/*
* Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/uio.h>
#include <unistd.h>
#include <errno.h>
#include <sys/poll.h>
#include <nativehelper/AsynchronousCloseMonitor.h>
extern "C" {
/*
* Signal to unblock thread
*/
// Android-changed: Bionic (and AsynchronousCloseMonitor) expects libcore to use
// __SIGRTMIN + 2, not __SIGRTMAX - 2
static int sigWakeup = (__SIGRTMIN + 2);
/*
* Close or dup2 a file descriptor ensuring that all threads blocked on
* the file descriptor are notified via a wakeup signal.
*
* fd1 < 0 => close(fd2)
* fd1 >= 0 => dup2(fd1, fd2)
*
* Returns -1 with errno set if operation fails.
*/
static int closefd(int fd1, int fd2) {
int rv, orig_errno;
AsynchronousCloseMonitor::signalBlockedThreads(fd2);
/*
* And close/dup the file descriptor
* (restart if interrupted by signal)
*/
do {
if (fd1 < 0) {
rv = close(fd2);
} else {
rv = dup2(fd1, fd2);
}
} while (rv == -1 && errno == EINTR);
return rv;
}
/*
* Wrapper for dup2 - same semantics as dup2 system call except
* that any threads blocked in an I/O system call on fd2 will be
* preempted and return -1/EBADF;
*/
int NET_Dup2(int fd, int fd2) {
if (fd < 0) {
errno = EBADF;
return -1;
}
return closefd(fd, fd2);
}
/*
* Wrapper for close - same semantics as close system call
* except that any threads blocked in an I/O on fd will be
* preempted and the I/O system call will return -1/EBADF.
*/
int NET_SocketClose(int fd) {
return closefd(-1, fd);
}
/************** Basic I/O operations here ***************/
/*
* Macro to perform a blocking IO operation. Restarts
* automatically if interrupted by signal (other than
* our wakeup signal)
*/
#define BLOCKING_IO_RETURN_INT(FD, FUNC) { \
int ret; \
int _syscallErrno; \
do { \
bool _wasSignaled; \
{ \
AsynchronousCloseMonitor _monitor(FD); \
ret = FUNC; \
_syscallErrno = errno; \
_wasSignaled = _monitor.wasSignaled(); \
} \
errno = _wasSignaled ? EBADF : _syscallErrno; \
} while (ret == -1 && errno == EINTR); \
return ret; \
}
int NET_Read(int s, void* buf, size_t len) {
BLOCKING_IO_RETURN_INT( s, recv(s, buf, len, 0) );
}
int NET_ReadV(int s, const struct iovec * vector, int count) {
BLOCKING_IO_RETURN_INT( s, readv(s, vector, count) );
}
int NET_RecvFrom(int s, void *buf, int len, unsigned int flags,
struct sockaddr *from, int *fromlen) {
socklen_t socklen = *fromlen;
BLOCKING_IO_RETURN_INT( s, recvfrom(s, buf, len, flags, from, &socklen) );
*fromlen = socklen;
}
int NET_Send(int s, void *msg, int len, unsigned int flags) {
BLOCKING_IO_RETURN_INT( s, send(s, msg, len, flags) );
}
int NET_WriteV(int s, const struct iovec * vector, int count) {
BLOCKING_IO_RETURN_INT( s, writev(s, vector, count) );
}
int NET_SendTo(int s, const void *msg, int len, unsigned int
flags, const struct sockaddr *to, int tolen) {
BLOCKING_IO_RETURN_INT( s, sendto(s, msg, len, flags, to, tolen) );
}
int NET_Accept(int s, struct sockaddr *addr, int *addrlen) {
socklen_t socklen = *addrlen;
BLOCKING_IO_RETURN_INT( s, accept(s, addr, &socklen) );
*addrlen = socklen;
}
int NET_Connect(int s, struct sockaddr *addr, int addrlen) {
BLOCKING_IO_RETURN_INT( s, connect(s, addr, addrlen) );
}
#ifndef USE_SELECT
int NET_Poll(struct pollfd *ufds, unsigned int nfds, int timeout) {
BLOCKING_IO_RETURN_INT( ufds[0].fd, poll(ufds, nfds, timeout) );
}
#else
int NET_Select(int s, fd_set *readfds, fd_set *writefds,
fd_set *exceptfds, struct timeval *timeout) {
BLOCKING_IO_RETURN_INT( s-1,
select(s, readfds, writefds, exceptfds, timeout) );
}
#endif
/*
* Wrapper for poll(s, timeout).
* Auto restarts with adjusted timeout if interrupted by
* signal other than our wakeup signal.
*
* If s < 0, exits early rather than delegating to poll().
* TODO: Investigate whether it'd be better to handle this
* case at the caller so that this function is never called
* for s < 0.
*/
int NET_Timeout(int s, long timeout) {
long prevtime = 0, newtime;
struct timeval t;
/*
* b/27763633
* Avoid blocking calls to poll() for invalid sockets, e.g. when
* called from PlainSocketImpl_socketAccept with fd == -1.
*/
if (s < 0) {
errno = EBADF;
return -1;
}
/*
* Pick up current time as may need to adjust timeout
*/
if (timeout > 0) {
gettimeofday(&t, NULL);
prevtime = t.tv_sec * 1000 + t.tv_usec / 1000;
}
for(;;) {
struct pollfd pfd;
int rv;
/*
* Poll the fd. If interrupted by our wakeup signal
* errno will be set to EBADF.
*/
pfd.fd = s;
pfd.events = POLLIN | POLLERR;
bool wasSignaled;
int syscallErrno;
{
AsynchronousCloseMonitor monitor(s);
rv = poll(&pfd, 1, timeout);
syscallErrno = errno;
wasSignaled = monitor.wasSignaled();
}
errno = wasSignaled ? EBADF : syscallErrno;
/*
* If interrupted then adjust timeout. If timeout
* has expired return 0 (indicating timeout expired).
*/
if (rv < 0 && errno == EINTR) {
if (timeout > 0) {
gettimeofday(&t, NULL);
newtime = t.tv_sec * 1000 + t.tv_usec / 1000;
timeout -= newtime - prevtime;
if (timeout <= 0) {
return 0;
}
prevtime = newtime;
}
} else {
return rv;
}
}
}
}