/*************************************************************************/ /* command_queue_mt.h */ /*************************************************************************/ /* This file is part of: */ /* GODOT ENGINE */ /* https://godotengine.org */ /*************************************************************************/ /* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */ /* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */ /* */ /* 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. */ /*************************************************************************/ #ifndef COMMAND_QUEUE_MT_H #define COMMAND_QUEUE_MT_H #include "core/os/memory.h" #include "core/os/mutex.h" #include "core/os/semaphore.h" #include "core/simple_type.h" #include "core/typedefs.h" #define COMMA(N) _COMMA_##N #define _COMMA_0 #define _COMMA_1 , #define _COMMA_2 , #define _COMMA_3 , #define _COMMA_4 , #define _COMMA_5 , #define _COMMA_6 , #define _COMMA_7 , #define _COMMA_8 , #define _COMMA_9 , #define _COMMA_10 , #define _COMMA_11 , #define _COMMA_12 , #define _COMMA_13 , // 1-based comma separated list of ITEMs #define COMMA_SEP_LIST(ITEM, LENGTH) _COMMA_SEP_LIST_##LENGTH(ITEM) #define _COMMA_SEP_LIST_13(ITEM) \ _COMMA_SEP_LIST_12(ITEM) \ , ITEM(13) #define _COMMA_SEP_LIST_12(ITEM) \ _COMMA_SEP_LIST_11(ITEM) \ , ITEM(12) #define _COMMA_SEP_LIST_11(ITEM) \ _COMMA_SEP_LIST_10(ITEM) \ , ITEM(11) #define _COMMA_SEP_LIST_10(ITEM) \ _COMMA_SEP_LIST_9(ITEM) \ , ITEM(10) #define _COMMA_SEP_LIST_9(ITEM) \ _COMMA_SEP_LIST_8(ITEM) \ , ITEM(9) #define _COMMA_SEP_LIST_8(ITEM) \ _COMMA_SEP_LIST_7(ITEM) \ , ITEM(8) #define _COMMA_SEP_LIST_7(ITEM) \ _COMMA_SEP_LIST_6(ITEM) \ , ITEM(7) #define _COMMA_SEP_LIST_6(ITEM) \ _COMMA_SEP_LIST_5(ITEM) \ , ITEM(6) #define _COMMA_SEP_LIST_5(ITEM) \ _COMMA_SEP_LIST_4(ITEM) \ , ITEM(5) #define _COMMA_SEP_LIST_4(ITEM) \ _COMMA_SEP_LIST_3(ITEM) \ , ITEM(4) #define _COMMA_SEP_LIST_3(ITEM) \ _COMMA_SEP_LIST_2(ITEM) \ , ITEM(3) #define _COMMA_SEP_LIST_2(ITEM) \ _COMMA_SEP_LIST_1(ITEM) \ , ITEM(2) #define _COMMA_SEP_LIST_1(ITEM) \ _COMMA_SEP_LIST_0(ITEM) \ ITEM(1) #define _COMMA_SEP_LIST_0(ITEM) // 1-based semicolon separated list of ITEMs #define SEMIC_SEP_LIST(ITEM, LENGTH) _SEMIC_SEP_LIST_##LENGTH(ITEM) #define _SEMIC_SEP_LIST_13(ITEM) \ _SEMIC_SEP_LIST_12(ITEM); \ ITEM(13) #define _SEMIC_SEP_LIST_12(ITEM) \ _SEMIC_SEP_LIST_11(ITEM); \ ITEM(12) #define _SEMIC_SEP_LIST_11(ITEM) \ _SEMIC_SEP_LIST_10(ITEM); \ ITEM(11) #define _SEMIC_SEP_LIST_10(ITEM) \ _SEMIC_SEP_LIST_9(ITEM); \ ITEM(10) #define _SEMIC_SEP_LIST_9(ITEM) \ _SEMIC_SEP_LIST_8(ITEM); \ ITEM(9) #define _SEMIC_SEP_LIST_8(ITEM) \ _SEMIC_SEP_LIST_7(ITEM); \ ITEM(8) #define _SEMIC_SEP_LIST_7(ITEM) \ _SEMIC_SEP_LIST_6(ITEM); \ ITEM(7) #define _SEMIC_SEP_LIST_6(ITEM) \ _SEMIC_SEP_LIST_5(ITEM); \ ITEM(6) #define _SEMIC_SEP_LIST_5(ITEM) \ _SEMIC_SEP_LIST_4(ITEM); \ ITEM(5) #define _SEMIC_SEP_LIST_4(ITEM) \ _SEMIC_SEP_LIST_3(ITEM); \ ITEM(4) #define _SEMIC_SEP_LIST_3(ITEM) \ _SEMIC_SEP_LIST_2(ITEM); \ ITEM(3) #define _SEMIC_SEP_LIST_2(ITEM) \ _SEMIC_SEP_LIST_1(ITEM); \ ITEM(2) #define _SEMIC_SEP_LIST_1(ITEM) \ _SEMIC_SEP_LIST_0(ITEM) \ ITEM(1) #define _SEMIC_SEP_LIST_0(ITEM) // 1-based space separated list of ITEMs #define SPACE_SEP_LIST(ITEM, LENGTH) _SPACE_SEP_LIST_##LENGTH(ITEM) #define _SPACE_SEP_LIST_13(ITEM) \ _SPACE_SEP_LIST_12(ITEM) \ ITEM(13) #define _SPACE_SEP_LIST_12(ITEM) \ _SPACE_SEP_LIST_11(ITEM) \ ITEM(12) #define _SPACE_SEP_LIST_11(ITEM) \ _SPACE_SEP_LIST_10(ITEM) \ ITEM(11) #define _SPACE_SEP_LIST_10(ITEM) \ _SPACE_SEP_LIST_9(ITEM) \ ITEM(10) #define _SPACE_SEP_LIST_9(ITEM) \ _SPACE_SEP_LIST_8(ITEM) \ ITEM(9) #define _SPACE_SEP_LIST_8(ITEM) \ _SPACE_SEP_LIST_7(ITEM) \ ITEM(8) #define _SPACE_SEP_LIST_7(ITEM) \ _SPACE_SEP_LIST_6(ITEM) \ ITEM(7) #define _SPACE_SEP_LIST_6(ITEM) \ _SPACE_SEP_LIST_5(ITEM) \ ITEM(6) #define _SPACE_SEP_LIST_5(ITEM) \ _SPACE_SEP_LIST_4(ITEM) \ ITEM(5) #define _SPACE_SEP_LIST_4(ITEM) \ _SPACE_SEP_LIST_3(ITEM) \ ITEM(4) #define _SPACE_SEP_LIST_3(ITEM) \ _SPACE_SEP_LIST_2(ITEM) \ ITEM(3) #define _SPACE_SEP_LIST_2(ITEM) \ _SPACE_SEP_LIST_1(ITEM) \ ITEM(2) #define _SPACE_SEP_LIST_1(ITEM) \ _SPACE_SEP_LIST_0(ITEM) \ ITEM(1) #define _SPACE_SEP_LIST_0(ITEM) #define ARG(N) p##N #define PARAM(N) P##N p##N #define TYPE_PARAM(N) class P##N #define PARAM_DECL(N) typename GetSimpleTypeT::type_t p##N #define DECL_CMD(N) \ template \ struct Command##N : public CommandBase { \ T *instance; \ M method; \ SEMIC_SEP_LIST(PARAM_DECL, N); \ virtual void call() { \ (instance->*method)(COMMA_SEP_LIST(ARG, N)); \ } \ }; #define DECL_CMD_RET(N) \ template \ struct CommandRet##N : public SyncCommand { \ R *ret; \ T *instance; \ M method; \ SEMIC_SEP_LIST(PARAM_DECL, N); \ virtual void call() { \ *ret = (instance->*method)(COMMA_SEP_LIST(ARG, N)); \ } \ }; #define DECL_CMD_SYNC(N) \ template \ struct CommandSync##N : public SyncCommand { \ T *instance; \ M method; \ SEMIC_SEP_LIST(PARAM_DECL, N); \ virtual void call() { \ (instance->*method)(COMMA_SEP_LIST(ARG, N)); \ } \ }; #define TYPE_ARG(N) P##N #define CMD_TYPE(N) Command##N #define CMD_ASSIGN_PARAM(N) cmd->p##N = p##N #define DECL_PUSH(N) \ template \ void push(T *p_instance, M p_method COMMA(N) COMMA_SEP_LIST(PARAM, N)) { \ CMD_TYPE(N) *cmd = allocate_and_lock(); \ cmd->instance = p_instance; \ cmd->method = p_method; \ SEMIC_SEP_LIST(CMD_ASSIGN_PARAM, N); \ unlock(); \ if (sync) \ sync->post(); \ } #define CMD_RET_TYPE(N) CommandRet##N #define DECL_PUSH_AND_RET(N) \ template \ void push_and_ret(T *p_instance, M p_method, COMMA_SEP_LIST(PARAM, N) COMMA(N) R *r_ret) { \ SyncSemaphore *ss = _alloc_sync_sem(); \ CMD_RET_TYPE(N) *cmd = allocate_and_lock(); \ cmd->instance = p_instance; \ cmd->method = p_method; \ SEMIC_SEP_LIST(CMD_ASSIGN_PARAM, N); \ cmd->ret = r_ret; \ cmd->sync_sem = ss; \ unlock(); \ if (sync) \ sync->post(); \ ss->sem.wait(); \ ss->in_use = false; \ } #define CMD_SYNC_TYPE(N) CommandSync##N #define DECL_PUSH_AND_SYNC(N) \ template \ void push_and_sync(T *p_instance, M p_method COMMA(N) COMMA_SEP_LIST(PARAM, N)) { \ SyncSemaphore *ss = _alloc_sync_sem(); \ CMD_SYNC_TYPE(N) *cmd = allocate_and_lock(); \ cmd->instance = p_instance; \ cmd->method = p_method; \ SEMIC_SEP_LIST(CMD_ASSIGN_PARAM, N); \ cmd->sync_sem = ss; \ unlock(); \ if (sync) \ sync->post(); \ ss->sem.wait(); \ ss->in_use = false; \ } #define MAX_CMD_PARAMS 13 class CommandQueueMT { struct SyncSemaphore { Semaphore sem; bool in_use; }; struct CommandBase { virtual void call() = 0; virtual void post(){}; virtual ~CommandBase(){}; }; struct SyncCommand : public CommandBase { SyncSemaphore *sync_sem; virtual void post() { sync_sem->sem.post(); } }; DECL_CMD(0) SPACE_SEP_LIST(DECL_CMD, 13) /* commands that return */ DECL_CMD_RET(0) SPACE_SEP_LIST(DECL_CMD_RET, 13) /* commands that don't return but sync */ DECL_CMD_SYNC(0) SPACE_SEP_LIST(DECL_CMD_SYNC, 13) /***** BASE *******/ enum { DEFAULT_COMMAND_MEM_SIZE_KB = 256, SYNC_SEMAPHORES = 8 }; uint8_t *command_mem; uint32_t read_ptr_and_epoch; uint32_t write_ptr_and_epoch; uint32_t dealloc_ptr; uint32_t command_mem_size; SyncSemaphore sync_sems[SYNC_SEMAPHORES]; Mutex mutex; Semaphore *sync; template T *allocate() { // alloc size is size+T+safeguard uint32_t alloc_size = ((sizeof(T) + 8 - 1) & ~(8 - 1)) + 8; // Assert that the buffer is big enough to hold at least two messages. ERR_FAIL_COND_V(alloc_size * 2 + sizeof(uint32_t) > command_mem_size, nullptr); tryagain: uint32_t write_ptr = write_ptr_and_epoch >> 1; if (write_ptr < dealloc_ptr) { // behind dealloc_ptr, check that there is room if ((dealloc_ptr - write_ptr) <= alloc_size) { // There is no more room, try to deallocate something if (dealloc_one()) { goto tryagain; } return nullptr; } } else { // ahead of dealloc_ptr, check that there is room if ((command_mem_size - write_ptr) < alloc_size + sizeof(uint32_t)) { // no room at the end, wrap down; if (dealloc_ptr == 0) { // don't want write_ptr to become dealloc_ptr // There is no more room, try to deallocate something if (dealloc_one()) { goto tryagain; } return nullptr; } // if this happens, it's a bug ERR_FAIL_COND_V((command_mem_size - write_ptr) < 8, nullptr); // zero means, wrap to beginning uint32_t *p = (uint32_t *)&command_mem[write_ptr]; *p = 1; write_ptr_and_epoch = 0 | (1 & ~write_ptr_and_epoch); // Invert epoch. // See if we can get the thread to run and clear up some more space while we wait. // This is required if alloc_size * 2 + 4 > COMMAND_MEM_SIZE if (sync) { sync->post(); } goto tryagain; } } // Allocate the size and the 'in use' bit. // First bit used to mark if command is still in use (1) // or if it has been destroyed and can be deallocated (0). uint32_t size = (sizeof(T) + 8 - 1) & ~(8 - 1); uint32_t *p = (uint32_t *)&command_mem[write_ptr]; *p = (size << 1) | 1; write_ptr += 8; // allocate the command T *cmd = memnew_placement(&command_mem[write_ptr], T); write_ptr += size; write_ptr_and_epoch = (write_ptr << 1) | (write_ptr_and_epoch & 1); return cmd; } template T *allocate_and_lock() { lock(); T *ret; while ((ret = allocate()) == nullptr) { unlock(); // sleep a little until fetch happened and some room is made wait_for_flush(); lock(); } return ret; } bool flush_one(bool p_lock = true) { if (p_lock) { lock(); } tryagain: // tried to read an empty queue if (read_ptr_and_epoch == write_ptr_and_epoch) { if (p_lock) { unlock(); } return false; } uint32_t read_ptr = read_ptr_and_epoch >> 1; uint32_t size_ptr = read_ptr; uint32_t size = *(uint32_t *)&command_mem[read_ptr] >> 1; if (size == 0) { *(uint32_t *)&command_mem[read_ptr] = 0; // clear in-use bit. //end of ringbuffer, wrap read_ptr_and_epoch = 0 | (1 & ~read_ptr_and_epoch); // Invert epoch. goto tryagain; } read_ptr += 8; CommandBase *cmd = reinterpret_cast(&command_mem[read_ptr]); read_ptr += size; read_ptr_and_epoch = (read_ptr << 1) | (read_ptr_and_epoch & 1); if (p_lock) { unlock(); } cmd->call(); if (p_lock) { lock(); } cmd->post(); cmd->~CommandBase(); *(uint32_t *)&command_mem[size_ptr] &= ~1; if (p_lock) { unlock(); } return true; } void lock(); void unlock(); void wait_for_flush(); SyncSemaphore *_alloc_sync_sem(); bool dealloc_one(); public: /* NORMAL PUSH COMMANDS */ DECL_PUSH(0) SPACE_SEP_LIST(DECL_PUSH, 13) /* PUSH AND RET COMMANDS */ DECL_PUSH_AND_RET(0) SPACE_SEP_LIST(DECL_PUSH_AND_RET, 13) /* PUSH AND RET SYNC COMMANDS*/ DECL_PUSH_AND_SYNC(0) SPACE_SEP_LIST(DECL_PUSH_AND_SYNC, 13) void wait_and_flush_one() { ERR_FAIL_COND(!sync); sync->wait(); flush_one(); } void flush_all() { //ERR_FAIL_COND(sync); lock(); while (flush_one(false)) { ; } unlock(); } CommandQueueMT(bool p_sync); ~CommandQueueMT(); }; #undef ARG #undef PARAM #undef TYPE_PARAM #undef PARAM_DECL #undef DECL_CMD #undef DECL_CMD_RET #undef DECL_CMD_SYNC #undef TYPE_ARG #undef CMD_TYPE #undef CMD_ASSIGN_PARAM #undef DECL_PUSH #undef CMD_RET_TYPE #undef DECL_PUSH_AND_RET #undef CMD_SYNC_TYPE #undef DECL_CMD_SYNC #endif