add hub instance info (#869)

- Improvement: Hub module listing now includes per-instance process metrics (memory, CPU time, working set, pagefile usage)
- Improvement: Hub now monitors provisioned instance health in the background and refreshes process metrics periodically
- Improvement: Hub no longer exposes raw `StorageServerInstance` pointers to callers; instance state is returned as value snapshots (`Hub::InstanceInfo`)
- Improvement: Hub instance access is now guarded by RAII per-instance locks (`SharedLockedPtr`/`ExclusiveLockedPtr`), preventing concurrent modifications during provisioning and deprovisioning
- Improvement: Hub instance lifecycle is now tracked as a `HubInstanceState` enum covering transitional states (Provisioning, Deprovisioning, Hibernating, Waking); exposed as a string in the HTTP API and dashboard

4 files changed, 16 insertions, 2 deletions

diff --git a/src/zencore/include/zencore/process.h b/src/zencore/include/zencore/process.h
index 3177f64c1..96afd5950 100644
--- a/src/zencore/include/zencore/process.h
+++ b/src/zencore/include/zencore/process.h
@@ -176,7 +176,7 @@ struct ProcessMetrics
 	uint64_t PeakPagefileUsage	= 0;
 };
 
-void GetProcessMetrics(ProcessHandle& Handle, ProcessMetrics& OutMetrics);
+void GetProcessMetrics(const ProcessHandle& Handle, ProcessMetrics& OutMetrics);
 
 void process_forcelink();  // internal
 
diff --git a/src/zencore/include/zencore/thread.h b/src/zencore/include/zencore/thread.h
index d0d710ee8..d7262324f 100644
--- a/src/zencore/include/zencore/thread.h
+++ b/src/zencore/include/zencore/thread.h
@@ -28,9 +28,11 @@ class RwLock
 {
 public:
 	void AcquireShared() noexcept;
+	bool TryAcquireShared() noexcept;
 	void ReleaseShared() noexcept;
 
 	void AcquireExclusive() noexcept;
+	bool TryAcquireExclusive() noexcept;
 	void ReleaseExclusive() noexcept;
 
 	struct SharedLockScope
diff --git a/src/zencore/process.cpp b/src/zencore/process.cpp
index 0c55e6c7e..29de107bd 100644
--- a/src/zencore/process.cpp
+++ b/src/zencore/process.cpp
@@ -1564,7 +1564,7 @@ WaitForThreads(uint64_t WaitTimeMs)
 }
 
 void
-GetProcessMetrics(ProcessHandle& Handle, ProcessMetrics& OutMetrics)
+GetProcessMetrics(const ProcessHandle& Handle, ProcessMetrics& OutMetrics)
 {
 #if ZEN_PLATFORM_WINDOWS
 	FILETIME CreationTime;
diff --git a/src/zencore/thread.cpp b/src/zencore/thread.cpp
index 54459cbaa..f74791333 100644
--- a/src/zencore/thread.cpp
+++ b/src/zencore/thread.cpp
@@ -146,6 +146,12 @@ RwLock::AcquireShared() noexcept
 	m_Mutex.lock_shared();
 }
 
+bool
+RwLock::TryAcquireShared() noexcept
+{
+	return m_Mutex.try_lock_shared();
+}
+
 void
 RwLock::ReleaseShared() noexcept
 {
@@ -158,6 +164,12 @@ RwLock::AcquireExclusive() noexcept
 	m_Mutex.lock();
 }
 
+bool
+RwLock::TryAcquireExclusive() noexcept
+{
+	return m_Mutex.try_lock();
+}
+
 void
 RwLock::ReleaseExclusive() noexcept
 {