/* * UNIVERSE.CPP Copyright (c) 2017-2024, Benoit Germain */ /* =============================================================================== Copyright (C) 2017-2024 Benoit Germain Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. =============================================================================== */ #include "_pch.hpp" #include "universe.hpp" #include "deep.hpp" #include "intercopycontext.hpp" #include "keeper.hpp" #include "lane.hpp" #include "linda.hpp" #include "state.hpp" extern LUAG_FUNC(linda); // ################################################################################################# static constexpr std::string_view kOnStateCreate{ "on_state_create" }; // update lanes.lua if the name changes! // ################################################################################################# // xxh64 of string "kUniverseFullRegKey" generated at https://www.pelock.com/products/hash-calculator static constexpr RegistryUniqueKey kUniverseFullRegKey{ 0x1C2D76870DD9DD9Full }; // ################################################################################################# Universe::Universe() { //--- // Linux needs SCHED_RR to change thread priorities, and that is only // allowed for sudo'ers. SCHED_OTHER (default) has no priorities. // SCHED_OTHER threads are always lower priority than SCHED_RR. // // ^-- those apply to 2.6 kernel. IF **wishful thinking** these // constraints will change in the future, non-sudo priorities can // be enabled also for Linux. // #ifdef PLATFORM_LINUX // If lower priorities (-2..-1) are wanted, we need to lift the main // thread to SCHED_RR and 50 (medium) level. Otherwise, we're always below // the launched threads (even -2). // #ifdef LINUX_SCHED_RR if (sudo) { struct sched_param sp; sp.sched_priority = _PRIO_0; PT_CALL(pthread_setschedparam(pthread_self(), SCHED_RR, &sp)); } #endif // LINUX_SCHED_RR #endif // PLATFORM_LINUX } // ################################################################################################# void Universe::callOnStateCreate(lua_State* const L_, lua_State* const from_, LookupMode const mode_) { if (std::holds_alternative(onStateCreateFunc)) { return; } STACK_CHECK_START_REL(L_, 0); DEBUGSPEW_CODE(DebugSpew(this) << "calling on_state_create()" << std::endl); if (std::holds_alternative(onStateCreateFunc)) { // C function: recreate a closure in the new state, bypassing the lookup scheme lua_pushcfunction(L_, std::get(onStateCreateFunc)); // on_state_create() } else { // Lua function located in the config table, copied when we opened "lanes_core" LUA_ASSERT(from_, std::holds_alternative(onStateCreateFunc)); if (mode_ != LookupMode::LaneBody) { // if attempting to call in a keeper state, do nothing because the function doesn't exist there // this doesn't count as an error though STACK_CHECK(L_, 0); return; } kConfigRegKey.pushValue(L_); // L_: config STACK_CHECK(L_, 1); LuaType const _funcType{ luaG_getfield(L_, kIdxTop, kOnStateCreate) }; // L_: config on_state_create() if (_funcType != LuaType::FUNCTION) { raise_luaL_error(L_, "INTERNAL ERROR: %s is a %s, not a function", kOnStateCreate.data(), luaG_typename(L_, _funcType).data()); } lua_remove(L_, -2); // L_: on_state_create() } STACK_CHECK(L_, 1); // capture error and raise it in caller state std::string_view const _stateType{ mode_ == LookupMode::LaneBody ? "lane" : "keeper" }; luaG_pushstring(L_, _stateType); // L_: on_state_create() "" if (lua_pcall(L_, 1, 0, 0) != LUA_OK) { raise_luaL_error(from_, "%s failed in %s: \"%s\"", kOnStateCreate.data(), _stateType.data(), lua_isstring(L_, -1) ? luaG_tostring(L_, kIdxTop).data() : luaG_typename(L_, kIdxTop).data()); } STACK_CHECK(L_, 0); } // ################################################################################################# // only called from the master state [[nodiscard]] Universe* Universe::Create(lua_State* const L_) { LUA_ASSERT(L_, Universe::Get(L_) == nullptr); static constexpr StackIndex kIdxSettings{ 1 }; LUA_ASSERT(L_, lua_gettop(L_) == 1 && lua_istable(L_, 1)); STACK_CHECK_START_REL(L_, 0); // L_: settings std::ignore = luaG_getfield(L_, kIdxSettings, "nb_user_keepers"); // L_: settings nb_user_keepers int const _nbUserKeepers{ static_cast(lua_tointeger(L_, -1)) + 1}; lua_pop(L_, 1); // L_: settings if (_nbUserKeepers < 1) { raise_luaL_error(L_, "Bad number of additional keepers (%d)", _nbUserKeepers); } STACK_CHECK(L_, 0); std::ignore = luaG_getfield(L_, kIdxSettings, "keepers_gc_threshold"); // L_: settings keepers_gc_threshold int const _keepers_gc_threshold{ static_cast(lua_tointeger(L_, -1)) }; lua_pop(L_, 1); // L_: settings STACK_CHECK(L_, 0); Universe* const _U{ new (L_) Universe{} }; // L_: settings universe STACK_CHECK(L_, 1); kUniverseFullRegKey.setValue(L_, [](lua_State* L_) { lua_pushvalue(L_, -2); }); kUniverseLightRegKey.setValue(L_, [U = _U](lua_State* L_) { lua_pushlightuserdata(L_, U); }); STACK_CHECK(L_, 1); // L_: settings DEBUGSPEW_CODE(DebugSpewIndentScope _scope{ _U }); lua_createtable(L_, 0, 1); // L_: settings universe {mt} std::ignore = luaG_getfield(L_, kIdxSettings, "shutdown_timeout"); // L_: settings universe {mt} shutdown_timeout lua_pushcclosure(L_, UniverseGC, 1); // L_: settings universe {mt} UniverseGC lua_setfield(L_, -2, "__gc"); // L_: settings universe {mt} lua_setmetatable(L_, -2); // L_: settings universe lua_pop(L_, 1); // L_: settings std::ignore = luaG_getfield(L_, kIdxSettings, "strip_functions"); // L_: settings strip_functions _U->stripFunctions = lua_toboolean(L_, -1) ? true : false; lua_pop(L_, 1); // L_: settings std::ignore = luaG_getfield(L_, kIdxSettings, "verbose_errors"); // L_: settings verbose_errors _U->verboseErrors = lua_toboolean(L_, -1) ? true : false; lua_pop(L_, 1); // L_: settings // tracking std::ignore = luaG_getfield(L_, kIdxSettings, "track_lanes"); // L_: settings track_lanes if (lua_toboolean(L_, -1)) { _U->tracker.activate(); } lua_pop(L_, 1); // L_: settings // Linked chains handling _U->selfdestructFirst = SELFDESTRUCT_END; _U->initializeAllocatorFunction(L_); _U->initializeOnStateCreate(L_); _U->keepers.initialize(*_U, L_, static_cast(_nbUserKeepers), _keepers_gc_threshold); STACK_CHECK(L_, 0); // Initialize 'timerLinda'; a common Linda object shared by all states _U->timerLinda = Linda::CreateTimerLinda(L_, PK); return _U; } // ################################################################################################# // ################################### custom allocator support #################################### // ################################################################################################# // same as PUC-Lua l_alloc [[nodiscard]] static void* libc_lua_Alloc([[maybe_unused]] void* const ud_, [[maybe_unused]] void* const ptr_, [[maybe_unused]] size_t const osize_, size_t const nsize_) { if (nsize_ == 0) { free(ptr_); return nullptr; } else { return realloc(ptr_, nsize_); } } // ################################################################################################# [[nodiscard]] static int luaG_provide_protected_allocator(lua_State* const L_) { Universe* const _U{ Universe::Get(L_) }; // push a new full userdata on the stack, giving access to the universe's protected allocator [[maybe_unused]] lanes::AllocatorDefinition* const _def{ new (L_) lanes::AllocatorDefinition{ _U->protectedAllocator.makeDefinition() } }; return 1; } // ################################################################################################# // called once at the creation of the universe (therefore L_ is the master Lua state everything originates from) // Do I need to disable this when compiling for LuaJIT to prevent issues? void Universe::initializeAllocatorFunction(lua_State* const L_) { // start by just grabbing whatever allocator was provided to the master state protectedAllocator.initFrom(L_); STACK_CHECK_START_REL(L_, 1); // L_: settings switch (luaG_getfield(L_, kIdxTop, "allocator")) { // L_: settings allocator|nil|"protected" case LuaType::NIL: // nothing else to do break; case LuaType::STRING: LUA_ASSERT(L_, luaG_tostring(L_, kIdxTop) == "protected"); // set the original allocator to call from inside protection by the mutex protectedAllocator.installIn(L_); // before a state is created, this function will be called to obtain the allocator provideAllocator = luaG_provide_protected_allocator; break; case LuaType::FUNCTION: provideAllocator = lua_tocfunction(L_, -1); // L_: settings allocator if (provideAllocator != nullptr) { // make sure the function doesn't have upvalues char const* _upname = lua_getupvalue(L_, -1, 1); // L_: settings allocator upval? if (_upname != nullptr) { // should be "" for C functions with upvalues if any raise_luaL_error(L_, "config.allocator() shouldn't have upvalues"); } // remove this C function from the config table so that it doesn't cause problems // when we transfer the config table in newly created Lua states lua_pushnil(L_); // L_: settings allocator nil lua_setfield(L_, -3, "allocator"); // L_: settings allocator } else { raise_luaL_error(L_, "Bad config.allocator, must be a C function"); } break; default: // should be filtered out in lanes.lua raise_luaL_error(L_, "Bad config.allocator type %s", luaG_typename(L_, kIdxTop).data()); } lua_pop(L_, 1); // L_: settings STACK_CHECK(L_, 1); std::ignore = luaG_getfield(L_, kIdxTop, "internal_allocator"); // L_: settings "libc"|"allocator" LUA_ASSERT(L_, lua_isstring(L_, kIdxTop)); // should be the case due to lanes.lua parameter validation std::string_view const _allocator{ luaG_tostring(L_, kIdxTop) }; if (_allocator == "libc") { internalAllocator = lanes::AllocatorDefinition{ libc_lua_Alloc, nullptr }; } else { // use whatever the provider provides internalAllocator = resolveAllocator(L_, "internal"); } lua_pop(L_, 1); // L_: settings STACK_CHECK(L_, 1); } // ################################################################################################# // should be called ONLY from the state that created the universe int Universe::InitializeFinalizer(lua_State* const L_) { luaL_argcheck(L_, lua_gettop(L_) <= 1, 1, "too many arguments"); // L_: f? lua_settop(L_, 1); // L_: f|nil luaL_argcheck(L_, lua_isnoneornil(L_, 1) || lua_isfunction(L_, 1), 1, "finalizer should be a function"); // make sure we are only called from the Master Lua State! kUniverseFullRegKey.pushValue(L_); // L_: f U if (luaG_type(L_, kIdxTop) != LuaType::USERDATA) { raise_luaL_error(L_, "lanes.%s called from inside a lane", kFinally); } lua_pop(L_, 1); // L_: f STACK_GROW(L_, 3); // _R[kFinalizerRegKey] = f kFinalizerRegKey.setValue(L_, [](lua_State* L_) { lua_insert(L_, -2); }); // L_: // no need to adjust the stack, Lua does this for us return 0; } // ################################################################################################# void Universe::initializeOnStateCreate(lua_State* const L_) { STACK_CHECK_START_REL(L_, 0); // L_: settings if (luaG_getfield(L_, kIdxTop, kOnStateCreate) != LuaType::NIL) { // L_: settings on_state_create|nil LUA_ASSERT(L_, luaG_type(L_, kIdxTop) == LuaType::FUNCTION); // ensured by lanes.lua parameter validation // store C function pointer in an internal variable lua_CFunction const _func{ lua_tocfunction(L_, -1) }; // L_: settings on_state_create if (_func) { // make sure the function doesn't have upvalues char const* _upname{ lua_getupvalue(L_, -1, 1) }; // L_: settings on_state_create upval? if (_upname != nullptr) { // should be "" for C functions with upvalues if any raise_luaL_error(L_, "%s shouldn't have upvalues", kOnStateCreate.data()); } onStateCreateFunc.emplace(_func); // remove this C function from the config table so that it doesn't cause problems // when we transfer the config table in newly created Lua states lua_pushnil(L_); // L_: settings on_state_create nil luaG_setfield(L_, StackIndex{ -3 }, kOnStateCreate); // L_: settings on_state_create } else { // the function is still in the config table. we indicate this with the uintptr_t alternative (actual value is irrelevant) onStateCreateFunc.emplace(std::bit_cast(kOnStateCreate.data())); } } else { LUA_ASSERT(L_, std::holds_alternative(onStateCreateFunc)); }; lua_pop(L_, 1); // L_: settings STACK_CHECK(L_, 0); } // ################################################################################################# lanes::AllocatorDefinition Universe::resolveAllocator(lua_State* const L_, std::string_view const& hint_) const { lanes::AllocatorDefinition _ret{ protectedAllocator }; if (provideAllocator == nullptr) { return _ret; } STACK_CHECK_START_REL(L_, 0); // here, we have a function we can call to obtain an allocator lua_pushcclosure(L_, provideAllocator, 0); // L_: provideAllocator() luaG_pushstring(L_, hint_); // L_: provideAllocator() "" lua_call(L_, 1, 1); // L_: result // make sure we have a valid AllocatorDefinition on the stack (an error is raised instead if it is not the case) _ret = lanes::AllocatorDefinition::Validated(L_, kIdxTop); lua_pop(L_, 1); // L_: STACK_CHECK(L_, 0); return _ret; } // ################################################################################################# bool Universe::terminateFreeRunningLanes(lua_Duration const shutdownTimeout_, CancelOp const op_) { if (selfdestructFirst != SELFDESTRUCT_END) { // Signal _all_ still running threads to exit (including the timer thread) { std::lock_guard _guard{ selfdestructMutex }; Lane* _lane{ selfdestructFirst }; while (_lane != SELFDESTRUCT_END) { // attempt the requested cancel with a small timeout. // if waiting on a linda, they will raise a cancel_error. // if a cancellation hook is desired, it will be installed to try to raise an error if (_lane->thread.joinable()) { std::ignore = _lane->cancel(op_, std::chrono::steady_clock::now() + 1us, WakeLane::Yes, 1); } _lane = _lane->selfdestruct_next; } } // When noticing their cancel, the lanes will remove themselves from the selfdestruct chain. { std::chrono::time_point _until{ std::chrono::steady_clock::now() + std::chrono::duration_cast(shutdownTimeout_) }; while (selfdestructFirst != SELFDESTRUCT_END) { // give threads time to act on their cancel std::this_thread::yield(); // count the number of cancelled thread that didn't have the time to act yet int _n{ 0 }; { std::lock_guard _guard{ selfdestructMutex }; Lane* _lane{ selfdestructFirst }; while (_lane != SELFDESTRUCT_END) { if (_lane->cancelRequest.load(std::memory_order_relaxed) != CancelRequest::None) ++_n; _lane = _lane->selfdestruct_next; } } // if timeout elapsed, or we know all threads have acted, stop waiting std::chrono::time_point _now = std::chrono::steady_clock::now(); if (_n == 0 || (_now >= _until)) { DEBUGSPEW_CODE(DebugSpew(this) << _n << " uncancelled lane(s) remain after waiting " << shutdownTimeout_.count() << "s at process end." << std::endl); break; } } } // If some lanes are currently cleaning after themselves, wait until they are done. // They are no longer listed in the selfdestruct chain, but they still have to lua_close(). while (selfdestructingCount.load(std::memory_order_acquire) > 0) { std::this_thread::yield(); } } // are all lanes successfully terminated? return selfdestructFirst == SELFDESTRUCT_END; } // ################################################################################################# // process end: cancel any still free-running threads int Universe::UniverseGC(lua_State* const L_) { lua_Duration const _shutdown_timeout{ lua_tonumber(L_, lua_upvalueindex(1)) }; STACK_CHECK_START_ABS(L_, 1); Universe* const _U{ luaG_tofulluserdata(L_, StackIndex{ 1 }) }; // L_: U // attempt to terminate all lanes with increasingly stronger cancel methods bool const _allLanesTerminated{ _U->terminateFreeRunningLanes(_shutdown_timeout, { CancelRequest::Soft, LuaHookMask::None }) || _U->terminateFreeRunningLanes(_shutdown_timeout, { CancelRequest::Hard, LuaHookMask::None }) || _U->terminateFreeRunningLanes(_shutdown_timeout, { CancelRequest::Hard, LuaHookMask::All }) }; // invoke the function installed by lanes.finally() kFinalizerRegKey.pushValue(L_); // L_: U finalizer|nil if (!lua_isnil(L_, -1)) { lua_pushboolean(L_, _allLanesTerminated); // L_: U finalizer bool // no protection. Lua rules for errors in finalizers apply normally lua_call(L_, 1, 1); // L_: U ret|error } STACK_CHECK(L_, 2); // if some lanes are still running here, we have no other choice than crashing or freezing and let the client figure out what's wrong bool const _throw{ luaG_tostring(L_, kIdxTop) == "throw" }; lua_pop(L_, 1); // L_: U while (_U->selfdestructFirst != SELFDESTRUCT_END) { if (_throw) { throw std::logic_error{ "Some lanes are still running at shutdown" }; } else { std::this_thread::yield(); } } // no need to mutex-protect this as all lanes in the universe are gone at that point Linda::DeleteTimerLinda(L_, std::exchange(_U->timerLinda, nullptr), PK); _U->keepers.close(); // remove the protected allocator, if any _U->protectedAllocator.removeFrom(L_); // no longer found in the registry kUniverseFullRegKey.setValue(L_, [](lua_State* L_) { lua_pushnil(L_); }); kUniverseLightRegKey.setValue(L_, [](lua_State* L_) { lua_pushnil(L_); }); _U->Universe::~Universe(); return 0; }