godot/core/templates/command_queue_mt.h
Pedro J. Estébanez ae418f9469 WorkerThreadPool: Avoid deadlocks when CommandQueueMT is involved
This commit lets CommandQueueMT play nicely with the WorkerThreadPool to avoid
non-progressable situations caused by an interdependence between both. While a
command queue is being flushed, it allows the WTP to release its lock while tasks
are being awaited so they can make progress in case they need in turn to post
to the command queue.
2024-01-08 12:45:43 +01:00

450 lines
15 KiB
C++

/**************************************************************************/
/* command_queue_mt.h */
/**************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
/* */
/* 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/object/worker_thread_pool.h"
#include "core/os/memory.h"
#include "core/os/mutex.h"
#include "core/os/semaphore.h"
#include "core/string/print_string.h"
#include "core/templates/local_vector.h"
#include "core/templates/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 ,
#define _COMMA_14 ,
#define _COMMA_15 ,
// 1-based comma separated list of ITEMs
#define COMMA_SEP_LIST(ITEM, LENGTH) _COMMA_SEP_LIST_##LENGTH(ITEM)
#define _COMMA_SEP_LIST_15(ITEM) \
_COMMA_SEP_LIST_14(ITEM) \
, ITEM(15)
#define _COMMA_SEP_LIST_14(ITEM) \
_COMMA_SEP_LIST_13(ITEM) \
, ITEM(14)
#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_15(ITEM) \
_SEMIC_SEP_LIST_14(ITEM); \
ITEM(15)
#define _SEMIC_SEP_LIST_14(ITEM) \
_SEMIC_SEP_LIST_13(ITEM); \
ITEM(14)
#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_15(ITEM) \
_SPACE_SEP_LIST_14(ITEM) \
ITEM(15)
#define _SPACE_SEP_LIST_14(ITEM) \
_SPACE_SEP_LIST_13(ITEM) \
ITEM(14)
#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<P##N>::type_t p##N
#define DECL_CMD(N) \
template <class T, class M COMMA(N) COMMA_SEP_LIST(TYPE_PARAM, N)> \
struct Command##N : public CommandBase { \
T *instance; \
M method; \
SEMIC_SEP_LIST(PARAM_DECL, N); \
virtual void call() override { \
(instance->*method)(COMMA_SEP_LIST(ARG, N)); \
} \
};
#define DECL_CMD_RET(N) \
template <class T, class M, COMMA_SEP_LIST(TYPE_PARAM, N) COMMA(N) class R> \
struct CommandRet##N : public SyncCommand { \
R *ret; \
T *instance; \
M method; \
SEMIC_SEP_LIST(PARAM_DECL, N); \
virtual void call() override { \
*ret = (instance->*method)(COMMA_SEP_LIST(ARG, N)); \
} \
};
#define DECL_CMD_SYNC(N) \
template <class T, class M COMMA(N) COMMA_SEP_LIST(TYPE_PARAM, N)> \
struct CommandSync##N : public SyncCommand { \
T *instance; \
M method; \
SEMIC_SEP_LIST(PARAM_DECL, N); \
virtual void call() override { \
(instance->*method)(COMMA_SEP_LIST(ARG, N)); \
} \
};
#define TYPE_ARG(N) P##N
#define CMD_TYPE(N) Command##N<T, M COMMA(N) COMMA_SEP_LIST(TYPE_ARG, N)>
#define CMD_ASSIGN_PARAM(N) cmd->p##N = p##N
#define DECL_PUSH(N) \
template <class T, class M COMMA(N) COMMA_SEP_LIST(TYPE_PARAM, N)> \
void push(T *p_instance, M p_method COMMA(N) COMMA_SEP_LIST(PARAM, N)) { \
CMD_TYPE(N) *cmd = allocate_and_lock<CMD_TYPE(N)>(); \
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<T, M, COMMA_SEP_LIST(TYPE_ARG, N) COMMA(N) R>
#define DECL_PUSH_AND_RET(N) \
template <class T, class M, COMMA_SEP_LIST(TYPE_PARAM, N) COMMA(N) class R> \
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_RET_TYPE(N)>(); \
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<T, M COMMA(N) COMMA_SEP_LIST(TYPE_ARG, N)>
#define DECL_PUSH_AND_SYNC(N) \
template <class T, class M COMMA(N) COMMA_SEP_LIST(TYPE_PARAM, N)> \
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_SYNC_TYPE(N)>(); \
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 15
class CommandQueueMT {
struct SyncSemaphore {
Semaphore sem;
bool in_use = false;
};
struct CommandBase {
virtual void call() = 0;
virtual SyncSemaphore *get_sync_semaphore() { return nullptr; }
virtual ~CommandBase() = default; // Won't be called.
};
struct SyncCommand : public CommandBase {
SyncSemaphore *sync_sem = nullptr;
virtual SyncSemaphore *get_sync_semaphore() override {
return sync_sem;
}
};
DECL_CMD(0)
SPACE_SEP_LIST(DECL_CMD, 15)
// Commands that return.
DECL_CMD_RET(0)
SPACE_SEP_LIST(DECL_CMD_RET, 15)
/* commands that don't return but sync */
DECL_CMD_SYNC(0)
SPACE_SEP_LIST(DECL_CMD_SYNC, 15)
/***** BASE *******/
enum {
DEFAULT_COMMAND_MEM_SIZE_KB = 256,
SYNC_SEMAPHORES = 8
};
LocalVector<uint8_t> command_mem;
SyncSemaphore sync_sems[SYNC_SEMAPHORES];
Mutex mutex;
Semaphore *sync = nullptr;
uint64_t flush_read_ptr = 0;
template <class T>
T *allocate() {
// alloc size is size+T+safeguard
uint32_t alloc_size = ((sizeof(T) + 8 - 1) & ~(8 - 1));
uint64_t size = command_mem.size();
command_mem.resize(size + alloc_size + 8);
*(uint64_t *)&command_mem[size] = alloc_size;
T *cmd = memnew_placement(&command_mem[size + 8], T);
return cmd;
}
template <class T>
T *allocate_and_lock() {
lock();
T *ret = allocate<T>();
return ret;
}
void _flush() {
lock();
WorkerThreadPool::thread_enter_command_queue_mt_flush(this);
while (flush_read_ptr < command_mem.size()) {
uint64_t size = *(uint64_t *)&command_mem[flush_read_ptr];
flush_read_ptr += 8;
CommandBase *cmd = reinterpret_cast<CommandBase *>(&command_mem[flush_read_ptr]);
SyncSemaphore *sync_sem = cmd->get_sync_semaphore();
cmd->call();
if (sync_sem) {
sync_sem->sem.post(); // Release in case it needs sync/ret.
}
if (unlikely(flush_read_ptr == 0)) {
// A reentrant call flushed.
DEV_ASSERT(command_mem.is_empty());
unlock();
return;
}
flush_read_ptr += size;
}
WorkerThreadPool::thread_exit_command_queue_mt_flush();
command_mem.clear();
flush_read_ptr = 0;
unlock();
}
void wait_for_flush();
SyncSemaphore *_alloc_sync_sem();
public:
void lock();
void unlock();
/* NORMAL PUSH COMMANDS */
DECL_PUSH(0)
SPACE_SEP_LIST(DECL_PUSH, 15)
/* PUSH AND RET COMMANDS */
DECL_PUSH_AND_RET(0)
SPACE_SEP_LIST(DECL_PUSH_AND_RET, 15)
/* PUSH AND RET SYNC COMMANDS*/
DECL_PUSH_AND_SYNC(0)
SPACE_SEP_LIST(DECL_PUSH_AND_SYNC, 15)
_FORCE_INLINE_ void flush_if_pending() {
if (unlikely(command_mem.size() > 0)) {
_flush();
}
}
void flush_all() {
_flush();
}
void wait_and_flush() {
ERR_FAIL_NULL(sync);
sync->wait();
_flush();
}
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 // COMMAND_QUEUE_MT_H