diff options
Diffstat (limited to 'indra/llcommon/llcoros.h')
| -rw-r--r-- | indra/llcommon/llcoros.h | 275 |
1 files changed, 138 insertions, 137 deletions
diff --git a/indra/llcommon/llcoros.h b/indra/llcommon/llcoros.h index c551413811..38c2356c99 100644 --- a/indra/llcommon/llcoros.h +++ b/indra/llcommon/llcoros.h @@ -29,21 +29,26 @@ #if ! defined(LL_LLCOROS_H) #define LL_LLCOROS_H -#include <boost/dcoroutine/coroutine.hpp> -#include <boost/dcoroutine/future.hpp> +#include "llexception.h" +#include <boost/fiber/fss.hpp> +#include <boost/fiber/future/promise.hpp> +#include <boost/fiber/future/future.hpp> +#include "mutex.h" #include "llsingleton.h" -#include <boost/ptr_container/ptr_map.hpp> +#include "llinstancetracker.h" #include <boost/function.hpp> -#include <boost/thread/tss.hpp> -#include <boost/noncopyable.hpp> #include <string> -#include <stdexcept> -#include "llcoro_get_id.h" // for friend declaration -// forward-declare helper class -namespace llcoro -{ -class Suspending; +// e.g. #include LLCOROS_MUTEX_HEADER +#define LLCOROS_MUTEX_HEADER <boost/fiber/mutex.hpp> +#define LLCOROS_CONDVAR_HEADER <boost/fiber/condition_variable.hpp> + +namespace boost { + namespace fibers { + class mutex; + enum class cv_status; + class condition_variable; + } } /** @@ -76,19 +81,21 @@ class Suspending; * name prefix; from your prefix it generates a distinct name, registers the * new coroutine and returns the actual name. * - * The name can be used to kill off the coroutine prematurely, if needed. It - * can also provide diagnostic info: we can look up the name of the + * The name + * can provide diagnostic info: we can look up the name of the * currently-running coroutine. - * - * Finally, the next frame ("mainloop" event) after the coroutine terminates, - * LLCoros will notice its demise and destroy it. */ class LL_COMMON_API LLCoros: public LLSingleton<LLCoros> { LLSINGLETON(LLCoros); + ~LLCoros(); public: - /// Canonical boost::dcoroutines::coroutine signature we use - typedef boost::dcoroutines::coroutine<void()> coro; + /// The viewer's use of the term "coroutine" became deeply embedded before + /// the industry term "fiber" emerged to distinguish userland threads from + /// simpler, more transient kinds of coroutines. Semantically they've + /// always been fibers. But at this point in history, we're pretty much + /// stuck with the term "coroutine." + typedef boost::fibers::fiber coro; /// Canonical callable type typedef boost::function<void()> callable_t; @@ -119,10 +126,10 @@ public: * DEV-32777 comments for an explanation. * * Pass a nullary callable. It works to directly pass a nullary free - * function (or static method); for all other cases use boost::bind(). Of - * course, for a non-static class method, the first parameter must be the - * class instance. Any other parameters should be passed via the bind() - * expression. + * function (or static method); for other cases use a lambda expression, + * std::bind() or boost::bind(). Of course, for a non-static class method, + * the first parameter must be the class instance. Any other parameters + * should be passed via the enclosing expression. * * launch() tweaks the suggested name so it won't collide with any * existing coroutine instance, creates the coroutine instance, registers @@ -138,7 +145,7 @@ public: * one prematurely. Returns @c true if the specified name was found and * still running at the time. */ - bool kill(const std::string& name); +// bool kill(const std::string& name); /** * From within a coroutine, look up the (tweaked) name string by which @@ -146,16 +153,27 @@ public: * (e.g. if the coroutine was launched by hand rather than using * LLCoros::launch()). */ - std::string getName() const; + static std::string getName(); - /// for delayed initialization + /** + * This variation returns a name suitable for log messages: the explicit + * name for an explicitly-launched coroutine, or "mainN" for the default + * coroutine on a thread. + */ + static std::string logname(); + + /** + * For delayed initialization. To be clear, this will only affect + * coroutines launched @em after this point. The underlying facility + * provides no way to alter the stack size of any running coroutine. + */ void setStackSize(S32 stacksize); - /// for delayed initialization - void printActiveCoroutines(); + /// diagnostic + void printActiveCoroutines(const std::string& when=std::string()); - /// get the current coro::self& for those who really really care - static coro::self& get_self(); + /// get the current coro::id for those who really really care + static coro::id get_self(); /** * Most coroutines, most of the time, don't "consume" the events for which @@ -180,6 +198,7 @@ public: { set_consuming(consuming); } + OverrideConsuming(const OverrideConsuming&) = delete; ~OverrideConsuming() { set_consuming(mPrevConsuming); @@ -189,142 +208,124 @@ public: bool mPrevConsuming; }; + /// set string coroutine status for diagnostic purposes + static void setStatus(const std::string& status); + static std::string getStatus(); + + /// RAII control of status + class TempStatus + { + public: + TempStatus(const std::string& status): + mOldStatus(getStatus()) + { + setStatus(status); + } + TempStatus(const TempStatus&) = delete; + ~TempStatus() + { + setStatus(mOldStatus); + } + + private: + std::string mOldStatus; + }; + + /// thrown by checkStop() + // It may sound ironic that Stop is derived from LLContinueError, but the + // point is that LLContinueError is the category of exception that should + // not immediately crash the viewer. Stop and its subclasses are to notify + // coroutines that the viewer intends to shut down. The expected response + // is to terminate the coroutine, rather than abort the viewer. + struct Stop: public LLContinueError + { + Stop(const std::string& what): LLContinueError(what) {} + }; + + /// early stages + struct Stopping: public Stop + { + Stopping(const std::string& what): Stop(what) {} + }; + + /// cleaning up + struct Stopped: public Stop + { + Stopped(const std::string& what): Stop(what) {} + }; + + /// cleaned up -- not much survives! + struct Shutdown: public Stop + { + Shutdown(const std::string& what): Stop(what) {} + }; + + /// Call this intermittently if there's a chance your coroutine might + /// continue running into application shutdown. Throws Stop if LLCoros has + /// been cleaned up. + static void checkStop(); + /** - * Please do NOT directly use boost::dcoroutines::future! It is essential - * to maintain the "current" coroutine at every context switch. This - * Future wraps the essential boost::dcoroutines::future functionality - * with that maintenance. + * Aliases for promise and future. An older underlying future implementation + * required us to wrap future; that's no longer needed. However -- if it's + * important to restore kill() functionality, we might need to provide a + * proxy, so continue using the aliases. */ template <typename T> - class Future; + using Promise = boost::fibers::promise<T>; + template <typename T> + using Future = boost::fibers::future<T>; + template <typename T> + static Future<T> getFuture(Promise<T>& promise) { return promise.get_future(); } + + // use mutex, lock, condition_variable suitable for coroutines + using Mutex = boost::fibers::mutex; + using LockType = std::unique_lock<Mutex>; + using cv_status = boost::fibers::cv_status; + using ConditionVariable = boost::fibers::condition_variable; + + /// for data local to each running coroutine + template <typename T> + using local_ptr = boost::fibers::fiber_specific_ptr<T>; private: - friend class llcoro::Suspending; - friend llcoro::id llcoro::get_id(); std::string generateDistinctName(const std::string& prefix) const; - bool cleanup(const LLSD&); + void toplevel(std::string name, callable_t callable); struct CoroData; - static void no_cleanup(CoroData*); #if LL_WINDOWS static void winlevel(const callable_t& callable); #endif - static void toplevel(coro::self& self, CoroData* data, const callable_t& callable); static CoroData& get_CoroData(const std::string& caller); S32 mStackSize; // coroutine-local storage, as it were: one per coro we track - struct CoroData + struct CoroData: public LLInstanceTracker<CoroData, std::string> { - 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; + CoroData(const std::string& name); + CoroData(int n); + // tweaked name of the current coroutine const std::string mName; - // the actual coroutine instance - LLCoros::coro mCoro; // set_consuming() state bool mConsuming; - // 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; + // setStatus() state + std::string mStatus; F64 mCreationTime; // since epoch }; - typedef boost::ptr_map<std::string, CoroData> CoroMap; - CoroMap mCoros; - // Identify the current coroutine's CoroData. Use a little helper class so - // a caller can either use a temporary instance, or instantiate a named - // variable and access it multiple times. - class Current - { - public: - Current(); - - operator LLCoros::CoroData*() { return get(); } - LLCoros::CoroData* operator->() { return get(); } - LLCoros::CoroData* get() { return mCurrent->get(); } - void reset(LLCoros::CoroData* ptr) { mCurrent->reset(ptr); } - - private: - boost::thread_specific_ptr<LLCoros::CoroData>* mCurrent; - }; + // Identify the current coroutine's CoroData. This local_ptr isn't static + // because it's a member of an LLSingleton, and we rely on it being + // cleaned up in proper dependency order. + local_ptr<CoroData> mCurrent; }; namespace llcoro { -/// Instantiate one of these in a block surrounding any leaf point when -/// control literally switches away from this coroutine. -class Suspending: boost::noncopyable -{ -public: - Suspending(); - ~Suspending(); - -private: - LLCoros::CoroData* mSuspended; -}; - -} // namespace llcoro - -template <typename T> -class LLCoros::Future -{ - typedef boost::dcoroutines::future<T> dfuture; - -public: - Future(): - mFuture(get_self()) - {} - - typedef typename boost::dcoroutines::make_callback_result<dfuture>::type callback_t; - - callback_t make_callback() - { - return boost::dcoroutines::make_callback(mFuture); - } - -#ifndef LL_LINUX - explicit -#endif - operator bool() const - { - return bool(mFuture); - } - - bool operator!() const - { - return ! mFuture; - } +inline +std::string logname() { return LLCoros::logname(); } - T get() - { - // instantiate Suspending to manage the "current" coroutine - llcoro::Suspending suspended; - return *mFuture; - } - -private: - dfuture mFuture; -}; +} // llcoro #endif /* ! defined(LL_LLCOROS_H) */ |