8150460: (linux|bsd|aix)_close.c: file descriptor table may become large or may not work at all
Reviewed-by: dsamersoff, rriggs
--- a/jdk/src/java.base/aix/native/libnet/aix_close.c Sun Apr 24 08:51:04 2016 +0100
+++ b/jdk/src/java.base/aix/native/libnet/aix_close.c Thu Mar 03 12:47:46 2016 +0100
@@ -1,5 +1,6 @@
/*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, SAP SE 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
@@ -50,6 +51,8 @@
...
*/
+#include <assert.h>
+#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
@@ -86,10 +89,35 @@
static int sigWakeup = (SIGRTMAX - 1);
/*
- * The fd table and the number of file descriptors
+ * 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.
*/
-static fdEntry_t *fdTable = NULL;
-static int fdCount = 0;
+
+/* 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
@@ -108,42 +136,42 @@
struct rlimit nbr_files;
sigset_t sigset;
struct sigaction sa;
+ int i = 0;
- /* Check already initialized */
- if (fdCount > 0 && fdTable != NULL) {
- return;
- }
-
- /*
- * Allocate table based on the maximum number of
- * file descriptors.
- */
+ /* 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();
}
- 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;
+ if (nbr_files.rlim_max != RLIM_INFINITY) {
+ fdLimit = nbr_files.rlim_max;
+ } else {
+ /* We just do not know. */
+ fdLimit = INT_MAX;
}
- fdTable = (fdEntry_t *)calloc(fdCount, sizeof(fdEntry_t));
+
+ /* 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);
+ }
}
- {
- int i;
- for (i=0; i < fdCount; 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();
}
}
@@ -161,17 +189,60 @@
}
/*
- * Return the fd table for this fd or NULL is fd out
- * of range.
+ * Return the fd table for this fd.
*/
static inline fdEntry_t *getFdEntry(int fd)
{
- if (fd < 0 || fd >= fdCount) {
+ fdEntry_t* result = NULL;
+
+ if (fd < 0) {
return NULL;
}
- return &fdTable[fd];
+
+ /* 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.
--- a/jdk/src/java.base/linux/native/libnet/linux_close.c Sun Apr 24 08:51:04 2016 +0100
+++ b/jdk/src/java.base/linux/native/libnet/linux_close.c Thu Mar 03 12:47:46 2016 +0100
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2016, 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
@@ -23,6 +23,8 @@
* questions.
*/
+#include <assert.h>
+#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
@@ -59,10 +61,35 @@
static int sigWakeup = (__SIGRTMAX - 2);
/*
- * The fd table and the number of file descriptors
+ * 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.
*/
-static fdEntry_t *fdTable;
-static int fdCount;
+
+/* 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
@@ -78,18 +105,43 @@
struct rlimit nbr_files;
sigset_t sigset;
struct sigaction sa;
+ int i = 0;
- /*
- * Allocate table based on the maximum number of
- * file descriptors.
- */
- getrlimit(RLIMIT_NOFILE, &nbr_files);
- fdCount = nbr_files.rlim_max;
- fdTable = (fdEntry_t *)calloc(fdCount, sizeof(fdEntry_t));
+ /* 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();
+ }
}
/*
@@ -106,15 +158,57 @@
}
/*
- * Return the fd table for this fd or NULL is fd out
- * of range.
+ * Return the fd table for this fd.
*/
static inline fdEntry_t *getFdEntry(int fd)
{
- if (fd < 0 || fd >= fdCount) {
+ fdEntry_t* result = NULL;
+
+ if (fd < 0) {
return NULL;
}
- return &fdTable[fd];
+
+ /* 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;
+
}
/*
--- a/jdk/src/java.base/macosx/native/libnet/bsd_close.c Sun Apr 24 08:51:04 2016 +0100
+++ b/jdk/src/java.base/macosx/native/libnet/bsd_close.c Thu Mar 03 12:47:46 2016 +0100
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2016, 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
@@ -23,6 +23,8 @@
* questions.
*/
+#include <assert.h>
+#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/param.h>
@@ -61,18 +63,35 @@
static int sigWakeup = SIGIO;
/*
- * The fd table and the number of file descriptors
+ * 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.
*/
-static fdEntry_t *fdTable;
-static int fdCount;
-/*
- * This limit applies if getlimit() returns unlimited.
- * Unfortunately, this means if someone wants a higher limit
- * then they have to set an explicit limit, higher than this,
- * which is probably counter-intuitive.
+/* 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.
*/
-#define MAX_FD_COUNT 4096
+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
@@ -88,26 +107,43 @@
struct rlimit nbr_files;
sigset_t sigset;
struct sigaction sa;
- int i;
+ int i = 0;
- /*
- * Allocate table based on the maximum number of
- * file descriptors.
- */
- getrlimit(RLIMIT_NOFILE, &nbr_files);
- if (nbr_files.rlim_max == RLIM_INFINITY) {
- fdCount = MAX_FD_COUNT;
+ /* 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 {
- fdCount = nbr_files.rlim_max;
+ /* We just do not know. */
+ fdLimit = INT_MAX;
}
- fdTable = (fdEntry_t *)calloc(fdCount, sizeof(fdEntry_t));
+
+ /* 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);
+ }
}
- for (i=0; i<fdCount; 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();
+ }
}
/*
@@ -124,17 +160,60 @@
}
/*
- * Return the fd table for this fd or NULL is fd out
- * of range.
+ * Return the fd table for this fd.
*/
static inline fdEntry_t *getFdEntry(int fd)
{
- if (fd < 0 || fd >= fdCount) {
+ fdEntry_t* result = NULL;
+
+ if (fd < 0) {
return NULL;
}
- return &fdTable[fd];
+
+ /* 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.