diff options
Diffstat (limited to 'indra/llcommon/llcoros.cpp')
| -rw-r--r-- | indra/llcommon/llcoros.cpp | 159 |
1 files changed, 124 insertions, 35 deletions
diff --git a/indra/llcommon/llcoros.cpp b/indra/llcommon/llcoros.cpp index 8e516d8beb..934f04287d 100644 --- a/indra/llcommon/llcoros.cpp +++ b/indra/llcommon/llcoros.cpp @@ -40,32 +40,83 @@ #include "stringize.h" #include "llexception.h" -// do nothing, when we need nothing done +#if LL_WINDOWS +#include <excpt.h> +#endif + +namespace { +void no_op() {} +} // anonymous namespace + +// Do nothing, when we need nothing done. This is a static member of LLCoros +// because CoroData is a private nested class. 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); +LLCoros::Current::Current() +{ + // Use a function-static instance so this thread_specific_ptr is + // instantiated on demand. Since we happen to know it's consumed by + // LLSingleton, this is likely to happen before the runtime has finished + // initializing module-static data. For the same reason, we can't package + // this pointer in an LLSingleton. + + // 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. + static boost::thread_specific_ptr<LLCoros::CoroData> sCurrent(LLCoros::no_cleanup); + + // If this is the first time we're accessing sCurrent for the running + // thread, its get() will be NULL. This could be a problem, in that + // llcoro::get_id() would return the same (NULL) token value for the "main + // coroutine" in every thread, whereas what we really want is a distinct + // value for every distinct stack in the process. So if get() is NULL, + // give it a heap CoroData: this ensures that llcoro::get_id() will return + // distinct values. + // This tactic is "leaky": sCurrent explicitly does not destroy any + // CoroData to which it points, and we do NOT enter these "main coroutine" + // CoroData instances in the LLCoros::mCoros map. They are dummy entries, + // and they will leak at process shutdown: one CoroData per thread. + if (! sCurrent.get()) + { + // It's tempting to provide a distinct name for each thread's "main + // coroutine." But as getName() has always returned the empty string + // to mean "not in a coroutine," empty string should suffice here -- + // and truthfully the additional (thread-safe!) machinery to ensure + // uniqueness just doesn't feel worth the trouble. + // We use a no-op callable and a minimal stack size because, although + // CoroData's constructor in fact initializes its mCoro with a + // coroutine with that stack size, no one ever actually enters it by + // calling mCoro(). + sCurrent.reset(new CoroData(0, // no prev + "", // not a named coroutine + no_op, // no-op callable + 1024)); // stacksize moot + } + + mCurrent = &sCurrent; +} //static LLCoros::CoroData& LLCoros::get_CoroData(const std::string& caller) { - CoroData* current = sCurrentCoro.get(); - if (! current) - { - LL_ERRS("LLCoros") << "Calling " << caller << " from non-coroutine context!" << LL_ENDL; - } + CoroData* current = Current(); + // With the dummy CoroData set in LLCoros::Current::Current(), this + // pointer should never be NULL. + llassert_always(current); return *current; } //static LLCoros::coro::self& LLCoros::get_self() { - return *get_CoroData("get_self()").mSelf; + CoroData& current = get_CoroData("get_self()"); + if (! current.mSelf) + { + LL_ERRS("LLCoros") << "Calling get_self() from non-coroutine context!" << LL_ENDL; + } + return *current.mSelf; } //static @@ -80,20 +131,23 @@ bool LLCoros::get_consuming() return get_CoroData("get_consuming()").mConsuming; } -llcoro::Suspending::Suspending(): - mSuspended(LLCoros::sCurrentCoro.get()) +llcoro::Suspending::Suspending() { - // Revert mCurrentCoro to the value it had at the moment we last switched + LLCoros::Current current; + // Remember currently-running coroutine: we're about to suspend it. + mSuspended = current; + // Revert Current to the value it had at the moment we last switched // into this coroutine. - LLCoros::sCurrentCoro.reset(mSuspended->mPrev); + current.reset(mSuspended->mPrev); } llcoro::Suspending::~Suspending() { + LLCoros::Current current; // Okay, we're back, update our mPrev - mSuspended->mPrev = LLCoros::sCurrentCoro.get(); - // and reinstate our sCurrentCoro. - LLCoros::sCurrentCoro.reset(mSuspended); + mSuspended->mPrev = current; + // and reinstate our Current. + current.reset(mSuspended); } LLCoros::LLCoros(): @@ -213,13 +267,7 @@ bool LLCoros::kill(const std::string& name) std::string LLCoros::getName() const { - CoroData* current = sCurrentCoro.get(); - if (! current) - { - // not in a coroutine - return ""; - } - return current->mName; + return Current()->mName; } void LLCoros::setStackSize(S32 stacksize) @@ -228,9 +276,46 @@ void LLCoros::setStackSize(S32 stacksize) mStackSize = stacksize; } +#if LL_WINDOWS + +static const U32 STATUS_MSC_EXCEPTION = 0xE06D7363; // compiler specific + +U32 exception_filter(U32 code, struct _EXCEPTION_POINTERS *exception_infop) +{ + if (code == STATUS_MSC_EXCEPTION) + { + // C++ exception, go on + return EXCEPTION_CONTINUE_SEARCH; + } + else + { + // handle it + return EXCEPTION_EXECUTE_HANDLER; + } +} + +void LLCoros::winlevel(const callable_t& callable) +{ + __try + { + callable(); + } + __except (exception_filter(GetExceptionCode(), GetExceptionInformation())) + { + // convert to C++ styled exception + // Note: it might be better to use _se_set_translator + // if you want exception to inherit full callstack + char integer_string[32]; + sprintf(integer_string, "SEH, code: %lu\n", GetExceptionCode()); + throw std::exception(integer_string); + } +} + +#endif + // 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. +// the coroutine library's implicit coro::self& parameter and saves it, but +// does not pass it down to the caller's callable. void LLCoros::toplevel(coro::self& self, CoroData* data, const callable_t& callable) { // capture the 'self' param in CoroData @@ -238,7 +323,11 @@ void LLCoros::toplevel(coro::self& self, CoroData* data, const callable_t& calla // run the code the caller actually wants in the coroutine try { +#if LL_WINDOWS + winlevel(callable); +#else callable(); +#endif } catch (const LLContinueError&) { @@ -254,8 +343,8 @@ void LLCoros::toplevel(coro::self& self, CoroData* data, const callable_t& calla CRASH_ON_UNHANDLED_EXCEPTION(STRINGIZE("coroutine " << data->mName)); } // 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); + // data->mPrev, but this is our last chance to reset Current. + Current().reset(data->mPrev); } /***************************************************************************** @@ -278,7 +367,7 @@ LLCoros::CoroData::CoroData(CoroData* prev, const std::string& name, 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. + // Current appropriately at startup and shutdown of each coroutine. mCoro(boost::bind(toplevel, _1, this, callable), stacksize), // don't consume events unless specifically directed mConsuming(false), @@ -289,13 +378,13 @@ LLCoros::CoroData::CoroData(CoroData* prev, const std::string& name, std::string LLCoros::launch(const std::string& prefix, const callable_t& callable) { std::string name(generateDistinctName(prefix)); - // pass the current value of sCurrentCoro as previous context - CoroData* newCoro = new CoroData(sCurrentCoro.get(), name, - callable, mStackSize); + Current current; + // pass the current value of Current as previous context + CoroData* newCoro = new CoroData(current, name, callable, mStackSize); // Store it in our pointer map mCoros.insert(name, newCoro); // also set it as current - sCurrentCoro.reset(newCoro); + current.reset(newCoro); /* Run the coroutine until its first wait, then return here */ (newCoro->mCoro)(std::nothrow); return name; |