internal void RemoveCacheEntry(MemoryCacheEntry cacheEntry)
{
lock (this)
{
UsageEntryRef entryRef = cacheEntry.UsageEntryRef;
if (entryRef.IsInvalid)
{
return;
}
UsageEntry[] entries = (_pages[(entryRef.PageIndex)]._entries);
int entryIndex = entryRef.Ref1Index;
cacheEntry.UsageEntryRef = UsageEntryRef.INVALID;
entries[entryIndex]._cacheEntry = null;
RemoveEntryFromLastRefList(entryRef);
AddUsageEntryToFreeList(entryRef);
Reduce();
Dbg.Trace("CacheUsageRemove",
"Removed item=" + cacheEntry.Key +
",_bucket=" + _bucket +
",ref=" + entryRef);
}
}
internal void EnableExpirationTimer(bool enable)
{
if (enable)
{
if (_timerHandleRef == null)
{
DateTime utcNow = DateTime.UtcNow;
TimeSpan due = _tsPerBucket - (new TimeSpan(utcNow.Ticks % _tsPerBucket.Ticks));
Timer timer = new Timer(new TimerCallback(this.TimerCallback), null,
due.Ticks / TimeSpan.TicksPerMillisecond, _tsPerBucket.Ticks / TimeSpan.TicksPerMillisecond);
_timerHandleRef = new GCHandleRef <Timer>(timer);
Dbg.Trace("Cache", "Cache expiration timer created.");
}
}
else
{
GCHandleRef <Timer> timerHandleRef = _timerHandleRef;
if (timerHandleRef != null && Interlocked.CompareExchange(ref _timerHandleRef, null, timerHandleRef) == timerHandleRef)
{
timerHandleRef.Dispose();
Dbg.Trace("Cache", "Cache expiration timer disposed.");
while (_inFlush != 0)
{
Thread.Sleep(100);
}
}
}
}
internal void UtcUpdate(MemoryCacheEntry cacheEntry, DateTime utcNewExpires)
{
int oldBucket = cacheEntry.ExpiresBucket;
int newBucket = UtcCalcExpiresBucket(utcNewExpires);
if (oldBucket != newBucket)
{
Dbg.Trace("CacheExpiresUpdate",
"Updating item " + cacheEntry.Key + " from bucket " + oldBucket + " to new bucket " + newBucket);
if (oldBucket != 0xff)
{
_buckets[oldBucket].RemoveCacheEntry(cacheEntry);
cacheEntry.UtcAbsExp = utcNewExpires;
_buckets[newBucket].AddCacheEntry(cacheEntry);
}
}
else
{
if (oldBucket != 0xff)
{
_buckets[oldBucket].UtcUpdateCacheEntry(cacheEntry, utcNewExpires);
}
}
}
private int FlushExpiredItems(bool checkDelta, bool useInsertBlock)
{
int flushed = 0;
if (Interlocked.Exchange(ref _inFlush, 1) == 0)
{
try
{
if (_timerHandleRef == null)
{
return(0);
}
DateTime utcNow = DateTime.UtcNow;
if (!checkDelta || utcNow - _utcLastFlush >= MIN_FLUSH_INTERVAL || utcNow < _utcLastFlush)
{
_utcLastFlush = utcNow;
foreach (ExpiresBucket bucket in _buckets)
{
flushed += bucket.FlushExpiredItems(utcNow, useInsertBlock);
}
Dbg.Trace("CacheExpiresFlushTotal", "FlushExpiredItems flushed a total of " + flushed + " items; Time=" + DateTime.Now.ToString("o", CultureInfo.InvariantCulture));
}
}
finally
{
Interlocked.Exchange(ref _inFlush, 0);
}
}
return(flushed);
}
internal void UtcUpdateCacheEntry(MemoryCacheEntry cacheEntry, DateTime utcExpires)
{
lock (this)
{
ExpiresEntryRef entryRef = cacheEntry.ExpiresEntryRef;
if (cacheEntry.ExpiresBucket != _bucket || entryRef.IsInvalid)
{
return;
}
ExpiresEntry[] entries = (_pages[(entryRef.PageIndex)]._entries);
int entryIndex = entryRef.Index;
Dbg.Assert(cacheEntry == entries[entryIndex]._cacheEntry);
RemoveCount(entries[entryIndex]._utcExpires);
AddCount(utcExpires);
entries[entryIndex]._utcExpires = utcExpires;
cacheEntry.UtcAbsExp = utcExpires;
Dbg.Validate("CacheValidateExpires", this);
Dbg.Trace("CacheExpiresUpdate", "Updated item " + cacheEntry.Key + " in bucket " + _bucket);
}
}
protected override int GetCurrentPressure()
{
// Call GetUpdatedTotalCacheSize to update the total
// cache size, if there has been a recent Gen 2 Collection.
// This update must happen, otherwise the CacheManager won't
// know the total cache size.
int gen2Count = GC.CollectionCount(2);
SRefMultiple sref = _sizedRefMultiple;
if (gen2Count != _gen2Count && sref != null)
{
// update _gen2Count
_gen2Count = gen2Count;
// the SizedRef is only updated after a Gen2 Collection
// increment the index (it's either 1 or 0)
Dbg.Assert(SAMPLE_COUNT == 2);
_idx = _idx ^ 1;
// remember the sample time
_cacheSizeSampleTimes[_idx] = DateTime.UtcNow;
// remember the sample value
_cacheSizeSamples[_idx] = sref.ApproximateSize;
#if DBG
Dbg.Trace("MemoryCacheStats", "SizedRef.ApproximateSize=" + _cacheSizeSamples[_idx]);
#endif
IMemoryCacheManager memoryCacheManager = s_memoryCacheManager;
if (memoryCacheManager != null)
{
memoryCacheManager.UpdateCacheSize(_cacheSizeSamples[_idx], _memoryCache);
}
}
// if there's no memory limit, then there's nothing more to do
if (_memoryLimit <= 0)
{
return(0);
}
long cacheSize = _cacheSizeSamples[_idx];
// use _memoryLimit as an upper bound so that pressure is a percentage (between 0 and 100, inclusive).
if (cacheSize > _memoryLimit)
{
cacheSize = _memoryLimit;
}
// 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
//
int result = (int)(cacheSize * 100 / _memoryLimit);
return(result);
}
internal long TrimInternal(int percent)
{
int count = Count;
int toTrim = 0;
// do we need to drop a percentage of entries?
if (percent > 0)
{
toTrim = (int)(((long)count * (long)percent) / 100L);
// would this leave us above MAX_COUNT?
int minTrim = count - MAX_COUNT;
if (toTrim < minTrim)
{
toTrim = minTrim;
}
// would this put us below MIN_COUNT?
int maxTrim = count - MIN_COUNT;
if (toTrim > maxTrim)
{
toTrim = maxTrim;
}
}
// do we need to trim?
if (toTrim <= 0 || _disposed == 1)
{
return(0);
}
int trimmed = 0; // total number of entries trimmed
int trimmedOrExpired = 0;
#if DBG
int beginTotalCount = count;
#endif
trimmedOrExpired = _expires.FlushExpiredItems(true);
if (trimmedOrExpired < toTrim)
{
trimmed = _usage.FlushUnderUsedItems(toTrim - trimmedOrExpired);
trimmedOrExpired += trimmed;
}
if (trimmed > 0 && _perfCounters != null)
{
// Update values for perfcounters
_perfCounters.IncrementBy(PerfCounterName.Trims, trimmed);
}
#if DBG
Dbg.Trace("MemoryCacheStore", "TrimInternal:"
+ " beginTotalCount=" + beginTotalCount
+ ", endTotalCount=" + count
+ ", percent=" + percent
+ ", trimmed=" + trimmed);
#endif
return(trimmedOrExpired);
}
internal long CacheManagerThread(int minPercent)
{
if (Interlocked.Exchange(ref _inCacheManagerThread, 1) != 0)
{
return(0);
}
try
{
if (_disposed == 1)
{
return(0);
}
#if DEBUG
Dbg.Trace("MemoryCacheStats", "**BEG** CacheManagerThread " + DateTime.Now.ToString("T", CultureInfo.InvariantCulture));
#endif
// The timer thread must always call Update so that the CacheManager
// knows the size of the cache.
Update();
AdjustTimer();
int percent = Math.Max(minPercent, GetPercentToTrim());
long beginTotalCount = _memoryCache.GetCount();
Stopwatch sw = Stopwatch.StartNew();
long trimmedOrExpired = _memoryCache.Trim(percent);
sw.Stop();
// 1) don't update stats if the trim happend because MAX_COUNT was exceeded
// 2) don't update stats unless we removed at least one entry
if (percent > 0 && trimmedOrExpired > 0)
{
SetTrimStats(sw.Elapsed.Ticks, beginTotalCount, trimmedOrExpired);
}
#if DEBUG
Dbg.Trace("MemoryCacheStats", "**END** CacheManagerThread: "
+ ", percent=" + percent
+ ", beginTotalCount=" + beginTotalCount
+ ", trimmed=" + trimmedOrExpired
+ ", Milliseconds=" + sw.ElapsedMilliseconds);
#endif
#if PERF
Debug.WriteLine("CacheCommon.CacheManagerThread:"
+ " minPercent= " + minPercent
+ ", percent= " + percent
+ ", beginTotalCount=" + beginTotalCount
+ ", trimmed=" + trimmedOrExpired
+ ", Milliseconds=" + sw.ElapsedMilliseconds + "\n");
#endif
return(trimmedOrExpired);
}
finally
{
Interlocked.Exchange(ref _inCacheManagerThread, 0);
}
}
internal void SetLimit(int physicalMemoryLimitPercentage)
{
if (physicalMemoryLimitPercentage == 0)
{
// use defaults
return;
}
_pressureHigh = Math.Max(3, physicalMemoryLimitPercentage);
_pressureLow = Math.Max(1, _pressureHigh - 9);
Dbg.Trace("MemoryCacheStats", $"PhysicalMemoryMonitor.SetLimit: _pressureHigh={_pressureHigh}, _pressureLow={_pressureLow}");
}
internal void EnableExpirationTimer(bool enable)
{
if (enable)
{
if (_timerHandleRef == null)
{
DateTime utcNow = DateTime.UtcNow;
TimeSpan due = _tsPerBucket - (new TimeSpan(utcNow.Ticks % _tsPerBucket.Ticks));
Timer timer;
// Don't capture the current ExecutionContext and its AsyncLocals onto the timer causing them to live forever
bool restoreFlow = false;
try
{
if (!ExecutionContext.IsFlowSuppressed())
{
ExecutionContext.SuppressFlow();
restoreFlow = true;
}
timer = new Timer(new TimerCallback(this.TimerCallback), null,
due.Ticks / TimeSpan.TicksPerMillisecond, _tsPerBucket.Ticks / TimeSpan.TicksPerMillisecond);
}
finally
{
// Restore the current ExecutionContext
if (restoreFlow)
{
ExecutionContext.RestoreFlow();
}
}
_timerHandleRef = new GCHandleRef <Timer>(timer);
Dbg.Trace("Cache", "Cache expiration timer created.");
}
}
else
{
GCHandleRef <Timer> timerHandleRef = _timerHandleRef;
if (timerHandleRef != null && Interlocked.CompareExchange(ref _timerHandleRef, null, timerHandleRef) == timerHandleRef)
{
timerHandleRef.Dispose();
Dbg.Trace("Cache", "Cache expiration timer disposed.");
while (_inFlush != 0)
{
Thread.Sleep(100);
}
}
}
}
// Get current pressure and update history
internal void Update()
{
int pressure = GetCurrentPressure();
_i0 = (_i0 + 1) % HISTORY_COUNT;
_pressureTotal -= _pressureHist[_i0];
_pressureTotal += pressure;
_pressureHist[_i0] = pressure;
Dbg.Trace("MemoryCacheStats", this.GetType().Name + ".Update: last=" + pressure
+ ",high=" + PressureHigh
+ ",low=" + PressureLow
+ " " + DateTime.Now.ToString("o", CultureInfo.InvariantCulture));
}
internal void SetLimit(int physicalMemoryLimitPercentage)
{
if (physicalMemoryLimitPercentage == 0)
{
// use defaults
return;
}
_pressureHigh = Math.Max(3, physicalMemoryLimitPercentage);
_pressureLow = Math.Max(1, _pressureHigh - 9);
#if DBG
Dbg.Trace("MemoryCacheStats", "PhysicalMemoryMonitor.SetLimit: _pressureHigh=" + _pressureHigh +
", _pressureLow=" + _pressureLow);
#endif
}
// Get current pressure and update history
internal void Update()
{
int pressure = GetCurrentPressure();
_i0 = (_i0 + 1) % HISTORY_COUNT;
_pressureTotal -= _pressureHist[_i0];
_pressureTotal += pressure;
_pressureHist[_i0] = pressure;
#if DBG
Dbg.Trace("MemoryCacheStats", this.GetType().Name + ".Update: last=" + pressure
+ ",high=" + PressureHigh
+ ",low=" + PressureLow
+ " " + Dbg.FormatLocalDate(DateTime.Now));
#endif
}
internal void SetLimit(int cacheMemoryLimitMegabytes)
{
long cacheMemoryLimit = cacheMemoryLimitMegabytes;
cacheMemoryLimit = cacheMemoryLimit << MEGABYTE_SHIFT;
//
_memoryLimit = 0;
// VSWhidbey 546381: never override what the user specifies as the limit;
// only call AutoPrivateBytesLimit when the user does not specify one.
if (cacheMemoryLimit == 0 && _memoryLimit == 0)
{
// Zero means we impose a limit
_memoryLimit = EffectiveProcessMemoryLimit;
}
else if (cacheMemoryLimit != 0 && _memoryLimit != 0)
{
// Take the min of "cache memory limit" and the host's "process memory limit".
_memoryLimit = Math.Min(_memoryLimit, cacheMemoryLimit);
}
else if (cacheMemoryLimit != 0)
{
// _memoryLimit is 0, but "cache memory limit" is non-zero, so use it as the limit
_memoryLimit = cacheMemoryLimit;
}
Dbg.Trace("MemoryCacheStats", "CacheMemoryMonitor.SetLimit: _memoryLimit=" + (_memoryLimit >> MEGABYTE_SHIFT) + "Mb");
if (_memoryLimit > 0)
{
_pressureHigh = 100;
_pressureLow = 80;
}
else
{
_pressureHigh = 99;
_pressureLow = 97;
}
Dbg.Trace("MemoryCacheStats", "CacheMemoryMonitor.SetLimit: _pressureHigh=" + _pressureHigh +
", _pressureLow=" + _pressureLow);
}
public void Dispose()
{
if (Interlocked.Exchange(ref _disposed, 1) == 0)
{
lock (_timerLock)
{
GCHandleRef <Timer> timerHandleRef = _timerHandleRef;
if (timerHandleRef != null && Interlocked.CompareExchange(ref _timerHandleRef, null, timerHandleRef) == timerHandleRef)
{
timerHandleRef.Dispose();
Dbg.Trace("MemoryCacheStats", "Stopped CacheMemoryTimers");
}
}
while (_inCacheManagerThread != 0)
{
Thread.Sleep(100);
}
_cacheMemoryMonitor?.Dispose();
// Don't need to call GC.SuppressFinalize(this) for sealed types without finalizers.
}
}
private void RemoveCacheEntryNoLock(MemoryCacheEntry cacheEntry)
{
ExpiresEntryRef entryRef = cacheEntry.ExpiresEntryRef;
if (cacheEntry.ExpiresBucket != _bucket || entryRef.IsInvalid)
{
return;
}
ExpiresEntry[] entries = (_pages[(entryRef.PageIndex)]._entries);
int entryIndex = entryRef.Index;
RemoveCount(entries[entryIndex]._utcExpires);
cacheEntry.ExpiresBucket = 0xff;
cacheEntry.ExpiresEntryRef = ExpiresEntryRef.INVALID;
entries[entryIndex]._cacheEntry = null;
AddExpiresEntryToFreeList(entryRef);
if (_cEntriesInUse == 0)
{
ResetCounts(DateTime.UtcNow);
}
Reduce();
Dbg.Trace("CacheExpiresRemove",
"Removed item=" + cacheEntry.Key +
",_bucket=" + _bucket +
",ref=" + entryRef +
",now=" + Dbg.FormatLocalDate(DateTime.Now) +
",expires=" + cacheEntry.UtcAbsExp.ToLocalTime());
Dbg.Validate("CacheValidateExpires", this);
Dbg.Dump("CacheExpiresRemove", this);
}
internal void SetLimit(int cacheMemoryLimitMegabytes)
{
long cacheMemoryLimit = cacheMemoryLimitMegabytes << MEGABYTE_SHIFT;
_memoryLimit = cacheMemoryLimit != 0 ?
cacheMemoryLimit :
EffectiveProcessMemoryLimit;
Dbg.Trace("MemoryCacheStats", "CacheMemoryMonitor.SetLimit: _memoryLimit=" + (_memoryLimit >> MEGABYTE_SHIFT) + "Mb");
if (_memoryLimit > 0)
{
_pressureHigh = 100;
_pressureLow = 80;
}
else
{
_pressureHigh = 99;
_pressureLow = 97;
}
Dbg.Trace("MemoryCacheStats", "CacheMemoryMonitor.SetLimit: _pressureHigh=" + _pressureHigh +
", _pressureLow=" + _pressureLow);
}
internal void AddCacheEntry(MemoryCacheEntry cacheEntry)
{
lock (this)
{
if (_freeEntryList._head == -1)
{
Expand();
}
UsageEntryRef freeRef1 = GetFreeUsageEntry();
UsageEntryRef freeRef2 = (new UsageEntryRef((freeRef1).PageIndex, -(freeRef1).Ref1Index));
Debug.Assert(cacheEntry.UsageEntryRef.IsInvalid, "cacheEntry.UsageEntryRef.IsInvalid");
cacheEntry.UsageEntryRef = freeRef1;
UsageEntry[] entries = (_pages[(freeRef1.PageIndex)]._entries);
int entryIndex = freeRef1.Ref1Index;
entries[entryIndex]._cacheEntry = cacheEntry;
entries[entryIndex]._utcDate = DateTime.UtcNow;
entries[entryIndex]._ref1._prev = UsageEntryRef.INVALID;
entries[entryIndex]._ref2._next = _addRef2Head;
if (_lastRefHead.IsInvalid)
{
entries[entryIndex]._ref1._next = freeRef2;
entries[entryIndex]._ref2._prev = freeRef1;
_lastRefTail = freeRef2;
}
else
{
entries[entryIndex]._ref1._next = _lastRefHead;
{ if ((_lastRefHead).IsRef1)
{
(_pages[((_lastRefHead).PageIndex)]._entries)[(_lastRefHead).Ref1Index]._ref1._prev = (freeRef1);
}
else if ((_lastRefHead).IsRef2)
{
(_pages[((_lastRefHead).PageIndex)]._entries)[(_lastRefHead).Ref2Index]._ref2._prev = (freeRef1);
}
else
{
_lastRefTail = (freeRef1);
} };
UsageEntryRef next, prev;
if (_addRef2Head.IsInvalid)
{
prev = _lastRefTail;
next = UsageEntryRef.INVALID;
}
else
{
prev = (_pages[(_addRef2Head.PageIndex)]._entries)[_addRef2Head.Ref2Index]._ref2._prev;
next = _addRef2Head;
}
entries[entryIndex]._ref2._prev = prev;
{ if ((prev).IsRef1)
{
(_pages[((prev).PageIndex)]._entries)[(prev).Ref1Index]._ref1._next = (freeRef2);
}
else if ((prev).IsRef2)
{
(_pages[((prev).PageIndex)]._entries)[(prev).Ref2Index]._ref2._next = (freeRef2);
}
else
{
_lastRefHead = (freeRef2);
} };
{ if ((next).IsRef1)
{
(_pages[((next).PageIndex)]._entries)[(next).Ref1Index]._ref1._prev = (freeRef2);
}
else if ((next).IsRef2)
{
(_pages[((next).PageIndex)]._entries)[(next).Ref2Index]._ref2._prev = (freeRef2);
}
else
{
_lastRefTail = (freeRef2);
} };
}
_lastRefHead = freeRef1;
_addRef2Head = freeRef2;
_cEntriesInUse++;
Dbg.Trace("CacheUsageAdd",
"Added item=" + cacheEntry.Key +
",_bucket=" + _bucket +
",ref=" + freeRef1);
}
}
internal int FlushExpiredItems(DateTime utcNow, bool useInsertBlock)
{
if (_cEntriesInUse == 0 || GetExpiresCount(utcNow) == 0)
{
return(0);
}
Debug.Assert(_cEntriesInFlush == 0, "_cEntriesInFlush == 0");
ExpiresEntryRef inFlushHead = ExpiresEntryRef.INVALID;
ExpiresEntry[] entries;
int entryIndex;
MemoryCacheEntry cacheEntry;
int flushed = 0;
try
{
if (useInsertBlock)
{
_cacheExpires.MemoryCacheStore.BlockInsert();
}
lock (this)
{
Debug.Assert(_blockReduce == false, "_blockReduce == false");
if (_cEntriesInUse == 0 || GetExpiresCount(utcNow) == 0)
{
return(0);
}
ResetCounts(utcNow);
int cPages = _cPagesInUse;
for (int i = 0; i < _pages.Length; i++)
{
entries = _pages[i]._entries;
if (entries != null)
{
int cEntries = NUM_ENTRIES - ((entries)[0]._cFree);
for (int j = 1; j < entries.Length; j++)
{
cacheEntry = entries[j]._cacheEntry;
if (cacheEntry != null)
{
if (entries[j]._utcExpires > utcNow)
{
AddCount(entries[j]._utcExpires);
}
else
{
cacheEntry.ExpiresBucket = 0xff;
cacheEntry.ExpiresEntryRef = ExpiresEntryRef.INVALID;
entries[j]._cFree = 1;
entries[j]._next = inFlushHead;
inFlushHead = new ExpiresEntryRef(i, j);
flushed++;
_cEntriesInFlush++;
}
cEntries--;
if (cEntries == 0)
{
break;
}
}
}
cPages--;
if (cPages == 0)
{
break;
}
}
}
if (flushed == 0)
{
Dbg.Trace("CacheExpiresFlushTotal", "FlushExpiredItems flushed " + flushed +
" expired items, bucket=" + _bucket + "; Time=" + DateTime.Now.ToString("o", CultureInfo.InvariantCulture));
return(0);
}
_blockReduce = true;
}
}
finally
{
if (useInsertBlock)
{
_cacheExpires.MemoryCacheStore.UnblockInsert();
}
}
Debug.Assert(!inFlushHead.IsInvalid, "!inFlushHead.IsInvalid");
MemoryCacheStore cacheStore = _cacheExpires.MemoryCacheStore;
ExpiresEntryRef current = inFlushHead;
ExpiresEntryRef next;
while (!current.IsInvalid)
{
entries = (_pages[(current.PageIndex)]._entries);
entryIndex = current.Index;
next = entries[entryIndex]._next;
cacheEntry = entries[entryIndex]._cacheEntry;
entries[entryIndex]._cacheEntry = null;
Debug.Assert(cacheEntry.ExpiresEntryRef.IsInvalid, "cacheEntry.ExpiresEntryRef.IsInvalid");
cacheStore.Remove(cacheEntry, cacheEntry, CacheEntryRemovedReason.Expired);
current = next;
}
try
{
if (useInsertBlock)
{
_cacheExpires.MemoryCacheStore.BlockInsert();
}
lock (this)
{
current = inFlushHead;
while (!current.IsInvalid)
{
entries = (_pages[(current.PageIndex)]._entries);
entryIndex = current.Index;
next = entries[entryIndex]._next;
_cEntriesInFlush--;
AddExpiresEntryToFreeList(current);
current = next;
}
Debug.Assert(_cEntriesInFlush == 0, "_cEntriesInFlush == 0");
_blockReduce = false;
Reduce();
Dbg.Trace("CacheExpiresFlushTotal", "FlushExpiredItems flushed " + flushed +
" expired items, bucket=" + _bucket + "; Time=" + DateTime.Now.ToString("o", CultureInfo.InvariantCulture));
}
}
finally
{
if (useInsertBlock)
{
_cacheExpires.MemoryCacheStore.UnblockInsert();
}
}
return(flushed);
}
internal long CacheManagerThread(int minPercent)
{
if (Interlocked.Exchange(ref _inCacheManagerThread, 1) != 0)
{
return(0);
}
try
{
if (_disposed == 1)
{
return(0);
}
Dbg.Trace("MemoryCacheStats", "**BEG** CacheManagerThread " + DateTime.Now.ToString("T", CultureInfo.InvariantCulture));
// The timer thread must always call Update so that the CacheManager
// knows the size of the cache.
Update();
AdjustTimer();
int percent = Math.Max(minPercent, GetPercentToTrim());
long beginTotalCount = _memoryCache.GetCount();
long trimmedOrExpired = 0;
Stopwatch sw = new Stopwatch();
// There is a small window here where the cache could be empty, but percentToTrim is > 0.
// In this case, it makes no sense to trim, and in fact causes a divide-by-zero exception.
// See - https://github.com/dotnet/runtime/issues/1423
if (percent > 0 && beginTotalCount > 0)
{
sw.Start();
trimmedOrExpired = _memoryCache.Trim(percent);
sw.Stop();
// 1) don't update stats if the trim happend because MAX_COUNT was exceeded
// 2) don't update stats unless we removed at least one entry
if (percent > 0 && trimmedOrExpired > 0)
{
SetTrimStats(sw.Elapsed.Ticks, beginTotalCount, trimmedOrExpired);
}
}
Dbg.Trace("MemoryCacheStats", "**END** CacheManagerThread: "
+ ", percent=" + percent
+ ", beginTotalCount=" + beginTotalCount
+ ", trimmed=" + trimmedOrExpired
+ ", Milliseconds=" + sw.ElapsedMilliseconds);
#if PERF
Debug.WriteLine("CacheCommon.CacheManagerThread:"
+ " minPercent= " + minPercent
+ ", percent= " + percent
+ ", beginTotalCount=" + beginTotalCount
+ ", trimmed=" + trimmedOrExpired
+ ", Milliseconds=" + sw.ElapsedMilliseconds + Environment.NewLine);
#endif
return(trimmedOrExpired);
}
catch (ObjectDisposedException)
{
// There is a small window for _memoryCache to be disposed after we check our own
// disposed bit. No big deal.
return(0);
}
finally
{
Interlocked.Exchange(ref _inCacheManagerThread, 0);
}
}
internal int FlushUnderUsedItems(int maxFlush, bool force)
{
if (_cEntriesInUse == 0)
{
return(0);
}
Debug.Assert(maxFlush > 0, "maxFlush is not greater than 0, instead is " + maxFlush);
Debug.Assert(_cEntriesInFlush == 0, "_cEntriesInFlush == 0");
UsageEntryRef inFlushHead = UsageEntryRef.INVALID;
UsageEntryRef prev, prevNext;
DateTime utcDate;
UsageEntry[] entries;
int entryIndex;
MemoryCacheEntry cacheEntry;
int flushed = 0;
try
{
_cacheUsage.MemoryCacheStore.BlockInsert();
lock (this)
{
Debug.Assert(_blockReduce == false, "_blockReduce == false");
if (_cEntriesInUse == 0)
{
return(0);
}
DateTime utcNow = DateTime.UtcNow;
for (prev = _lastRefTail; _cEntriesInFlush < maxFlush && !prev.IsInvalid; prev = prevNext)
{
Debug.Assert(_cEntriesInUse > 0, "_cEntriesInUse > 0");
prevNext = (_pages[(prev.PageIndex)]._entries)[prev.Ref2Index]._ref2._prev;
while (prevNext.IsRef1)
{
prevNext = (_pages[(prevNext.PageIndex)]._entries)[prevNext.Ref1Index]._ref1._prev;
}
entries = (_pages[(prev.PageIndex)]._entries);
entryIndex = prev.Ref2Index;
if (!force)
{
utcDate = entries[entryIndex]._utcDate;
Debug.Assert(utcDate != DateTime.MinValue, "utcDate != DateTime.MinValue");
if (utcNow - utcDate <= CacheUsage.NEWADD_INTERVAL && utcNow >= utcDate)
{
continue;
}
}
UsageEntryRef prev1 = (new UsageEntryRef((prev).PageIndex, (prev).Ref2Index));
cacheEntry = entries[entryIndex]._cacheEntry;
Debug.Assert(cacheEntry.UsageEntryRef == prev1, "cacheEntry.UsageEntryRef == prev1");
Dbg.Trace("CacheUsageFlushUnderUsedItem", "Flushing underused items, item=" + cacheEntry.Key + ", bucket=" + _bucket);
cacheEntry.UsageEntryRef = UsageEntryRef.INVALID;
RemoveEntryFromLastRefList(prev1);
entries[entryIndex]._ref1._next = inFlushHead;
inFlushHead = prev1;
flushed++;
_cEntriesInFlush++;
}
if (flushed == 0)
{
Dbg.Trace("CacheUsageFlushTotal", "Flush(" + maxFlush + "," + force + ") removed " + flushed +
" underused items; Time=" + DateTime.Now.ToString("o", CultureInfo.InvariantCulture));
return(0);
}
_blockReduce = true;
}
}
finally
{
_cacheUsage.MemoryCacheStore.UnblockInsert();
}
Debug.Assert(!inFlushHead.IsInvalid, "!inFlushHead.IsInvalid");
MemoryCacheStore cacheStore = _cacheUsage.MemoryCacheStore;
UsageEntryRef current = inFlushHead;
UsageEntryRef next;
while (!current.IsInvalid)
{
entries = (_pages[(current.PageIndex)]._entries);
entryIndex = current.Ref1Index;
next = entries[entryIndex]._ref1._next;
cacheEntry = entries[entryIndex]._cacheEntry;
entries[entryIndex]._cacheEntry = null;
Debug.Assert(cacheEntry.UsageEntryRef.IsInvalid, "cacheEntry.UsageEntryRef.IsInvalid");
cacheStore.Remove(cacheEntry, cacheEntry, CacheEntryRemovedReason.Evicted);
current = next;
}
try
{
_cacheUsage.MemoryCacheStore.BlockInsert();
lock (this)
{
current = inFlushHead;
while (!current.IsInvalid)
{
entries = (_pages[(current.PageIndex)]._entries);
entryIndex = current.Ref1Index;
next = entries[entryIndex]._ref1._next;
_cEntriesInFlush--;
AddUsageEntryToFreeList(current);
current = next;
}
Debug.Assert(_cEntriesInFlush == 0, "_cEntriesInFlush == 0");
_blockReduce = false;
Reduce();
Dbg.Trace("CacheUsageFlushTotal", "Flush(" + maxFlush + "," + force + ") removed " + flushed +
" underused items; Time=" + DateTime.Now.ToString("o", CultureInfo.InvariantCulture));
}
}
finally
{
_cacheUsage.MemoryCacheStore.UnblockInsert();
}
return(flushed);
}
internal void UpdateCacheEntry(MemoryCacheEntry cacheEntry)
{
lock (this)
{
UsageEntryRef entryRef = cacheEntry.UsageEntryRef;
if (entryRef.IsInvalid)
{
return;
}
UsageEntry[] entries = (_pages[(entryRef.PageIndex)]._entries);
int entryIndex = entryRef.Ref1Index;
UsageEntryRef entryRef2 = (new UsageEntryRef((entryRef).PageIndex, -(entryRef).Ref1Index));
UsageEntryRef prev = entries[entryIndex]._ref2._prev;
UsageEntryRef next = entries[entryIndex]._ref2._next;
{ if ((prev).IsRef1)
{
(_pages[((prev).PageIndex)]._entries)[(prev).Ref1Index]._ref1._next = (next);
}
else if ((prev).IsRef2)
{
(_pages[((prev).PageIndex)]._entries)[(prev).Ref2Index]._ref2._next = (next);
}
else
{
_lastRefHead = (next);
} };
{ if ((next).IsRef1)
{
(_pages[((next).PageIndex)]._entries)[(next).Ref1Index]._ref1._prev = (prev);
}
else if ((next).IsRef2)
{
(_pages[((next).PageIndex)]._entries)[(next).Ref2Index]._ref2._prev = (prev);
}
else
{
_lastRefTail = (prev);
} };
if (_addRef2Head == entryRef2)
{
_addRef2Head = next;
}
entries[entryIndex]._ref2 = entries[entryIndex]._ref1;
prev = entries[entryIndex]._ref2._prev;
next = entries[entryIndex]._ref2._next;
{ if ((prev).IsRef1)
{
(_pages[((prev).PageIndex)]._entries)[(prev).Ref1Index]._ref1._next = (entryRef2);
}
else if ((prev).IsRef2)
{
(_pages[((prev).PageIndex)]._entries)[(prev).Ref2Index]._ref2._next = (entryRef2);
}
else
{
_lastRefHead = (entryRef2);
} };
{ if ((next).IsRef1)
{
(_pages[((next).PageIndex)]._entries)[(next).Ref1Index]._ref1._prev = (entryRef2);
}
else if ((next).IsRef2)
{
(_pages[((next).PageIndex)]._entries)[(next).Ref2Index]._ref2._prev = (entryRef2);
}
else
{
_lastRefTail = (entryRef2);
} };
entries[entryIndex]._ref1._prev = UsageEntryRef.INVALID;
entries[entryIndex]._ref1._next = _lastRefHead;
{ if ((_lastRefHead).IsRef1)
{
(_pages[((_lastRefHead).PageIndex)]._entries)[(_lastRefHead).Ref1Index]._ref1._prev = (entryRef);
}
else if ((_lastRefHead).IsRef2)
{
(_pages[((_lastRefHead).PageIndex)]._entries)[(_lastRefHead).Ref2Index]._ref2._prev = (entryRef);
}
else
{
_lastRefTail = (entryRef);
} };
_lastRefHead = entryRef;
Dbg.Trace("CacheUsageUpdate",
"Updated item=" + cacheEntry.Key +
",_bucket=" + _bucket +
",ref=" + entryRef);
}
}
