100 lines
3.4 KiB
C#
100 lines
3.4 KiB
C#
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Microsoft Research Singularity
|
|
//
|
|
// Copyright (c) Microsoft Corporation. All rights reserved.
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
|
|
using System;
|
|
using System.Collections;
|
|
using System.Text;
|
|
|
|
namespace Singularity.Application.SPECWeb99.WebFiles
|
|
{
|
|
class Cache {
|
|
private const bool verbose = false;
|
|
private UrlSet cache;
|
|
private UrlSet free;
|
|
private int size;
|
|
|
|
public Cache(int cacheSize, int deckSize)
|
|
{
|
|
cache = new UrlSet(cacheSize);
|
|
free = new UrlSet(deckSize);
|
|
this.size = cacheSize;
|
|
}
|
|
|
|
public FileSpec GetUrl(Client/*!*/ client, int id) {
|
|
// first check the local cache
|
|
// then see if anyone else is generating the global
|
|
|
|
if (cache.pos > 0) {
|
|
return cache.urls[--cache.pos];
|
|
}
|
|
|
|
// return local free to global free pool
|
|
|
|
client.globalLock.WaitOne();
|
|
while (free.pos > 0) {
|
|
if (client.freeDeck.pos >= client.freeDeck.urls.Length) {
|
|
//Console.WriteLine(" too many free slots!");
|
|
free.urls[--free.pos] = null;
|
|
//DebugStub.Break();
|
|
free.pos--;
|
|
}
|
|
else {
|
|
client.freeDeck.urls[client.freeDeck.pos++] =
|
|
free.urls[--free.pos];
|
|
}
|
|
}
|
|
|
|
// now see if there are any urls available
|
|
// if not either wait on or generate the global deck
|
|
|
|
while (client.urlDeck.pos == 0){
|
|
if (client.generatingUrls == false) {
|
|
//Console.WriteLine("Generating cache");
|
|
UrlSet temp = client.urlDeck;
|
|
client.urlDeck = client.spareDeck;
|
|
client.spareDeck = temp;
|
|
client.generatingUrls = true;
|
|
client.syncLock.WaitOne();
|
|
client.globalLock.ReleaseMutex();
|
|
client.GenerateFileSpecs();
|
|
client.globalLock.WaitOne();
|
|
client.generatingUrls = false;
|
|
client.syncLock.ReleaseMutex();
|
|
}
|
|
else {
|
|
//Console.WriteLine("Waiting for cache");
|
|
client.globalLock.ReleaseMutex();
|
|
client.syncLock.WaitOne();
|
|
client.syncLock.ReleaseMutex();
|
|
client.globalLock.WaitOne();
|
|
}
|
|
}
|
|
|
|
// the global deck is ok -- prime our cache
|
|
|
|
if (client.urlDeck.pos > 0 ) {
|
|
for (int i =0; i < cache.urls.Length && (client.urlDeck.pos > 0); i++) {
|
|
cache.urls[cache.pos++] =
|
|
client.urlDeck.urls[--client.urlDeck.pos];
|
|
}
|
|
}
|
|
client.globalLock.ReleaseMutex();
|
|
return cache.urls[--cache.pos];
|
|
}
|
|
|
|
public void FreeUrl(FileSpec url) {
|
|
if (free.pos+1 >= free.urls.Length) {
|
|
//Console.WriteLine("free cache full! de-allocating");
|
|
url = null;
|
|
return;
|
|
}
|
|
free.urls[free.pos++] = url;
|
|
}
|
|
}
|
|
}
|