diff options
| -rwxr-xr-x | indra/llcommon/llcoros.cpp | 111 | ||||
| -rwxr-xr-x | indra/llcommon/llcoros.h | 57 | ||||
| -rwxr-xr-x | indra/llcommon/lleventcoro.cpp | 4 |
3 files changed, 106 insertions, 66 deletions
diff --git a/indra/llcommon/llcoros.cpp b/indra/llcommon/llcoros.cpp index 957fe034e1..d76401d01b 100755 --- a/indra/llcommon/llcoros.cpp +++ b/indra/llcommon/llcoros.cpp @@ -34,63 +34,47 @@ // std headers // external library headers #include <boost/bind.hpp> -#include <boost/thread/tss.hpp> // other Linden headers #include "llevents.h" #include "llerror.h" #include "stringize.h" -namespace { - // do nothing, when we need nothing done -void no_cleanup(LLCoros::coro::self*) {} - -// When the dcoroutine library calls a top-level callable, it implicitly -// passes coro::self& as the first parameter. All our consumer code used to -// explicitly pass coro::self& down through all levels of call stack, because -// at the leaf level we need it for context-switching. But since coroutines -// are based on cooperative switching, we can cause the top-level entry point -// to stash a static pointer to the currently-running coroutine, and manage it -// appropriately as we switch out and back in. That eliminates the need to -// pass it as an explicit parameter down through every level, which is -// unfortunately viral in nature. Finding it implicitly rather than explicitly -// allows minor maintenance in which a leaf-level function adds a new async -// I/O call that suspends the calling coroutine, WITHOUT having to propagate -// coro::self& through every function signature down to that point -- and of -// course through every other caller of every such function. -// We use a boost::thread_specific_ptr because each thread potentially has its -// own distinct pool of coroutines. -// This thread_specific_ptr does NOT own the 'self' object! It merely -// identifies it. For this reason we instantiate it with a no-op cleanup -// function. -static boost::thread_specific_ptr<LLCoros::coro::self> -sCurrentSelf(no_cleanup); - -} // anonymous +void LLCoros::no_cleanup(CoroData*) {} + +// CoroData for the currently-running coroutine. Use a thread_specific_ptr +// because each thread potentially has its own distinct pool of coroutines. +// This thread_specific_ptr does NOT own the CoroData object! That's owned by +// LLCoros::mCoros. It merely identifies it. For this reason we instantiate +// it with a no-op cleanup function. +boost::thread_specific_ptr<LLCoros::CoroData> +LLCoros::sCurrentCoro(LLCoros::no_cleanup); //static -LLCoros::coro::self& llcoro::get_self() +LLCoros::coro::self& LLCoros::get_self() { - LLCoros::coro::self* current_self = sCurrentSelf.get(); - if (! current_self) + CoroData* current = sCurrentCoro.get(); + if (! current) { LL_ERRS("LLCoros") << "Calling get_self() from non-coroutine context!" << LL_ENDL; } - return *current_self; + return *current->mSelf; } llcoro::Suspending::Suspending(): - mSuspended(sCurrentSelf.get()) + mSuspended(LLCoros::sCurrentCoro.get()) { - // For the duration of our time away from this coroutine, sCurrentSelf - // must NOT refer to this coroutine. - sCurrentSelf.reset(); + // Revert mCurrentCoro to the value it had at the moment we last switched + // into this coroutine. + LLCoros::sCurrentCoro.reset(mSuspended->mPrev); } llcoro::Suspending::~Suspending() { - // Okay, we're back, reinstate previous value of sCurrentSelf. - sCurrentSelf.reset(mSuspended); + // Okay, we're back, update our mPrev + mSuspended->mPrev = LLCoros::sCurrentCoro.get(); + // and reinstate our sCurrentCoro. + LLCoros::sCurrentCoro.reset(mSuspended); } LLCoros::LLCoros(): @@ -112,7 +96,7 @@ bool LLCoros::cleanup(const LLSD&) { // Has this coroutine exited (normal return, exception, exit() call) // since last tick? - if (mi->second->exited()) + if (mi->second->mCoro.exited()) { LL_INFOS("LLCoros") << "LLCoros: cleaning up coroutine " << mi->first << LL_ENDL; // The erase() call will invalidate its passed iterator value -- @@ -170,18 +154,13 @@ bool LLCoros::kill(const std::string& name) std::string LLCoros::getName() const { - // Walk the existing coroutines, looking for the current one. - void* self_id = llcoro::get_self().get_id(); - for (CoroMap::const_iterator mi(mCoros.begin()), mend(mCoros.end()); mi != mend; ++mi) + CoroData* current = sCurrentCoro.get(); + if (! current) { - namespace coro_private = boost::dcoroutines::detail; - if (static_cast<void*>(coro_private::coroutine_accessor::get_impl(const_cast<coro&>(*mi->second)).get()) - == self_id) - { - return mi->first; - } + // not in a coroutine + return ""; } - return ""; + return current->mName; } void LLCoros::setStackSize(S32 stacksize) @@ -190,20 +169,20 @@ void LLCoros::setStackSize(S32 stacksize) mStackSize = stacksize; } -namespace { - // Top-level wrapper around caller's coroutine callable. This function accepts // the coroutine library's implicit coro::self& parameter and sets sCurrentSelf // but does not pass it down to the caller's callable. -void toplevel(LLCoros::coro::self& self, const LLCoros::callable_t& callable) +void LLCoros::toplevel(coro::self& self, CoroData* data, const callable_t& callable) { - sCurrentSelf.reset(&self); + // capture the 'self' param in CoroData + data->mSelf = &self; + // run the code the caller actually wants in the coroutine callable(); - sCurrentSelf.reset(); + // This cleanup isn't perfectly symmetrical with the way we initially set + // data->mPrev, but this is our last chance to reset mCurrentCoro. + sCurrentCoro.reset(data->mPrev); } -} // anonymous - /***************************************************************************** * MUST BE LAST *****************************************************************************/ @@ -215,19 +194,33 @@ void toplevel(LLCoros::coro::self& self, const LLCoros::callable_t& callable) #if LL_MSVC // work around broken optimizations #pragma warning(disable: 4748) +#pragma warning(disable: 4355) // 'this' used in initializer list: yes, intentionally #pragma optimize("", off) #endif // LL_MSVC +LLCoros::CoroData::CoroData(CoroData* prev, const std::string& name, + const callable_t& callable, S32 stacksize): + mPrev(prev), + mName(name), + // Wrap the caller's callable in our toplevel() function so we can manage + // sCurrentCoro appropriately at startup and shutdown of each coroutine. + mCoro(boost::bind(toplevel, _1, this, callable), stacksize), + mSelf(0) +{ +} + std::string LLCoros::launch(const std::string& prefix, const callable_t& callable) { std::string name(generateDistinctName(prefix)); - // Wrap the caller's callable in our toplevel() function so we can manage - // sCurrentSelf appropriately at startup and shutdown of each coroutine. - coro* newCoro = new coro(boost::bind(toplevel, _1, callable), mStackSize); + // pass the current value of sCurrentCoro as previous context + CoroData* newCoro = new CoroData(sCurrentCoro.get(), name, + callable, mStackSize); // Store it in our pointer map mCoros.insert(name, newCoro); + // also set it as current + sCurrentCoro.reset(newCoro); /* Run the coroutine until its first wait, then return here */ - (*newCoro)(std::nothrow); + (newCoro->mCoro)(std::nothrow); return name; } diff --git a/indra/llcommon/llcoros.h b/indra/llcommon/llcoros.h index e478600f00..56eed8cafe 100755 --- a/indra/llcommon/llcoros.h +++ b/indra/llcommon/llcoros.h @@ -33,9 +33,16 @@ #include "llsingleton.h" #include <boost/ptr_container/ptr_map.hpp> #include <boost/function.hpp> +#include <boost/thread/tss.hpp> #include <string> #include <stdexcept> +// forward-declare helper class +namespace llcoro +{ +class Suspending; +} + /** * Registry of named Boost.Coroutine instances * @@ -140,23 +147,63 @@ public: /// for delayed initialization void setStackSize(S32 stacksize); + /// get the current coro::self& for those who really really care + static coro::self& get_self(); + private: LLCoros(); friend class LLSingleton<LLCoros>; + friend class llcoro::Suspending; std::string generateDistinctName(const std::string& prefix) const; bool cleanup(const LLSD&); + struct CoroData; + static void no_cleanup(CoroData*); + static void toplevel(coro::self& self, CoroData* data, const callable_t& callable); S32 mStackSize; - typedef boost::ptr_map<std::string, coro> CoroMap; + + // coroutine-local storage, as it were: one per coro we track + struct CoroData + { + CoroData(CoroData* prev, const std::string& name, + const callable_t& callable, S32 stacksize); + + // The boost::dcoroutines library supports asymmetric coroutines. Every + // time we context switch out of a coroutine, we pass control to the + // previously-active one (or to the non-coroutine stack owned by the + // thread). So our management of the "current" coroutine must be able to + // restore the previous value when we're about to switch away. + CoroData* mPrev; + // tweaked name of the current coroutine + const std::string mName; + // the actual coroutine instance + LLCoros::coro mCoro; + // When the dcoroutine library calls a top-level callable, it implicitly + // passes coro::self& as the first parameter. All our consumer code used + // to explicitly pass coro::self& down through all levels of call stack, + // because at the leaf level we need it for context-switching. But since + // coroutines are based on cooperative switching, we can cause the + // top-level entry point to stash a pointer to the currently-running + // coroutine, and manage it appropriately as we switch out and back in. + // That eliminates the need to pass it as an explicit parameter down + // through every level, which is unfortunately viral in nature. Finding it + // implicitly rather than explicitly allows minor maintenance in which a + // leaf-level function adds a new async I/O call that suspends the calling + // coroutine, WITHOUT having to propagate coro::self& through every + // function signature down to that point -- and of course through every + // other caller of every such function. + LLCoros::coro::self* mSelf; + }; + typedef boost::ptr_map<std::string, CoroData> CoroMap; CoroMap mCoros; + + // identify the current coroutine's CoroData + static boost::thread_specific_ptr<LLCoros::CoroData> sCurrentCoro; }; namespace llcoro { -/// get the current coro::self& for those who really really care -LLCoros::coro::self& get_self(); - /// Instantiate one of these in a block surrounding any leaf point when /// control literally switches away from this coroutine. class Suspending @@ -166,7 +213,7 @@ public: ~Suspending(); private: - LLCoros::coro::self* mSuspended; + LLCoros::CoroData* mSuspended; }; } // namespace llcoro diff --git a/indra/llcommon/lleventcoro.cpp b/indra/llcommon/lleventcoro.cpp index ad02e139b8..85af0d9b9f 100755 --- a/indra/llcommon/lleventcoro.cpp +++ b/indra/llcommon/lleventcoro.cpp @@ -157,7 +157,7 @@ LLSD llcoro::postAndWait(const LLSD& event, const LLEventPumpOrPumpName& request const LLEventPumpOrPumpName& replyPump, const LLSD& replyPumpNamePath) { // declare the future - boost::dcoroutines::future<LLSD> future(llcoro::get_self()); + boost::dcoroutines::future<LLSD> future(LLCoros::get_self()); // make a callback that will assign a value to the future, and listen on // the specified LLEventPump with that callback std::string listenerName(listenerNameForCoro()); @@ -250,7 +250,7 @@ LLEventWithID postAndWait2(const LLSD& event, const LLSD& replyPump1NamePath) { // declare the future - boost::dcoroutines::future<LLEventWithID> future(llcoro::get_self()); + boost::dcoroutines::future<LLEventWithID> future(LLCoros::get_self()); // either callback will assign a value to this future; listen on // each specified LLEventPump with a callback std::string name(listenerNameForCoro()); |