--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/linux/native/libnet/linux_close.c Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,458 @@
+/*
+ * Copyright (c) 2001, 2017, 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 <assert.h>
+#include <limits.h>
+#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 <poll.h>
+#include "jvm.h"
+#include "net_util.h"
+
+/*
+ * 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 - 2);
+
+/*
+ * fdTable holds one entry per file descriptor, up to a certain
+ * maximum.
+ * Theoretically, the number of possible file descriptors can get
+ * large, though usually it does not. Entries for small value file
+ * descriptors are kept in a simple table, which covers most scenarios.
+ * Entries for large value file descriptors are kept in an overflow
+ * table, which is organized as a sparse two dimensional array whose
+ * slabs are allocated on demand. This covers all corner cases while
+ * keeping memory consumption reasonable.
+ */
+
+/* Base table for low value file descriptors */
+static fdEntry_t* fdTable = NULL;
+/* Maximum size of base table (in number of entries). */
+static const int fdTableMaxSize = 0x1000; /* 4K */
+/* Actual size of base table (in number of entries) */
+static int fdTableLen = 0;
+/* Max. theoretical number of file descriptors on system. */
+static int fdLimit = 0;
+
+/* Overflow table, should base table not be large enough. Organized as
+ * an array of n slabs, each holding 64k entries.
+ */
+static fdEntry_t** fdOverflowTable = NULL;
+/* Number of slabs in the overflow table */
+static int fdOverflowTableLen = 0;
+/* Number of entries in one slab */
+static const int fdOverflowTableSlabSize = 0x10000; /* 64k */
+pthread_mutex_t fdOverflowTableLock = PTHREAD_MUTEX_INITIALIZER;
+
+/*
+ * Null signal handler
+ */
+static void sig_wakeup(int sig) {
+}
+
+/*
+ * Initialization routine (executed when library is loaded)
+ * Allocate fd tables and sets up signal handler.
+ */
+static void __attribute((constructor)) init() {
+ struct rlimit nbr_files;
+ sigset_t sigset;
+ struct sigaction sa;
+ int i = 0;
+
+ /* Determine the maximum number of possible file descriptors. */
+ if (-1 == getrlimit(RLIMIT_NOFILE, &nbr_files)) {
+ fprintf(stderr, "library initialization failed - "
+ "unable to get max # of allocated fds\n");
+ abort();
+ }
+ if (nbr_files.rlim_max != RLIM_INFINITY) {
+ fdLimit = nbr_files.rlim_max;
+ } else {
+ /* We just do not know. */
+ fdLimit = INT_MAX;
+ }
+
+ /* Allocate table for low value file descriptors. */
+ fdTableLen = fdLimit < fdTableMaxSize ? fdLimit : fdTableMaxSize;
+ fdTable = (fdEntry_t*) calloc(fdTableLen, sizeof(fdEntry_t));
+ if (fdTable == NULL) {
+ fprintf(stderr, "library initialization failed - "
+ "unable to allocate file descriptor table - out of memory");
+ abort();
+ } else {
+ for (i = 0; i < fdTableLen; i ++) {
+ pthread_mutex_init(&fdTable[i].lock, NULL);
+ }
+ }
+
+ /* Allocate overflow table, if needed */
+ if (fdLimit > fdTableMaxSize) {
+ fdOverflowTableLen = ((fdLimit - fdTableMaxSize) / fdOverflowTableSlabSize) + 1;
+ fdOverflowTable = (fdEntry_t**) calloc(fdOverflowTableLen, sizeof(fdEntry_t*));
+ if (fdOverflowTable == NULL) {
+ fprintf(stderr, "library initialization failed - "
+ "unable to allocate file descriptor overflow table - out of memory");
+ abort();
+ }
+ }
+
+ /*
+ * 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.
+ */
+static inline fdEntry_t *getFdEntry(int fd)
+{
+ fdEntry_t* result = NULL;
+
+ if (fd < 0) {
+ return NULL;
+ }
+
+ /* This should not happen. If it does, our assumption about
+ * max. fd value was wrong. */
+ assert(fd < fdLimit);
+
+ if (fd < fdTableMaxSize) {
+ /* fd is in base table. */
+ assert(fd < fdTableLen);
+ result = &fdTable[fd];
+ } else {
+ /* fd is in overflow table. */
+ const int indexInOverflowTable = fd - fdTableMaxSize;
+ const int rootindex = indexInOverflowTable / fdOverflowTableSlabSize;
+ const int slabindex = indexInOverflowTable % fdOverflowTableSlabSize;
+ fdEntry_t* slab = NULL;
+ assert(rootindex < fdOverflowTableLen);
+ assert(slabindex < fdOverflowTableSlabSize);
+ pthread_mutex_lock(&fdOverflowTableLock);
+ /* Allocate new slab in overflow table if needed */
+ if (fdOverflowTable[rootindex] == NULL) {
+ fdEntry_t* const newSlab =
+ (fdEntry_t*)calloc(fdOverflowTableSlabSize, sizeof(fdEntry_t));
+ if (newSlab == NULL) {
+ fprintf(stderr, "Unable to allocate file descriptor overflow"
+ " table slab - out of memory");
+ pthread_mutex_unlock(&fdOverflowTableLock);
+ abort();
+ } else {
+ int i;
+ for (i = 0; i < fdOverflowTableSlabSize; i ++) {
+ pthread_mutex_init(&newSlab[i].lock, NULL);
+ }
+ fdOverflowTable[rootindex] = newSlab;
+ }
+ }
+ pthread_mutex_unlock(&fdOverflowTableLock);
+ slab = fdOverflowTable[rootindex];
+ result = &slab[slabindex];
+ }
+
+ return result;
+
+}
+
+/*
+ * 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_NonBlockingRead(int s, void* buf, size_t len) {
+ BLOCKING_IO_RETURN_INT( s, recv(s, buf, len, MSG_DONTWAIT) );
+}
+
+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, socklen_t *fromlen) {
+ BLOCKING_IO_RETURN_INT( s, recvfrom(s, buf, len, flags, from, fromlen) );
+}
+
+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, socklen_t *addrlen) {
+ BLOCKING_IO_RETURN_INT( s, accept(s, addr, addrlen) );
+}
+
+int NET_Connect(int s, struct sockaddr *addr, int addrlen) {
+ BLOCKING_IO_RETURN_INT( s, connect(s, addr, addrlen) );
+}
+
+int NET_Poll(struct pollfd *ufds, unsigned int nfds, int timeout) {
+ BLOCKING_IO_RETURN_INT( ufds[0].fd, poll(ufds, nfds, timeout) );
+}
+
+/*
+ * Wrapper for poll(s, timeout).
+ * Auto restarts with adjusted timeout if interrupted by
+ * signal other than our wakeup signal.
+ */
+int NET_Timeout(JNIEnv *env, int s, long timeout, jlong nanoTimeStamp) {
+ jlong prevNanoTime = nanoTimeStamp;
+ jlong nanoTimeout = (jlong)timeout * NET_NSEC_PER_MSEC;
+ fdEntry_t *fdEntry = getFdEntry(s);
+
+ /*
+ * Check that fd hasn't been closed.
+ */
+ if (fdEntry == NULL) {
+ errno = EBADF;
+ return -1;
+ }
+
+ 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, nanoTimeout / NET_NSEC_PER_MSEC);
+ endOp(fdEntry, &self);
+ /*
+ * If interrupted then adjust timeout. If timeout
+ * has expired return 0 (indicating timeout expired).
+ */
+ if (rv < 0 && errno == EINTR) {
+ jlong newNanoTime = JVM_NanoTime(env, 0);
+ nanoTimeout -= newNanoTime - prevNanoTime;
+ if (nanoTimeout < NET_NSEC_PER_MSEC) {
+ return 0;
+ }
+ prevNanoTime = newNanoTime;
+ } else {
+ return rv;
+ }
+ }
+}