static void bufferevent_readcb(int32_t fd, short event, void *arg)
{
struct bufferevent_common *bufev = arg;
struct evbuffer *input;
int res = 0;
int len = 0;
short what = BEV_EVENT_READING;
struct evbuffer_common *pInput = bufev->input;
if (event == EV_TIMEOUT) {
/* Note that we only check for event==EV_TIMEOUT. If
* event==EV_TIMEOUT|EV_READ, we can safely ignore the
* timeout, since a read has occurred */
what |= BEV_EVENT_TIMEOUT;
goto error;
}
len = read(fd, pInput->data, 16384-pInput->len);
pInput->data.len += len;
if(pInput->data.len >= 4) {
bev->len = *((int32_t *)(pInput->data));
}
if (len == -1) {
int err = evutil_socket_geterror(fd);
if (EVUTIL_ERR_RW_RETRIABLE(err))
goto reschedule;
/* error case */
what |= BEV_EVENT_ERROR;
} else if (len == 0) {
/* eof case */
what |= BEV_EVENT_EOF;
}
goto done:
error:
if (event & EV_READ) {
event_del(&bufev->ev_read);
}
bufev->errorcb(bufev, what);
done:
}
int32_t BUFFER_add(BUFFER *buffer, void *data, uint32_t len)
{
uint32_t end = buffer->index + buffer->len;
if(!buffer || len+buffer->len > buffer->capacity)
return -1;
if(end+len > buffer->capacity)
{
memcpy(buffer->data+end, data, capacity-end);
memcpy(buffer->data, data+(capacity-end), end+len-buffer->capacity);
}
else
{
memcpy(buffer->data+end, data, len);
}
buffer->len += len;
return 0;
}
void
do_read(evutil_socket_t fd, short events, void *arg)
{
struct fd_state *state = arg;
char buf[1024];
int i;
ev_ssize_t result;
printf("do_read(): fd = %d\r\n", fd);
while (1) {
assert(state->write_event);
result = recv(fd, buf, sizeof(buf), 0);
printf("recv(): result = %d\r\n", result);
if (result <= 0)
break;
for (i=0; i < result; ++i) {
if (state->buffer_used < sizeof(state->buffer))
state->buffer[state->buffer_used++] = rot13_char(buf[i]);
if (buf[i] == '\n') {
//assert(state->write_event);
//event_add(state->write_event, NULL);
state->write_upto = state->buffer_used;
buf[state->buffer_used] = '\0';
printf("\r\n");
printf("bufsize = %d, buf = %s\r\n", state->buffer_used, buf);
}
}
}
if (result == 0) {
free_fd_state(state);
} else if (result < 0) {
//if (errno == EAGAIN) // XXXX use evutil macro
// return;
int err = evutil_socket_geterror(fd);
if (EVUTIL_ERR_RW_RETRIABLE(err)) {
// WSAEWOULDBLOCK or WSAEINTR
printf("event_del(state->read_event);\r\n");
event_del(state->read_event);
return;
}
else {
perror("recv");
free_fd_state(state);
}
}
}
void
do_write(evutil_socket_t fd, short events, void *arg)
{
struct fd_state *state = arg;
char buf[512];
int n_written = 0, write_upto = sizeof(buf);
int buffer_used = 0;
printf("do_write(): fd = %d\r\n", fd);
memset(buf, 0, write_upto);
strcpy(buf, "Hello World!\r\n");
printf("\r\n");
printf("bufsize = %d, buf = %s\r\n", state->buffer_used, buf);
write_upto = strlen(buf);
while (n_written < write_upto) {
ev_ssize_t result = send(fd, buf + n_written,
write_upto - n_written, 0);
printf("send(): result = %d\r\n", result);
if (result < 0) {
//if (errno == EAGAIN) // XXX use evutil macro
// return;
int err = evutil_socket_geterror(fd);
if (EVUTIL_ERR_RW_RETRIABLE(err)) {
// WSAEWOULDBLOCK or WSAEINTR
break;
}
else {
printf("event_del(state->write_event);\r\n");
event_del(state->write_event);
return;
}
}
assert(result != 0);
n_written += result;
}
if (n_written == buffer_used)
n_written = write_upto = buffer_used = 1;
printf("event_del(state->write_event);\r\n");
event_del(state->write_event);
}
/* Callback for when the signal handler write a byte to our signaling socket */
static void
evsig_cb(evutil_socket_t fd, short what, void *arg)
{
static char signals[1024];
ev_ssize_t n;
int i;
int ncaught[NSIG];
struct event_base *base;
base = arg;
memset(&ncaught, 0, sizeof(ncaught));
while (1) {
#ifdef _WIN32
n = recv(fd, signals, sizeof(signals), 0);
#else
n = read(fd, signals, sizeof(signals));
#endif
if (n == -1) {
int err = evutil_socket_geterror(fd);
if (! EVUTIL_ERR_RW_RETRIABLE(err))
event_sock_err(1, fd, "%s: recv", __func__);
break;
} else if (n == 0) {
/* XXX warn? */
break;
}
for (i = 0; i < n; ++i) {
ev_uint8_t sig = signals[i];
if (sig < NSIG)
ncaught[sig]++;
}
}
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
for (i = 0; i < NSIG; ++i) {
if (ncaught[i])
evmap_signal_active_(base, i, ncaught[i]);
}
EVBASE_RELEASE_LOCK(base, th_base_lock);
}
/* Callback for when the signal handler write a byte to our signaling socket */
static void
evsig_cb(evutil_socket_t fd, short what, void *arg)
{
static char signals[1024];//用来存放信号处理函数传过来的的信号？
ev_ssize_t n;
int i;
int ncaught[NSIG];//NSIG在哪定义？
struct event_base *base;
base = arg;
memset(&ncaught, 0, sizeof(ncaught));
while (1) {
n = recv(fd, signals, sizeof(signals), 0);
if (n == -1) {
int err = evutil_socket_geterror(fd);//windows平台这是函数，而linux平台这是宏函数
if (! EVUTIL_ERR_RW_RETRIABLE(err)) //判断是否可重读写，即检查EINTR和EAGAIN
event_sock_err(1, fd, "%s: recv", __func__);
break;
} else if (n == 0) {
/* XXX warn? */
break;
}
for (i = 0; i < n; ++i) {
ev_uint8_t sig = signals[i];
if (sig < NSIG)
ncaught[sig]++;//记录传进来的信号
}
}
EVBASE_ACQUIRE_LOCK(base, th_base_lock);//base虽然是在本函数中定义的，貌似在栈上，但是他指向的地址是从外部传过来的，所以需要加锁
for (i = 0; i < NSIG; ++i) {
if (ncaught[i])
evmap_signal_active(base, i, ncaught[i]);//激活base中等待的信号
}
EVBASE_RELEASE_LOCK(base, th_base_lock);
}
static void
bufferevent_writecb(evutil_socket_t fd, short event, void *arg)
{
struct bufferevent *bufev = arg;
struct bufferevent_private *bufev_p =
EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
int res = 0;
short what = BEV_EVENT_WRITING;
int connected = 0;
ev_ssize_t atmost = -1;
bufferevent_incref_and_lock_(bufev);
if (event == EV_TIMEOUT) {
/* Note that we only check for event==EV_TIMEOUT. If
* event==EV_TIMEOUT|EV_WRITE, we can safely ignore the
* timeout, since a read has occurred */
what |= BEV_EVENT_TIMEOUT;
goto error;
}
if (bufev_p->connecting) {
int c = evutil_socket_finished_connecting_(fd);
/* we need to fake the error if the connection was refused
* immediately - usually connection to localhost on BSD */
if (bufev_p->connection_refused) {
bufev_p->connection_refused = 0;
c = -1;
}
if (c == 0)
goto done;
bufev_p->connecting = 0;
if (c < 0) {
event_del(&bufev->ev_write);
event_del(&bufev->ev_read);
bufferevent_run_eventcb_(bufev, BEV_EVENT_ERROR);
goto done;
} else {
connected = 1;
#ifdef _WIN32
if (BEV_IS_ASYNC(bufev)) {
event_del(&bufev->ev_write);
bufferevent_async_set_connected_(bufev);
bufferevent_run_eventcb_(bufev,
BEV_EVENT_CONNECTED);
goto done;
}
#endif
bufferevent_run_eventcb_(bufev,
BEV_EVENT_CONNECTED);
if (!(bufev->enabled & EV_WRITE) ||
bufev_p->write_suspended) {
event_del(&bufev->ev_write);
goto done;
}
}
}
atmost = bufferevent_get_write_max_(bufev_p);
if (bufev_p->write_suspended)
goto done;
if (evbuffer_get_length(bufev->output)) {
evbuffer_unfreeze(bufev->output, 1);
res = evbuffer_write_atmost(bufev->output, fd, atmost);
evbuffer_freeze(bufev->output, 1);
if (res == -1) {
int err = evutil_socket_geterror(fd);
if (EVUTIL_ERR_RW_RETRIABLE(err))
goto reschedule;
what |= BEV_EVENT_ERROR;
} else if (res == 0) {
/* eof case
XXXX Actually, a 0 on write doesn't indicate
an EOF. An ECONNRESET might be more typical.
*/
what |= BEV_EVENT_EOF;
}
if (res <= 0)
goto error;
bufferevent_decrement_write_buckets_(bufev_p, res);
}
if (evbuffer_get_length(bufev->output) == 0) {
event_del(&bufev->ev_write);
}
/*
* Invoke the user callback if our buffer is drained or below the
* low watermark.
*/
if ((res || !connected) &&
evbuffer_get_length(bufev->output) <= bufev->wm_write.low) {
bufferevent_run_writecb_(bufev);
}
goto done;
reschedule:
if (evbuffer_get_length(bufev->output) == 0) {
event_del(&bufev->ev_write);
}
goto done;
error:
bufferevent_disable(bufev, EV_WRITE);
bufferevent_run_eventcb_(bufev, what);
done:
bufferevent_decref_and_unlock_(bufev);
}
static void
bufferevent_readcb(evutil_socket_t fd, short event, void *arg)
{
struct bufferevent *bufev = arg;
struct bufferevent_private *bufev_p =
EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
struct evbuffer *input;
int res = 0;
short what = BEV_EVENT_READING;
ev_ssize_t howmuch = -1, readmax=-1;
bufferevent_incref_and_lock_(bufev);
if (event == EV_TIMEOUT) {
/* Note that we only check for event==EV_TIMEOUT. If
* event==EV_TIMEOUT|EV_READ, we can safely ignore the
* timeout, since a read has occurred */
what |= BEV_EVENT_TIMEOUT;
goto error;
}
input = bufev->input;
/*
* If we have a high watermark configured then we don't want to
* read more data than would make us reach the watermark.
*/
if (bufev->wm_read.high != 0) {
howmuch = bufev->wm_read.high - evbuffer_get_length(input);
/* we somehow lowered the watermark, stop reading */
if (howmuch <= 0) {
bufferevent_wm_suspend_read(bufev);
goto done;
}
}
readmax = bufferevent_get_read_max_(bufev_p);
if (howmuch < 0 || howmuch > readmax) /* The use of -1 for "unlimited"
* uglifies this code. XXXX */
howmuch = readmax;
if (bufev_p->read_suspended)
goto done;
evbuffer_unfreeze(input, 0);
res = evbuffer_read(input, fd, (int)howmuch); /* XXXX evbuffer_read would do better to take and return ev_ssize_t */
evbuffer_freeze(input, 0);
if (res == -1) {
int err = evutil_socket_geterror(fd);
if (EVUTIL_ERR_RW_RETRIABLE(err))
goto reschedule;
/* error case */
what |= BEV_EVENT_ERROR;
} else if (res == 0) {
/* eof case */
what |= BEV_EVENT_EOF;
}
if (res <= 0)
goto error;
bufferevent_decrement_read_buckets_(bufev_p, res);
/* Invoke the user callback - must always be called last */
if (evbuffer_get_length(input) >= bufev->wm_read.low)
bufferevent_run_readcb_(bufev);
goto done;
reschedule:
goto done;
error:
bufferevent_disable(bufev, EV_READ);
bufferevent_run_eventcb_(bufev, what);
done:
bufferevent_decref_and_unlock_(bufev);
}
static void
bufferevent_writecb(evutil_socket_t fd, short event, void *arg)
{
struct bufferevent *bufev = arg;
struct bufferevent_private *bufev_p =
EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
int res = 0;
short what = BEV_EVENT_WRITING;
int connected = 0;
ev_ssize_t atmost = -1;
_bufferevent_incref_and_lock(bufev);
if (event == EV_TIMEOUT) {
/* Note that we only check for event==EV_TIMEOUT. If
* event==EV_TIMEOUT|EV_WRITE, we can safely ignore the
* timeout, since a read has occurred */
what |= BEV_EVENT_TIMEOUT;
goto error;
}
//正在连接服务器...
if (bufev_p->connecting) {
int c = evutil_socket_finished_connecting(fd);
/* we need to fake the error if the connection was refused
* immediately - usually connection to localhost on BSD */
if (bufev_p->connection_refused) { //在bufferevent_socket_connect中被设置
bufev_p->connection_refused = 0;
c = -1;
}
if (c == 0) //正在连接，继续监听可写。
goto done;
bufev_p->connecting = 0;
if (c < 0) { //连接发生错误
event_del(&bufev->ev_write);
event_del(&bufev->ev_read);
_bufferevent_run_eventcb(bufev, BEV_EVENT_ERROR);
goto done;
} else { //连接成功
connected = 1;
#ifdef WIN32
if (BEV_IS_ASYNC(bufev)) {
event_del(&bufev->ev_write);
bufferevent_async_set_connected(bufev);
_bufferevent_run_eventcb(bufev,
BEV_EVENT_CONNECTED);
goto done;
}
#endif
//连接成功，调用用户错误处理函数。比较奇怪。
_bufferevent_run_eventcb(bufev,
BEV_EVENT_CONNECTED);
if (!(bufev->enabled & EV_WRITE) ||
bufev_p->write_suspended) {
event_del(&bufev->ev_write);
goto done;
}
}
}
atmost = _bufferevent_get_write_max(bufev_p);
//写被挂起
if (bufev_p->write_suspended)
goto done;
//存在可写数据
if (evbuffer_get_length(bufev->output)) {
evbuffer_unfreeze(bufev->output, 1);
//将缓冲区数据写入socket。
res = evbuffer_write_atmost(bufev->output, fd, atmost);
evbuffer_freeze(bufev->output, 1);
if (res == -1) { //写发生错误
int err = evutil_socket_geterror(fd);
if (EVUTIL_ERR_RW_RETRIABLE(err)) //socket缓冲区满，一次未写完，继续监听可写事件，等待下次写入。
goto reschedule;
what |= BEV_EVENT_ERROR; //写发生异常错误
} else if (res == 0) {
/* eof case
XXXX Actually, a 0 on write doesn't indicate
an EOF. An ECONNRESET might be more typical.
*/
what |= BEV_EVENT_EOF;
}
if (res <= 0)
goto error;
_bufferevent_decrement_write_buckets(bufev_p, res);
}
//缓冲区数据已写完，删除写事件。
if (evbuffer_get_length(bufev->output) == 0) {
event_del(&bufev->ev_write);
}
/* 低于写低水位，调用用户回调。
*/
if ((res || !connected) &&
evbuffer_get_length(bufev->output) <= bufev->wm_write.low) {
_bufferevent_run_writecb(bufev);
}
goto done;
reschedule:
if (evbuffer_get_length(bufev->output) == 0) {
event_del(&bufev->ev_write);
}
goto done;
error:
bufferevent_disable(bufev, EV_WRITE);
_bufferevent_run_eventcb(bufev, what);
done:
_bufferevent_decref_and_unlock(bufev);
}
static void
bufferevent_readcb(evutil_socket_t fd, short event, void *arg)
{
struct bufferevent *bufev = arg;
struct bufferevent_private *bufev_p =
EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
struct evbuffer *input;
int res = 0;
short what = BEV_EVENT_READING;
ev_ssize_t howmuch = -1, readmax=-1;
_bufferevent_incref_and_lock(bufev);
if (event == EV_TIMEOUT) {
/* Note that we only check for event==EV_TIMEOUT. If
* event==EV_TIMEOUT|EV_READ, we can safely ignore the
* timeout, since a read has occurred */
what |= BEV_EVENT_TIMEOUT;
goto error;
}
input = bufev->input;
/*
* If we have a high watermark configured then we don't want to
* read more data than would make us reach the watermark.
*/
if (bufev->wm_read.high != 0) {
howmuch = bufev->wm_read.high - evbuffer_get_length(input);
/* 缓冲区超过高水位，挂起读。 */
if (howmuch <= 0) {
bufferevent_wm_suspend_read(bufev);
goto done;
}
}
//因为用户可以限速，所以这么要检测最大的可读大小。
//如果没有限速的话，那么将返回16384字节，即16K
//默认情况下是没有限速的。
readmax = _bufferevent_get_read_max(bufev_p);
if (howmuch < 0 || howmuch > readmax) /* The use of -1 for "unlimited"
* uglifies this code. XXXX */
howmuch = readmax;
if (bufev_p->read_suspended)
goto done;
evbuffer_unfreeze(input, 0);
res = evbuffer_read(input, fd, (int)howmuch); /* XXXX evbuffer_read would do better to take and return ev_ssize_t */
evbuffer_freeze(input, 0);
if (res == -1) {
int err = evutil_socket_geterror(fd);
if (EVUTIL_ERR_RW_RETRIABLE(err)) //EINTER or EAGAIN
goto reschedule;
/* error case */
what |= BEV_EVENT_ERROR;
} else if (res == 0) {
/* eof case */
what |= BEV_EVENT_EOF;
}
if (res <= 0)
goto error;
_bufferevent_decrement_read_buckets(bufev_p, res);
/* 数据大于低水平，调用用户设置的回调。 */
if (evbuffer_get_length(input) >= bufev->wm_read.low)
_bufferevent_run_readcb(bufev);
goto done;
reschedule:
goto done;
error:
bufferevent_disable(bufev, EV_READ);
_bufferevent_run_eventcb(bufev, what);
done:
_bufferevent_decref_and_unlock(bufev);
}