transmission/libtransmission/trevent.c

341 lines
7.9 KiB
C

/*
* This file Copyright (C) Mnemosyne LLC
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2 (b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*
* $Id$
*/
#include <assert.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <event2/dns.h>
#include <event2/event.h>
#include "transmission.h"
#include "log.h"
#include "net.h"
#include "session.h"
#ifdef WIN32
#include "utils.h"
#include <winsock2.h>
static int
pgpipe (int handles[2])
{
SOCKET s;
struct sockaddr_in serv_addr;
int len = sizeof (serv_addr);
handles[0] = handles[1] = INVALID_SOCKET;
if ((s = socket (AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
{
tr_logAddDebug ("pgpipe failed to create socket: %ui", WSAGetLastError ());
return -1;
}
memset (&serv_addr, 0, sizeof (serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_port = htons (0);
serv_addr.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
if (bind (s, (SOCKADDR *) & serv_addr, len) == SOCKET_ERROR)
{
tr_logAddDebug ("pgpipe failed to bind: %ui", WSAGetLastError ());
closesocket (s);
return -1;
}
if (listen (s, 1) == SOCKET_ERROR)
{
tr_logAddNamedDbg ("event","pgpipe failed to listen: %ui", WSAGetLastError ());
closesocket (s);
return -1;
}
if (getsockname (s, (SOCKADDR *) & serv_addr, &len) == SOCKET_ERROR)
{
tr_logAddDebug ("pgpipe failed to getsockname: %ui", WSAGetLastError ());
closesocket (s);
return -1;
}
if ((handles[1] = socket (PF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
{
tr_logAddDebug ("pgpipe failed to create socket 2: %ui", WSAGetLastError ());
closesocket (s);
return -1;
}
if (connect (handles[1], (SOCKADDR *) & serv_addr, len) == SOCKET_ERROR)
{
tr_logAddDebug ("pgpipe failed to connect socket: %ui", WSAGetLastError ());
closesocket (s);
return -1;
}
if ((handles[0] = accept (s, (SOCKADDR *) & serv_addr, &len)) == INVALID_SOCKET)
{
tr_logAddDebug ("pgpipe failed to accept socket: %ui", WSAGetLastError ());
closesocket (handles[1]);
handles[1] = INVALID_SOCKET;
closesocket (s);
return -1;
}
closesocket (s);
return 0;
}
static int
piperead (int s, char *buf, int len)
{
int ret = recv (s, buf, len, 0);
if (ret < 0) {
const int werror= WSAGetLastError ();
switch (werror) {
/* simplified error mapping (not valid for connect) */
case WSAEWOULDBLOCK:
errno = EAGAIN;
break;
case WSAECONNRESET:
/* EOF on the pipe! (win32 socket based implementation) */
ret = 0;
/* fall through */
default:
errno = werror;
break;
}
} else
errno = 0;
return ret;
}
#define pipe(a) pgpipe (a)
#define pipewrite(a,b,c) send (a, (char*)b,c,0)
#else
#define piperead(a,b,c) read (a,b,c)
#define pipewrite(a,b,c) write (a,b,c)
#endif
#include <unistd.h> /* read (), write (), pipe () */
#include "transmission.h"
#include "platform.h" /* tr_lockLock () */
#include "trevent.h"
#include "utils.h"
/***
****
***/
typedef struct tr_event_handle
{
uint8_t die;
int fds[2];
tr_lock * lock;
tr_session * session;
tr_thread * thread;
struct event_base * base;
struct event * pipeEvent;
}
tr_event_handle;
struct tr_run_data
{
void (*func)(void *);
void * user_data;
};
#define dbgmsg(...) \
do { \
if (tr_logGetDeepEnabled ()) \
tr_logAddDeep (__FILE__, __LINE__, "event", __VA_ARGS__); \
} while (0)
static void
readFromPipe (evutil_socket_t fd,
short eventType,
void * veh)
{
char ch;
int ret;
tr_event_handle * eh = veh;
dbgmsg ("readFromPipe: eventType is %hd", eventType);
/* read the command type */
ch = '\0';
do
{
ret = piperead (fd, &ch, 1);
}
while (!eh->die && ret < 0 && errno == EAGAIN);
dbgmsg ("command is [%c], ret is %d, errno is %d", ch, ret, (int)errno);
switch (ch)
{
case 'r': /* run in libevent thread */
{
struct tr_run_data data;
const size_t nwant = sizeof (data);
const ssize_t ngot = piperead (fd, &data, nwant);
if (!eh->die && (ngot == (ssize_t)nwant))
{
dbgmsg ("invoking function in libevent thread");
(data.func)(data.user_data);
}
break;
}
case '\0': /* eof */
{
dbgmsg ("pipe eof reached... removing event listener");
event_free (eh->pipeEvent);
break;
}
default:
{
assert (0 && "unhandled command type!");
break;
}
}
}
static void
logFunc (int severity, const char * message)
{
if (severity >= _EVENT_LOG_ERR)
tr_logAddError ("%s", message);
else
tr_logAddDebug ("%s", message);
}
static void
libeventThreadFunc (void * veh)
{
struct event_base * base;
tr_event_handle * eh = veh;
#ifndef WIN32
/* Don't exit when writing on a broken socket */
signal (SIGPIPE, SIG_IGN);
#endif
/* create the libevent bases */
base = event_base_new ();
/* set the struct's fields */
eh->base = base;
eh->session->event_base = base;
eh->session->evdns_base = evdns_base_new (base, true);
eh->session->events = eh;
/* listen to the pipe's read fd */
eh->pipeEvent = event_new (base, eh->fds[0], EV_READ | EV_PERSIST, readFromPipe, veh);
event_add (eh->pipeEvent, NULL);
event_set_log_callback (logFunc);
/* loop until all the events are done */
while (!eh->die)
event_base_dispatch (base);
/* shut down the thread */
tr_lockFree (eh->lock);
event_base_free (base);
eh->session->events = NULL;
tr_free (eh);
tr_logAddDebug ("Closing libevent thread");
}
void
tr_eventInit (tr_session * session)
{
tr_event_handle * eh;
session->events = NULL;
eh = tr_new0 (tr_event_handle, 1);
eh->lock = tr_lockNew ();
if (pipe (eh->fds) == -1)
tr_logAddError ("Unable to write to pipe() in libtransmission: %s", tr_strerror(errno));
eh->session = session;
eh->thread = tr_threadNew (libeventThreadFunc, eh);
/* wait until the libevent thread is running */
while (session->events == NULL)
tr_wait_msec (100);
}
void
tr_eventClose (tr_session * session)
{
assert (tr_isSession (session));
session->events->die = true;
tr_logAddDeep (__FILE__, __LINE__, NULL, "closing trevent pipe");
tr_netCloseSocket (session->events->fds[1]);
}
/**
***
**/
bool
tr_amInEventThread (const tr_session * session)
{
assert (tr_isSession (session));
assert (session->events != NULL);
return tr_amInThread (session->events->thread);
}
/**
***
**/
void
tr_runInEventThread (tr_session * session,
void func (void*), void * user_data)
{
assert (tr_isSession (session));
assert (session->events != NULL);
if (tr_amInThread (session->events->thread))
{
(func)(user_data);
}
else
{
int fd;
char ch;
ssize_t res_1;
ssize_t res_2;
tr_event_handle * e = session->events;
struct tr_run_data data;
tr_lockLock (e->lock);
fd = e->fds[1];
ch = 'r';
res_1 = pipewrite (fd, &ch, 1);
data.func = func;
data.user_data = user_data;
res_2 = pipewrite (fd, &data, sizeof (data));
tr_lockUnlock (e->lock);
if ((res_1 == -1) || (res_2 == -1))
tr_logAddError ("Unable to write to libtransmisison event queue: %s", tr_strerror(errno));
}
}