static void* _timer_instance(void *arg)
{
int fatal;
static int fatal_count = 0;
struct timeval timeout;
kv_timer_event_t *ev;
kv_timer_t *timer = (kv_timer_t*)arg;
assert(timer->state == KV_TIMER_STATE_LOADING);
timer->state = KV_TIMER_STATE_RUNNING;
for (;;) {
timeout.tv_sec = 0;
timeout.tv_usec = timer->interval;
/** interval is very short, ignore signal interrupt */
fatal = select(0, NULL, NULL, NULL, &timeout);
if (fatal == -1) {
fatal_count++;
if (fatal_count >= 3) abort();
continue;
}
fatal_count = 0;
ev = timer->list;
while(ev) {
if (ustime() - ev->elapse_base >= ev->timeout) {
ev->elapse_base = ustime(); /** restart */
ev->proc();
}
ev = ev->next;
}
}
}
void busysleep(int usec) {
int64_t t = ustime() + usec;
while (t > ustime()) {
; // Nothing.
}
}
int do_delete_event(struct redisClient *c,sds funcname)
{
redisSrand48(0);
server.lua_random_dirty = 0;
server.lua_write_dirty = 0;
lua_getglobal(server.lua,(char *)funcname);
if (lua_isnil(server.lua,1)) {
addReplyError(c,"no funcname triggle_scipts in lua");
return 0;
}
luaTriggleSetGlobalArray(server.lua,"KEYS",c->argv+1,c->argc-1);
redisLog(REDIS_NOTICE,"stack: %d",lua_gettop(server.lua));
#ifdef BRIDGE_DEBUG
for(int i=0;i<c->argc-1;i++){
redisLog(REDIS_NOTICE,"%s",(c->argv+1)[i]->ptr);
}
#endif
selectDb(server.lua_client,c->db->id);
server.lua_time_start = ustime()/1000;
server.lua_kill = 0;
if (server.lua_time_limit > 0) {
lua_sethook(server.lua,luaMaskCountHook,LUA_MASKCOUNT,100000);
server.lua_time_start = ustime()/1000;
} else {
lua_sethook(server.lua,luaMaskCountHook,0,0);
}
if (lua_pcall(server.lua,0,1,0)) {
selectDb(c,server.lua_client->db->id);
addReplyErrorFormat(c,"Error running script (call to %s): %s\n",
(char*)funcname, lua_tostring(server.lua,-1));
lua_pop(server.lua,1);
lua_gc(server.lua,LUA_GCCOLLECT,0);
return -1;
}
selectDb(c,server.lua_client->db->id);
// luaReplyToRedisReply(c,server.lua);
server.lua_timedout = 0;
server.lua_caller = NULL;
lua_gc(server.lua,LUA_GCSTEP,1);
//for slaves
//
return 0;
}
// get web from redis and calculate pagerank
void pagerank_redis(redisContext **conts, float v_quadratic_error, web* w) {
redisContext *c = conts[0];
redisReply *reply;
long long t_start;
long long t_end;
unsigned int i;
float q = 1;
printf("Start PageRank from redis: \n");
printf("Damping factor: %f\n", g_damping_factor);
printf("Quadratic error range: %f\n", v_quadratic_error);
printf("----------------------------------\n");
reply = redisCommand(c, "GET next.uid");
if (reply->str == NULL)
die("Cannot not find data in redis!");
unsigned long user_num = atol(reply->str) + 1;
printf("user num: %ld\n", user_num);
freeReplyObject(reply);
t_start = ustime();
if (w->size == 0) {
for (i = 0; i < g_n_sharded; ++i) {
reply = redisCommand(conts[i], "DEL newly.edited.linkto");
freeReplyObject(reply);
reply = redisCommand(conts[i], "DEL newly.edited.linkfrom");
freeReplyObject(reply);
}
web_init(w, user_num);
gen_web_sharded_redis(conts, w, 0);
} else {
size_t origin_size = w->size;
web_init_from_oldweb(w, user_num);
printf("web expansion fin...");
update_web_sharded_redis(conts, w);
printf("web update fin...\n");
//printf("origin dangpage size: %zd\n", w->dangling_pages->size);
update_dangling_pages(w, origin_size);
//printf("updated dangpage size: %zd\n", w->dangling_pages->size);
}
printf("dangling user size: %zd\n", w->dangling_pages->size);
t_end = ustime();
printf("init: %lf seconds\n", getruntime(t_end, t_start));
t_start = ustime();
for (i = 1; q > v_quadratic_error; ++i) {
q = calculate_pagerank_parallel(w);
//printf("iteration %d deviate value: %f\n", i, q);
//web_display_pagerank(w);
}
t_end = ustime();
printf("calculate: %lf seconds(%d iterations)\n", getruntime(t_end, t_start), i - 1);
}
/* Call() is the core of execution of a command */
static void call(ugClient *c, int flags) {
long long start = ustime(), duration;
/* Call the command. */
c->cmd->proc(c);
duration = ustime()-start;
c->cmd->microseconds += duration;
c->cmd->calls++;
}
/* This is how rewriting of the append only file in background works:
*
* 1) The user calls BGREWRITEAOF
* 2) Redis calls this function, that forks():
* 2a) the child rewrite the append only file in a temp file.
* 2b) the parent accumulates differences in server.aof_rewrite_buf.
* 3) When the child finished '2a' exists.
* 4) The parent will trap the exit code, if it's OK, will append the
* data accumulated into server.aof_rewrite_buf into the temp file, and
* finally will rename(2) the temp file in the actual file name.
* The the new file is reopened as the new append only file. Profit!
*/
int rewriteAppendOnlyFileBackground(void) {
pid_t childpid;
long long start;
if (server.aof_child_pid != -1) return REDIS_ERR;
start = ustime();
if ((childpid = fork()) == 0) {
char tmpfile[256];
/* Child */
closeListeningSockets(0);
redisSetProcTitle("redis-aof-rewrite");
snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof", (int) getpid());
if (rewriteAppendOnlyFile(tmpfile) == REDIS_OK) {
size_t private_dirty = zmalloc_get_private_dirty();
if (private_dirty) {
redisLog(REDIS_NOTICE,
"AOF rewrite: %zu MB of memory used by copy-on-write",
private_dirty/(1024*1024));
}
exitFromChild(0);
} else {
exitFromChild(1);
}
} else {
/* Parent */
server.stat_fork_time = ustime()-start;
server.stat_fork_rate = (double) zmalloc_used_memory() * 1000000 / server.stat_fork_time / (1024*1024*1024); /* GB per second. */
latencyAddSampleIfNeeded("fork",server.stat_fork_time/1000);
if (childpid == -1) {
redisLog(REDIS_WARNING,
"Can't rewrite append only file in background: fork: %s",
strerror(errno));
return REDIS_ERR;
}
redisLog(REDIS_NOTICE,
"Background append only file rewriting started by pid %d",childpid);
server.aof_rewrite_scheduled = 0;
server.aof_rewrite_time_start = time(NULL);
server.aof_child_pid = childpid;
updateDictResizePolicy();
/* We set appendseldb to -1 in order to force the next call to the
* feedAppendOnlyFile() to issue a SELECT command, so the differences
* accumulated by the parent into server.aof_rewrite_buf will start
* with a SELECT statement and it will be safe to merge. */
server.aof_selected_db = -1;
replicationScriptCacheFlush();
return REDIS_OK;
}
return REDIS_OK; /* unreached */
}
/*
* 脚本超时钩子
*/
void luaMaskCountHook(lua_State *lua, lua_Debug *ar)
{
long long elapsed;
REDIS_NOTUSED(ar);
REDIS_NOTUSED(lua);
// 计算已执行时间
elapsed = (ustime()/1000) - server.lua_time_start;
if (elapsed >= server.lua_time_limit && server.lua_timedout == 0)
{
redisLog(REDIS_WARNING,"Lua slow script detected: still in execution after %lld milliseconds. You can try killing the script using the SCRIPT KILL command.",elapsed);
// 已超时
server.lua_timedout = 1;
/* Once the script timeouts we reenter the event loop to permit others
* to call SCRIPT KILL or SHUTDOWN NOSAVE if needed. For this reason
* we need to mask the client executing the script from the event loop.
* If we don't do that the client may disconnect and could no longer be
* here when the EVAL command will return. */
// 当脚本运行超时时，将正在执行的客户端从读事件中移除
// 并允许其他客户端执行 SCRIPT KILL 或者 SHUTDOWN NOSAVE
aeDeleteFileEvent(server.el, server.lua_caller->fd, AE_READABLE);
}
if (server.lua_timedout)
// 在脚本上下文中，启动文件事件处理（等待 SCRIPT KILL 或 SHUTDOWN NOSAVE）
aeProcessEvents(server.el, AE_FILE_EVENTS|AE_DONT_WAIT);
if (server.lua_kill)
{
// 杀死脚本
redisLog(REDIS_WARNING,"Lua script killed by user with SCRIPT KILL.");
lua_pushstring(lua,"Script killed by user with SCRIPT KILL...");
lua_error(lua);
}
}
static void write_handler(ae_event_loop *el, int fd, void *priv, int mask) {
client *c = (client *)priv;
/* Initialize request when nothing was written. */
if (c->written == 0) {
if (conf.requests_issued++ >= conf.requests) {
free_client(c);
return;
}
c->start = ustime();
c->latency = -1;
}
if (sdslen(c->obuf) > c->written) {
char *ptr = c->obuf + c->written;
int nwritten = write(c->fd, ptr, sdslen(c->obuf) - c->written);
if (nwritten == -1) {
if (errno != EPIPE) {
fprintf(stderr, "write failed:%s\n", strerror(errno));
}
free_client(c);
return;
}
c->written += nwritten;
if (sdslen(c->obuf) == c->written) {
ae_delete_file_event(conf.el, c->fd, AE_WRITABLE);
ae_create_file_event(conf.el, c->fd,
AE_READABLE, read_handler, c);
}
}
}
// 判断超时，并作超时的处理
void luaMaskCountHook(lua_State *lua, lua_Debug *ar) {
long long elapsed;
REDIS_NOTUSED(ar);
REDIS_NOTUSED(lua);
// 计算已经超时的时间
elapsed = (ustime()/1000) - server.lua_time_start;
if (elapsed >= server.lua_time_limit && server.lua_timedout == 0) {
redisLog(REDIS_WARNING,"Lua slow script detected: still in execution after %lld milliseconds. You can try killing the script using the SCRIPT KILL command.",elapsed);
server.lua_timedout = 1;
// 超时了，关闭监听发送 lua 脚本命令的客户端
/* Once the script timeouts we reenter the event loop to permit others
* to call SCRIPT KILL or SHUTDOWN NOSAVE if needed. For this reason
* we need to mask the client executing the script from the event loop.
* If we don't do that the client may disconnect and could no longer be
* here when the EVAL command will return. */
aeDeleteFileEvent(server.el, server.lua_caller->fd, AE_READABLE);
}
// lua 脚本执行超时，redis 会检测对否有其他客户端会发送 SCRIPT KILL 命令
// 尝试终结这个脚本的执行
if (server.lua_timedout)
aeProcessEvents(server.el, AE_FILE_EVENTS|AE_DONT_WAIT);
// 如果 lua 脚本被停止了，强制产生错误，结束 lua
if (server.lua_kill) {
redisLog(REDIS_WARNING,"Lua script killed by user with SCRIPT KILL.");
lua_pushstring(lua,"Script killed by user with SCRIPT KILL...");
lua_error(lua);
}
}
static void readHandler(aeEventLoop *el, int fd, void *privdata, int mask) {
client c = privdata;
void *reply = NULL;
REDIS_NOTUSED(el);
REDIS_NOTUSED(fd);
REDIS_NOTUSED(mask);
/* Calculate latency only for the first read event. This means that the
* server already sent the reply and we need to parse it. Parsing overhead
* is not part of the latency, so calculate it only once, here. */
if (c->latency < 0) c->latency = ustime()-(c->start);
if (redisBufferRead(c->context) != REDIS_OK) {
fprintf(stderr,"Error: %s\n",c->context->errstr);
exit(1);
} else {
if (redisGetReply(c->context,&reply) != REDIS_OK) {
fprintf(stderr,"Error: %s\n",c->context->errstr);
exit(1);
}
if (reply != NULL) {
if (reply == (void*)REDIS_REPLY_ERROR) {
fprintf(stderr,"Unexpected error reply, exiting...\n");
exit(1);
}
if (config.requests_finished < config.requests)
config.latency[config.requests_finished++] = c->latency;
clientDone(c);
}
}
}
/* convert a linked list encoding to a list array encoding */
robj *cowListCopy(robj *val) {
long long sttime;
robj *newval;
sttime = ustime();
if (val->encoding == REDIS_ENCODING_ZIPLIST) {
size_t bytes;
redisLog(REDIS_NOTICE, "cowListCopy REDIS_ENCODING_ZIPLIST");
newval = createZiplistObject();
/* do raw memory copy */
bytes = ziplistBlobLen(val->ptr);
newval->ptr = zrealloc(newval->ptr, bytes);
memcpy(newval->ptr, val->ptr, bytes);
return newval;
} else if (val->encoding == REDIS_ENCODING_LINKEDLIST) {
list *list = val->ptr;
cowListArray *lar;
redisLog(REDIS_NOTICE, "cowListCopy REDIS_ENCODING_LINKEDLIST");
lar = cowConvertListToArray(list);
newval = createObject(REDIS_LIST, lar);
newval->encoding = REDIS_ENCODING_LINKEDLISTARRAY;
return newval;
} else {
/* error. unexpected encoding */
return NULL;
}
}
/* if copy on write active, then ensure there is a
copy of the value that is safe to modify or delete,
and update DB dict entry to refer to this value*/
void cowEnsureExpiresCopy(redisDb *db) {
long long sttime;
if (server.isBackgroundSaving == 0 ||
server.cowDictCopied == NULL ||
server.cowSaveDb[db->id].expires == NULL) {
/* no copy needed */
return;
} else {
/* ensure DB expires is copied */
if (server.cowSaveDb[db->id].expires == server.db[db->id].expires) {
sttime = ustime();
server.db[db->id].expires = copyonwrite_dictobj(server.cowSaveDb[db->id].expires, NULL);
redisLog(REDIS_NOTICE, "elapsed COW DB expires time %d", (unsigned int)(ustime() - sttime));
}
}
}
static void readHandler(aeEventLoop *el, int fd, void *privdata, int mask) {
client c = privdata;
void *reply = NULL;
REDIS_NOTUSED(el);
REDIS_NOTUSED(fd);
REDIS_NOTUSED(mask);
/* Calculate latency only for the first read event. This means that the
* server already sent the reply and we need to parse it. Parsing overhead
* is not part of the latency, so calculate it only once, here. */
if (c->latency < 0) c->latency = ustime()-(c->start);
if (redisBufferRead(c->context) != REDIS_OK) {
fprintf(stderr,"Error: %s\n",c->context->errstr);
exit(1);
} else {
while(c->pending) {
if (redisGetReply(c->context,&reply) != REDIS_OK) {
fprintf(stderr,"Error: %s\n",c->context->errstr);
exit(1);
}
if (reply != NULL) {
if (reply == (void*)REDIS_REPLY_ERROR) {
fprintf(stderr,"Unexpected error reply, exiting...\n");
exit(1);
}
freeReplyObject(reply);
/* This is an OK for prefix commands such as auth and select.*/
if (c->prefix_pending > 0) {
c->prefix_pending--;
c->pending--;
/* Discard prefix commands on first response.*/
if (c->prefixlen > 0) {
size_t j;
sdsrange(c->obuf, c->prefixlen, -1);
/* We also need to fix the pointers to the strings
* we need to randomize. */
for (j = 0; j < c->randlen; j++)
c->randptr[j] -= c->prefixlen;
c->prefixlen = 0;
}
continue;
}
if (config.requests_finished < config.requests)
config.latency[config.requests_finished++] = c->latency;
c->pending--;
if (c->pending == 0) {
clientDone(c);
break;
}
} else {
break;
}
}
}
}
static void
init_per_lcore() {
lcore_conf_t *qconf;
unsigned lcore_id = rte_lcore_id();
qconf = &sk.lcore_conf[lcore_id];
qconf->tsc_hz = rte_get_tsc_hz();
qconf->start_us = (uint64_t )ustime();
qconf->start_tsc = rte_rdtsc();
}
/* This is how rewriting of the append only file in background works:
*
* 1) The user calls BGREWRITEAOF
* 2) Redis calls this function, that forks():
* 2a) the child rewrite the append only file in a temp file.
* 2b) the parent accumulates differences in server.bgrewritebuf.
* 3) When the child finished '2a' exists.
* 4) The parent will trap the exit code, if it's OK, will append the
* data accumulated into server.bgrewritebuf into the temp file, and
* finally will rename(2) the temp file in the actual file name.
* The the new file is reopened as the new append only file. Profit!
*/
int rewriteAppendOnlyFileBackground(void) {
pid_t childpid;
long long start;
if (server.bgrewritechildpid != -1) return REDIS_ERR;
if (server.vm_enabled) waitEmptyIOJobsQueue();
start = ustime();
if ((childpid = fork()) == 0) {
char tmpfile[256];
/* Child */
if (server.vm_enabled) vmReopenSwapFile();
if (server.ipfd > 0) close(server.ipfd);
if (server.sofd > 0) close(server.sofd);
snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof", (int) getpid());
if (rewriteAppendOnlyFile(tmpfile) == REDIS_OK) {
_exit(0);
} else {
_exit(1);
}
} else {
/* Parent */
server.stat_fork_time = ustime()-start;
if (childpid == -1) {
redisLog(REDIS_WARNING,
"Can't rewrite append only file in background: fork: %s",
strerror(errno));
return REDIS_ERR;
}
redisLog(REDIS_NOTICE,
"Background append only file rewriting started by pid %d",childpid);
server.aofrewrite_scheduled = 0;
server.bgrewritechildpid = childpid;
updateDictResizePolicy();
/* We set appendseldb to -1 in order to force the next call to the
* feedAppendOnlyFile() to issue a SELECT command, so the differences
* accumulated by the parent into server.bgrewritebuf will start
* with a SELECT statement and it will be safe to merge. */
server.appendseldb = -1;
return REDIS_OK;
}
return REDIS_OK; /* unreached */
}
void kv_timer_add(kv_timer_t *timer, long long usec, timer_proc proc)
{
kv_timer_event_t *te;
te = zmalloc(sizeof(*te));
te->timeout = usec < 0 ? -usec : usec;
te->elapse_base = ustime();
te->proc = proc;
te->next = 0;
if (!timer->list) {
timer->list = te;
} else {
te->next = timer->list;
timer->list = te;
}
}
static void writeHandler(aeEventLoop *el, int fd, void *privdata, int mask) {
client c = privdata;
REDIS_NOTUSED(el);
REDIS_NOTUSED(fd);
REDIS_NOTUSED(mask);
/* Initialize request when nothing was written. */
if (c->written == 0) {
/* Enforce upper bound to number of requests. */
if (config.requests_issued++ >= config.requests) {
freeClient(c);
return;
}
/* Really initialize: randomize keys and set start time. */
if (config.randomkeys) randomizeClientKey(c);
c->start = ustime();
c->latency = -1;
}
if (sdslen(c->obuf) > c->written) {
void *ptr = c->obuf+c->written;
#ifdef _WIN32
int nwritten = send(c->context->fd,ptr,sdslen(c->obuf)-c->written, 0);
#else
int nwritten = write(c->context->fd,ptr,sdslen(c->obuf)-c->written);
#endif
if (nwritten == -1) {
if (errno != EPIPE)
fprintf(stderr, "Writing to socket: %s\n", strerror(errno));
freeClient(c);
return;
}
c->written += nwritten;
if (sdslen(c->obuf) == c->written) {
aeDeleteFileEvent(config.el,c->context->fd,AE_WRITABLE);
aeCreateFileEvent(config.el,c->context->fd,AE_READABLE,readHandler,c);
}
}
}
static void read_handler(ae_event_loop *el, int fd, void *priv, int mask) {
client *c = (client *)priv;
int nread;
char buffer[4096];
nread = read(fd, buffer, 4096);
if (nread == -1) {
if (errno == EAGAIN) {
return;
}
fprintf(stderr, "Error: %s\n", strerror(errno));
exit(1);
} else if (nread == 0) {
fprintf(stderr, "Error: %s\n", "Server close connection.");
exit(1);
}
c->read += nread;
if (c->read == sdslen(c->obuf)) {
c->latency = ustime() - c->start;
++conf.requests_finished;
client_done(c);
}
}
/* A background append only file rewriting (BGREWRITEAOF) terminated its work.
* Handle this. */
void backgroundRewriteDoneHandler(int exitcode, int bysignal) {
if (!bysignal && exitcode == 0) {
int newfd, oldfd;
char tmpfile[256];
long long now = ustime();
redisLog(REDIS_NOTICE,
"Background AOF rewrite terminated with success");
/* Flush the differences accumulated by the parent to the
* rewritten AOF. */
snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof",
(int)server.aof_child_pid);
newfd = open(tmpfile,O_WRONLY|O_APPEND);
if (newfd == -1) {
redisLog(REDIS_WARNING,
"Unable to open the temporary AOF produced by the child: %s", strerror(errno));
goto cleanup;
}
if (aofRewriteBufferWrite(newfd) == -1) {
redisLog(REDIS_WARNING,
"Error trying to flush the parent diff to the rewritten AOF: %s", strerror(errno));
close(newfd);
goto cleanup;
}
redisLog(REDIS_NOTICE,
"Parent diff successfully flushed to the rewritten AOF (%lu bytes)", aofRewriteBufferSize());
/* The only remaining thing to do is to rename the temporary file to
* the configured file and switch the file descriptor used to do AOF
* writes. We don't want close(2) or rename(2) calls to block the
* server on old file deletion.
*
* There are two possible scenarios:
*
* 1) AOF is DISABLED and this was a one time rewrite. The temporary
* file will be renamed to the configured file. When this file already
* exists, it will be unlinked, which may block the server.
*
* 2) AOF is ENABLED and the rewritten AOF will immediately start
* receiving writes. After the temporary file is renamed to the
* configured file, the original AOF file descriptor will be closed.
* Since this will be the last reference to that file, closing it
* causes the underlying file to be unlinked, which may block the
* server.
*
* To mitigate the blocking effect of the unlink operation (either
* caused by rename(2) in scenario 1, or by close(2) in scenario 2), we
* use a background thread to take care of this. First, we
* make scenario 1 identical to scenario 2 by opening the target file
* when it exists. The unlink operation after the rename(2) will then
* be executed upon calling close(2) for its descriptor. Everything to
* guarantee atomicity for this switch has already happened by then, so
* we don't care what the outcome or duration of that close operation
* is, as long as the file descriptor is released again. */
if (server.aof_fd == -1) {
/* AOF disabled */
/* Don't care if this fails: oldfd will be -1 and we handle that.
* One notable case of -1 return is if the old file does
* not exist. */
oldfd = open(server.aof_filename,O_RDONLY|O_NONBLOCK);
} else {
/* AOF enabled */
oldfd = -1; /* We'll set this to the current AOF filedes later. */
}
/* Rename the temporary file. This will not unlink the target file if
* it exists, because we reference it with "oldfd". */
if (rename(tmpfile,server.aof_filename) == -1) {
redisLog(REDIS_WARNING,
"Error trying to rename the temporary AOF file: %s", strerror(errno));
close(newfd);
if (oldfd != -1) close(oldfd);
goto cleanup;
}
if (server.aof_fd == -1) {
/* AOF disabled, we don't need to set the AOF file descriptor
* to this new file, so we can close it. */
close(newfd);
} else {
/* AOF enabled, replace the old fd with the new one. */
oldfd = server.aof_fd;
server.aof_fd = newfd;
if (server.aof_fsync == AOF_FSYNC_ALWAYS)
aof_fsync(newfd);
else if (server.aof_fsync == AOF_FSYNC_EVERYSEC)
aof_background_fsync(newfd);
server.aof_selected_db = -1; /* Make sure SELECT is re-issued */
aofUpdateCurrentSize();
server.aof_rewrite_base_size = server.aof_current_size;
/* Clear regular AOF buffer since its contents was just written to
* the new AOF from the background rewrite buffer. */
sdsfree(server.aof_buf);
server.aof_buf = sdsempty();
}
server.aof_lastbgrewrite_status = REDIS_OK;
redisLog(REDIS_NOTICE, "Background AOF rewrite finished successfully");
/* Change state from WAIT_REWRITE to ON if needed */
if (server.aof_state == REDIS_AOF_WAIT_REWRITE)
server.aof_state = REDIS_AOF_ON;
/* Asynchronously close the overwritten AOF. */
if (oldfd != -1) bioCreateBackgroundJob(REDIS_BIO_CLOSE_FILE,(void*)(long)oldfd,NULL,NULL);
redisLog(REDIS_VERBOSE,
"Background AOF rewrite signal handler took %lldus", ustime()-now);
} else if (!bysignal && exitcode != 0) {
server.aof_lastbgrewrite_status = REDIS_ERR;
redisLog(REDIS_WARNING,
"Background AOF rewrite terminated with error");
} else {
server.aof_lastbgrewrite_status = REDIS_ERR;
redisLog(REDIS_WARNING,
"Background AOF rewrite terminated by signal %d", bysignal);
}
cleanup:
aofRewriteBufferReset();
aofRemoveTempFile(server.aof_child_pid);
server.aof_child_pid = -1;
server.aof_rewrite_time_last = time(NULL)-server.aof_rewrite_time_start;
server.aof_rewrite_time_start = -1;
/* Schedule a new rewrite if we are waiting for it to switch the AOF ON. */
if (server.aof_state == REDIS_AOF_WAIT_REWRITE)
server.aof_rewrite_scheduled = 1;
}
static void test_splinlock_speed() {
spinlock_init(&simple_spin);
ticketlock_init(&simple_ticket);
pthread_t threads[10];
printf("spinlock speed test (lock):\n");
for (int num = 1; num <= 16; num *= 2) {
printf("%2d threads: ", num);
fflush(stdout);
spinlock_lock(&simple_spin);
for (int t = 0; t < num; ++t) {
pthread_create(&threads[t], 0, simple_spinlock, 0);
}
int64_t start = ustime();
spinlock_unlock(&simple_spin);
for (int t = 0; t < num; ++t) {
pthread_join(threads[t], 0);
}
int64_t end = ustime();
printf("%6ld milliseconds\n", (end - start) / 1000);
}
printf("spinlock speed test (yieldock):\n");
for (int num = 1; num <= 16; num *= 2) {
printf("%2d threads: ", num);
fflush(stdout);
spinlock_lock(&simple_spin);
for (int t = 0; t < num; ++t) {
pthread_create(&threads[t], 0, simple_spinlock_yield, 0);
}
int64_t start = ustime();
spinlock_unlock(&simple_spin);
for (int t = 0; t < num; ++t) {
pthread_join(threads[t], 0);
}
int64_t end = ustime();
printf("%6ld milliseconds\n", (end - start) / 1000);
}
printf("ticketlock speed test (lock):\n");
for (int num = 1; num <= 8; num *= 2) {
printf("%2d threads: ", num);
fflush(stdout);
ticketlock_lock(&simple_ticket);
for (int t = 0; t < num; ++t) {
pthread_create(&threads[t], 0, simple_ticketlock, 0);
}
int64_t start = ustime();
ticketlock_unlock(&simple_ticket);
for (int t = 0; t < num; ++t) {
pthread_join(threads[t], 0);
}
int64_t end = ustime();
printf("%6ld milliseconds\n", (end - start) / 1000);
}
printf("ticketlock speed test (yieldlock):\n");
for (int num = 1; num <= 8; num *= 2) {
printf("%2d threads: ", num);
fflush(stdout);
ticketlock_lock(&simple_ticket);
for (int t = 0; t < num; ++t) {
pthread_create(&threads[t], 0, simple_ticketlock_yield, 0);
}
int64_t start = ustime();
ticketlock_unlock(&simple_ticket);
for (int t = 0; t < num; ++t) {
pthread_join(threads[t], 0);
}
int64_t end = ustime();
printf("%6ld milliseconds\n", (end - start) / 1000);
}
}
/* if copy on write active, then ensure there is a
copy of the value that is safe to modify or delete,
and update DB dict entry to refer to this value*/
robj *cowEnsureWriteCopy(redisDb *db, robj *key, robj *val) {
long long sttime;
if (server.isBackgroundSaving == 0 ||
server.cowDictCopied == NULL) {
/* no copy needed */
return val;
} else {
int added = 0;
sds keyname;
robj *newval = NULL;
sttime = ustime();
/* first ensure DB dict readonly copy exists */
cowLock();
if (server.cowSaveDbExt[db->id].dictArray == NULL) {
/* make clone with modified cow destructors for db dict */
server.cowSaveDbExt[db->id].dictArray = copyReadonly_dictobj(server.db[db->id].dict,
&server.cowSaveDbExt[db->id]);
/* migrate iterator */
roDBMigrateIterator(server.db[db->id].dict, server.cowSaveDbExt[db->id].dictArray);
}
cowUnlock();
if (val == NULL || key == NULL) {
return NULL;
}
if (dictFind(server.cowDictCopied, (sds)key->ptr) != NULL) {
/* already copied */
return val;
}
/* need to duplicate object, add key to cowDictCopied,
add original to deferred delete list, and update db entry */
cowLock();
switch (val->type) {
case REDIS_STRING:
/* updates always duplicate, original uses defered delete destructor */
break;
case REDIS_LIST:
newval = cowListCopy(val);
break;
case REDIS_SET:
newval = cowSetCopy(val);
break;
case REDIS_ZSET:
newval = cowZSetCopy(val);
break;
case REDIS_HASH:
newval = cowHashCopy(val);
break;
default:
break;
}
cowUnlock();
if (newval == NULL) {
/* no duplicate needed. return original */
return val;
}
/* add key to copied dictionary to avoid extra copies */
keyname = sdsdup((sds)key->ptr);
dictAdd(server.cowDictCopied, keyname, NULL);
/* rewitten iterators are added to converted for lookup
* during save. For other objects, replace DB entry */
if (newval->encoding == REDIS_ENCODING_HTARRAY ||
newval->encoding == REDIS_ENCODING_LINKEDLISTARRAY ||
newval->encoding == REDIS_ENCODING_HTZARRAY) {
cowLock();
/* add value to converted dictionary for iterator lookup */
dictAdd(server.cowDictConverted, keyname, newval);
/* migrate current iterator */
if (newval->encoding == REDIS_ENCODING_HTARRAY) {
roDictMigrateIterator((dict *)val->ptr, (cowDictArray *)newval->ptr);
} else if (newval->encoding == REDIS_ENCODING_LINKEDLISTARRAY) {
roListMigrateIterator((list *)val->ptr, (cowListArray *)newval->ptr);
} else if (newval->encoding == REDIS_ENCODING_HTZARRAY) {
roZDictMigrateIterator((dict *)val->ptr, (cowDictZArray *)newval->ptr);
}
cowUnlock();
} else {
/* replace active DB entry */
dbOverwrite(db, key, newval);
val = newval;
}
redisLog(REDIS_NOTICE, "elapsed COW time %d", (unsigned int)(ustime() - sttime));
return val;
}
}
int triggle_event(struct redisClient *c,sds funcname)
{
redisSrand48(0);
server.lua_random_dirty = 0;
server.lua_write_dirty = 0;
//redisLog(REDIS_NOTICE,"step into stack: %d",lua_gettop(server.lua));
lua_getglobal(server.lua,funcname);
if (lua_isnil(server.lua,1)) {
lua_pop(server.lua,1); /* remove the nil from the stack */
redisLog(REDIS_NOTICE,"no funcname triggle_scipts in lua");
struct dictEntry *de = dictFind(server.bridge_db.triggle_scipts[c->db->id],funcname);
if(de)
{
struct bridge_db_triggle_t * tmptrg=dictGetVal(de);
if (luatriggleCreateFunction(server.lua,funcname,tmptrg->lua_scripts) == REDIS_ERR) return -1;
/* Now the following is guaranteed to return non nil */
lua_getglobal(server.lua, funcname);
redisAssert(!lua_isnil(server.lua,1));
}
else
{
redisLog(REDIS_WARNING,"triggle not found");
return -1;
}
}
luaTriggleSetGlobalArray(server.lua,"KEYS",c->argv,c->argc);
// redisLog(REDIS_NOTICE,"stack: %d",lua_gettop(server.lua));
/* for(int i=0;i<c->argc;i++){
redisLog(REDIS_NOTICE,"%s",c->argv[i]->ptr);
}
*/
/* Select the right DB in the context of the Lua client */
selectDb(server.lua_client,c->db->id);
server.lua_time_start = ustime()/1000;
server.lua_kill = 0;
if (server.lua_time_limit > 0) {
lua_sethook(server.lua,luaMaskCountHook,LUA_MASKCOUNT,100000);
server.lua_time_start = ustime()/1000;
} else {
lua_sethook(server.lua,luaMaskCountHook,0,0);
}
/* At this point whatever this script was never seen before or if it was
* already defined, we can call it. We have zero arguments and expect
* a single return value. */
if (lua_pcall(server.lua,0,1,0)) {
selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */
redisLog(REDIS_WARNING,"Error running script (call to %s): %s\n",
(char*)funcname, lua_tostring(server.lua,-1));
lua_pop(server.lua,1);
lua_gc(server.lua,LUA_GCCOLLECT,0);
return -1;
}
selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */
// luaReplyToRedisReply(c,server.lua);
lua_pop(server.lua,1);
server.lua_timedout = 0;
server.lua_caller = NULL;
lua_gc(server.lua,LUA_GCSTEP,1);
// redisLog(REDIS_NOTICE,"after stack: %d",lua_gettop(server.lua));
//for slaves
//
return 0;
}
int triggle_expire_event(redisDb *db,sds funcname,robj *key)
{
redisSrand48(0);
server.lua_random_dirty = 0;
server.lua_write_dirty = 0;
lua_getglobal(server.lua,funcname);
if (lua_isnil(server.lua,1)) {
lua_pop(server.lua,1); /* remove the nil from the stack */
redisLog(REDIS_NOTICE,"no funcname triggle_scipts in lua");
struct dictEntry *de = dictFind(server.bridge_db.triggle_scipts[db->id],funcname);
if(de)
{
struct bridge_db_triggle_t * tmptrg=dictGetVal(de);
if (luatriggleCreateFunction(server.lua,funcname,tmptrg->lua_scripts) == REDIS_ERR) return -1;
/* Now the following is guaranteed to return non nil */
lua_getglobal(server.lua, funcname);
redisAssert(!lua_isnil(server.lua,1));
}
else
{
redisLog(REDIS_WARNING,"triggle not found");
return -1;
}
}
luaTriggleSetGlobalArray(server.lua,"KEYS",&key,1);
server.lua_time_start = ustime()/1000;
server.lua_kill = 0;
if (server.lua_time_limit > 0) {
lua_sethook(server.lua,luaMaskCountHook,LUA_MASKCOUNT,100000);
server.lua_time_start = ustime()/1000;
} else {
lua_sethook(server.lua,luaMaskCountHook,0,0);
}
/* At this point whatever this script was never seen before or if it was
* already defined, we can call it. We have zero arguments and expect
* a single return value. */
if (lua_pcall(server.lua,0,1,0)) {
//selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */
redisLog(REDIS_WARNING,"exec the script error:%s",lua_tostring(server.lua,-1));
lua_pop(server.lua,1);
lua_gc(server.lua,LUA_GCCOLLECT,0);
return -1;
}
//selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */
server.lua_timedout = 0;
server.lua_caller = NULL;
lua_pop(server.lua,1);
lua_gc(server.lua,LUA_GCSTEP,1);
return 0;
}
void evalGenericCommand(redisClient *c, int evalsha)
{
lua_State *lua = server.lua;
char funcname[43];
long long numkeys;
int delhook = 0;
/* We want the same PRNG sequence at every call so that our PRNG is
* not affected by external state.
*
* 在每次执行 EVAL 时重置随机 seed ，从而保证可以生成相同的随机序列。
*/
redisSrand48(0);
/* We set this flag to zero to remember that so far no random command
* was called. This way we can allow the user to call commands like
* SRANDMEMBER or RANDOMKEY from Lua scripts as far as no write command
* is called (otherwise the replication and AOF would end with non
* deterministic sequences).
*
* Thanks to this flag we'll raise an error every time a write command
* is called after a random command was used.
*
* 用两个变量，对命令进行检查
* 确保在调用随机命令之后，再调用写命令将出现错误
*/
server.lua_random_dirty = 0;
server.lua_write_dirty = 0;
/* Get the number of arguments that are keys */
// 获取输入键的数量
if (getLongLongFromObjectOrReply(c,c->argv[2],&numkeys,NULL) != REDIS_OK)
return;
// 对键的正确性做一个快速检查
if (numkeys > (c->argc - 3))
{
addReplyError(c,"Number of keys can't be greater than number of args");
return;
}
/* We obtain the script SHA1, then check if this function is already
* defined into the Lua state */
// 组合出函数的名字，例如 f_282297a0228f48cd3fc6a55de6316f31422f5d17
funcname[0] = 'f';
funcname[1] = '_';
if (!evalsha)
{
/* Hash the code if this is an EVAL call */
// 如果执行的是 EVAL 命令，那么计算脚本的 SHA1 校验和
sha1hex(funcname+2,c->argv[1]->ptr,sdslen(c->argv[1]->ptr));
}
else
{
// 如果执行的是 EVALSHA 命令，直接使用传入的 SHA1 值
/* We already have the SHA if it is a EVALSHA */
int j;
char *sha = c->argv[1]->ptr;
for (j = 0; j < 40; j++)
funcname[j+2] = tolower(sha[j]);
funcname[42] = '\0';
}
/* Try to lookup the Lua function */
// 按名查找函数
lua_getglobal(lua, funcname);
if (lua_isnil(lua,1))
{
// 没找到脚本相应的脚本
lua_pop(lua,1); /* remove the nil from the stack */
/* Function not defined... let's define it if we have the
* body of the funciton. If this is an EVALSHA call we can just
* return an error. */
if (evalsha)
{
// 如果执行的是 EVALSHA ，返回脚本未找到错误
addReply(c, shared.noscripterr);
return;
}
// 如果执行的是 EVAL ，那么创建并执行新函数，然后将代码添加到脚本字典中
if (luaCreateFunction(c,lua,funcname,c->argv[1]) == REDIS_ERR) return;
/* Now the following is guaranteed to return non nil */
lua_getglobal(lua, funcname);
redisAssert(!lua_isnil(lua,1));
}
/* Populate the argv and keys table accordingly to the arguments that
* EVAL received. */
// 设置 KEYS 和 ARGV 全局变量到 Lua 环境
luaSetGlobalArray(lua,"KEYS",c->argv+3,numkeys);
luaSetGlobalArray(lua,"ARGV",c->argv+3+numkeys,c->argc-3-numkeys);
/* Select the right DB in the context of the Lua client */
// 为 Lua 所属的（伪）客户端设置数据库
selectDb(server.lua_client,c->db->id);
/* Set an hook in order to be able to stop the script execution if it
* is running for too much time.
*
* 设置一个钩子，用于在运行时间过长时停止脚本的运作。
*
* We set the hook only if the time limit is enabled as the hook will
* make the Lua script execution slower.
*
* 只在开启了时间限制选项时使用钩子，因为它会拖慢脚本的运行速度。
*/
// 调用客户端
server.lua_caller = c;
// 脚本开始时间
server.lua_time_start = ustime()/1000;
// 是否杀死脚本
server.lua_kill = 0;
// 只在开启时间限制时使用钩子
if (server.lua_time_limit > 0 && server.masterhost == NULL)
{
lua_sethook(lua,luaMaskCountHook,LUA_MASKCOUNT,100000);
delhook = 1;
}
/* At this point whatever this script was never seen before or if it was
* already defined, we can call it. We have zero arguments and expect
* a single return value. */
// 执行脚本（所属的函数）
if (lua_pcall(lua,0,1,0))
{
// 以下是脚本执行出错的代码。。。
// 删除钩子
if (delhook) lua_sethook(lua,luaMaskCountHook,0,0); /* Disable hook */
// 脚本执行已超时
if (server.lua_timedout)
{
// 清除超时 FLAG
server.lua_timedout = 0;
/* Restore the readable handler that was unregistered when the
* script timeout was detected. */
// 将超时钩子里删除的读事件重新加上
aeCreateFileEvent(server.el,c->fd,AE_READABLE,
readQueryFromClient,c);
}
// 清空调用者
server.lua_caller = NULL;
// 更新目标数据库
selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */
addReplyErrorFormat(c,"Error running script (call to %s): %s\n",
funcname, lua_tostring(lua,-1));
// 弹出函数
lua_pop(lua,1);
// 执行完整的废料回首循环（full garbage-collection cycle）
lua_gc(lua,LUA_GCCOLLECT,0);
// 返回
return;
}
// 以下是脚本执行成功时执行的代码。。。
// 删除钩子
if (delhook) lua_sethook(lua,luaMaskCountHook,0,0); /* Disable hook */
// 清空超时 FLAG
server.lua_timedout = 0;
// 清空调用者
server.lua_caller = NULL;
// 更新 DB
selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */
// 将 Lua 回复转换成 Redis 回复
luaReplyToRedisReply(c,lua);
// 执行 1 步渐进式 GC
lua_gc(lua,LUA_GCSTEP,1);
/* If we have slaves attached we want to replicate this command as
* EVAL instead of EVALSHA. We do this also in the AOF as currently there
* is no easy way to propagate a command in a different way in the AOF
* and in the replication link.
*
* 如果有附属节点，那么使用 EVAL 而不是 EVALSHA 来传播脚本
* 因为目前还没有代码可以检测脚本是否已经传送到附属节点中
*
* IMPROVEMENT POSSIBLE:
* 1) Replicate this command as EVALSHA in the AOF.
* 2) Remember what slave already received a given script, and replicate
* the EVALSHA against this slaves when possible.
*/
// 如果执行的是 EVALSHA 命令
if (evalsha)
{
// 取出脚本代码体（body）
robj *script = dictFetchValue(server.lua_scripts,c->argv[1]->ptr);
redisAssertWithInfo(c,NULL,script != NULL);
// 重写客户端命令为 EVAL
rewriteClientCommandArgument(c,0,
resetRefCount(createStringObject("EVAL",4)));
rewriteClientCommandArgument(c,1,script);
}
}
void update() {
this->t = ustime();
}
uint64_t tick() {
uint64_t ret = this->t;
this->t = ustime();
return this->t - ret;
}
void evalGenericCommand(redisClient *c, int evalsha) {
lua_State *lua = server.lua;
char funcname[43];
long long numkeys;
int delhook = 0, err;
/* We want the same PRNG sequence at every call so that our PRNG is
* not affected by external state. */
redisSrand48(0);
/* We set this flag to zero to remember that so far no random command
* was called. This way we can allow the user to call commands like
* SRANDMEMBER or RANDOMKEY from Lua scripts as far as no write command
* is called (otherwise the replication and AOF would end with non
* deterministic sequences).
*
* Thanks to this flag we'll raise an error every time a write command
* is called after a random command was used. */
server.lua_random_dirty = 0;
server.lua_write_dirty = 0;
/* Get the number of arguments that are keys */
if (getLongLongFromObjectOrReply(c,c->argv[2],&numkeys,NULL) != REDIS_OK)
return;
if (numkeys > (c->argc - 3)) {
addReplyError(c,"Number of keys can't be greater than number of args");
return;
}
/* We obtain the script SHA1, then check if this function is already
* defined into the Lua state */
funcname[0] = 'f';
funcname[1] = '_';
if (!evalsha) {
/* Hash the code if this is an EVAL call */
sha1hex(funcname+2,c->argv[1]->ptr,sdslen(c->argv[1]->ptr));
} else {
/* We already have the SHA if it is a EVALSHA */
int j;
char *sha = c->argv[1]->ptr;
for (j = 0; j < 40; j++)
funcname[j+2] = tolower(sha[j]);
funcname[42] = '\0';
}
/* Push the pcall error handler function on the stack. */
lua_getglobal(lua, "__redis__err__handler");
/* Try to lookup the Lua function */
lua_getglobal(lua, funcname);
if (lua_isnil(lua,-1)) {
lua_pop(lua,1); /* remove the nil from the stack */
/* Function not defined... let's define it if we have the
* body of the function. If this is an EVALSHA call we can just
* return an error. */
if (evalsha) {
lua_pop(lua,1); /* remove the error handler from the stack. */
addReply(c, shared.noscripterr);
return;
}
if (luaCreateFunction(c,lua,funcname,c->argv[1]) == REDIS_ERR) return;
/* Now the following is guaranteed to return non nil */
lua_getglobal(lua, funcname);
redisAssert(!lua_isnil(lua,-1));
}
/* Populate the argv and keys table accordingly to the arguments that
* EVAL received. */
luaSetGlobalArray(lua,"KEYS",c->argv+3,numkeys);
luaSetGlobalArray(lua,"ARGV",c->argv+3+numkeys,c->argc-3-numkeys);
/* Select the right DB in the context of the Lua client */
selectDb(server.lua_client,c->db->id);
/* Set an hook in order to be able to stop the script execution if it
* is running for too much time.
* We set the hook only if the time limit is enabled as the hook will
* make the Lua script execution slower. */
server.lua_caller = c;
server.lua_time_start = ustime()/1000;
server.lua_kill = 0;
if (server.lua_time_limit > 0 && server.masterhost == NULL) {
lua_sethook(lua,luaMaskCountHook,LUA_MASKCOUNT,100000);
delhook = 1;
}
/* At this point whether this script was never seen before or if it was
* already defined, we can call it. We have zero arguments and expect
* a single return value. */
err = lua_pcall(lua,0,1,-2);
/* Perform some cleanup that we need to do both on error and success. */
if (delhook) lua_sethook(lua,luaMaskCountHook,0,0); /* Disable hook */
if (server.lua_timedout) {
server.lua_timedout = 0;
/* Restore the readable handler that was unregistered when the
* script timeout was detected. */
aeCreateFileEvent(server.el,c->fd,AE_READABLE,
readQueryFromClient,c);
}
server.lua_caller = NULL;
selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */
lua_gc(lua,LUA_GCSTEP,1);
if (err) {
addReplyErrorFormat(c,"Error running script (call to %s): %s\n",
funcname, lua_tostring(lua,-1));
lua_pop(lua,1); /* Consume the Lua reply. */
} else {
/* On success convert the Lua return value into Redis protocol, and
* send it to * the client. */
luaReplyToRedisReply(c,lua);
}
/* EVALSHA should be propagated to Slave and AOF file as full EVAL, unless
* we are sure that the script was already in the context of all the
* attached slaves *and* the current AOF file if enabled.
*
* To do so we use a cache of SHA1s of scripts that we already propagated
* as full EVAL, that's called the Replication Script Cache.
*
* For repliation, everytime a new slave attaches to the master, we need to
* flush our cache of scripts that can be replicated as EVALSHA, while
* for AOF we need to do so every time we rewrite the AOF file. */
if (evalsha) {
if (!replicationScriptCacheExists(c->argv[1]->ptr)) {
/* This script is not in our script cache, replicate it as
* EVAL, then add it into the script cache, as from now on
* slaves and AOF know about it. */
robj *script = dictFetchValue(server.lua_scripts,c->argv[1]->ptr);
replicationScriptCacheAdd(c->argv[1]->ptr);
redisAssertWithInfo(c,NULL,script != NULL);
rewriteClientCommandArgument(c,0,
resetRefCount(createStringObject("EVAL",4)));
rewriteClientCommandArgument(c,1,script);
}
}
}
/* Return the UNIX time in milliseconds */
long long mstime(void) {
return ustime()/1000;
}
int main(int argc, char *argv[]) {
printf("Second:%d, Millisecond:%lld, Microsecond:%lld\n",
time(NULL), mstime(), ustime());
exit(0);
}
void evalGenericCommand(redisClient *c, int evalsha) {
lua_State *lua = server.lua;
char funcname[43];
long long numkeys;
int delhook = 0, err;
// 随机数的种子，在产生哈希值的时候会用到
/* We want the same PRNG sequence at every call so that our PRNG is
* not affected by external state. */
redisSrand48(0);
/* We set this flag to zero to remember that so far no random command
* was called. This way we can allow the user to call commands like
* SRANDMEMBER or RANDOMKEY from Lua scripts as far as no write command
* is called (otherwise the replication and AOF would end with non
* deterministic sequences).
*
* Thanks to this flag we'll raise an error every time a write command
* is called after a random command was used. */
server.lua_random_dirty = 0;
server.lua_write_dirty = 0;
// 检查参数的有效性
/* Get the number of arguments that are keys */
if (getLongLongFromObjectOrReply(c,c->argv[2],&numkeys,NULL) != REDIS_OK)
return;
if (numkeys > (c->argc - 3)) {
addReplyError(c,"Number of keys can't be greater than number of args");
return;
}
// 函数名以 f_ 开头
/* We obtain the script SHA1, then check if this function is already
* defined into the Lua state */
funcname[0] = 'f';
funcname[1] = '_';
// 如果没有哈希值，需要计算 lua 脚本的哈希值
if (!evalsha) {
// 计算哈希值，会放入到 SHA1 -> lua_script 哈希表中
// c->argv[1]->ptr 是用户指定的 lua 脚本
// sha1hex() 产生的哈希值存在 funcname 中
/* Hash the code if this is an EVAL call */
sha1hex(funcname+2,c->argv[1]->ptr,sdslen(c->argv[1]->ptr));
} else {
// 用户自己指定了哈希值
/* We already have the SHA if it is a EVALSHA */
int j;
char *sha = c->argv[1]->ptr;
for (j = 0; j < 40; j++)
funcname[j+2] = tolower(sha[j]);
funcname[42] = '\0';
}
// 将错误处理函数入栈
// lua_getglobal() 会将读取指定的全局变量，且将其入栈
/* Push the pcall error handler function on the stack. */
lua_getglobal(lua, "__redis__err__handler");
/* Try to lookup the Lua function */
// 在 lua 中查找是否注册了此函数。这一句尝试将 funcname 入栈
lua_getglobal(lua, funcname);
if (lua_isnil(lua,-1)) { // funcname 在 lua 中不存在
// 将 nil 出栈
lua_pop(lua,1); /* remove the nil from the stack */
// 已经确定 funcname 在 lua 中没有定义，需要创建
/* Function not defined... let's define it if we have the
* body of the function. If this is an EVALSHA call we can just
* return an error. */
if (evalsha) {
lua_pop(lua,1); /* remove the error handler from the stack. */
addReply(c, shared.noscripterr);
return;
}
// 创建 lua 函数 funcname
// c->argv[1] 指向用户指定的 lua 脚本
if (luaCreateFunction(c,lua,funcname,c->argv[1]) == REDIS_ERR) {
lua_pop(lua,1); /* remove the error handler from the stack. */
/* The error is sent to the client by luaCreateFunction()
* itself when it returns REDIS_ERR. */
return;
}
// 现在 lua 中已经有 funcname 这个全局变量了，将其读取并入栈，
// 准备调用
/* Now the following is guaranteed to return non nil */
lua_getglobal(lua, funcname);
redisAssert(!lua_isnil(lua,-1));
}
// 设置参数，包括键和值
/* Populate the argv and keys table accordingly to the arguments that
* EVAL received. */
luaSetGlobalArray(lua,"KEYS",c->argv+3,numkeys);
luaSetGlobalArray(lua,"ARGV",c->argv+3+numkeys,c->argc-3-numkeys);
// 选择数据集，lua_client 有专用的数据集
/* Select the right DB in the context of the Lua client */
selectDb(server.lua_client,c->db->id);
// 设置超时回调函数，以在 lua 脚本执行过长时间的时候停止脚本的运行
/* Set a hook in order to be able to stop the script execution if it
* is running for too much time.
* We set the hook only if the time limit is enabled as the hook will
* make the Lua script execution slower. */
server.lua_caller = c;
server.lua_time_start = ustime()/1000;
server.lua_kill = 0;
if (server.lua_time_limit > 0 && server.masterhost == NULL) {
// 当 lua 解释器执行了 100000，luaMaskCountHook() 会被调用
lua_sethook(lua,luaMaskCountHook,LUA_MASKCOUNT,100000);
delhook = 1;
}
// 现在，我们确定函数已经注册成功了.可以直接调用 lua 脚本
/* At this point whether this script was never seen before or if it was
* already defined, we can call it. We have zero arguments and expect
* a single return value. */
err = lua_pcall(lua,0,1,-2);
// 删除超时回调函数
/* Perform some cleanup that we need to do both on error and success. */
if (delhook) lua_sethook(lua,luaMaskCountHook,0,0); /* Disable hook */
// 如果已经超时了，说明 lua 脚本已在超时后背 SCRPIT KILL 终结了
// 恢复监听发送 lua 脚本命令的客户端
if (server.lua_timedout) {
server.lua_timedout = 0;
/* Restore the readable handler that was unregistered when the
* script timeout was detected. */
aeCreateFileEvent(server.el,c->fd,AE_READABLE,
readQueryFromClient,c);
}
// lua_caller 置空
server.lua_caller = NULL;
// 执行 lua 脚本用的是 lua 脚本执行专用的数据集。现在恢复原有的数据集
selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */
// Garbage collection 垃圾回收
lua_gc(lua,LUA_GCSTEP,1);
// 处理执行 lua 脚本的错误
if (err) {
// 告知客户端
addReplyErrorFormat(c,"Error running script (call to %s): %s\n",
funcname, lua_tostring(lua,-1));
lua_pop(lua,2); /* Consume the Lua reply and remove error handler. */
// 成功了
} else {
/* On success convert the Lua return value into Redis protocol, and
* send it to * the client. */
luaReplyToRedisReply(c,lua); /* Convert and consume the reply. */
lua_pop(lua,1); /* Remove the error handler. */
}
// 将 lua 脚本发布到主从复制上，并写入 AOF 文件
/* EVALSHA should be propagated to Slave and AOF file as full EVAL, unless
* we are sure that the script was already in the context of all the
* attached slaves *and* the current AOF file if enabled.
*
* To do so we use a cache of SHA1s of scripts that we already propagated
* as full EVAL, that's called the Replication Script Cache.
*
* For repliation, everytime a new slave attaches to the master, we need to
* flush our cache of scripts that can be replicated as EVALSHA, while
* for AOF we need to do so every time we rewrite the AOF file. */
if (evalsha) {
if (!replicationScriptCacheExists(c->argv[1]->ptr)) {
/* This script is not in our script cache, replicate it as
* EVAL, then add it into the script cache, as from now on
* slaves and AOF know about it. */
// 从 server.lua_scripts 获取 lua 脚本
// c->argv[1]->ptr 是 SHA1
robj *script = dictFetchValue(server.lua_scripts,c->argv[1]->ptr);
// 添加到主从复制专用的脚本缓存中
replicationScriptCacheAdd(c->argv[1]->ptr);
redisAssertWithInfo(c,NULL,script != NULL);
// 重写命令
// 参数 1 为：EVAL
// 参数 2 为：lua_script
// 如此一来在执行 AOF 持久化和主从复制的时候，lua 脚本就能得到传播
rewriteClientCommandArgument(c,0,
resetRefCount(createStringObject("EVAL",4)));
rewriteClientCommandArgument(c,1,script);
}
}
}
