Add support for keep-alive thread.

This commit is contained in:
Michael Jumper 2013-10-09 15:57:16 -07:00
parent 4ebafa0482
commit eac99e0ce1
2 changed files with 116 additions and 1 deletions

View File

@ -42,6 +42,8 @@
#include <stdint.h>
#include <unistd.h>
#include "timestamp.h"
/**
* Defines the guac_socket object and functionss for using and manipulating it.
*
@ -53,6 +55,12 @@
*/
#define GUAC_SOCKET_OUTPUT_BUFFER_SIZE 8192
/**
* The number of milliseconds to wait between keep-alive pings on a socket
* with keep-alive enabled.
*/
#define GUAC_SOCKET_KEEP_ALIVE_INTERVAL 5000
typedef struct guac_socket guac_socket;
/**
@ -104,6 +112,23 @@ typedef int guac_socket_select_handler(guac_socket* socket, int usec_timeout);
*/
typedef int guac_socket_free_handler(guac_socket* socket);
/**
* Possible current states of a guac_socket.
*/
typedef enum guac_socket_state {
/**
* The socket is open and can be written to / read from.
*/
GUAC_SOCKET_OPEN,
/**
* The socket is closed. Reads and writes will fail.
*/
GUAC_SOCKET_CLOSED
} guac_socket_state;
/**
* The core I/O object of Guacamole. guac_socket provides buffered input and
* output as well as convenience methods for efficiently writing base64 data.
@ -137,7 +162,18 @@ struct guac_socket {
* Handler which will be called when the socket is free'd (closed).
*/
guac_socket_free_handler* free_handler;
/**
* The current state of this guac_socket.
*/
guac_socket_state state;
/**
* The timestamp associated with the time the last block of data was
* written to this guac_socket.
*/
guac_timestamp last_write_timestamp;
/**
* The number of bytes present in the base64 "ready" buffer.
*/
@ -195,6 +231,16 @@ struct guac_socket {
*/
pthread_mutex_t __buffer_lock;
/**
* Whether automatic keep-alive is enabled.
*/
int __keep_alive_enabled;
/**
* The keep-alive thread.
*/
pthread_t __keep_alive_thread;
};
/**
@ -224,6 +270,17 @@ void guac_socket_free(guac_socket* socket);
*/
void guac_socket_require_threadsafe(guac_socket* socket);
/**
* Declares that the given socket must automatically send a keep-alive ping
* to ensure neither side of the socket times out while the socket is open.
* This ping will take the form of a "nop" instruction. Enabling keep-alive
* automatically enables threadsafety.
*
* @param socket The guac_socket to declare as requiring an automatic
* keep-alive ping.
*/
void guac_socket_require_keep_alive(guac_socket* socket);
/**
* Marks the beginning of a Guacamole protocol instruction. If threadsafety
* is enabled on the socket, other instructions will be blocked from sending

View File

@ -55,6 +55,8 @@
#include <sys/time.h>
#include "socket.h"
#include "protocol.h"
#include "timestamp.h"
#include "error.h"
char __guac_socket_BASE64_CHARACTERS[64] = {
@ -65,9 +67,44 @@ char __guac_socket_BASE64_CHARACTERS[64] = {
'8', '9', '+', '/'
};
static void* __guac_socket_keep_alive_thread(void* data) {
/* Calculate sleep interval */
struct timespec interval;
interval.tv_sec = GUAC_SOCKET_KEEP_ALIVE_INTERVAL / 1000;
interval.tv_nsec = (GUAC_SOCKET_KEEP_ALIVE_INTERVAL % 1000) * 1000000L;
/* Socket keep-alive loop */
guac_socket* socket = (guac_socket*) data;
while (socket->state == GUAC_SOCKET_OPEN) {
/* Send NOP keep-alive if it's been a while since the last output */
guac_timestamp timestamp = guac_timestamp_current();
if (timestamp - socket->last_write_timestamp >
GUAC_SOCKET_KEEP_ALIVE_INTERVAL) {
/* Send NOP */
if (guac_protocol_send_nop(socket)
|| guac_socket_flush(socket))
break;
}
/* Sleep until next keep-alive check */
nanosleep(&interval, NULL);
}
return NULL;
}
static ssize_t __guac_socket_write(guac_socket* socket,
const void* buf, size_t count) {
/* Update timestamp of last write */
socket->last_write_timestamp = guac_timestamp_current();
/* If handler defined, call it. */
if (socket->write_handler)
return socket->write_handler(socket, buf, count);
@ -138,6 +175,7 @@ guac_socket* guac_socket_alloc() {
socket->__ready = 0;
socket->__written = 0;
socket->data = NULL;
socket->state = GUAC_SOCKET_OPEN;
/* Init members */
socket->__instructionbuf_unparsed_start = socket->__instructionbuf;
@ -166,6 +204,18 @@ void guac_socket_require_threadsafe(guac_socket* socket) {
socket->__threadsafe_instructions = 1;
}
void guac_socket_require_keep_alive(guac_socket* socket) {
/* Keep-alive thread requires a threadsafe socket */
guac_socket_require_threadsafe(socket);
/* Start keep-alive thread */
socket->__keep_alive_enabled = 1;
pthread_create(&(socket->__keep_alive_thread), NULL,
__guac_socket_keep_alive_thread, (void*) socket);
}
void guac_socket_instruction_begin(guac_socket* socket) {
/* Lock writes if threadsafety enabled */
@ -205,6 +255,14 @@ void guac_socket_free(guac_socket* socket) {
socket->free_handler(socket);
guac_socket_flush(socket);
/* Mark as closed */
socket->state = GUAC_SOCKET_CLOSED;
/* Wait for keep-alive, if enabled */
if (socket->__keep_alive_enabled)
pthread_join(socket->__keep_alive_thread, NULL);
pthread_mutex_destroy(&(socket->__instruction_write_lock));
free(socket);
}