diff -r 62542b8be764 -r 7515a991bb37 jdk/src/aix/native/java/net/aix_close.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/jdk/src/aix/native/java/net/aix_close.c Tue Nov 26 16:40:31 2013 +0100 @@ -0,0 +1,427 @@ +/* + * Copyright (c) 2001, 2013, 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. + */ + +/* + * This file contains implementations of NET_... functions. The NET_.. functions are + * wrappers for common file- and socket functions plus provisions for non-blocking IO. + * + * (basically, the layers remember all file descriptors waiting for a particular fd; + * all threads waiting on a certain fd can be woken up by sending them a signal; this + * is done e.g. when the fd is closed.) + * + * This was originally copied from the linux_close.c implementation. + * + * Side Note: This coding needs initialization. Under Linux this is done + * automatically via __attribute((constructor)), on AIX this is done manually + * (see aix_close_init). + * + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +/* + * Stack allocated by thread when doing blocking operation + */ +typedef struct threadEntry { + pthread_t thr; /* this thread */ + struct threadEntry *next; /* next thread */ + int intr; /* interrupted */ +} threadEntry_t; + +/* + * Heap allocated during initialized - one entry per fd + */ +typedef struct { + pthread_mutex_t lock; /* fd lock */ + threadEntry_t *threads; /* threads blocked on fd */ +} fdEntry_t; + +/* + * Signal to unblock thread + */ +static int sigWakeup = (SIGRTMAX - 1); + +/* + * The fd table and the number of file descriptors + */ +static fdEntry_t *fdTable = NULL; +static int fdCount = 0; + +/* + * Null signal handler + */ +static void sig_wakeup(int sig) { +} + +/* + * Initialization routine (executed when library is loaded) + * Allocate fd tables and sets up signal handler. + * + * On AIX we don't have __attribute((constructor)) so we need to initialize + * manually (from JNI_OnLoad() in 'src/share/native/java/net/net_util.c') + */ +void aix_close_init() { + struct rlimit nbr_files; + sigset_t sigset; + struct sigaction sa; + + /* Check already initialized */ + if (fdCount > 0 && fdTable != NULL) { + return; + } + + /* + * Allocate table based on the maximum number of + * file descriptors. + */ + if (-1 == getrlimit(RLIMIT_NOFILE, &nbr_files)) { + fprintf(stderr, "library initialization failed - " + "unable to get max # of allocated fds\n"); + abort(); + } + fdCount = nbr_files.rlim_max; + /* + * We have a conceptual problem here, when the number of files is + * unlimited. As a kind of workaround, we ensure the table is big + * enough for handle even a large number of files. Since SAP itself + * recommends a limit of 32000 files, we just use 64000 as 'infinity'. + */ + if (nbr_files.rlim_max == RLIM_INFINITY) { + fdCount = 64000; + } + fdTable = (fdEntry_t *)calloc(fdCount, sizeof(fdEntry_t)); + if (fdTable == NULL) { + fprintf(stderr, "library initialization failed - " + "unable to allocate file descriptor table - out of memory"); + abort(); + } + + { + int i; + for (i=0; i < fdCount; i++) { + pthread_mutex_init(&fdTable[i].lock, NULL); + } + } + + /* + * Setup the signal handler + */ + sa.sa_handler = sig_wakeup; + sa.sa_flags = 0; + sigemptyset(&sa.sa_mask); + sigaction(sigWakeup, &sa, NULL); + + sigemptyset(&sigset); + sigaddset(&sigset, sigWakeup); + sigprocmask(SIG_UNBLOCK, &sigset, NULL); +} + +/* + * Return the fd table for this fd or NULL is fd out + * of range. + */ +static inline fdEntry_t *getFdEntry(int fd) +{ + if (fd < 0 || fd >= fdCount) { + return NULL; + } + return &fdTable[fd]; +} + +/* + * Start a blocking operation :- + * Insert thread onto thread list for the fd. + */ +static inline void startOp(fdEntry_t *fdEntry, threadEntry_t *self) +{ + self->thr = pthread_self(); + self->intr = 0; + + pthread_mutex_lock(&(fdEntry->lock)); + { + self->next = fdEntry->threads; + fdEntry->threads = self; + } + pthread_mutex_unlock(&(fdEntry->lock)); +} + +/* + * End a blocking operation :- + * Remove thread from thread list for the fd + * If fd has been interrupted then set errno to EBADF + */ +static inline void endOp + (fdEntry_t *fdEntry, threadEntry_t *self) +{ + int orig_errno = errno; + pthread_mutex_lock(&(fdEntry->lock)); + { + threadEntry_t *curr, *prev=NULL; + curr = fdEntry->threads; + while (curr != NULL) { + if (curr == self) { + if (curr->intr) { + orig_errno = EBADF; + } + if (prev == NULL) { + fdEntry->threads = curr->next; + } else { + prev->next = curr->next; + } + break; + } + prev = curr; + curr = curr->next; + } + } + pthread_mutex_unlock(&(fdEntry->lock)); + errno = orig_errno; +} + +/* + * 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; + fdEntry_t *fdEntry = getFdEntry(fd2); + if (fdEntry == NULL) { + errno = EBADF; + return -1; + } + + /* + * Lock the fd to hold-off additional I/O on this fd. + */ + pthread_mutex_lock(&(fdEntry->lock)); + + { + /* + * 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); + + /* + * Send a wakeup signal to all threads blocked on this + * file descriptor. + */ + threadEntry_t *curr = fdEntry->threads; + while (curr != NULL) { + curr->intr = 1; + pthread_kill( curr->thr, sigWakeup ); + curr = curr->next; + } + } + + /* + * Unlock without destroying errno + */ + orig_errno = errno; + pthread_mutex_unlock(&(fdEntry->lock)); + errno = orig_errno; + + 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; \ + threadEntry_t self; \ + fdEntry_t *fdEntry = getFdEntry(FD); \ + if (fdEntry == NULL) { \ + errno = EBADF; \ + return -1; \ + } \ + do { \ + startOp(fdEntry, &self); \ + ret = FUNC; \ + endOp(fdEntry, &self); \ + } 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. + */ +int NET_Timeout(int s, long timeout) { + long prevtime = 0, newtime; + struct timeval t; + fdEntry_t *fdEntry = getFdEntry(s); + + /* + * Check that fd hasn't been closed. + */ + if (fdEntry == NULL) { + 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; + threadEntry_t self; + + /* + * Poll the fd. If interrupted by our wakeup signal + * errno will be set to EBADF. + */ + pfd.fd = s; + pfd.events = POLLIN | POLLERR; + + startOp(fdEntry, &self); + rv = poll(&pfd, 1, timeout); + endOp(fdEntry, &self); + + /* + * 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; + } + + } +}