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--- xnu/xnu-517.7.21/libkern/c++/OSSymbol.cpp
+++ xnu/xnu-1504.9.37/libkern/c++/OSSymbol.cpp
@@ -1,23 +1,29 @@
/*
- * 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 */
@@ -45,6 +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:
@@ -55,7 +79,7 @@
Bucket *buckets;
unsigned int nBuckets;
unsigned int count;
- mutex_t *poolGate;
+ lck_mtx_t *poolGate;
static inline void hashSymbol(const char *s,
unsigned int *hashP,
@@ -78,7 +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);
@@ -90,8 +115,8 @@
bool init();
- inline void closeGate() { mutex_lock(poolGate); };
- inline void openGate() { mutex_unlock(poolGate); };
+ inline void closeGate() { lck_mtx_lock(poolGate); };
+ inline void openGate() { lck_mtx_unlock(poolGate); };
OSSymbol *findSymbol(const char *cString) const;
OSSymbol *insertSymbol(OSSymbol *sym);
@@ -113,14 +138,16 @@
void OSSymbolPool::operator delete(void *mem, size_t size)
{
- kfree((vm_offset_t)mem, size);
+ kfree(mem, size);
ACCUMSIZE(-size);
}
+extern lck_grp_t *IOLockGroup;
+
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)
@@ -128,7 +155,7 @@
bzero(buckets, nBuckets * sizeof(Bucket));
- poolGate = mutex_alloc(0);
+ poolGate = lck_mtx_alloc_init(IOLockGroup, LCK_ATTR_NULL);
return poolGate != 0;
}
@@ -145,12 +172,12 @@
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);
+ lck_mtx_free(poolGate, IOLockGroup);
}
unsigned long OSSymbolPool::log2(unsigned int x)
@@ -192,14 +219,35 @@
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 */
@@ -227,7 +275,7 @@
probeSymbol = (OSSymbol *) thisBucket->symbolP;
if (inLen == probeSymbol->length
- && (strcmp(probeSymbol->string, cString) == 0))
+ && (strncmp(probeSymbol->string, cString, probeSymbol->length) == 0))
return probeSymbol;
return 0;
}
@@ -235,7 +283,7 @@
for (list = thisBucket->symbolP; j--; list++) {
probeSymbol = *list;
if (inLen == probeSymbol->length
- && (strcmp(probeSymbol->string, cString) == 0))
+ && (strncmp(probeSymbol->string, cString, probeSymbol->length) == 0))
return probeSymbol;
}
@@ -264,7 +312,7 @@
probeSymbol = (OSSymbol *) thisBucket->symbolP;
if (inLen == probeSymbol->length
- && strcmp(probeSymbol->string, cString) == 0)
+ && strncmp(probeSymbol->string, cString, probeSymbol->length) == 0)
return probeSymbol;
list = (OSSymbol **) kalloc(2 * sizeof(OSSymbol *));
@@ -275,8 +323,7 @@
thisBucket->symbolP = list;
thisBucket->count++;
count++;
- if (count > nBuckets)
- reconstructSymbols();
+ GROW_POOL();
return sym;
}
@@ -284,7 +331,7 @@
for (list = thisBucket->symbolP; j--; list++) {
probeSymbol = *list;
if (inLen == probeSymbol->length
- && strcmp(probeSymbol->string, cString) == 0)
+ && strncmp(probeSymbol->string, cString, probeSymbol->length) == 0)
return probeSymbol;
}
@@ -295,11 +342,10 @@
/* @@@ 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();
+ GROW_POOL();
return sym;
}
@@ -325,6 +371,7 @@
thisBucket->symbolP = 0;
count--;
thisBucket->count--;
+ SHRINK_POOL();
return;
}
return;
@@ -334,20 +381,22 @@
probeSymbol = list[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 (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;
@@ -367,7 +416,7 @@
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--;