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--- xnu/xnu-124.7/libkern/c++/OSSymbol.cpp
+++ xnu/xnu-4570.41.2/libkern/c++/OSSymbol.cpp
@@ -1,47 +1,62 @@
/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2016 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
-#include <kern/lock.h>
-__END_DECLS
+#include <kern/locks.h>
#include <libkern/c++/OSSymbol.h>
#include <libkern/c++/OSLib.h>
+#include <string.h>
#define super OSString
-typedef struct { int i, j; } OSSymbolPoolState;
-
-#if OSALLOCDEBUG
-extern "C" {
- extern int debug_container_malloc_size;
-};
-#define ACCUMSIZE(s) do { debug_container_malloc_size += (s); } while(0)
-#else
-#define ACCUMSIZE(s)
-#endif
+typedef struct { unsigned int i, j; } OSSymbolPoolState;
+
+#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
{
@@ -53,7 +68,7 @@
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,
@@ -76,24 +91,25 @@
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);
static void operator delete(void *mem, size_t size);
- OSSymbolPool() { };
+ OSSymbolPool() { }
OSSymbolPool(const OSSymbolPool *old);
virtual ~OSSymbolPool();
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);
- void removeSymbol(const char *cString);
+ void removeSymbol(OSSymbol *sym);
OSSymbolPoolState initHashState();
OSSymbol *nextHashState(OSSymbolPoolState *stateP);
@@ -101,8 +117,8 @@
void * OSSymbolPool::operator new(size_t size)
{
- void *mem = (void *)kalloc(size);
- ACCUMSIZE(size);
+ void *mem = (void *)kalloc_tag(size, VM_KERN_MEMORY_LIBKERN);
+ OSMETA_ACCUMSIZE(size);
assert(mem);
bzero(mem, size);
@@ -111,22 +127,24 @@
void OSSymbolPool::operator delete(void *mem, size_t size)
{
- kfree((vm_offset_t)mem, size);
- ACCUMSIZE(-size);
-}
+ kfree(mem, size);
+ OSMETA_ACCUMSIZE(-size);
+}
+
+extern lck_grp_t *IOLockGroup;
bool OSSymbolPool::init()
{
count = 0;
- nBuckets = exp2ml(1 + log2(kInitBucketCount));
- buckets = (Bucket *) kalloc(nBuckets * sizeof(Bucket));
- ACCUMSIZE(nBuckets * sizeof(Bucket));
+ nBuckets = INITIAL_POOL_SIZE;
+ buckets = (Bucket *) kalloc_tag(nBuckets * sizeof(Bucket), VM_KERN_MEMORY_LIBKERN);
+ OSMETA_ACCUMSIZE(nBuckets * sizeof(Bucket));
if (!buckets)
return false;
bzero(buckets, nBuckets * sizeof(Bucket));
- poolGate = mutex_alloc(0);
+ poolGate = lck_mtx_alloc_init(IOLockGroup, LCK_ATTR_NULL);
return poolGate != 0;
}
@@ -143,12 +161,19 @@
OSSymbolPool::~OSSymbolPool()
{
if (buckets) {
- kfree((vm_offset_t)buckets, nBuckets * sizeof(Bucket));
- ACCUMSIZE(-(nBuckets * sizeof(Bucket)));
+ Bucket *thisBucket;
+ for (thisBucket = &buckets[0]; thisBucket < &buckets[nBuckets]; thisBucket++) {
+ if (thisBucket->count > 1) {
+ kfree(thisBucket->symbolP, thisBucket->count * sizeof(OSSymbol *));
+ OSMETA_ACCUMSIZE(-(thisBucket->count * sizeof(OSSymbol *)));
+ }
+ }
+ kfree(buckets, nBuckets * sizeof(Bucket));
+ OSMETA_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)
@@ -190,16 +215,37 @@
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;
- buckets = (Bucket *) kalloc(nBuckets * sizeof(Bucket));
- ACCUMSIZE(nBuckets * sizeof(Bucket));
+ nBuckets = new_nBuckets;
+ buckets = (Bucket *) kalloc_tag(nBuckets * sizeof(Bucket), VM_KERN_MEMORY_LIBKERN);
+ OSMETA_ACCUMSIZE(nBuckets * sizeof(Bucket));
/* @@@ gvdl: Zero test and panic if can't set up pool */
bzero(buckets, nBuckets * sizeof(Bucket));
@@ -225,18 +271,15 @@
probeSymbol = (OSSymbol *) thisBucket->symbolP;
if (inLen == probeSymbol->length
- && (strcmp(probeSymbol->string, cString) == 0)
- && (probeSymbol->getRetainCount() >= 1)) // WRONG need when
+ && (strncmp(probeSymbol->string, cString, probeSymbol->length) == 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
+ && (strncmp(probeSymbol->string, cString, probeSymbol->length) == 0))
return probeSymbol;
}
@@ -258,113 +301,117 @@
thisBucket->symbolP = (OSSymbol **) sym;
thisBucket->count++;
count++;
- return 0;
+ return sym;
}
if (j == 1) {
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 *));
- ACCUMSIZE(2 * sizeof(OSSymbol *));
+ list = (OSSymbol **) kalloc_tag(2 * sizeof(OSSymbol *), VM_KERN_MEMORY_LIBKERN);
+ OSMETA_ACCUMSIZE(2 * sizeof(OSSymbol *));
/* @@@ gvdl: Zero test and panic if can't set up pool */
list[0] = sym;
list[1] = probeSymbol;
thisBucket->symbolP = list;
thisBucket->count++;
count++;
- if (count > nBuckets)
- reconstructSymbols();
-
- return 0;
+ GROW_POOL();
+
+ return sym;
}
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;
}
j = thisBucket->count++;
count++;
- list = (OSSymbol **) kalloc(thisBucket->count * sizeof(OSSymbol *));
- ACCUMSIZE(thisBucket->count * sizeof(OSSymbol *));
+ list = (OSSymbol **) kalloc_tag(thisBucket->count * sizeof(OSSymbol *), VM_KERN_MEMORY_LIBKERN);
+ OSMETA_ACCUMSIZE(thisBucket->count * sizeof(OSSymbol *));
/* @@@ 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 *));
- ACCUMSIZE(-(j * sizeof(OSSymbol *)));
+ kfree(thisBucket->symbolP, j * sizeof(OSSymbol *));
+ OSMETA_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;
- if (!j)
+ if (!j) {
+ // couldn't find the symbol; probably means string hash changed
+ panic("removeSymbol %s count %d ", sym->string ? sym->string : "no string", count);
return;
+ }
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;
}
+ // couldn't find the symbol; probably means string hash changed
+ panic("removeSymbol %s count %d ", sym->string ? sym->string : "no string", count);
return;
}
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 *));
- ACCUMSIZE(-(2 * sizeof(OSSymbol *)));
+ kfree(list, 2 * sizeof(OSSymbol *));
+ OSMETA_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 *));
- ACCUMSIZE(-(2 * sizeof(OSSymbol *)));
+ kfree(list, 2 * sizeof(OSSymbol *));
+ OSMETA_ACCUMSIZE(-(2 * sizeof(OSSymbol *)));
count--;
thisBucket->count--;
+ SHRINK_POOL();
return;
}
+ // couldn't find the symbol; probably means string hash changed
+ panic("removeSymbol %s count %d ", sym->string ? sym->string : "no string", count);
return;
}
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 *));
- ACCUMSIZE((thisBucket->count-1) * sizeof(OSSymbol *));
+ kalloc_tag((thisBucket->count-1) * sizeof(OSSymbol *), VM_KERN_MEMORY_LIBKERN);
+ OSMETA_ACCUMSIZE((thisBucket->count-1) * sizeof(OSSymbol *));
if (thisBucket->count-1 != j)
bcopy(thisBucket->symbolP, list,
(thisBucket->count-1-j) * sizeof(OSSymbol *));
@@ -372,14 +419,16 @@
bcopy(thisBucket->symbolP + thisBucket->count-j,
list + thisBucket->count-1-j,
j * sizeof(OSSymbol *));
- kfree((vm_offset_t)thisBucket->symbolP, thisBucket->count * sizeof(OSSymbol *));
- ACCUMSIZE(-(thisBucket->count * sizeof(OSSymbol *)));
+ kfree(thisBucket->symbolP, thisBucket->count * sizeof(OSSymbol *));
+ OSMETA_ACCUMSIZE(-(thisBucket->count * sizeof(OSSymbol *)));
thisBucket->symbolP = list;
count--;
thisBucket->count--;
return;
}
}
+ // couldn't find the symbol; probably means string hash changed
+ panic("removeSymbol %s count %d ", sym->string ? sym->string : "no string", count);
}
/*
@@ -405,7 +454,7 @@
pool = new OSSymbolPool;
assert(pool);
- if (!pool->init()) {
+ if (pool && !pool->init()) {
delete pool;
assert(false);
};
@@ -432,40 +481,60 @@
{
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();
+ }
+
+ if (oldSymb) 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)
@@ -477,23 +546,27 @@
state = pool->initHashState();
while ( (probeSymbol = pool->nextHashState(&state)) ) {
if (probeSymbol->string >= startAddr && probeSymbol->string < endAddr) {
- const char *oldString = probeSymbol->string;
-
- probeSymbol->string = (char *) kalloc(probeSymbol->length);
- ACCUMSIZE(probeSymbol->length);
- bcopy(oldString, probeSymbol->string, probeSymbol->length);
- probeSymbol->flags &= ~kOSStringNoCopy;
+ probeSymbol->OSString::initWithCString(probeSymbol->string);
}
}
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();
}
@@ -519,3 +592,33 @@
else
return false;
}
+
+unsigned int
+OSSymbol::bsearch(
+ const void * key,
+ const void * array,
+ unsigned int arrayCount,
+ size_t memberSize)
+{
+ const void **p;
+ unsigned int baseIdx = 0;
+ unsigned int lim;
+
+ for (lim = arrayCount; lim; lim >>= 1)
+ {
+ p = (typeof(p)) (((uintptr_t) array) + (baseIdx + (lim >> 1)) * memberSize);
+ if (key == *p)
+ {
+ return (baseIdx + (lim >> 1));
+ }
+ if (key > *p)
+ {
+ // move right
+ baseIdx += (lim >> 1) + 1;
+ lim--;
+ }
+ // else move left
+ }
+ // not found, insertion point here
+ return (baseIdx + (lim >> 1));
+}