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--- xnu/xnu-124.13/libkern/c++/OSSymbol.cpp
+++ xnu/xnu-1228.15.4/libkern/c++/OSSymbol.cpp
@@ -1,26 +1,33 @@
/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License"). You may not use this file except in compliance with the
- * License. Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
*
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
*
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* IOSymbol.cpp created by gvdl on Fri 1998-11-17 */
+#include <string.h>
#include <sys/cdefs.h>
__BEGIN_DECLS
@@ -29,6 +36,7 @@
#include <libkern/c++/OSSymbol.h>
#include <libkern/c++/OSLib.h>
+#include <string.h>
#define super OSString
@@ -43,6 +51,24 @@
#define ACCUMSIZE(s)
#endif
+#define INITIAL_POOL_SIZE (exp2ml(1 + log2(kInitBucketCount)))
+
+#define GROW_FACTOR (1)
+#define SHRINK_FACTOR (3)
+
+#define GROW_POOL() do \
+ if (count * GROW_FACTOR > nBuckets) { \
+ reconstructSymbols(true); \
+ } \
+while (0)
+
+#define SHRINK_POOL() do \
+ if (count * SHRINK_FACTOR < nBuckets && \
+ nBuckets > INITIAL_POOL_SIZE) { \
+ reconstructSymbols(false); \
+ } \
+while (0)
+
class OSSymbolPool
{
private:
@@ -76,7 +102,8 @@
static unsigned long log2(unsigned int x);
static unsigned long exp2ml(unsigned int x);
- void reconstructSymbols();
+ void reconstructSymbols(void);
+ void reconstructSymbols(bool grow);
public:
static void *operator new(size_t size);
@@ -93,7 +120,7 @@
OSSymbol *findSymbol(const char *cString) const;
OSSymbol *insertSymbol(OSSymbol *sym);
- void removeSymbol(const char *cString);
+ void removeSymbol(OSSymbol *sym);
OSSymbolPoolState initHashState();
OSSymbol *nextHashState(OSSymbolPoolState *stateP);
@@ -111,14 +138,14 @@
void OSSymbolPool::operator delete(void *mem, size_t size)
{
- kfree((vm_offset_t)mem, size);
+ kfree(mem, size);
ACCUMSIZE(-size);
}
bool OSSymbolPool::init()
{
count = 0;
- nBuckets = exp2ml(1 + log2(kInitBucketCount));
+ nBuckets = INITIAL_POOL_SIZE;
buckets = (Bucket *) kalloc(nBuckets * sizeof(Bucket));
ACCUMSIZE(nBuckets * sizeof(Bucket));
if (!buckets)
@@ -143,12 +170,12 @@
OSSymbolPool::~OSSymbolPool()
{
if (buckets) {
- kfree((vm_offset_t)buckets, nBuckets * sizeof(Bucket));
+ kfree(buckets, nBuckets * sizeof(Bucket));
ACCUMSIZE(-(nBuckets * sizeof(Bucket)));
}
if (poolGate)
- kfree((vm_offset_t) poolGate, 36 * 4);
+ kfree(poolGate, 36 * 4);
}
unsigned long OSSymbolPool::log2(unsigned int x)
@@ -190,14 +217,35 @@
return thisBucket->symbolP[stateP->j];
}
-void OSSymbolPool::reconstructSymbols()
-{
- OSSymbolPool old(this);
+void OSSymbolPool::reconstructSymbols(void)
+{
+ this->reconstructSymbols(true);
+}
+
+void OSSymbolPool::reconstructSymbols(bool grow)
+{
+ unsigned int new_nBuckets = nBuckets;
OSSymbol *insert;
OSSymbolPoolState state;
- nBuckets += nBuckets + 1;
+ if (grow) {
+ new_nBuckets += new_nBuckets + 1;
+ } else {
+ /* Don't shrink the pool below the default initial size.
+ */
+ if (nBuckets <= INITIAL_POOL_SIZE) {
+ return;
+ }
+ new_nBuckets = (new_nBuckets - 1) / 2;
+ }
+
+ /* Create old pool to iterate after doing above check, cause it
+ * gets finalized at return.
+ */
+ OSSymbolPool old(this);
+
count = 0;
+ nBuckets = new_nBuckets;
buckets = (Bucket *) kalloc(nBuckets * sizeof(Bucket));
ACCUMSIZE(nBuckets * sizeof(Bucket));
/* @@@ gvdl: Zero test and panic if can't set up pool */
@@ -225,18 +273,15 @@
probeSymbol = (OSSymbol *) thisBucket->symbolP;
if (inLen == probeSymbol->length
- && (strcmp(probeSymbol->string, cString) == 0)
- && (probeSymbol->getRetainCount() >= 1)) // WRONG need when
+ && (strcmp(probeSymbol->string, cString) == 0))
return probeSymbol;
- else
- return 0;
+ return 0;
}
for (list = thisBucket->symbolP; j--; list++) {
probeSymbol = *list;
if (inLen == probeSymbol->length
- && (strcmp(probeSymbol->string, cString) == 0)
- && (probeSymbol->getRetainCount() >= 1)) // WRONG need when
+ && (strcmp(probeSymbol->string, cString) == 0))
return probeSymbol;
}
@@ -258,7 +303,7 @@
thisBucket->symbolP = (OSSymbol **) sym;
thisBucket->count++;
count++;
- return 0;
+ return sym;
}
if (j == 1) {
@@ -276,10 +321,9 @@
thisBucket->symbolP = list;
thisBucket->count++;
count++;
- if (count > nBuckets)
- reconstructSymbols();
-
- return 0;
+ GROW_POOL();
+
+ return sym;
}
for (list = thisBucket->symbolP; j--; list++) {
@@ -296,22 +340,21 @@
/* @@@ gvdl: Zero test and panic if can't set up pool */
list[0] = sym;
bcopy(thisBucket->symbolP, list + 1, j * sizeof(OSSymbol *));
- kfree((vm_offset_t)thisBucket->symbolP, j * sizeof(OSSymbol *));
+ kfree(thisBucket->symbolP, j * sizeof(OSSymbol *));
ACCUMSIZE(-(j * sizeof(OSSymbol *)));
thisBucket->symbolP = list;
- if (count > nBuckets)
- reconstructSymbols();
-
- return 0;
-}
-
-void OSSymbolPool::removeSymbol(const char *cString)
+ GROW_POOL();
+
+ return sym;
+}
+
+void OSSymbolPool::removeSymbol(OSSymbol *sym)
{
Bucket *thisBucket;
unsigned int j, inLen, hash;
OSSymbol *probeSymbol, **list;
- hashSymbol(cString, &hash, &inLen); inLen++;
+ hashSymbol(sym->string, &hash, &inLen); inLen++;
thisBucket = &buckets[hash % nBuckets];
j = thisBucket->count;
list = thisBucket->symbolP;
@@ -322,11 +365,11 @@
if (j == 1) {
probeSymbol = (OSSymbol *) list;
- if (inLen == probeSymbol->length
- && strcmp(probeSymbol->string, cString) == 0) {
+ if (probeSymbol == sym) {
thisBucket->symbolP = 0;
count--;
thisBucket->count--;
+ SHRINK_POOL();
return;
}
return;
@@ -334,24 +377,24 @@
if (j == 2) {
probeSymbol = list[0];
- if (inLen == probeSymbol->length
- && strcmp(probeSymbol->string, cString) == 0) {
+ if (probeSymbol == sym) {
thisBucket->symbolP = (OSSymbol **) list[1];
- kfree((vm_offset_t)list, 2 * sizeof(OSSymbol *));
+ kfree(list, 2 * sizeof(OSSymbol *));
ACCUMSIZE(-(2 * sizeof(OSSymbol *)));
count--;
thisBucket->count--;
+ SHRINK_POOL();
return;
}
probeSymbol = list[1];
- if (inLen == probeSymbol->length
- && strcmp(probeSymbol->string, cString) == 0) {
+ if (probeSymbol == sym) {
thisBucket->symbolP = (OSSymbol **) list[0];
- kfree((vm_offset_t)list, 2 * sizeof(OSSymbol *));
+ kfree(list, 2 * sizeof(OSSymbol *));
ACCUMSIZE(-(2 * sizeof(OSSymbol *)));
count--;
thisBucket->count--;
+ SHRINK_POOL();
return;
}
return;
@@ -359,8 +402,7 @@
for (; j--; list++) {
probeSymbol = *list;
- if (inLen == probeSymbol->length
- && strcmp(probeSymbol->string, cString) == 0) {
+ if (probeSymbol == sym) {
list = (OSSymbol **)
kalloc((thisBucket->count-1) * sizeof(OSSymbol *));
@@ -372,7 +414,7 @@
bcopy(thisBucket->symbolP + thisBucket->count-j,
list + thisBucket->count-1-j,
j * sizeof(OSSymbol *));
- kfree((vm_offset_t)thisBucket->symbolP, thisBucket->count * sizeof(OSSymbol *));
+ kfree(thisBucket->symbolP, thisBucket->count * sizeof(OSSymbol *));
ACCUMSIZE(-(thisBucket->count * sizeof(OSSymbol *)));
thisBucket->symbolP = list;
count--;
@@ -432,40 +474,60 @@
{
pool->closeGate();
- OSSymbol *newSymb = pool->findSymbol(cString);
- if (newSymb)
- newSymb->retain();
- else if ( (newSymb = new OSSymbol) ) {
+ OSSymbol *oldSymb = pool->findSymbol(cString);
+ if (!oldSymb) {
+ OSSymbol *newSymb = new OSSymbol;
+ if (!newSymb) {
+ pool->openGate();
+ return newSymb;
+ }
+
if (newSymb->OSString::initWithCString(cString))
- pool->insertSymbol(newSymb);
- else {
- newSymb->free();
- newSymb = 0;
- }
- }
+ oldSymb = pool->insertSymbol(newSymb);
+
+ if (newSymb == oldSymb) {
+ pool->openGate();
+ return newSymb; // return the newly created & inserted symbol.
+ }
+ else
+ // Somebody else inserted the new symbol so free our copy
+ newSymb->OSString::free();
+ }
+
+ oldSymb->retain(); // Retain the old symbol before releasing the lock.
+
pool->openGate();
-
- return newSymb;
+ return oldSymb;
}
const OSSymbol *OSSymbol::withCStringNoCopy(const char *cString)
{
pool->closeGate();
- OSSymbol *newSymb = pool->findSymbol(cString);
- if (newSymb)
- newSymb->retain();
- else if ( (newSymb = new OSSymbol) ) {
+ OSSymbol *oldSymb = pool->findSymbol(cString);
+ if (!oldSymb) {
+ OSSymbol *newSymb = new OSSymbol;
+ if (!newSymb) {
+ pool->openGate();
+ return newSymb;
+ }
+
if (newSymb->OSString::initWithCStringNoCopy(cString))
- pool->insertSymbol(newSymb);
- else {
- newSymb->free();
- newSymb = 0;
- }
- }
+ oldSymb = pool->insertSymbol(newSymb);
+
+ if (newSymb == oldSymb) {
+ pool->openGate();
+ return newSymb; // return the newly created & inserted symbol.
+ }
+ else
+ // Somebody else inserted the new symbol so free our copy
+ newSymb->OSString::free();
+ }
+
+ oldSymb->retain(); // Retain the old symbol before releasing the lock.
+
pool->openGate();
-
- return newSymb;
+ return oldSymb;
}
void OSSymbol::checkForPageUnload(void *startAddr, void *endAddr)
@@ -488,12 +550,21 @@
pool->openGate();
}
+void OSSymbol::taggedRelease(const void *tag) const
+{
+ super::taggedRelease(tag);
+}
+
+void OSSymbol::taggedRelease(const void *tag, const int when) const
+{
+ pool->closeGate();
+ super::taggedRelease(tag, when);
+ pool->openGate();
+}
+
void OSSymbol::free()
{
- pool->closeGate();
- pool->removeSymbol(string);
- pool->openGate();
-
+ pool->removeSymbol(this);
super::free();
}