Stack vs Heap Optimization

Comprehensive guide to understanding and optimizing memory allocation between stack and heap in Go. This guide covers escape analysis, allocation strategies, and performance optimization techniques.
Introduction
Memory Model Fundamentals
Escape Analysis
Stack Allocation Optimization
Heap Allocation Control
Performance Analysis
Optimization Strategies
Profiling and Monitoring
Best Practices
Introduction

Understanding stack vs heap allocation is crucial for Go performance optimization. This guide provides comprehensive strategies for optimizing memory allocation patterns to minimize garbage collection pressure and maximize performance.
Memory Allocation Framework

package main

import (
    "fmt"
    "reflect"
    "runtime"
    "sync"
    "sync/atomic"
    "time"
    "unsafe"
)

// MemoryAnalyzer provides comprehensive memory allocation analysis
type MemoryAnalyzer struct {
    config       AnalysisConfig
    profiler     *AllocationProfiler
    escapeTracker *EscapeTracker
    optimizer    *AllocationOptimizer
    monitor      *MemoryMonitor
    metrics      *AllocationMetrics
    mu           sync.RWMutex
}

// AnalysisConfig contains memory analysis configuration
type AnalysisConfig struct {
    TrackAllocations  bool
    TrackEscapes      bool
    SampleRate       float64
    ProfileDuration  time.Duration
    OptimizationLevel int
    EnableProfiling  bool
    ReportThreshold  int64
}

// AllocationProfiler profiles memory allocations
type AllocationProfiler struct {
    stackAllocations map[string]*AllocationInfo
    heapAllocations  map[string]*AllocationInfo
    escapeAnalysis   map[string]*EscapeInfo
    callSites        map[string]*CallSiteInfo
    hotspots         []*AllocationHotspot
    baseline         runtime.MemStats
}

// AllocationInfo tracks allocation details
type AllocationInfo struct {
    Location     string
    Type         reflect.Type
    Size         int64
    Count        int64
    TotalSize    int64
    AllocType    AllocationType
    CallStack    []uintptr
    FirstSeen    time.Time
    LastSeen     time.Time
    EscapeReason string
}

// AllocationType defines allocation location
type AllocationType int

const (
    StackAllocation AllocationType = iota
    HeapAllocation
    EscapedAllocation
    InlineAllocation
)

// EscapeInfo tracks escape analysis information
type EscapeInfo struct {
    Function     string
    Variable     string
    Type         string
    Size         int64
    EscapeReason EscapeReason
    CallSite     string
    Frequency    int64
    CanOptimize  bool
}

// EscapeReason defines why a variable escapes
type EscapeReason int

const (
    UnknownEscape EscapeReason = iota
    ReturnedPointer
    StoredInGlobal
    PassedToInterface
    ClosureCaptured
    ChannelSend
    SliceGrowth
    MapOperation
    InterfaceConversion
    GoroutineCapture
)

// CallSiteInfo tracks allocation call sites
type CallSiteInfo struct {
    Function      string
    File          string
    Line          int
    AllocCount    int64
    TotalSize     int64
    HeapAllocRate float64
    Optimizable   bool
}

// AllocationHotspot identifies allocation hotspots
type AllocationHotspot struct {
    Location       string
    Function       string
    Type           string
    AllocationsPerSec float64
    BytesPerSec    float64
    HeapPressure   float64
    Severity       HotspotSeverity
}

// HotspotSeverity defines hotspot severity levels
type HotspotSeverity int

const (
    LowSeverity HotspotSeverity = iota
    MediumSeverity
    HighSeverity
    CriticalSeverity
)

// EscapeTracker tracks variable escapes
type EscapeTracker struct {
    escapes       map[string]*EscapeEvent
    patterns      map[string]*EscapePattern
    suggestions   []*OptimizationSuggestion
    analysis      *EscapeAnalysisResult
}

// EscapeEvent represents an escape event
type EscapeEvent struct {
    Variable     string
    Function     string
    Type         string
    Size         int64
    Reason       EscapeReason
    StackTrace   []uintptr
    Timestamp    time.Time
    Preventable  bool
}

// EscapePattern identifies common escape patterns
type EscapePattern struct {
    Pattern      string
    Frequency    int64
    TotalSize    int64
    Preventable  bool
    Optimization string
}

// OptimizationSuggestion provides optimization recommendations
type OptimizationSuggestion struct {
    Type            SuggestionType
    Location        string
    Description     string
    PotentialSaving int64
    Difficulty      OptimizationDifficulty
    Implementation  string
    Example         string
}

// SuggestionType defines suggestion types
type SuggestionType int

const (
    AvoidEscape SuggestionType = iota
    UseStackAllocation
    ReducePointerChasing
    OptimizeDataStructure
    ImplementObjectPool
    UseValueReceiver
    AvoidSliceGrowth
    OptimizeInterface
)

// OptimizationDifficulty defines implementation difficulty
type OptimizationDifficulty int

const (
    EasyOptimization OptimizationDifficulty = iota
    MediumOptimization
    HardOptimization
)

// AllocationOptimizer optimizes allocation patterns
type AllocationOptimizer struct {
    strategies   []OptimizationStrategy
    patterns     map[string]*AllocationPattern
    transforms   []CodeTransform
    results      *OptimizationResult
}

// OptimizationStrategy defines optimization strategies
type OptimizationStrategy interface {
    Analyze(info *AllocationInfo) *OptimizationSuggestion
    Apply(code string) (string, error)
    Estimate(info *AllocationInfo) int64
}

// AllocationPattern identifies allocation patterns
type AllocationPattern struct {
    Name          string
    Pattern       string
    Frequency     int64
    AverageSize   int64
    StackEligible bool
    Optimization  string
}

// CodeTransform represents code transformations
type CodeTransform struct {
    Pattern     string
    Replacement string
    Description string
    Impact      TransformImpact
}

// TransformImpact measures transformation impact
type TransformImpact struct {
    AllocationReduction int64
    PerformanceGain     float64
    ComplexityChange    int
}

// OptimizationResult contains optimization results
type OptimizationResult struct {
    TotalSavings     int64
    AllocationReduction float64
    HeapPressureReduction float64
    AppliedOptimizations []string
    FailedOptimizations  []string
}

// MemoryMonitor monitors memory allocation patterns
type MemoryMonitor struct {
    allocations  chan AllocationEvent
    metrics      *AllocationMetrics
    collectors   []AllocationCollector
    alerting     *AllocationAlerting
    running      bool
}

// AllocationEvent represents a memory allocation event
type AllocationEvent struct {
    Type        AllocationType
    Size        int64
    Location    string
    Function    string
    StackTrace  []uintptr
    Timestamp   time.Time
}

// AllocationMetrics tracks allocation metrics
type AllocationMetrics struct {
    StackAllocations    int64
    HeapAllocations     int64
    TotalStackBytes     int64
    TotalHeapBytes      int64
    EscapeRate          float64
    AllocationRate      float64
    GCPressure          float64
    MemoryEfficiency    float64
}

// AllocationCollector collects allocation metrics
type AllocationCollector interface {
    CollectAllocation(event AllocationEvent)
    GetMetrics() map[string]interface{}
    Reset()
}

// AllocationAlerting provides alerting for allocation issues
type AllocationAlerting struct {
    thresholds   AllocationThresholds
    alerts       chan AllocationAlert
    handlers     []AllocationAlertHandler
}

// AllocationThresholds defines alerting thresholds
type AllocationThresholds struct {
    MaxEscapeRate      float64
    MaxAllocationRate  float64
    MaxHeapPressure    float64
    MaxGCFrequency     int
}

// AllocationAlert represents an allocation alert
type AllocationAlert struct {
    Type        AlertType
    Severity    AlertSeverity
    Message     string
    Metrics     map[string]interface{}
    Timestamp   time.Time
}

// AlertType defines alert types
type AlertType int

const (
    EscapeRateAlert AlertType = iota
    AllocationRateAlert
    HeapPressureAlert
    GCFrequencyAlert
)

// AlertSeverity defines alert severity
type AlertSeverity int

const (
    InfoAlert AlertSeverity = iota
    WarningAlert
    ErrorAlert
    CriticalAlert
)

// AllocationAlertHandler handles allocation alerts
type AllocationAlertHandler interface {
    HandleAlert(alert AllocationAlert) error
}

// NewMemoryAnalyzer creates a new memory analyzer
func NewMemoryAnalyzer(config AnalysisConfig) *MemoryAnalyzer {
    return &MemoryAnalyzer{
        config:        config,
        profiler:      NewAllocationProfiler(),
        escapeTracker: NewEscapeTracker(),
        optimizer:     NewAllocationOptimizer(),
        monitor:       NewMemoryMonitor(),
        metrics:       &AllocationMetrics{},
    }
}

// NewAllocationProfiler creates a new allocation profiler
func NewAllocationProfiler() *AllocationProfiler {
    profiler := &AllocationProfiler{
        stackAllocations: make(map[string]*AllocationInfo),
        heapAllocations:  make(map[string]*AllocationInfo),
        escapeAnalysis:   make(map[string]*EscapeInfo),
        callSites:        make(map[string]*CallSiteInfo),
        hotspots:         make([]*AllocationHotspot, 0),
    }

    runtime.ReadMemStats(&profiler.baseline)
    return profiler
}

// AnalyzeAllocations performs comprehensive allocation analysis
func (ma *MemoryAnalyzer) AnalyzeAllocations() (*AllocationAnalysisResult, error) {
    ma.mu.Lock()
    defer ma.mu.Unlock()

    // Start profiling
    if err := ma.startProfiling(); err != nil {
        return nil, fmt.Errorf("failed to start profiling: %w", err)
    }

    // Collect allocation data
    if err := ma.collectAllocationData(); err != nil {
        return nil, fmt.Errorf("failed to collect allocation data: %w", err)
    }

    // Analyze escape patterns
    escapeAnalysis, err := ma.escapeTracker.analyzeEscapes()
    if err != nil {
        return nil, fmt.Errorf("escape analysis failed: %w", err)
    }

    // Identify optimization opportunities
    optimizations := ma.optimizer.identifyOptimizations(ma.profiler)

    // Generate recommendations
    suggestions := ma.generateSuggestions(escapeAnalysis, optimizations)

    return &AllocationAnalysisResult{
        StackAllocations:  ma.profiler.stackAllocations,
        HeapAllocations:   ma.profiler.heapAllocations,
        EscapeAnalysis:    escapeAnalysis,
        Optimizations:     optimizations,
        Suggestions:       suggestions,
        Metrics:          *ma.metrics,
    }, nil
}

// AllocationAnalysisResult contains allocation analysis results
type AllocationAnalysisResult struct {
    StackAllocations  map[string]*AllocationInfo
    HeapAllocations   map[string]*AllocationInfo
    EscapeAnalysis    *EscapeAnalysisResult
    Optimizations     []*OptimizationSuggestion
    Suggestions       []*OptimizationSuggestion
    Metrics           AllocationMetrics
}

// EscapeAnalysisResult contains escape analysis results
type EscapeAnalysisResult struct {
    TotalEscapes     int64
    EscapesByReason  map[EscapeReason]int64
    PreventableEscapes int64
    Patterns         map[string]*EscapePattern
    Impact           EscapeImpact
}

// EscapeImpact measures escape impact
type EscapeImpact struct {
    MemoryOverhead   int64
    GCPressure       float64
    AllocationRate   float64
    PerformanceImpact float64
}

// startProfiling starts allocation profiling
func (ma *MemoryAnalyzer) startProfiling() error {
    if !ma.config.EnableProfiling {
        return nil
    }

    // Set up memory profiling
    runtime.MemProfileRate = int(1.0 / ma.config.SampleRate)

    // Start monitoring
    if err := ma.monitor.Start(); err != nil {
        return fmt.Errorf("failed to start monitor: %w", err)
    }

    return nil
}

// collectAllocationData collects allocation data
func (ma *MemoryAnalyzer) collectAllocationData() error {
    var memStats runtime.MemStats
    runtime.ReadMemStats(&memStats)

    // Calculate allocation metrics
    ma.metrics.HeapAllocations = int64(memStats.Mallocs)
    ma.metrics.TotalHeapBytes = int64(memStats.TotalAlloc)
    ma.metrics.AllocationRate = float64(memStats.Mallocs-ma.profiler.baseline.Mallocs) / 
                               ma.config.ProfileDuration.Seconds()

    // Profile current allocations
    if err := ma.profileCurrentAllocations(); err != nil {
        return fmt.Errorf("failed to profile allocations: %w", err)
    }

    return nil
}

// profileCurrentAllocations profiles current memory allocations
func (ma *MemoryAnalyzer) profileCurrentAllocations() error {
    // Get memory profile
    profile := runtime.MemProfile(nil, true)

    for _, record := range profile {
        location := fmt.Sprintf("%p", record.Stack()[0])

        info := &AllocationInfo{
            Location:  location,
            Size:      int64(record.AllocBytes),
            Count:     int64(record.AllocObjects),
            TotalSize: int64(record.AllocBytes),
            CallStack: record.Stack(),
            FirstSeen: time.Now(),
            LastSeen:  time.Now(),
        }

        // Determine allocation type
        if ma.isStackAllocation(record) {
            info.AllocType = StackAllocation
            ma.profiler.stackAllocations[location] = info
        } else {
            info.AllocType = HeapAllocation
            ma.profiler.heapAllocations[location] = info
        }
    }

    return nil
}

// isStackAllocation determines if allocation is on stack
func (ma *MemoryAnalyzer) isStackAllocation(record runtime.MemProfileRecord) bool {
    // Simplified heuristic - in practice, this would use escape analysis
    return record.AllocBytes < 1024 && record.InUseObjects == 0
}

// NewEscapeTracker creates a new escape tracker
func NewEscapeTracker() *EscapeTracker {
    return &EscapeTracker{
        escapes:     make(map[string]*EscapeEvent),
        patterns:    make(map[string]*EscapePattern),
        suggestions: make([]*OptimizationSuggestion, 0),
    }
}

// analyzeEscapes analyzes variable escapes
func (et *EscapeTracker) analyzeEscapes() (*EscapeAnalysisResult, error) {
    result := &EscapeAnalysisResult{
        EscapesByReason:    make(map[EscapeReason]int64),
        Patterns:          make(map[string]*EscapePattern),
    }

    // Analyze escape events
    preventableCount := int64(0)
    totalEscapes := int64(len(et.escapes))

    for _, escape := range et.escapes {
        result.EscapesByReason[escape.Reason]++

        if escape.Preventable {
            preventableCount++
        }

        // Update patterns
        pattern := et.getEscapePattern(escape)
        if existing, found := et.patterns[pattern]; found {
            existing.Frequency++
            existing.TotalSize += escape.Size
        } else {
            et.patterns[pattern] = &EscapePattern{
                Pattern:     pattern,
                Frequency:   1,
                TotalSize:   escape.Size,
                Preventable: escape.Preventable,
            }
        }
    }

    result.TotalEscapes = totalEscapes
    result.PreventableEscapes = preventableCount
    result.Patterns = et.patterns

    // Calculate impact
    result.Impact = et.calculateEscapeImpact()

    return result, nil
}

// getEscapePattern extracts escape pattern from event
func (et *EscapeTracker) getEscapePattern(escape *EscapeEvent) string {
    switch escape.Reason {
    case ReturnedPointer:
        return "returned_pointer"
    case StoredInGlobal:
        return "stored_global"
    case PassedToInterface:
        return "interface_conversion"
    case ClosureCaptured:
        return "closure_capture"
    case ChannelSend:
        return "channel_operation"
    case SliceGrowth:
        return "slice_growth"
    case MapOperation:
        return "map_operation"
    case InterfaceConversion:
        return "interface_conversion"
    case GoroutineCapture:
        return "goroutine_capture"
    default:
        return "unknown"
    }
}

// calculateEscapeImpact calculates the impact of escapes
func (et *EscapeTracker) calculateEscapeImpact() EscapeImpact {
    totalMemory := int64(0)
    totalEscapes := int64(0)

    for _, escape := range et.escapes {
        totalMemory += escape.Size
        totalEscapes++
    }

    // Simplified impact calculation
    gcPressure := float64(totalMemory) / (1024 * 1024) // MB
    allocationRate := float64(totalEscapes) / time.Minute.Seconds()

    return EscapeImpact{
        MemoryOverhead:    totalMemory,
        GCPressure:       gcPressure,
        AllocationRate:   allocationRate,
        PerformanceImpact: gcPressure * 0.1, // Simplified calculation
    }
}

// NewAllocationOptimizer creates a new allocation optimizer
func NewAllocationOptimizer() *AllocationOptimizer {
    optimizer := &AllocationOptimizer{
        strategies: make([]OptimizationStrategy, 0),
        patterns:   make(map[string]*AllocationPattern),
        transforms: make([]CodeTransform, 0),
    }

    // Initialize optimization strategies
    optimizer.initializeStrategies()

    return optimizer
}

// initializeStrategies initializes optimization strategies
func (ao *AllocationOptimizer) initializeStrategies() {
    // Add common optimization strategies
    ao.strategies = append(ao.strategies, &StackAllocationStrategy{})
    ao.strategies = append(ao.strategies, &PointerAvoidanceStrategy{})
    ao.strategies = append(ao.strategies, &InterfaceOptimizationStrategy{})
    ao.strategies = append(ao.strategies, &SliceOptimizationStrategy{})
}

// identifyOptimizations identifies optimization opportunities
func (ao *AllocationOptimizer) identifyOptimizations(profiler *AllocationProfiler) []*OptimizationSuggestion {
    suggestions := make([]*OptimizationSuggestion, 0)

    // Analyze heap allocations for optimization opportunities
    for _, allocation := range profiler.heapAllocations {
        for _, strategy := range ao.strategies {
            if suggestion := strategy.Analyze(allocation); suggestion != nil {
                suggestions = append(suggestions, suggestion)
            }
        }
    }

    // Sort suggestions by potential savings
    ao.sortSuggestionsByImpact(suggestions)

    return suggestions
}

// sortSuggestionsByImpact sorts suggestions by potential impact
func (ao *AllocationOptimizer) sortSuggestionsByImpact(suggestions []*OptimizationSuggestion) {
    for i := 0; i < len(suggestions)-1; i++ {
        for j := i + 1; j < len(suggestions); j++ {
            if suggestions[i].PotentialSaving < suggestions[j].PotentialSaving {
                suggestions[i], suggestions[j] = suggestions[j], suggestions[i]
            }
        }
    }
}

// StackAllocationStrategy optimizes for stack allocation
type StackAllocationStrategy struct{}

// Analyze analyzes allocation for stack optimization
func (sas *StackAllocationStrategy) Analyze(info *AllocationInfo) *OptimizationSuggestion {
    if info.AllocType == HeapAllocation && info.Size < 1024 {
        return &OptimizationSuggestion{
            Type:            UseStackAllocation,
            Location:        info.Location,
            Description:     "Small allocation can be moved to stack",
            PotentialSaving: info.TotalSize,
            Difficulty:      EasyOptimization,
            Implementation:  "Use value types instead of pointers",
            Example:         "var x MyStruct instead of x := &MyStruct{}",
        }
    }
    return nil
}

// Apply applies stack allocation optimization
func (sas *StackAllocationStrategy) Apply(code string) (string, error) {
    // Simplified code transformation
    return code, nil
}

// Estimate estimates optimization impact
func (sas *StackAllocationStrategy) Estimate(info *AllocationInfo) int64 {
    return info.TotalSize
}

// PointerAvoidanceStrategy optimizes pointer usage
type PointerAvoidanceStrategy struct{}

// Analyze analyzes allocation for pointer optimization
func (pas *PointerAvoidanceStrategy) Analyze(info *AllocationInfo) *OptimizationSuggestion {
    if info.EscapeReason == "returned_pointer" {
        return &OptimizationSuggestion{
            Type:            AvoidEscape,
            Location:        info.Location,
            Description:     "Avoid returning pointer to local variable",
            PotentialSaving: info.TotalSize,
            Difficulty:      MediumOptimization,
            Implementation:  "Return value instead of pointer",
            Example:         "func() MyStruct instead of func() *MyStruct",
        }
    }
    return nil
}

// Apply applies pointer avoidance optimization
func (pas *PointerAvoidanceStrategy) Apply(code string) (string, error) {
    return code, nil
}

// Estimate estimates optimization impact
func (pas *PointerAvoidanceStrategy) Estimate(info *AllocationInfo) int64 {
    return info.TotalSize * 2 // Account for GC overhead
}

// InterfaceOptimizationStrategy optimizes interface usage
type InterfaceOptimizationStrategy struct{}

// Analyze analyzes allocation for interface optimization
func (ios *InterfaceOptimizationStrategy) Analyze(info *AllocationInfo) *OptimizationSuggestion {
    if info.EscapeReason == "interface_conversion" && info.Size < 256 {
        return &OptimizationSuggestion{
            Type:            OptimizeInterface,
            Location:        info.Location,
            Description:     "Small type escapes through interface conversion",
            PotentialSaving: info.TotalSize,
            Difficulty:      MediumOptimization,
            Implementation:  "Use concrete types or type assertions",
            Example:         "Avoid fmt.Printf with small types",
        }
    }
    return nil
}

// Apply applies interface optimization
func (ios *InterfaceOptimizationStrategy) Apply(code string) (string, error) {
    return code, nil
}

// Estimate estimates optimization impact
func (ios *InterfaceOptimizationStrategy) Estimate(info *AllocationInfo) int64 {
    return info.TotalSize
}

// SliceOptimizationStrategy optimizes slice usage
type SliceOptimizationStrategy struct{}

// Analyze analyzes allocation for slice optimization
func (sos *SliceOptimizationStrategy) Analyze(info *AllocationInfo) *OptimizationSuggestion {
    if info.EscapeReason == "slice_growth" {
        return &OptimizationSuggestion{
            Type:            AvoidSliceGrowth,
            Location:        info.Location,
            Description:     "Slice growth causes allocations",
            PotentialSaving: info.TotalSize / 2, // Estimate savings
            Difficulty:      EasyOptimization,
            Implementation:  "Pre-allocate slice with known capacity",
            Example:         "make([]T, 0, expectedSize)",
        }
    }
    return nil
}

// Apply applies slice optimization
func (sos *SliceOptimizationStrategy) Apply(code string) (string, error) {
    return code, nil
}

// Estimate estimates optimization impact
func (sos *SliceOptimizationStrategy) Estimate(info *AllocationInfo) int64 {
    return info.TotalSize / 2
}

// generateSuggestions generates optimization suggestions
func (ma *MemoryAnalyzer) generateSuggestions(escapeAnalysis *EscapeAnalysisResult, 
                                              optimizations []*OptimizationSuggestion) []*OptimizationSuggestion {
    suggestions := make([]*OptimizationSuggestion, 0)

    // Add optimization suggestions
    suggestions = append(suggestions, optimizations...)

    // Add escape-specific suggestions
    for reason, count := range escapeAnalysis.EscapesByReason {
        if count > 100 { // Threshold for suggesting optimization
            suggestion := ma.createEscapeSuggestion(reason, count)
            if suggestion != nil {
                suggestions = append(suggestions, suggestion)
            }
        }
    }

    return suggestions
}

// createEscapeSuggestion creates suggestion for escape reason
func (ma *MemoryAnalyzer) createEscapeSuggestion(reason EscapeReason, count int64) *OptimizationSuggestion {
    switch reason {
    case ReturnedPointer:
        return &OptimizationSuggestion{
            Type:            AvoidEscape,
            Description:     "High frequency of returned pointer escapes",
            PotentialSaving: count * 64, // Estimate
            Difficulty:      MediumOptimization,
            Implementation:  "Return values instead of pointers where possible",
        }
    case InterfaceConversion:
        return &OptimizationSuggestion{
            Type:            OptimizeInterface,
            Description:     "High frequency of interface conversion escapes",
            PotentialSaving: count * 32, // Estimate
            Difficulty:      MediumOptimization,
            Implementation:  "Use type assertions or avoid unnecessary conversions",
        }
    case SliceGrowth:
        return &OptimizationSuggestion{
            Type:            AvoidSliceGrowth,
            Description:     "High frequency of slice growth allocations",
            PotentialSaving: count * 128, // Estimate
            Difficulty:      EasyOptimization,
            Implementation:  "Pre-allocate slices with appropriate capacity",
        }
    default:
        return nil
    }
}

// NewMemoryMonitor creates a new memory monitor
func NewMemoryMonitor() *MemoryMonitor {
    return &MemoryMonitor{
        allocations: make(chan AllocationEvent, 10000),
        metrics:     &AllocationMetrics{},
        collectors:  make([]AllocationCollector, 0),
        alerting:    NewAllocationAlerting(),
    }
}

// Start starts the memory monitor
func (mm *MemoryMonitor) Start() error {
    mm.running = true
    go mm.monitorLoop()
    return nil
}

// monitorLoop processes allocation events
func (mm *MemoryMonitor) monitorLoop() {
    ticker := time.NewTicker(time.Second)
    defer ticker.Stop()

    for mm.running {
        select {
        case event := <-mm.allocations:
            mm.processAllocationEvent(event)

        case <-ticker.C:
            mm.updateMetrics()
            mm.checkAlerts()
        }
    }
}

// processAllocationEvent processes a single allocation event
func (mm *MemoryMonitor) processAllocationEvent(event AllocationEvent) {
    // Update allocation counters
    switch event.Type {
    case StackAllocation:
        atomic.AddInt64(&mm.metrics.StackAllocations, 1)
        atomic.AddInt64(&mm.metrics.TotalStackBytes, event.Size)
    case HeapAllocation:
        atomic.AddInt64(&mm.metrics.HeapAllocations, 1)
        atomic.AddInt64(&mm.metrics.TotalHeapBytes, event.Size)
    }

    // Notify collectors
    for _, collector := range mm.collectors {
        collector.CollectAllocation(event)
    }
}

// updateMetrics updates allocation metrics
func (mm *MemoryMonitor) updateMetrics() {
    total := mm.metrics.StackAllocations + mm.metrics.HeapAllocations
    if total > 0 {
        mm.metrics.EscapeRate = float64(mm.metrics.HeapAllocations) / float64(total)
    }

    mm.metrics.AllocationRate = float64(total) / time.Minute.Seconds()
}

// checkAlerts checks for allocation alerts
func (mm *MemoryMonitor) checkAlerts() {
    if mm.metrics.EscapeRate > mm.alerting.thresholds.MaxEscapeRate {
        alert := AllocationAlert{
            Type:      EscapeRateAlert,
            Severity:  WarningAlert,
            Message:   fmt.Sprintf("High escape rate: %.2f%%", mm.metrics.EscapeRate*100),
            Timestamp: time.Now(),
        }
        mm.alerting.SendAlert(alert)
    }
}

// NewAllocationAlerting creates a new allocation alerting system
func NewAllocationAlerting() *AllocationAlerting {
    return &AllocationAlerting{
        thresholds: AllocationThresholds{
            MaxEscapeRate:     0.3,  // 30%
            MaxAllocationRate: 1000, // 1000 allocs/min
            MaxHeapPressure:   0.8,  // 80%
            MaxGCFrequency:    10,   // 10 GC/min
        },
        alerts:   make(chan AllocationAlert, 1000),
        handlers: make([]AllocationAlertHandler, 0),
    }
}

// SendAlert sends an allocation alert
func (aa *AllocationAlerting) SendAlert(alert AllocationAlert) {
    select {
    case aa.alerts <- alert:
    default:
        // Alert channel full
    }

    // Notify handlers
    for _, handler := range aa.handlers {
        go handler.HandleAlert(alert)
    }
}

// GetMetrics returns current allocation metrics
func (ma *MemoryAnalyzer) GetMetrics() AllocationMetrics {
    ma.mu.RLock()
    defer ma.mu.RUnlock()
    return *ma.metrics
}

// OptimizeFunction provides function-level optimization suggestions
func (ma *MemoryAnalyzer) OptimizeFunction(funcName string) ([]*OptimizationSuggestion, error) {
    suggestions := make([]*OptimizationSuggestion, 0)

    // Analyze function allocations
    for _, allocation := range ma.profiler.heapAllocations {
        if allocation.Location == funcName {
            for _, strategy := range ma.optimizer.strategies {
                if suggestion := strategy.Analyze(allocation); suggestion != nil {
                    suggestions = append(suggestions, suggestion)
                }
            }
        }
    }

    return suggestions, nil
}

// GetStackUsage analyzes stack usage patterns
func (ma *MemoryAnalyzer) GetStackUsage() map[string]int64 {
    usage := make(map[string]int64)

    for location, allocation := range ma.profiler.stackAllocations {
        usage[location] = allocation.TotalSize
    }

    return usage
}

// GetHeapUsage analyzes heap usage patterns
func (ma *MemoryAnalyzer) GetHeapUsage() map[string]int64 {
    usage := make(map[string]int64)

    for location, allocation := range ma.profiler.heapAllocations {
        usage[location] = allocation.TotalSize
    }

    return usage
}

// GetEscapeHotspots identifies escape hotspots
func (ma *MemoryAnalyzer) GetEscapeHotspots() []*AllocationHotspot {
    hotspots := make([]*AllocationHotspot, 0)

    for location, allocation := range ma.profiler.heapAllocations {
        if allocation.Count > 1000 { // Threshold
            hotspot := &AllocationHotspot{
                Location:          location,
                AllocationsPerSec: float64(allocation.Count) / time.Minute.Seconds(),
                BytesPerSec:      float64(allocation.TotalSize) / time.Minute.Seconds(),
                HeapPressure:     float64(allocation.TotalSize) / (1024 * 1024),
                Severity:         ma.calculateHotspotSeverity(allocation),
            }
            hotspots = append(hotspots, hotspot)
        }
    }

    return hotspots
}

// calculateHotspotSeverity calculates hotspot severity
func (ma *MemoryAnalyzer) calculateHotspotSeverity(allocation *AllocationInfo) HotspotSeverity {
    if allocation.TotalSize > 10*1024*1024 { // > 10MB
        return CriticalSeverity
    } else if allocation.TotalSize > 1024*1024 { // > 1MB
        return HighSeverity
    } else if allocation.TotalSize > 100*1024 { // > 100KB
        return MediumSeverity
    }
    return LowSeverity
}
Performance Analysis

Advanced techniques for analyzing stack vs heap performance characteristics.
Allocation Profiling

Detailed allocation profiling to understand memory patterns.
Escape Analysis Tools

Tools and techniques for understanding escape analysis results.
Performance Benchmarking

Benchmarking methodologies for comparing stack and heap performance.
Optimization Strategies

Proven strategies for optimizing stack vs heap allocation.
Value vs Pointer Types

Guidelines for choosing between value and pointer types.
Interface Optimization

Optimizing interface usage to reduce allocations.
Slice and Map Optimization

Efficient slice and map usage patterns.
Best Practices

Prefer Stack Allocation: Use value types when possible
Avoid Unnecessary Pointers: Return values instead of pointers for small types
Pre-allocate Slices: Use make([]T, 0, capacity) for known sizes
Minimize Interface Conversions: Avoid unnecessary interface{} usage
Profile Regularly: Use allocation profiling to identify hotspots
Understand Escape Analysis: Learn when and why variables escape
Optimize Hot Paths: Focus optimization efforts on frequently called code
Use Object Pools: For frequently allocated objects that escape
Summary

Stack vs heap optimization is fundamental to Go performance:
Understanding: Know when variables escape to heap
Analysis: Use profiling tools to identify allocation patterns
Optimization: Apply systematic optimization strategies
Monitoring: Continuously monitor allocation behavior
Measurement: Benchmark optimization impact
These techniques enable developers to write memory-efficient Go applications with minimal garbage collection pressure.
Stack vs Heap
