Modernize host pool management

- Add context-aware host pool operations
- Implement rate limiting for host connections
- Improve concurrency handling with mutexes
- Add host connection tracking

hostPool/hostPool.go

@@ -0,0 +1,81 @@
+package hostPool
+
+import (
+	"context"
+	"math/rand"
+	"sync"
+	"time"
+
+	"gemini-grc/common/contextlog"
+	"gemini-grc/contextutil"
+	"gemini-grc/logging"
+)
+
+var hostPool = HostPool{hostnames: make(map[string]struct{})}
+
+type HostPool struct {
+	hostnames map[string]struct{}
+	lock      sync.RWMutex
+}
+
+// RemoveHostFromPool removes a host from the pool with context awareness
+func RemoveHostFromPool(ctx context.Context, key string) {
+	// Create a hostPool-specific context
+	hostCtx := contextutil.ContextWithComponent(ctx, "hostPool")
+
+	contextlog.LogDebugWithContext(hostCtx, logging.GetSlogger(), "Removing host %s from pool", key)
+
+	hostPool.lock.Lock()
+	delete(hostPool.hostnames, key)
+	hostPool.lock.Unlock()
+
+	// Add some jitter
+	time.Sleep(time.Duration(rand.Intn(1000)) * time.Millisecond)
+
+	contextlog.LogDebugWithContext(hostCtx, logging.GetSlogger(), "Host %s removed from pool", key)
+}
+
+// AddHostToHostPool adds a host to the host pool with context awareness.
+// Blocks until the host is added or the context is canceled.
+func AddHostToHostPool(ctx context.Context, key string) error {
+	// Create a hostPool-specific context
+	hostCtx := contextutil.ContextWithComponent(ctx, "hostPool")
+
+	contextlog.LogDebugWithContext(hostCtx, logging.GetSlogger(), "Adding host %s to pool", key)
+
+	// Use a ticker to periodically check if we can add the host
+	ticker := time.NewTicker(500 * time.Millisecond)
+	defer ticker.Stop()
+
+	for {
+		// Check if context is done before attempting to acquire lock
+		select {
+		case <-ctx.Done():
+			contextlog.LogDebugWithContext(hostCtx, logging.GetSlogger(), "Context canceled while waiting to add host %s", key)
+			return ctx.Err()
+		default:
+			// Continue with attempt to add host
+		}
+
+		hostPool.lock.Lock()
+		_, exists := hostPool.hostnames[key]
+		if !exists {
+			hostPool.hostnames[key] = struct{}{}
+			hostPool.lock.Unlock()
+			contextlog.LogDebugWithContext(hostCtx, logging.GetSlogger(), "Added host %s to pool", key)
+			return nil
+		}
+		hostPool.lock.Unlock()
+
+		contextlog.LogDebugWithContext(hostCtx, logging.GetSlogger(), "Host %s busy, waiting...", key)
+
+		// Wait for next tick or context cancellation
+		select {
+		case <-ticker.C:
+			// Try again on next tick
+		case <-ctx.Done():
+			contextlog.LogDebugWithContext(hostCtx, logging.GetSlogger(), "Context canceled while waiting for host %s", key)
+			return ctx.Err()
+		}
+	}
+}