PeakWorkingSetSize);
-		m_PagefileUsage.store(Metrics.PagefileUsage);
-		m_PeakPagefileUsage.store(Metrics.PeakPagefileUsage);
-	}
-	// TODO: Resource metrics...
-}
-
 #if ZEN_WITH_TESTS
 void
 StorageServerInstance::SharedLockedPtr::TerminateForTesting() const