homework-jianmu/source/util/src/ttimer.c

664 lines
20 KiB
C

/*
* Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
*
* This program is free software: you can use, redistribute, and/or modify
* it under the terms of the GNU Affero General Public License, version 3
* or later ("AGPL"), as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#define _DEFAULT_SOURCE
#include "ttimer.h"
#include "taoserror.h"
#include "tdef.h"
#include "tlog.h"
#include "tsched.h"
#define tmrFatal(...) \
{ \
if (tmrDebugFlag & DEBUG_FATAL) { \
taosPrintLog("TMR FATAL ", DEBUG_FATAL, tmrDebugFlag, __VA_ARGS__); \
} \
}
#define tmrError(...) \
{ \
if (tmrDebugFlag & DEBUG_ERROR) { \
taosPrintLog("TMR ERROR ", DEBUG_ERROR, tmrDebugFlag, __VA_ARGS__); \
} \
}
#define tmrWarn(...) \
{ \
if (tmrDebugFlag & DEBUG_WARN) { \
taosPrintLog("TMR WARN ", DEBUG_WARN, tmrDebugFlag, __VA_ARGS__); \
} \
}
#define tmrInfo(...) \
{ \
if (tmrDebugFlag & DEBUG_INFO) { \
taosPrintLog("TMR ", DEBUG_INFO, tmrDebugFlag, __VA_ARGS__); \
} \
}
#define tmrDebug(...) \
{ \
if (tmrDebugFlag & DEBUG_DEBUG) { \
taosPrintLog("TMR ", DEBUG_DEBUG, tmrDebugFlag, __VA_ARGS__); \
} \
}
#define tmrTrace(...) \
{ \
if (tmrDebugFlag & DEBUG_TRACE) { \
taosPrintLog("TMR ", DEBUG_TRACE, tmrDebugFlag, __VA_ARGS__); \
} \
}
#define TIMER_STATE_WAITING 0
#define TIMER_STATE_EXPIRED 1
#define TIMER_STATE_STOPPED 2
#define TIMER_STATE_CANCELED 3
typedef union _tmr_ctrl_t {
char label[16];
struct {
// pad to ensure 'next' is the end of this union
char padding[16 - sizeof(union _tmr_ctrl_t*)];
union _tmr_ctrl_t* next;
};
} tmr_ctrl_t;
typedef struct tmr_obj_t {
uintptr_t id;
tmr_ctrl_t* ctrl;
struct tmr_obj_t* mnext;
struct tmr_obj_t* prev;
struct tmr_obj_t* next;
uint16_t slot;
uint8_t wheel;
uint8_t state;
uint8_t refCount;
uint8_t reserved1;
uint16_t reserved2;
union {
int64_t expireAt;
int64_t executedBy;
};
TAOS_TMR_CALLBACK fp;
void* param;
} tmr_obj_t;
typedef struct timer_list_t {
int64_t lockedBy;
tmr_obj_t* timers;
} timer_list_t;
typedef struct timer_map_t {
uint32_t size;
uint32_t count;
timer_list_t* slots;
} timer_map_t;
typedef struct time_wheel_t {
TdThreadMutex mutex;
int64_t nextScanAt;
uint32_t resolution;
uint16_t size;
uint16_t index;
tmr_obj_t** slots;
} time_wheel_t;
static int32_t tsMaxTmrCtrl = TSDB_MAX_VNODES_PER_DB + 100;
static int32_t tmrModuleInit = 0;
static TdThreadMutex tmrCtrlMutex;
static tmr_ctrl_t* tmrCtrls;
static tmr_ctrl_t* unusedTmrCtrl = NULL;
static void* tmrQhandle;
static int32_t numOfTmrCtrl = 0;
int32_t taosTmrThreads = 1;
static uintptr_t nextTimerId = 0;
static time_wheel_t wheels[] = {
{.resolution = MSECONDS_PER_TICK, .size = 4096},
{.resolution = 1000, .size = 1024},
{.resolution = 60000, .size = 1024},
};
static timer_map_t timerMap;
static uintptr_t getNextTimerId() {
uintptr_t id;
do {
id = (uintptr_t)atomic_add_fetch_ptr((void**)&nextTimerId, 1);
} while (id == 0);
return id;
}
static void timerAddRef(tmr_obj_t* timer) { atomic_add_fetch_8(&timer->refCount, 1); }
static void timerDecRef(tmr_obj_t* timer) {
if (atomic_sub_fetch_8(&timer->refCount, 1) == 0) {
taosMemoryFree(timer);
}
}
static void lockTimerList(timer_list_t* list) {
int64_t tid = taosGetSelfPthreadId();
int32_t i = 0;
while (atomic_val_compare_exchange_64(&(list->lockedBy), 0, tid) != 0) {
if (++i % 1000 == 0) {
sched_yield();
}
}
}
static void unlockTimerList(timer_list_t* list) {
int64_t tid = taosGetSelfPthreadId();
if (atomic_val_compare_exchange_64(&(list->lockedBy), tid, 0) != tid) {
ASSERTS(false, "%" PRId64 " trying to unlock a timer list not locked by current thread.", tid);
}
}
static void addTimer(tmr_obj_t* timer) {
timerAddRef(timer);
timer->wheel = tListLen(wheels);
uint32_t idx = (uint32_t)(timer->id % timerMap.size);
timer_list_t* list = timerMap.slots + idx;
lockTimerList(list);
timer->mnext = list->timers;
list->timers = timer;
unlockTimerList(list);
}
static tmr_obj_t* findTimer(uintptr_t id) {
tmr_obj_t* timer = NULL;
if (id > 0) {
uint32_t idx = (uint32_t)(id % timerMap.size);
timer_list_t* list = timerMap.slots + idx;
lockTimerList(list);
for (timer = list->timers; timer != NULL; timer = timer->mnext) {
if (timer->id == id) {
timerAddRef(timer);
break;
}
}
unlockTimerList(list);
}
return timer;
}
static void removeTimer(uintptr_t id) {
tmr_obj_t* prev = NULL;
uint32_t idx = (uint32_t)(id % timerMap.size);
timer_list_t* list = timerMap.slots + idx;
lockTimerList(list);
for (tmr_obj_t* p = list->timers; p != NULL; p = p->mnext) {
if (p->id == id) {
if (prev == NULL) {
list->timers = p->mnext;
} else {
prev->mnext = p->mnext;
}
timerDecRef(p);
break;
}
prev = p;
}
unlockTimerList(list);
}
static void addToWheel(tmr_obj_t* timer, uint32_t delay) {
timerAddRef(timer);
// select a wheel for the timer, we are not an accurate timer,
// but the inaccuracy should not be too large.
timer->wheel = tListLen(wheels) - 1;
for (uint8_t i = 0; i < tListLen(wheels); i++) {
time_wheel_t* wheel = wheels + i;
if (delay < wheel->resolution * wheel->size) {
timer->wheel = i;
break;
}
}
time_wheel_t* wheel = wheels + timer->wheel;
timer->prev = NULL;
timer->expireAt = taosGetMonotonicMs() + delay;
taosThreadMutexLock(&wheel->mutex);
uint32_t idx = 0;
if (timer->expireAt > wheel->nextScanAt) {
// adjust delay according to next scan time of this wheel
// so that the timer is not fired earlier than desired.
delay = (uint32_t)(timer->expireAt - wheel->nextScanAt);
idx = (delay + wheel->resolution - 1) / wheel->resolution;
}
timer->slot = (uint16_t)((wheel->index + idx + 1) % wheel->size);
tmr_obj_t* p = wheel->slots[timer->slot];
wheel->slots[timer->slot] = timer;
timer->next = p;
if (p != NULL) {
p->prev = timer;
}
taosThreadMutexUnlock(&wheel->mutex);
}
static bool removeFromWheel(tmr_obj_t* timer) {
uint8_t wheelIdx = timer->wheel;
if (wheelIdx >= tListLen(wheels)) {
return false;
}
time_wheel_t* wheel = wheels + wheelIdx;
bool removed = false;
taosThreadMutexLock(&wheel->mutex);
// other thread may modify timer->wheel, check again.
if (timer->wheel < tListLen(wheels)) {
if (timer->prev != NULL) {
timer->prev->next = timer->next;
}
if (timer->next != NULL) {
timer->next->prev = timer->prev;
}
if (timer == wheel->slots[timer->slot]) {
wheel->slots[timer->slot] = timer->next;
}
timer->wheel = tListLen(wheels);
timer->next = NULL;
timer->prev = NULL;
timerDecRef(timer);
removed = true;
}
taosThreadMutexUnlock(&wheel->mutex);
return removed;
}
static void processExpiredTimer(void* handle, void* arg) {
tmr_obj_t* timer = (tmr_obj_t*)handle;
timer->executedBy = taosGetSelfPthreadId();
uint8_t state = atomic_val_compare_exchange_8(&timer->state, TIMER_STATE_WAITING, TIMER_STATE_EXPIRED);
if (state == TIMER_STATE_WAITING) {
const char* fmt = "%s timer[id=%" PRIuPTR ", fp=%p, param=%p] execution start.";
tmrDebug(fmt, timer->ctrl->label, timer->id, timer->fp, timer->param);
(*timer->fp)(timer->param, (tmr_h)timer->id);
atomic_store_8(&timer->state, TIMER_STATE_STOPPED);
fmt = "%s timer[id=%" PRIuPTR ", fp=%p, param=%p] execution end.";
tmrDebug(fmt, timer->ctrl->label, timer->id, timer->fp, timer->param);
}
removeTimer(timer->id);
timerDecRef(timer);
}
static void addToExpired(tmr_obj_t* head) {
const char* fmt = "%s adding expired timer[id=%" PRIuPTR ", fp=%p, param=%p] to queue.";
while (head != NULL) {
uintptr_t id = head->id;
tmr_obj_t* next = head->next;
tmrDebug(fmt, head->ctrl->label, id, head->fp, head->param);
SSchedMsg schedMsg;
schedMsg.fp = NULL;
schedMsg.tfp = processExpiredTimer;
schedMsg.msg = NULL;
schedMsg.ahandle = head;
schedMsg.thandle = NULL;
taosScheduleTask(tmrQhandle, &schedMsg);
tmrDebug("timer[id=%" PRIuPTR "] has been added to queue.", id);
head = next;
}
}
static uintptr_t doStartTimer(tmr_obj_t* timer, TAOS_TMR_CALLBACK fp, int32_t mseconds, void* param, tmr_ctrl_t* ctrl) {
uintptr_t id = getNextTimerId();
timer->id = id;
timer->state = TIMER_STATE_WAITING;
timer->fp = fp;
timer->param = param;
timer->ctrl = ctrl;
addTimer(timer);
const char* fmt = "%s timer[id=%" PRIuPTR ", fp=%p, param=%p] started";
tmrDebug(fmt, ctrl->label, timer->id, timer->fp, timer->param);
if (mseconds == 0) {
timer->wheel = tListLen(wheels);
timerAddRef(timer);
addToExpired(timer);
} else {
addToWheel(timer, mseconds);
}
// note: use `timer->id` here is unsafe as `timer` may already be freed
return id;
}
tmr_h taosTmrStart(TAOS_TMR_CALLBACK fp, int32_t mseconds, void* param, void* handle) {
tmr_ctrl_t* ctrl = (tmr_ctrl_t*)handle;
if (ctrl == NULL || ctrl->label[0] == 0) {
return NULL;
}
tmr_obj_t* timer = (tmr_obj_t*)taosMemoryCalloc(1, sizeof(tmr_obj_t));
if (timer == NULL) {
tmrError("%s failed to allocated memory for new timer object.", ctrl->label);
return NULL;
}
return (tmr_h)doStartTimer(timer, fp, mseconds, param, ctrl);
}
static void taosTimerLoopFunc(int32_t signo) {
int64_t now = taosGetMonotonicMs();
for (int32_t i = 0; i < tListLen(wheels); i++) {
// `expried` is a temporary expire list.
// expired timers are first add to this list, then move
// to expired queue as a batch to improve performance.
// note this list is used as a stack in this function.
tmr_obj_t* expired = NULL;
time_wheel_t* wheel = wheels + i;
while (now >= wheel->nextScanAt) {
taosThreadMutexLock(&wheel->mutex);
wheel->index = (wheel->index + 1) % wheel->size;
tmr_obj_t* timer = wheel->slots[wheel->index];
while (timer != NULL) {
tmr_obj_t* next = timer->next;
if (now < timer->expireAt) {
timer = next;
continue;
}
// remove from the wheel
if (timer->prev == NULL) {
wheel->slots[wheel->index] = next;
if (next != NULL) {
next->prev = NULL;
}
} else {
timer->prev->next = next;
if (next != NULL) {
next->prev = timer->prev;
}
}
timer->wheel = tListLen(wheels);
// add to temporary expire list
timer->next = expired;
timer->prev = NULL;
if (expired != NULL) {
expired->prev = timer;
}
expired = timer;
timer = next;
}
wheel->nextScanAt += wheel->resolution;
taosThreadMutexUnlock(&wheel->mutex);
}
addToExpired(expired);
}
}
static bool doStopTimer(tmr_obj_t* timer, uint8_t state) {
if (state == TIMER_STATE_WAITING) {
bool reusable = false;
if (removeFromWheel(timer)) {
removeTimer(timer->id);
// only safe to reuse the timer when timer is removed from the wheel.
// we cannot guarantee the thread safety of the timr in all other cases.
reusable = true;
}
const char* fmt = "%s timer[id=%" PRIuPTR ", fp=%p, param=%p] is cancelled.";
tmrDebug(fmt, timer->ctrl->label, timer->id, timer->fp, timer->param);
return reusable;
}
if (state != TIMER_STATE_EXPIRED) {
// timer already stopped or cancelled, has nothing to do in this case
return false;
}
if (timer->executedBy == taosGetSelfPthreadId()) {
// taosTmrReset is called in the timer callback, should do nothing in this
// case to avoid dead lock. note taosTmrReset must be the last statement
// of the callback funtion, will be a bug otherwise.
return false;
}
// timer callback is executing in another thread, we SHOULD wait it to stop,
// BUT this may result in dead lock if current thread are holding a lock which
// the timer callback need to acquire. so, we HAVE TO return directly.
const char* fmt = "%s timer[id=%" PRIuPTR ", fp=%p, param=%p] is executing and cannot be stopped.";
tmrDebug(fmt, timer->ctrl->label, timer->id, timer->fp, timer->param);
return false;
}
bool taosTmrStop(tmr_h timerId) {
uintptr_t id = (uintptr_t)timerId;
tmr_obj_t* timer = findTimer(id);
if (timer == NULL) {
tmrDebug("timer[id=%" PRIuPTR "] does not exist", id);
return false;
}
uint8_t state = atomic_val_compare_exchange_8(&timer->state, TIMER_STATE_WAITING, TIMER_STATE_CANCELED);
doStopTimer(timer, state);
timerDecRef(timer);
return state == TIMER_STATE_WAITING;
}
bool taosTmrStopA(tmr_h* timerId) {
bool ret = taosTmrStop(*timerId);
*timerId = NULL;
return ret;
}
bool taosTmrReset(TAOS_TMR_CALLBACK fp, int32_t mseconds, void* param, void* handle, tmr_h* pTmrId) {
tmr_ctrl_t* ctrl = (tmr_ctrl_t*)handle;
if (ctrl == NULL || ctrl->label[0] == 0) {
return false;
}
uintptr_t id = (uintptr_t)*pTmrId;
bool stopped = false;
tmr_obj_t* timer = findTimer(id);
if (timer == NULL) {
tmrDebug("%s timer[id=%" PRIuPTR "] does not exist", ctrl->label, id);
} else {
uint8_t state = atomic_val_compare_exchange_8(&timer->state, TIMER_STATE_WAITING, TIMER_STATE_CANCELED);
if (!doStopTimer(timer, state)) {
timerDecRef(timer);
timer = NULL;
}
stopped = state == TIMER_STATE_WAITING;
}
if (timer == NULL) {
*pTmrId = taosTmrStart(fp, mseconds, param, handle);
return stopped;
}
tmrDebug("%s timer[id=%" PRIuPTR "] is reused", ctrl->label, timer->id);
// wait until there's no other reference to this timer,
// so that we can reuse this timer safely.
for (int32_t i = 1; atomic_load_8(&timer->refCount) > 1; ++i) {
if (i % 1000 == 0) {
sched_yield();
}
}
ASSERTS(timer->refCount == 1, "timer refCount=%d not expected 1", timer->refCount);
memset(timer, 0, sizeof(*timer));
*pTmrId = (tmr_h)doStartTimer(timer, fp, mseconds, param, ctrl);
return stopped;
}
static int32_t taosTmrModuleInit(void) {
tmrCtrls = taosMemoryMalloc(sizeof(tmr_ctrl_t) * tsMaxTmrCtrl);
if (tmrCtrls == NULL) {
tmrError("failed to allocate memory for timer controllers.");
return -1;
}
memset(&timerMap, 0, sizeof(timerMap));
for (uint32_t i = 0; i < tsMaxTmrCtrl - 1; ++i) {
tmr_ctrl_t* ctrl = tmrCtrls + i;
ctrl->next = ctrl + 1;
}
(tmrCtrls + tsMaxTmrCtrl - 1)->next = NULL;
unusedTmrCtrl = tmrCtrls;
taosThreadMutexInit(&tmrCtrlMutex, NULL);
int64_t now = taosGetMonotonicMs();
for (int32_t i = 0; i < tListLen(wheels); i++) {
time_wheel_t* wheel = wheels + i;
if (taosThreadMutexInit(&wheel->mutex, NULL) != 0) {
tmrError("failed to create the mutex for wheel, reason:%s", strerror(errno));
return -1;
}
wheel->nextScanAt = now + wheel->resolution;
wheel->index = 0;
wheel->slots = (tmr_obj_t**)taosMemoryCalloc(wheel->size, sizeof(tmr_obj_t*));
if (wheel->slots == NULL) {
tmrError("failed to allocate wheel slots");
return -1;
}
timerMap.size += wheel->size;
}
timerMap.count = 0;
timerMap.slots = (timer_list_t*)taosMemoryCalloc(timerMap.size, sizeof(timer_list_t));
if (timerMap.slots == NULL) {
tmrError("failed to allocate hash map");
return -1;
}
tmrQhandle = taosInitScheduler(10000, taosTmrThreads, "tmr", NULL);
taosInitTimer(taosTimerLoopFunc, MSECONDS_PER_TICK);
tmrDebug("timer module is initialized, number of threads: %d", taosTmrThreads);
return 2;
}
static int32_t taosTmrInitModule(void) {
if (atomic_load_32(&tmrModuleInit) == 2) {
return 0;
}
if (atomic_load_32(&tmrModuleInit) < 0) {
return -1;
}
while (true) {
if (0 == atomic_val_compare_exchange_32(&tmrModuleInit, 0, 1)) {
atomic_store_32(&tmrModuleInit, taosTmrModuleInit());
} else if (atomic_load_32(&tmrModuleInit) < 0) {
return -1;
} else if (atomic_load_32(&tmrModuleInit) == 2) {
return 0;
} else {
taosMsleep(1);
}
}
return -1;
}
void* taosTmrInit(int32_t maxNumOfTmrs, int32_t resolution, int32_t longest, const char* label) {
const char* ret = taosMonotonicInit();
tmrDebug("ttimer monotonic clock source:%s", ret);
if (taosTmrInitModule() < 0) {
return NULL;
}
taosThreadMutexLock(&tmrCtrlMutex);
tmr_ctrl_t* ctrl = unusedTmrCtrl;
if (ctrl != NULL) {
unusedTmrCtrl = ctrl->next;
numOfTmrCtrl++;
}
taosThreadMutexUnlock(&tmrCtrlMutex);
if (ctrl == NULL) {
tmrError("%s too many timer controllers, failed to create timer controller.", label);
terrno = TSDB_CODE_OUT_OF_MEMORY;
return NULL;
}
tstrncpy(ctrl->label, label, sizeof(ctrl->label));
tmrDebug("%s timer controller is initialized, number of timer controllers: %d.", label, numOfTmrCtrl);
return ctrl;
}
void taosTmrCleanUp(void* handle) {
tmr_ctrl_t* ctrl = (tmr_ctrl_t*)handle;
if (ctrl == NULL || ctrl->label[0] == 0) {
return;
}
tmrDebug("%s timer controller is cleaned up.", ctrl->label);
ctrl->label[0] = 0;
taosThreadMutexLock(&tmrCtrlMutex);
ctrl->next = unusedTmrCtrl;
numOfTmrCtrl--;
unusedTmrCtrl = ctrl;
taosThreadMutexUnlock(&tmrCtrlMutex);
tmrDebug("time controller's tmr ctrl size: %d", numOfTmrCtrl);
if (numOfTmrCtrl <= 0) {
taosUninitTimer();
taosCleanUpScheduler(tmrQhandle);
taosMemoryFreeClear(tmrQhandle);
for (int32_t i = 0; i < tListLen(wheels); i++) {
time_wheel_t* wheel = wheels + i;
taosThreadMutexDestroy(&wheel->mutex);
taosMemoryFree(wheel->slots);
}
taosThreadMutexDestroy(&tmrCtrlMutex);
for (size_t i = 0; i < timerMap.size; i++) {
timer_list_t* list = timerMap.slots + i;
tmr_obj_t* t = list->timers;
while (t != NULL) {
tmr_obj_t* next = t->mnext;
taosMemoryFree(t);
t = next;
}
}
taosMemoryFree(timerMap.slots);
taosMemoryFree(tmrCtrls);
tmrCtrls = NULL;
unusedTmrCtrl = NULL;
atomic_store_32(&tmrModuleInit, 0);
}
}