1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/netwerk/cache2/CacheIOThread.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,347 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +#include "CacheIOThread.h"
1.9 +#include "CacheFileIOManager.h"
1.10 +
1.11 +#include "nsIRunnable.h"
1.12 +#include "nsISupportsImpl.h"
1.13 +#include "nsPrintfCString.h"
1.14 +#include "nsThreadUtils.h"
1.15 +#include "mozilla/IOInterposer.h"
1.16 +#include "mozilla/VisualEventTracer.h"
1.17 +
1.18 +namespace mozilla {
1.19 +namespace net {
1.20 +
1.21 +CacheIOThread* CacheIOThread::sSelf = nullptr;
1.22 +
1.23 +NS_IMPL_ISUPPORTS(CacheIOThread, nsIThreadObserver)
1.24 +
1.25 +CacheIOThread::CacheIOThread()
1.26 +: mMonitor("CacheIOThread")
1.27 +, mThread(nullptr)
1.28 +, mLowestLevelWaiting(LAST_LEVEL)
1.29 +, mCurrentlyExecutingLevel(0)
1.30 +, mHasXPCOMEvents(false)
1.31 +, mRerunCurrentEvent(false)
1.32 +, mShutdown(false)
1.33 +{
1.34 + sSelf = this;
1.35 +}
1.36 +
1.37 +CacheIOThread::~CacheIOThread()
1.38 +{
1.39 + sSelf = nullptr;
1.40 +#ifdef DEBUG
1.41 + for (uint32_t level = 0; level < LAST_LEVEL; ++level) {
1.42 + MOZ_ASSERT(!mEventQueue[level].Length());
1.43 + }
1.44 +#endif
1.45 +}
1.46 +
1.47 +nsresult CacheIOThread::Init()
1.48 +{
1.49 + mThread = PR_CreateThread(PR_USER_THREAD, ThreadFunc, this,
1.50 + PR_PRIORITY_NORMAL, PR_GLOBAL_THREAD,
1.51 + PR_JOINABLE_THREAD, 128 * 1024);
1.52 + if (!mThread)
1.53 + return NS_ERROR_FAILURE;
1.54 +
1.55 + return NS_OK;
1.56 +}
1.57 +
1.58 +nsresult CacheIOThread::Dispatch(nsIRunnable* aRunnable, uint32_t aLevel)
1.59 +{
1.60 + NS_ENSURE_ARG(aLevel < LAST_LEVEL);
1.61 +
1.62 + MonitorAutoLock lock(mMonitor);
1.63 +
1.64 + if (mShutdown && (PR_GetCurrentThread() != mThread))
1.65 + return NS_ERROR_UNEXPECTED;
1.66 +
1.67 + return DispatchInternal(aRunnable, aLevel);
1.68 +}
1.69 +
1.70 +nsresult CacheIOThread::DispatchAfterPendingOpens(nsIRunnable* aRunnable)
1.71 +{
1.72 + MonitorAutoLock lock(mMonitor);
1.73 +
1.74 + if (mShutdown && (PR_GetCurrentThread() != mThread))
1.75 + return NS_ERROR_UNEXPECTED;
1.76 +
1.77 + // Move everything from later executed OPEN level to the OPEN_PRIORITY level
1.78 + // where we post the (eviction) runnable.
1.79 + mEventQueue[OPEN_PRIORITY].AppendElements(mEventQueue[OPEN]);
1.80 + mEventQueue[OPEN].Clear();
1.81 +
1.82 + return DispatchInternal(aRunnable, OPEN_PRIORITY);
1.83 +}
1.84 +
1.85 +nsresult CacheIOThread::DispatchInternal(nsIRunnable* aRunnable, uint32_t aLevel)
1.86 +{
1.87 + mMonitor.AssertCurrentThreadOwns();
1.88 +
1.89 + mEventQueue[aLevel].AppendElement(aRunnable);
1.90 + if (mLowestLevelWaiting > aLevel)
1.91 + mLowestLevelWaiting = aLevel;
1.92 +
1.93 + mMonitor.NotifyAll();
1.94 +
1.95 + return NS_OK;
1.96 +}
1.97 +
1.98 +bool CacheIOThread::IsCurrentThread()
1.99 +{
1.100 + return mThread == PR_GetCurrentThread();
1.101 +}
1.102 +
1.103 +bool CacheIOThread::YieldInternal()
1.104 +{
1.105 + if (!IsCurrentThread()) {
1.106 + NS_WARNING("Trying to yield to priority events on non-cache2 I/O thread? "
1.107 + "You probably do something wrong.");
1.108 + return false;
1.109 + }
1.110 +
1.111 + if (mCurrentlyExecutingLevel == XPCOM_LEVEL) {
1.112 + // Doesn't make any sense, since this handler is the one
1.113 + // that would be executed as the next one.
1.114 + return false;
1.115 + }
1.116 +
1.117 + if (!EventsPending(mCurrentlyExecutingLevel))
1.118 + return false;
1.119 +
1.120 + mRerunCurrentEvent = true;
1.121 + return true;
1.122 +}
1.123 +
1.124 +nsresult CacheIOThread::Shutdown()
1.125 +{
1.126 + {
1.127 + MonitorAutoLock lock(mMonitor);
1.128 + mShutdown = true;
1.129 + mMonitor.NotifyAll();
1.130 + }
1.131 +
1.132 + PR_JoinThread(mThread);
1.133 + mThread = nullptr;
1.134 +
1.135 + return NS_OK;
1.136 +}
1.137 +
1.138 +already_AddRefed<nsIEventTarget> CacheIOThread::Target()
1.139 +{
1.140 + nsCOMPtr<nsIEventTarget> target;
1.141 +
1.142 + target = mXPCOMThread;
1.143 + if (!target && mThread)
1.144 + {
1.145 + MonitorAutoLock lock(mMonitor);
1.146 + if (!mXPCOMThread)
1.147 + lock.Wait();
1.148 +
1.149 + target = mXPCOMThread;
1.150 + }
1.151 +
1.152 + return target.forget();
1.153 +}
1.154 +
1.155 +// static
1.156 +void CacheIOThread::ThreadFunc(void* aClosure)
1.157 +{
1.158 + PR_SetCurrentThreadName("Cache2 I/O");
1.159 + mozilla::IOInterposer::RegisterCurrentThread();
1.160 + CacheIOThread* thread = static_cast<CacheIOThread*>(aClosure);
1.161 + thread->ThreadFunc();
1.162 + mozilla::IOInterposer::UnregisterCurrentThread();
1.163 +}
1.164 +
1.165 +void CacheIOThread::ThreadFunc()
1.166 +{
1.167 + nsCOMPtr<nsIThreadInternal> threadInternal;
1.168 +
1.169 + {
1.170 + MonitorAutoLock lock(mMonitor);
1.171 +
1.172 + // This creates nsThread for this PRThread
1.173 + nsCOMPtr<nsIThread> xpcomThread = NS_GetCurrentThread();
1.174 +
1.175 + threadInternal = do_QueryInterface(xpcomThread);
1.176 + if (threadInternal)
1.177 + threadInternal->SetObserver(this);
1.178 +
1.179 + mXPCOMThread.swap(xpcomThread);
1.180 +
1.181 + lock.NotifyAll();
1.182 +
1.183 + do {
1.184 +loopStart:
1.185 + // Reset the lowest level now, so that we can detect a new event on
1.186 + // a lower level (i.e. higher priority) has been scheduled while
1.187 + // executing any previously scheduled event.
1.188 + mLowestLevelWaiting = LAST_LEVEL;
1.189 +
1.190 + // Process xpcom events first
1.191 + while (mHasXPCOMEvents) {
1.192 + eventtracer::AutoEventTracer tracer(this, eventtracer::eExec, eventtracer::eDone,
1.193 + "net::cache::io::level(xpcom)");
1.194 +
1.195 + mHasXPCOMEvents = false;
1.196 + mCurrentlyExecutingLevel = XPCOM_LEVEL;
1.197 +
1.198 + MonitorAutoUnlock unlock(mMonitor);
1.199 +
1.200 + bool processedEvent;
1.201 + nsresult rv;
1.202 + do {
1.203 + rv = mXPCOMThread->ProcessNextEvent(false, &processedEvent);
1.204 + } while (NS_SUCCEEDED(rv) && processedEvent);
1.205 + }
1.206 +
1.207 + uint32_t level;
1.208 + for (level = 0; level < LAST_LEVEL; ++level) {
1.209 + if (!mEventQueue[level].Length()) {
1.210 + // no events on this level, go to the next level
1.211 + continue;
1.212 + }
1.213 +
1.214 + LoopOneLevel(level);
1.215 +
1.216 + // Go to the first (lowest) level again
1.217 + goto loopStart;
1.218 + }
1.219 +
1.220 + if (EventsPending())
1.221 + continue;
1.222 +
1.223 + if (mShutdown)
1.224 + break;
1.225 +
1.226 + lock.Wait(PR_INTERVAL_NO_TIMEOUT);
1.227 +
1.228 + if (EventsPending())
1.229 + continue;
1.230 +
1.231 + } while (true);
1.232 +
1.233 + MOZ_ASSERT(!EventsPending());
1.234 + } // lock
1.235 +
1.236 + if (threadInternal)
1.237 + threadInternal->SetObserver(nullptr);
1.238 +}
1.239 +
1.240 +static const char* const sLevelTraceName[] = {
1.241 + "net::cache::io::level(0)",
1.242 + "net::cache::io::level(1)",
1.243 + "net::cache::io::level(2)",
1.244 + "net::cache::io::level(3)",
1.245 + "net::cache::io::level(4)",
1.246 + "net::cache::io::level(5)",
1.247 + "net::cache::io::level(6)",
1.248 + "net::cache::io::level(7)",
1.249 + "net::cache::io::level(8)",
1.250 + "net::cache::io::level(9)",
1.251 + "net::cache::io::level(10)",
1.252 + "net::cache::io::level(11)",
1.253 + "net::cache::io::level(12)"
1.254 +};
1.255 +
1.256 +void CacheIOThread::LoopOneLevel(uint32_t aLevel)
1.257 +{
1.258 + eventtracer::AutoEventTracer tracer(this, eventtracer::eExec, eventtracer::eDone,
1.259 + sLevelTraceName[aLevel]);
1.260 +
1.261 + nsTArray<nsRefPtr<nsIRunnable> > events;
1.262 + events.SwapElements(mEventQueue[aLevel]);
1.263 + uint32_t length = events.Length();
1.264 +
1.265 + mCurrentlyExecutingLevel = aLevel;
1.266 +
1.267 + bool returnEvents = false;
1.268 + uint32_t index;
1.269 + {
1.270 + MonitorAutoUnlock unlock(mMonitor);
1.271 +
1.272 + for (index = 0; index < length; ++index) {
1.273 + if (EventsPending(aLevel)) {
1.274 + // Somebody scheduled a new event on a lower level, break and harry
1.275 + // to execute it! Don't forget to return what we haven't exec.
1.276 + returnEvents = true;
1.277 + break;
1.278 + }
1.279 +
1.280 + // Drop any previous flagging, only an event on the current level may set
1.281 + // this flag.
1.282 + mRerunCurrentEvent = false;
1.283 +
1.284 + events[index]->Run();
1.285 +
1.286 + if (mRerunCurrentEvent) {
1.287 + // The event handler yields to higher priority events and wants to rerun.
1.288 + returnEvents = true;
1.289 + break;
1.290 + }
1.291 +
1.292 + // Release outside the lock.
1.293 + events[index] = nullptr;
1.294 + }
1.295 + }
1.296 +
1.297 + if (returnEvents)
1.298 + mEventQueue[aLevel].InsertElementsAt(0, events.Elements() + index, length - index);
1.299 +}
1.300 +
1.301 +bool CacheIOThread::EventsPending(uint32_t aLastLevel)
1.302 +{
1.303 + return mLowestLevelWaiting < aLastLevel || mHasXPCOMEvents;
1.304 +}
1.305 +
1.306 +NS_IMETHODIMP CacheIOThread::OnDispatchedEvent(nsIThreadInternal *thread)
1.307 +{
1.308 + MonitorAutoLock lock(mMonitor);
1.309 + mHasXPCOMEvents = true;
1.310 + MOZ_ASSERT(!mShutdown || (PR_GetCurrentThread() == mThread));
1.311 + lock.Notify();
1.312 + return NS_OK;
1.313 +}
1.314 +
1.315 +NS_IMETHODIMP CacheIOThread::OnProcessNextEvent(nsIThreadInternal *thread, bool mayWait, uint32_t recursionDepth)
1.316 +{
1.317 + return NS_OK;
1.318 +}
1.319 +
1.320 +NS_IMETHODIMP CacheIOThread::AfterProcessNextEvent(nsIThreadInternal *thread, uint32_t recursionDepth,
1.321 + bool eventWasProcessed)
1.322 +{
1.323 + return NS_OK;
1.324 +}
1.325 +
1.326 +// Memory reporting
1.327 +
1.328 +size_t CacheIOThread::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
1.329 +{
1.330 + MonitorAutoLock lock(const_cast<CacheIOThread*>(this)->mMonitor);
1.331 +
1.332 + size_t n = 0;
1.333 + n += mallocSizeOf(mThread);
1.334 + for (uint32_t level = 0; level < LAST_LEVEL; ++level) {
1.335 + n += mEventQueue[level].SizeOfExcludingThis(mallocSizeOf);
1.336 + // Events referenced by the queues are arbitrary objects we cannot be sure
1.337 + // are reported elsewhere as well as probably not implementing nsISizeOf
1.338 + // interface. Deliberatly omitting them from reporting here.
1.339 + }
1.340 +
1.341 + return n;
1.342 +}
1.343 +
1.344 +size_t CacheIOThread::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
1.345 +{
1.346 + return mallocSizeOf(this) + SizeOfExcludingThis(mallocSizeOf);
1.347 +}
1.348 +
1.349 +} // net
1.350 +} // mozilla
