diff options
Diffstat (limited to 'content/browser/browser_thread_impl.cc')
| -rw-r--r-- | content/browser/browser_thread_impl.cc | 160 |
1 files changed, 90 insertions, 70 deletions
diff --git a/content/browser/browser_thread_impl.cc b/content/browser/browser_thread_impl.cc index 023259b..0025f77 100644 --- a/content/browser/browser_thread_impl.cc +++ b/content/browser/browser_thread_impl.cc @@ -4,16 +4,19 @@ #include "content/browser/browser_thread_impl.h" +#include "base/atomicops.h" #include "base/bind.h" #include "base/lazy_instance.h" #include "base/message_loop.h" #include "base/message_loop_proxy.h" #include "base/threading/thread_restrictions.h" +namespace content { + namespace { // Friendly names for the well-known threads. -static const char* browser_thread_names[content::BrowserThread::ID_COUNT] = { +static const char* g_browser_thread_names[BrowserThread::ID_COUNT] = { "", // UI (name assembled in browser_main.cc). "Chrome_DBThread", // DB "Chrome_WebKitThread", // WEBKIT @@ -26,38 +29,86 @@ static const char* browser_thread_names[content::BrowserThread::ID_COUNT] = { #endif }; -} // namespace - -namespace content { - -namespace { - -// This lock protects |g_browser_threads|. Do not read or modify that array -// without holding this lock. Do not block while holding this lock. +// This lock protects |g_browser_threads|. Do not read or modify that +// array without holding this lock. Do not block while holding this +// lock. base::LazyInstance<base::Lock, base::LeakyLazyInstanceTraits<base::Lock> > g_lock = LAZY_INSTANCE_INITIALIZER; - -// An array of the BrowserThread objects. This array is protected by |g_lock|. -// The threads are not owned by this array. Typically, the threads are owned -// on the UI thread by the g_browser_process object. BrowserThreads remove +// This array is protected by |g_lock|. The threads are not owned by this +// array. Typically, the threads are owned on the UI thread by +// content::BrowserMainLoop. BrowserThreadImpl objects remove // themselves from this array upon destruction. -BrowserThread* g_browser_threads[BrowserThread::ID_COUNT]; +static BrowserThreadImpl* g_browser_threads[BrowserThread::ID_COUNT]; + +// Only atomic operations are used on this array. The delegates are +// not owned by this array, rather by whoever calls +// BrowserThread::SetDelegate. +static BrowserThreadDelegate* g_browser_thread_delegates[ + BrowserThread::ID_COUNT]; } // namespace -BrowserThreadImpl::BrowserThreadImpl(BrowserThread::ID identifier) - : BrowserThread(identifier) { +BrowserThreadImpl::BrowserThreadImpl(ID identifier) + : Thread(g_browser_thread_names[identifier]), + identifier_(identifier) { + Initialize(); } -BrowserThreadImpl::BrowserThreadImpl(BrowserThread::ID identifier, +BrowserThreadImpl::BrowserThreadImpl(ID identifier, MessageLoop* message_loop) - : BrowserThread(identifier, message_loop) { + : Thread(message_loop->thread_name().c_str()), + identifier_(identifier) { + set_message_loop(message_loop); + Initialize(); +} + +void BrowserThreadImpl::Init() { + using base::subtle::AtomicWord; + AtomicWord* storage = + reinterpret_cast<AtomicWord*>(&g_browser_thread_delegates[identifier_]); + AtomicWord stored_pointer = base::subtle::NoBarrier_Load(storage); + BrowserThreadDelegate* delegate = + reinterpret_cast<BrowserThreadDelegate*>(stored_pointer); + if (delegate) + delegate->Init(); +} + +void BrowserThreadImpl::CleanUp() { + using base::subtle::AtomicWord; + AtomicWord* storage = + reinterpret_cast<AtomicWord*>(&g_browser_thread_delegates[identifier_]); + AtomicWord stored_pointer = base::subtle::NoBarrier_Load(storage); + BrowserThreadDelegate* delegate = + reinterpret_cast<BrowserThreadDelegate*>(stored_pointer); + + if (delegate) + delegate->CleanUp(); +} + +void BrowserThreadImpl::Initialize() { + base::AutoLock lock(g_lock.Get()); + DCHECK(identifier_ >= 0 && identifier_ < ID_COUNT); + DCHECK(g_browser_threads[identifier_] == NULL); + g_browser_threads[identifier_] = this; } BrowserThreadImpl::~BrowserThreadImpl() { + // All Thread subclasses must call Stop() in the destructor. This is + // doubly important here as various bits of code check they are on + // the right BrowserThread. Stop(); + + base::AutoLock lock(g_lock.Get()); + g_browser_threads[identifier_] = NULL; +#ifndef NDEBUG + // Double check that the threads are ordered correctly in the enumeration. + for (int i = identifier_ + 1; i < ID_COUNT; ++i) { + DCHECK(!g_browser_threads[i]) << + "Threads must be listed in the reverse order that they die"; + } +#endif } // static @@ -77,7 +128,7 @@ bool BrowserThreadImpl::PostTaskHelper( BrowserThread::ID current_thread; bool guaranteed_to_outlive_target_thread = GetCurrentThreadIdentifier(¤t_thread) && - current_thread >= identifier; + current_thread <= identifier; if (!guaranteed_to_outlive_target_thread) g_lock.Get().Acquire(); @@ -118,7 +169,7 @@ bool BrowserThreadImpl::PostTaskHelper( BrowserThread::ID current_thread; bool guaranteed_to_outlive_target_thread = GetCurrentThreadIdentifier(¤t_thread) && - current_thread >= identifier; + current_thread <= identifier; if (!guaranteed_to_outlive_target_thread) g_lock.Get().Acquire(); @@ -139,18 +190,6 @@ bool BrowserThreadImpl::PostTaskHelper( return !!message_loop; } -// TODO(joi): Remove -DeprecatedBrowserThread::DeprecatedBrowserThread(BrowserThread::ID identifier) - : BrowserThread(identifier) { -} -DeprecatedBrowserThread::DeprecatedBrowserThread(BrowserThread::ID identifier, - MessageLoop* message_loop) - : BrowserThread(identifier, message_loop) { -} -DeprecatedBrowserThread::~DeprecatedBrowserThread() { - Stop(); -} - // An implementation of MessageLoopProxy to be used in conjunction // with BrowserThread. class BrowserThreadMessageLoopProxy : public base::MessageLoopProxy { @@ -215,44 +254,6 @@ class BrowserThreadMessageLoopProxy : public base::MessageLoopProxy { DISALLOW_COPY_AND_ASSIGN(BrowserThreadMessageLoopProxy); }; -BrowserThread::BrowserThread(ID identifier) - : Thread(browser_thread_names[identifier]), - identifier_(identifier) { - Initialize(); -} - -BrowserThread::BrowserThread(ID identifier, - MessageLoop* message_loop) - : Thread(message_loop->thread_name().c_str()), - identifier_(identifier) { - set_message_loop(message_loop); - Initialize(); -} - -void BrowserThread::Initialize() { - base::AutoLock lock(g_lock.Get()); - DCHECK(identifier_ >= 0 && identifier_ < ID_COUNT); - DCHECK(g_browser_threads[identifier_] == NULL); - g_browser_threads[identifier_] = this; -} - -BrowserThread::~BrowserThread() { - // Stop the thread here, instead of the parent's class destructor. This is so - // that if there are pending tasks that run, code that checks that it's on the - // correct BrowserThread succeeds. - Stop(); - - base::AutoLock lock(g_lock.Get()); - g_browser_threads[identifier_] = NULL; -#ifndef NDEBUG - // Double check that the threads are ordered correctly in the enumeration. - for (int i = identifier_ + 1; i < ID_COUNT; ++i) { - DCHECK(!g_browser_threads[i]) << - "Threads must be listed in the reverse order that they die"; - } -#endif -} - // static bool BrowserThread::IsWellKnownThread(ID identifier) { base::AutoLock lock(g_lock.Get()); @@ -393,4 +394,23 @@ BrowserThread::GetMessageLoopProxyForThread( return proxy; } +base::Thread* BrowserThread::UnsafeGetBrowserThread(ID identifier) { + base::AutoLock lock(g_lock.Get()); + base::Thread* thread = g_browser_threads[identifier]; + DCHECK(thread); + return thread; +} + +void BrowserThread::SetDelegate(ID identifier, + BrowserThreadDelegate* delegate) { + using base::subtle::AtomicWord; + AtomicWord* storage = reinterpret_cast<AtomicWord*>( + &g_browser_thread_delegates[identifier]); + AtomicWord old_pointer = base::subtle::NoBarrier_AtomicExchange( + storage, reinterpret_cast<AtomicWord>(delegate)); + + // This catches registration when previously registered. + DCHECK(!delegate || !old_pointer); +} + } // namespace content |