Code:
/ Dotnetfx_Vista_SP2 / Dotnetfx_Vista_SP2 / 8.0.50727.4016 / DEVDIV / depot / DevDiv / releases / whidbey / NetFxQFE / ndp / fx / src / xsp / System / Web / Cache / CacheMemory.cs / 1 / CacheMemory.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //----------------------------------------------------------------------------- namespace System.Web.Caching { using System.Web.Configuration; using System.Runtime.InteropServices; using System.Web.Util; using System.Web; using System.Web.Hosting; abstract class CacheMemoryPressure { protected const int TERABYTE_SHIFT = 40; protected const long TERABYTE = 1L << TERABYTE_SHIFT; protected const int GIGABYTE_SHIFT = 30; protected const long GIGABYTE = 1L << GIGABYTE_SHIFT; protected const int MEGABYTE_SHIFT = 20; protected const long MEGABYTE = 1L << MEGABYTE_SHIFT; // 1048576 protected const int KILOBYTE_SHIFT = 10; protected const long KILOBYTE = 1L << KILOBYTE_SHIFT; // 1024 protected const int HISTORY_COUNT = 6; protected int _pressureHigh; // high pressure level protected int _pressureMiddle; // middle pressure level - target protected int _pressureLow; // low pressure level - slow growth here protected int _i0; protected int[] _pressureHist; protected int _pressureTotal; protected int _pressureAvg; private static long s_totalPhysical; private static long s_totalVirtual; internal static void GetMemoryStatusOnce() { UnsafeNativeMethods.MEMORYSTATUSEX memoryStatusEx = new UnsafeNativeMethods.MEMORYSTATUSEX(); memoryStatusEx.Init(); if (UnsafeNativeMethods.GlobalMemoryStatusEx(ref memoryStatusEx) != 0) { s_totalPhysical = memoryStatusEx.ullTotalPhys; s_totalVirtual = memoryStatusEx.ullTotalVirtual; } } internal static long TotalPhysical { get { return s_totalPhysical; } } internal static long TotalVirtual { get { return s_totalVirtual; } } protected abstract int GetCurrentPressure(); internal virtual void ReadConfig(CacheSection cacheSection) {} protected void InitHistory() { Debug.Assert(_pressureHigh > 0, "_pressureHigh > 0"); Debug.Assert(_pressureLow > 0, "_pressureLow > 0"); Debug.Assert(_pressureLow <= _pressureHigh, "_pressureLow <= _pressureHigh"); int pressure = GetCurrentPressure(); _pressureHist = new int[HISTORY_COUNT]; for (int i = 0; i < HISTORY_COUNT; i++) { _pressureHist[i] = pressure; _pressureTotal += pressure; } _pressureAvg = pressure; } // Get current pressure and update history internal void Update() { int pressure = GetCurrentPressure(); #if FEATURE_PAL // _pressureHist may not be initialized if calls to // GlobalMemoryStatusEx fail. if (_pressureHist != null) #endif // FEATURE_PAL { _i0 = (_i0 + 1) % HISTORY_COUNT; _pressureTotal -= _pressureHist[_i0]; _pressureTotal += pressure; _pressureHist[_i0] = pressure; _pressureAvg = _pressureTotal / HISTORY_COUNT; } #if DBG if (HttpRuntime.AppDomainAppIdInternal != null && HttpRuntime.AppDomainAppIdInternal.Length > 0) { if (!(pressure == 0 && PressureHigh == 99)) { Debug.Trace("CacheMemory", this.GetType().Name + ".Update: last=" + pressure + ",avg=" + PressureAvg + ",high=" + PressureHigh + ",low=" + PressureLow + ",middle=" + PressureMiddle + " " + Debug.FormatLocalDate(DateTime.Now)); } } #endif } internal int PressureLast { get { #if FEATURE_PAL // _pressureHist may not be initialized if calls to // GlobalMemoryStatusEx fail. return (_pressureHist != null) ? _pressureHist[_i0] : 0; #else // FEATURE_PAL return _pressureHist[_i0]; #endif // FEATURE_PAL } } internal int PressureAvg { get { return _pressureAvg; } } internal int PressureHigh { get { return _pressureHigh; } } internal int PressureLow { get { return _pressureLow; } } internal int PressureMiddle { get { return _pressureMiddle; } } internal bool IsAboveHighPressure() { return PressureLast >= PressureHigh; } internal bool IsAboveMediumPressure() { return PressureLast > PressureMiddle; } } // The GC aggressively collects when it receives a low memory notification. Make sure // we have released references before it aggressively collects. sealed class CacheMemoryTotalMemoryPressure : CacheMemoryPressure { internal CacheMemoryTotalMemoryPressure() { /* The chart below shows physical memory in megabytes, and the 1, 3, and 10% values. When we reach "middle" pressure, we begin trimming the cache. RAM 1% 3% 10% ----------------------------- 128 1.28 3.84 12.8 256 2.56 7.68 25.6 512 5.12 15.36 51.2 1024 10.24 30.72 102.4 2048 20.48 61.44 204.8 4096 40.96 122.88 409.6 8192 81.92 245.76 819.2 Low memory notifications from CreateMemoryResourceNotification are calculated as follows (.\base\ntos\mm\initsup.c): MiInitializeMemoryEvents() { ... // // Scale the threshold so on servers the low threshold is // approximately 32MB per 4GB, capping it at 64MB. // MmLowMemoryThreshold = MmPlentyFreePages; if (MmNumberOfPhysicalPages > 0x40000) { MmLowMemoryThreshold = MI_MB_TO_PAGES (32); MmLowMemoryThreshold += ((MmNumberOfPhysicalPages - 0x40000) >> 7); } else if (MmNumberOfPhysicalPages > 0x8000) { MmLowMemoryThreshold += ((MmNumberOfPhysicalPages - 0x8000) >> 5); } if (MmLowMemoryThreshold > MI_MB_TO_PAGES (64)) { MmLowMemoryThreshold = MI_MB_TO_PAGES (64); } ... E.g. RAM(mb) low % ------------------- 256 20 92% 512 24 95% 768 28 96% 1024 32 97% 2048 40 98% 3072 48 98% 4096 56 99% 5120 64 99% */ long memory = TotalPhysical; Debug.Assert(memory != 0, "memory != 0"); if (memory >= 0x100000000) { _pressureHigh = 99; } else if (memory >= 0x80000000) { _pressureHigh = 98; } else if (memory >= 0x40000000) { _pressureHigh = 97; } else if (memory >= 0x30000000) { _pressureHigh = 96; } else { _pressureHigh = 95; } _pressureMiddle = _pressureHigh - 2; _pressureLow = _pressureHigh - 9; InitHistory(); // PerfCounter: Cache Percentage Machine Memory Limit Used // = total physical memory used / total physical memory used limit PerfCounters.SetCounter(AppPerfCounter.CACHE_PERCENT_MACH_MEM_LIMIT_USED_BASE, _pressureHigh); } override internal void ReadConfig(CacheSection cacheSection) { // Read the percentagePhysicalMemoryUsedLimit set in config int limit = cacheSection.PercentagePhysicalMemoryUsedLimit; if (limit == 0) { // use defaults return; } _pressureHigh = Math.Max(3, limit); _pressureMiddle = Math.Max(2, _pressureHigh - 2); _pressureLow = Math.Max(1, _pressureHigh - 9); // PerfCounter: Cache Percentage Machine Memory Limit Used // = total physical memory used / total physical memory used limit PerfCounters.SetCounter(AppPerfCounter.CACHE_PERCENT_MACH_MEM_LIMIT_USED_BASE, _pressureHigh); Debug.Trace("CacheMemory", "CacheMemoryTotalMemoryPressure.ReadConfig: _pressureHigh=" + _pressureHigh + ", _pressureMiddle=" + _pressureMiddle + ", _pressureLow=" + _pressureLow); } override protected int GetCurrentPressure() { UnsafeNativeMethods.MEMORYSTATUSEX memoryStatusEx = new UnsafeNativeMethods.MEMORYSTATUSEX(); memoryStatusEx.Init(); if (UnsafeNativeMethods.GlobalMemoryStatusEx(ref memoryStatusEx) == 0) return 0; int memoryLoad = memoryStatusEx.dwMemoryLoad; if (_pressureHigh != 0) { // PerfCounter: Cache Percentage Machine Memory Limit Used // = total physical memory used / total physical memory used limit PerfCounters.SetCounter(AppPerfCounter.CACHE_PERCENT_MACH_MEM_LIMIT_USED, memoryLoad); } return memoryLoad; } // Returns the percentage of physical machine memory that can be consumed by an // application before ASP.NET starts forcibly removing items from the cache. internal long MemoryLimit { get { return _pressureHigh; } } } // Make sure we don't hit the per-process private bytes memory limit, // or the process will be restarted sealed class CacheMemoryPrivateBytesPressure : CacheMemoryPressure { long _memoryLimit; static bool s_isIIS6 = HostingEnvironment.IsUnderIIS6Process; static long s_autoPrivateBytesLimit = -1; static long s_lastReadPrivateBytes; static DateTime s_lastTimeReadPrivateBytes = DateTime.MinValue; static uint s_pid = 0; static int s_pollInterval; const long PRIVATE_BYTES_LIMIT_2GB = 800 * MEGABYTE; const long PRIVATE_BYTES_LIMIT_3GB = 1800 * MEGABYTE; const long PRIVATE_BYTES_LIMIT_64BIT = 1L * TERABYTE; DateTime _startupTime; long _pressureHighMemoryLimit; // high pressure in bytes = _pressureHigh * _memoryLimit / 100 internal CacheMemoryPrivateBytesPressure() { _pressureHigh = 99; _pressureMiddle = 98; _pressureLow = 97; _startupTime = DateTime.UtcNow; InitHistory(); } // Auto-generate the private bytes limit: // - On 64bit, the auto value is MIN(60% physical_ram, 1 TB) // - On x86, for 2GB, the auto value is MIN(60% physical_ram, 800 MB) // - On x86, for 3GB, the auto value is MIN(60% physical_ram, 1800 MB) // // - If it's not a hosted environment (e.g. console app), the 60% in the above // formulas will become 100% because in un-hosted environment we don't launch // other processes such as compiler, etc. internal static long AutoPrivateBytesLimit { get { if (s_autoPrivateBytesLimit == -1) { bool is64bit = (IntPtr.Size == 8); long totalPhysical = TotalPhysical; long totalVirtual = TotalVirtual; if (totalPhysical != 0) { long recommendedPrivateByteLimit; if (is64bit) { recommendedPrivateByteLimit = PRIVATE_BYTES_LIMIT_64BIT; } else { // Figure out if it's 2GB or 3GB if (totalVirtual > 2 * GIGABYTE) { recommendedPrivateByteLimit = PRIVATE_BYTES_LIMIT_3GB; } else { recommendedPrivateByteLimit = PRIVATE_BYTES_LIMIT_2GB; } } // if we're hosted, use 60% of physical RAM; otherwise 100% long usableMemory = HostingEnvironment.IsHosted ? totalPhysical * 3 / 5 : totalPhysical; s_autoPrivateBytesLimit = Math.Min(usableMemory, recommendedPrivateByteLimit); } else { // If GlobalMemoryStatusEx fails, we'll use these as our auto-gen private bytes limit s_autoPrivateBytesLimit = is64bit ? PRIVATE_BYTES_LIMIT_64BIT : PRIVATE_BYTES_LIMIT_2GB; } } return s_autoPrivateBytesLimit; } } override internal void ReadConfig(CacheSection cacheSection) { // Read the private bytes limit set in config long privateBytesLimit; privateBytesLimit = cacheSection.PrivateBytesLimit; // per-process information if (UnsafeNativeMethods.GetModuleHandle(ModName.WP_FULL_NAME) != IntPtr.Zero) { _memoryLimit = (long)UnsafeNativeMethods.PMGetMemoryLimitInMB() << MEGABYTE_SHIFT; } else if (UnsafeNativeMethods.GetModuleHandle(ModName.W3WP_FULL_NAME) != IntPtr.Zero) { IServerConfig serverConfig = ServerConfig.GetInstance(); _memoryLimit = (long)serverConfig.GetW3WPMemoryLimitInKB() << KILOBYTE_SHIFT; } // VSWhidbey 546381: never override what the user specifies as the limit; // only call AutoPrivateBytesLimit when the user does not specify one. if (privateBytesLimit == 0 && _memoryLimit == 0) { // Zero means we impose a limit _memoryLimit = AutoPrivateBytesLimit; } else if (privateBytesLimit != 0 && _memoryLimit != 0) { // Take the min of "process recycle limit" and our internal "private bytes limit" _memoryLimit = Math.Min(_memoryLimit, privateBytesLimit); } else if (privateBytesLimit != 0) { // _memoryLimit is 0, but privateBytesLimit is non-zero, so use it as the limit _memoryLimit = privateBytesLimit; } Debug.Trace("CacheMemory", "CacheMemoryPrivateBytesPressure.ReadConfig: _memoryLimit=" + (_memoryLimit >> MEGABYTE_SHIFT) + "Mb"); if (_memoryLimit > 0) { if (s_pid == 0) // only set this once s_pid = (uint) SafeNativeMethods.GetCurrentProcessId(); if (_memoryLimit >= 256 * MEGABYTE) { // we leave arbitrary breathing room // _pressureHigh = (int)Math.Max(90, (_memoryLimit - (96 * MEGABYTE)) * 100 / _memoryLimit); _pressureLow = (int)Math.Max(80, (_memoryLimit - (224 * MEGABYTE)) * 100 / _memoryLimit); _pressureMiddle = (_pressureHigh + _pressureLow) / 2; } else { // if memory limit is small, use these hard coded values _pressureHigh = 90; _pressureMiddle = 85; _pressureLow = 78; } _pressureHighMemoryLimit = _pressureHigh * _memoryLimit / 100; } // convertto milliseconds s_pollInterval = (int)Math.Min(cacheSection.PrivateBytesPollTime.TotalMilliseconds, (double)Int32.MaxValue); // PerfCounter: Cache Percentage Process Memory Limit Used // = memory used by this process / process memory limit at pressureHigh // Set private bytes limit in kilobytes becuase the counter is a DWORD PerfCounters.SetCounter(AppPerfCounter.CACHE_PERCENT_PROC_MEM_LIMIT_USED_BASE, (int)(_pressureHighMemoryLimit >> KILOBYTE_SHIFT)); Debug.Trace("CacheMemory", "CacheMemoryPrivateBytesPressure.ReadConfig: _pressureHigh=" + _pressureHigh + ", _pressureMiddle=" + _pressureMiddle + ", _pressureLow=" + _pressureLow); } internal long MemoryLimit { get { return _memoryLimit; } } internal static int PollInterval { get { return s_pollInterval; } } // Get Private Bytes if we have not updated it within the poll interval, otherwise // use the cached value. internal static long GetPrivateBytes(bool nocache) { long privateBytes; int hr = 0; // NtQuerySystemInformation is a very expensive call. A new function // exists on XP Pro and later versions of the OS and it performs much // better. The name of that function is GetProcessMemoryInfo. For hosting // scenarios where a larger number of w3wp.exe instances are running, we // want to use the new API (VSWhidbey 417366). if (s_isIIS6) { long privatePageCount; hr = UnsafeNativeMethods.GetPrivateBytesIIS6(out privatePageCount, nocache); privateBytes = privatePageCount; } else { uint dummy; uint privatePageCount = 0; hr = UnsafeNativeMethods.GetProcessMemoryInformation(s_pid, out privatePageCount, out dummy, nocache); privateBytes = (long)privatePageCount << MEGABYTE_SHIFT; } // for debugging, store value and time that we last got private bytes if (hr == 0) { s_lastReadPrivateBytes = privateBytes; s_lastTimeReadPrivateBytes = DateTime.UtcNow; } Debug.Trace("CacheMemory", "GetPrivateBytes: hr=" + hr + ",privateBytes=" + (privateBytes >> MEGABYTE_SHIFT) + "Mb"); return privateBytes; } override protected int GetCurrentPressure() { if (_memoryLimit == 0) { return 0; } long privateBytes = GetPrivateBytes(false); if (_pressureHighMemoryLimit != 0) { // PerfCounter: Cache Percentage Process Memory Limit Used // = memory used by this process / process memory limit at pressureHigh // Set private bytes used in kilobytes because the counter is a DWORD PerfCounters.SetCounter(AppPerfCounter.CACHE_PERCENT_PROC_MEM_LIMIT_USED, (int)(privateBytes >> KILOBYTE_SHIFT)); } int result = (int)(privateBytes * 100 / _memoryLimit); return result; } internal long PressureHighMemoryLimit { get { return _pressureHighMemoryLimit; } } internal bool HasLimit() { return _memoryLimit != 0; } } class CacheMemoryStats { CacheMemoryTotalMemoryPressure _pressureTotalMemory; CacheMemoryPrivateBytesPressure _pressurePrivateBytes; long _minTotalMemoryChange = -1; // if a collection didn't reduce the heaps by this amount, it was ineffective long _lastTotalMemoryChange; // updated after each collection to track effectiveness of collections internal CacheMemoryStats() { CacheMemoryPressure.GetMemoryStatusOnce(); _pressureTotalMemory = new CacheMemoryTotalMemoryPressure(); _pressurePrivateBytes = new CacheMemoryPrivateBytesPressure(); } internal CacheMemoryPrivateBytesPressure PrivateBytesPressure { get {return _pressurePrivateBytes;} } internal CacheMemoryTotalMemoryPressure TotalMemoryPressure { get {return _pressureTotalMemory;} } internal bool IsGcCollectIneffective(long totalMemoryChange) { if (_minTotalMemoryChange == -1 && _pressurePrivateBytes.HasLimit()) { // need to initialize // 1% of memory limit _minTotalMemoryChange = _pressurePrivateBytes.MemoryLimit / 100; } // store this to assist debugging _lastTotalMemoryChange = totalMemoryChange; return (totalMemoryChange < _minTotalMemoryChange); } internal bool IsAboveHighPressure() { return _pressureTotalMemory.IsAboveHighPressure() || _pressurePrivateBytes.IsAboveHighPressure(); } internal bool IsAboveMediumPressure() { return _pressureTotalMemory.IsAboveMediumPressure() || _pressurePrivateBytes.IsAboveMediumPressure(); } internal void ReadConfig(CacheSection cacheSection) { _pressureTotalMemory.ReadConfig(cacheSection); _pressurePrivateBytes.ReadConfig(cacheSection); } internal void Update() { _pressureTotalMemory.Update(); _pressurePrivateBytes.Update(); } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. //------------------------------------------------------------------------------ // // Copyright (c) Microsoft Corporation. All rights reserved. // //----------------------------------------------------------------------------- namespace System.Web.Caching { using System.Web.Configuration; using System.Runtime.InteropServices; using System.Web.Util; using System.Web; using System.Web.Hosting; abstract class CacheMemoryPressure { protected const int TERABYTE_SHIFT = 40; protected const long TERABYTE = 1L << TERABYTE_SHIFT; protected const int GIGABYTE_SHIFT = 30; protected const long GIGABYTE = 1L << GIGABYTE_SHIFT; protected const int MEGABYTE_SHIFT = 20; protected const long MEGABYTE = 1L << MEGABYTE_SHIFT; // 1048576 protected const int KILOBYTE_SHIFT = 10; protected const long KILOBYTE = 1L << KILOBYTE_SHIFT; // 1024 protected const int HISTORY_COUNT = 6; protected int _pressureHigh; // high pressure level protected int _pressureMiddle; // middle pressure level - target protected int _pressureLow; // low pressure level - slow growth here protected int _i0; protected int[] _pressureHist; protected int _pressureTotal; protected int _pressureAvg; private static long s_totalPhysical; private static long s_totalVirtual; internal static void GetMemoryStatusOnce() { UnsafeNativeMethods.MEMORYSTATUSEX memoryStatusEx = new UnsafeNativeMethods.MEMORYSTATUSEX(); memoryStatusEx.Init(); if (UnsafeNativeMethods.GlobalMemoryStatusEx(ref memoryStatusEx) != 0) { s_totalPhysical = memoryStatusEx.ullTotalPhys; s_totalVirtual = memoryStatusEx.ullTotalVirtual; } } internal static long TotalPhysical { get { return s_totalPhysical; } } internal static long TotalVirtual { get { return s_totalVirtual; } } protected abstract int GetCurrentPressure(); internal virtual void ReadConfig(CacheSection cacheSection) {} protected void InitHistory() { Debug.Assert(_pressureHigh > 0, "_pressureHigh > 0"); Debug.Assert(_pressureLow > 0, "_pressureLow > 0"); Debug.Assert(_pressureLow <= _pressureHigh, "_pressureLow <= _pressureHigh"); int pressure = GetCurrentPressure(); _pressureHist = new int[HISTORY_COUNT]; for (int i = 0; i < HISTORY_COUNT; i++) { _pressureHist[i] = pressure; _pressureTotal += pressure; } _pressureAvg = pressure; } // Get current pressure and update history internal void Update() { int pressure = GetCurrentPressure(); #if FEATURE_PAL // _pressureHist may not be initialized if calls to // GlobalMemoryStatusEx fail. if (_pressureHist != null) #endif // FEATURE_PAL { _i0 = (_i0 + 1) % HISTORY_COUNT; _pressureTotal -= _pressureHist[_i0]; _pressureTotal += pressure; _pressureHist[_i0] = pressure; _pressureAvg = _pressureTotal / HISTORY_COUNT; } #if DBG if (HttpRuntime.AppDomainAppIdInternal != null && HttpRuntime.AppDomainAppIdInternal.Length > 0) { if (!(pressure == 0 && PressureHigh == 99)) { Debug.Trace("CacheMemory", this.GetType().Name + ".Update: last=" + pressure + ",avg=" + PressureAvg + ",high=" + PressureHigh + ",low=" + PressureLow + ",middle=" + PressureMiddle + " " + Debug.FormatLocalDate(DateTime.Now)); } } #endif } internal int PressureLast { get { #if FEATURE_PAL // _pressureHist may not be initialized if calls to // GlobalMemoryStatusEx fail. return (_pressureHist != null) ? _pressureHist[_i0] : 0; #else // FEATURE_PAL return _pressureHist[_i0]; #endif // FEATURE_PAL } } internal int PressureAvg { get { return _pressureAvg; } } internal int PressureHigh { get { return _pressureHigh; } } internal int PressureLow { get { return _pressureLow; } } internal int PressureMiddle { get { return _pressureMiddle; } } internal bool IsAboveHighPressure() { return PressureLast >= PressureHigh; } internal bool IsAboveMediumPressure() { return PressureLast > PressureMiddle; } } // The GC aggressively collects when it receives a low memory notification. Make sure // we have released references before it aggressively collects. sealed class CacheMemoryTotalMemoryPressure : CacheMemoryPressure { internal CacheMemoryTotalMemoryPressure() { /* The chart below shows physical memory in megabytes, and the 1, 3, and 10% values. When we reach "middle" pressure, we begin trimming the cache. RAM 1% 3% 10% ----------------------------- 128 1.28 3.84 12.8 256 2.56 7.68 25.6 512 5.12 15.36 51.2 1024 10.24 30.72 102.4 2048 20.48 61.44 204.8 4096 40.96 122.88 409.6 8192 81.92 245.76 819.2 Low memory notifications from CreateMemoryResourceNotification are calculated as follows (.\base\ntos\mm\initsup.c): MiInitializeMemoryEvents() { ... // // Scale the threshold so on servers the low threshold is // approximately 32MB per 4GB, capping it at 64MB. // MmLowMemoryThreshold = MmPlentyFreePages; if (MmNumberOfPhysicalPages > 0x40000) { MmLowMemoryThreshold = MI_MB_TO_PAGES (32); MmLowMemoryThreshold += ((MmNumberOfPhysicalPages - 0x40000) >> 7); } else if (MmNumberOfPhysicalPages > 0x8000) { MmLowMemoryThreshold += ((MmNumberOfPhysicalPages - 0x8000) >> 5); } if (MmLowMemoryThreshold > MI_MB_TO_PAGES (64)) { MmLowMemoryThreshold = MI_MB_TO_PAGES (64); } ... E.g. RAM(mb) low % ------------------- 256 20 92% 512 24 95% 768 28 96% 1024 32 97% 2048 40 98% 3072 48 98% 4096 56 99% 5120 64 99% */ long memory = TotalPhysical; Debug.Assert(memory != 0, "memory != 0"); if (memory >= 0x100000000) { _pressureHigh = 99; } else if (memory >= 0x80000000) { _pressureHigh = 98; } else if (memory >= 0x40000000) { _pressureHigh = 97; } else if (memory >= 0x30000000) { _pressureHigh = 96; } else { _pressureHigh = 95; } _pressureMiddle = _pressureHigh - 2; _pressureLow = _pressureHigh - 9; InitHistory(); // PerfCounter: Cache Percentage Machine Memory Limit Used // = total physical memory used / total physical memory used limit PerfCounters.SetCounter(AppPerfCounter.CACHE_PERCENT_MACH_MEM_LIMIT_USED_BASE, _pressureHigh); } override internal void ReadConfig(CacheSection cacheSection) { // Read the percentagePhysicalMemoryUsedLimit set in config int limit = cacheSection.PercentagePhysicalMemoryUsedLimit; if (limit == 0) { // use defaults return; } _pressureHigh = Math.Max(3, limit); _pressureMiddle = Math.Max(2, _pressureHigh - 2); _pressureLow = Math.Max(1, _pressureHigh - 9); // PerfCounter: Cache Percentage Machine Memory Limit Used // = total physical memory used / total physical memory used limit PerfCounters.SetCounter(AppPerfCounter.CACHE_PERCENT_MACH_MEM_LIMIT_USED_BASE, _pressureHigh); Debug.Trace("CacheMemory", "CacheMemoryTotalMemoryPressure.ReadConfig: _pressureHigh=" + _pressureHigh + ", _pressureMiddle=" + _pressureMiddle + ", _pressureLow=" + _pressureLow); } override protected int GetCurrentPressure() { UnsafeNativeMethods.MEMORYSTATUSEX memoryStatusEx = new UnsafeNativeMethods.MEMORYSTATUSEX(); memoryStatusEx.Init(); if (UnsafeNativeMethods.GlobalMemoryStatusEx(ref memoryStatusEx) == 0) return 0; int memoryLoad = memoryStatusEx.dwMemoryLoad; if (_pressureHigh != 0) { // PerfCounter: Cache Percentage Machine Memory Limit Used // = total physical memory used / total physical memory used limit PerfCounters.SetCounter(AppPerfCounter.CACHE_PERCENT_MACH_MEM_LIMIT_USED, memoryLoad); } return memoryLoad; } // Returns the percentage of physical machine memory that can be consumed by an // application before ASP.NET starts forcibly removing items from the cache. internal long MemoryLimit { get { return _pressureHigh; } } } // Make sure we don't hit the per-process private bytes memory limit, // or the process will be restarted sealed class CacheMemoryPrivateBytesPressure : CacheMemoryPressure { long _memoryLimit; static bool s_isIIS6 = HostingEnvironment.IsUnderIIS6Process; static long s_autoPrivateBytesLimit = -1; static long s_lastReadPrivateBytes; static DateTime s_lastTimeReadPrivateBytes = DateTime.MinValue; static uint s_pid = 0; static int s_pollInterval; const long PRIVATE_BYTES_LIMIT_2GB = 800 * MEGABYTE; const long PRIVATE_BYTES_LIMIT_3GB = 1800 * MEGABYTE; const long PRIVATE_BYTES_LIMIT_64BIT = 1L * TERABYTE; DateTime _startupTime; long _pressureHighMemoryLimit; // high pressure in bytes = _pressureHigh * _memoryLimit / 100 internal CacheMemoryPrivateBytesPressure() { _pressureHigh = 99; _pressureMiddle = 98; _pressureLow = 97; _startupTime = DateTime.UtcNow; InitHistory(); } // Auto-generate the private bytes limit: // - On 64bit, the auto value is MIN(60% physical_ram, 1 TB) // - On x86, for 2GB, the auto value is MIN(60% physical_ram, 800 MB) // - On x86, for 3GB, the auto value is MIN(60% physical_ram, 1800 MB) // // - If it's not a hosted environment (e.g. console app), the 60% in the above // formulas will become 100% because in un-hosted environment we don't launch // other processes such as compiler, etc. internal static long AutoPrivateBytesLimit { get { if (s_autoPrivateBytesLimit == -1) { bool is64bit = (IntPtr.Size == 8); long totalPhysical = TotalPhysical; long totalVirtual = TotalVirtual; if (totalPhysical != 0) { long recommendedPrivateByteLimit; if (is64bit) { recommendedPrivateByteLimit = PRIVATE_BYTES_LIMIT_64BIT; } else { // Figure out if it's 2GB or 3GB if (totalVirtual > 2 * GIGABYTE) { recommendedPrivateByteLimit = PRIVATE_BYTES_LIMIT_3GB; } else { recommendedPrivateByteLimit = PRIVATE_BYTES_LIMIT_2GB; } } // if we're hosted, use 60% of physical RAM; otherwise 100% long usableMemory = HostingEnvironment.IsHosted ? totalPhysical * 3 / 5 : totalPhysical; s_autoPrivateBytesLimit = Math.Min(usableMemory, recommendedPrivateByteLimit); } else { // If GlobalMemoryStatusEx fails, we'll use these as our auto-gen private bytes limit s_autoPrivateBytesLimit = is64bit ? PRIVATE_BYTES_LIMIT_64BIT : PRIVATE_BYTES_LIMIT_2GB; } } return s_autoPrivateBytesLimit; } } override internal void ReadConfig(CacheSection cacheSection) { // Read the private bytes limit set in config long privateBytesLimit; privateBytesLimit = cacheSection.PrivateBytesLimit; // per-process information if (UnsafeNativeMethods.GetModuleHandle(ModName.WP_FULL_NAME) != IntPtr.Zero) { _memoryLimit = (long)UnsafeNativeMethods.PMGetMemoryLimitInMB() << MEGABYTE_SHIFT; } else if (UnsafeNativeMethods.GetModuleHandle(ModName.W3WP_FULL_NAME) != IntPtr.Zero) { IServerConfig serverConfig = ServerConfig.GetInstance(); _memoryLimit = (long)serverConfig.GetW3WPMemoryLimitInKB() << KILOBYTE_SHIFT; } // VSWhidbey 546381: never override what the user specifies as the limit; // only call AutoPrivateBytesLimit when the user does not specify one. if (privateBytesLimit == 0 && _memoryLimit == 0) { // Zero means we impose a limit _memoryLimit = AutoPrivateBytesLimit; } else if (privateBytesLimit != 0 && _memoryLimit != 0) { // Take the min of "process recycle limit" and our internal "private bytes limit" _memoryLimit = Math.Min(_memoryLimit, privateBytesLimit); } else if (privateBytesLimit != 0) { // _memoryLimit is 0, but privateBytesLimit is non-zero, so use it as the limit _memoryLimit = privateBytesLimit; } Debug.Trace("CacheMemory", "CacheMemoryPrivateBytesPressure.ReadConfig: _memoryLimit=" + (_memoryLimit >> MEGABYTE_SHIFT) + "Mb"); if (_memoryLimit > 0) { if (s_pid == 0) // only set this once s_pid = (uint) SafeNativeMethods.GetCurrentProcessId(); if (_memoryLimit >= 256 * MEGABYTE) { // we leave arbitrary breathing room // _pressureHigh = (int)Math.Max(90, (_memoryLimit - (96 * MEGABYTE)) * 100 / _memoryLimit); _pressureLow = (int)Math.Max(80, (_memoryLimit - (224 * MEGABYTE)) * 100 / _memoryLimit); _pressureMiddle = (_pressureHigh + _pressureLow) / 2; } else { // if memory limit is small, use these hard coded values _pressureHigh = 90; _pressureMiddle = 85; _pressureLow = 78; } _pressureHighMemoryLimit = _pressureHigh * _memoryLimit / 100; } // convertto milliseconds s_pollInterval = (int)Math.Min(cacheSection.PrivateBytesPollTime.TotalMilliseconds, (double)Int32.MaxValue); // PerfCounter: Cache Percentage Process Memory Limit Used // = memory used by this process / process memory limit at pressureHigh // Set private bytes limit in kilobytes becuase the counter is a DWORD PerfCounters.SetCounter(AppPerfCounter.CACHE_PERCENT_PROC_MEM_LIMIT_USED_BASE, (int)(_pressureHighMemoryLimit >> KILOBYTE_SHIFT)); Debug.Trace("CacheMemory", "CacheMemoryPrivateBytesPressure.ReadConfig: _pressureHigh=" + _pressureHigh + ", _pressureMiddle=" + _pressureMiddle + ", _pressureLow=" + _pressureLow); } internal long MemoryLimit { get { return _memoryLimit; } } internal static int PollInterval { get { return s_pollInterval; } } // Get Private Bytes if we have not updated it within the poll interval, otherwise // use the cached value. internal static long GetPrivateBytes(bool nocache) { long privateBytes; int hr = 0; // NtQuerySystemInformation is a very expensive call. A new function // exists on XP Pro and later versions of the OS and it performs much // better. The name of that function is GetProcessMemoryInfo. For hosting // scenarios where a larger number of w3wp.exe instances are running, we // want to use the new API (VSWhidbey 417366). if (s_isIIS6) { long privatePageCount; hr = UnsafeNativeMethods.GetPrivateBytesIIS6(out privatePageCount, nocache); privateBytes = privatePageCount; } else { uint dummy; uint privatePageCount = 0; hr = UnsafeNativeMethods.GetProcessMemoryInformation(s_pid, out privatePageCount, out dummy, nocache); privateBytes = (long)privatePageCount << MEGABYTE_SHIFT; } // for debugging, store value and time that we last got private bytes if (hr == 0) { s_lastReadPrivateBytes = privateBytes; s_lastTimeReadPrivateBytes = DateTime.UtcNow; } Debug.Trace("CacheMemory", "GetPrivateBytes: hr=" + hr + ",privateBytes=" + (privateBytes >> MEGABYTE_SHIFT) + "Mb"); return privateBytes; } override protected int GetCurrentPressure() { if (_memoryLimit == 0) { return 0; } long privateBytes = GetPrivateBytes(false); if (_pressureHighMemoryLimit != 0) { // PerfCounter: Cache Percentage Process Memory Limit Used // = memory used by this process / process memory limit at pressureHigh // Set private bytes used in kilobytes because the counter is a DWORD PerfCounters.SetCounter(AppPerfCounter.CACHE_PERCENT_PROC_MEM_LIMIT_USED, (int)(privateBytes >> KILOBYTE_SHIFT)); } int result = (int)(privateBytes * 100 / _memoryLimit); return result; } internal long PressureHighMemoryLimit { get { return _pressureHighMemoryLimit; } } internal bool HasLimit() { return _memoryLimit != 0; } } class CacheMemoryStats { CacheMemoryTotalMemoryPressure _pressureTotalMemory; CacheMemoryPrivateBytesPressure _pressurePrivateBytes; long _minTotalMemoryChange = -1; // if a collection didn't reduce the heaps by this amount, it was ineffective long _lastTotalMemoryChange; // updated after each collection to track effectiveness of collections internal CacheMemoryStats() { CacheMemoryPressure.GetMemoryStatusOnce(); _pressureTotalMemory = new CacheMemoryTotalMemoryPressure(); _pressurePrivateBytes = new CacheMemoryPrivateBytesPressure(); } internal CacheMemoryPrivateBytesPressure PrivateBytesPressure { get {return _pressurePrivateBytes;} } internal CacheMemoryTotalMemoryPressure TotalMemoryPressure { get {return _pressureTotalMemory;} } internal bool IsGcCollectIneffective(long totalMemoryChange) { if (_minTotalMemoryChange == -1 && _pressurePrivateBytes.HasLimit()) { // need to initialize // 1% of memory limit _minTotalMemoryChange = _pressurePrivateBytes.MemoryLimit / 100; } // store this to assist debugging _lastTotalMemoryChange = totalMemoryChange; return (totalMemoryChange < _minTotalMemoryChange); } internal bool IsAboveHighPressure() { return _pressureTotalMemory.IsAboveHighPressure() || _pressurePrivateBytes.IsAboveHighPressure(); } internal bool IsAboveMediumPressure() { return _pressureTotalMemory.IsAboveMediumPressure() || _pressurePrivateBytes.IsAboveMediumPressure(); } internal void ReadConfig(CacheSection cacheSection) { _pressureTotalMemory.ReadConfig(cacheSection); _pressurePrivateBytes.ReadConfig(cacheSection); } internal void Update() { _pressureTotalMemory.Update(); _pressurePrivateBytes.Update(); } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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