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1 //
2 // Copyright (C) 2002-2005  3Dlabs Inc. Ltd.
3 // All rights reserved.
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions
7 // are met:
8 //
9 //    Redistributions of source code must retain the above copyright
10 //    notice, this list of conditions and the following disclaimer.
11 //
12 //    Redistributions in binary form must reproduce the above
13 //    copyright notice, this list of conditions and the following
14 //    disclaimer in the documentation and/or other materials provided
15 //    with the distribution.
16 //
17 //    Neither the name of 3Dlabs Inc. Ltd. nor the names of its
18 //    contributors may be used to endorse or promote products derived
19 //    from this software without specific prior written permission.
20 //
21 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 // FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 // COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 // BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 // LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
29 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
31 // ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32 // POSSIBILITY OF SUCH DAMAGE.
33 //
34 
35 #include "../Include/Common.h"
36 #include "../Include/PoolAlloc.h"
37 
38 #include "../Include/InitializeGlobals.h"
39 #include "../OSDependent/osinclude.h"
40 
41 namespace glslang {
42 
43 // Process-wide TLS index
44 OS_TLSIndex PoolIndex;
45 
46 // Return the thread-specific current pool.
GetThreadPoolAllocator()47 TPoolAllocator& GetThreadPoolAllocator()
48 {
49     return *static_cast<TPoolAllocator*>(OS_GetTLSValue(PoolIndex));
50 }
51 
52 // Set the thread-specific current pool.
SetThreadPoolAllocator(TPoolAllocator * poolAllocator)53 void SetThreadPoolAllocator(TPoolAllocator* poolAllocator)
54 {
55     OS_SetTLSValue(PoolIndex, poolAllocator);
56 }
57 
58 // Process-wide set up of the TLS pool storage.
InitializePoolIndex()59 bool InitializePoolIndex()
60 {
61     // Allocate a TLS index.
62     if ((PoolIndex = OS_AllocTLSIndex()) == OS_INVALID_TLS_INDEX)
63         return false;
64 
65     return true;
66 }
67 
68 //
69 // Implement the functionality of the TPoolAllocator class, which
70 // is documented in PoolAlloc.h.
71 //
TPoolAllocator(int growthIncrement,int allocationAlignment)72 TPoolAllocator::TPoolAllocator(int growthIncrement, int allocationAlignment) :
73     pageSize(growthIncrement),
74     alignment(allocationAlignment),
75     freeList(nullptr),
76     inUseList(nullptr),
77     numCalls(0)
78 {
79     //
80     // Don't allow page sizes we know are smaller than all common
81     // OS page sizes.
82     //
83     if (pageSize < 4*1024)
84         pageSize = 4*1024;
85 
86     //
87     // A large currentPageOffset indicates a new page needs to
88     // be obtained to allocate memory.
89     //
90     currentPageOffset = pageSize;
91 
92     //
93     // Adjust alignment to be at least pointer aligned and
94     // power of 2.
95     //
96     size_t minAlign = sizeof(void*);
97     alignment &= ~(minAlign - 1);
98     if (alignment < minAlign)
99         alignment = minAlign;
100     size_t a = 1;
101     while (a < alignment)
102         a <<= 1;
103     alignment = a;
104     alignmentMask = a - 1;
105 
106     //
107     // Align header skip
108     //
109     headerSkip = minAlign;
110     if (headerSkip < sizeof(tHeader)) {
111         headerSkip = (sizeof(tHeader) + alignmentMask) & ~alignmentMask;
112     }
113 
114     push();
115 }
116 
~TPoolAllocator()117 TPoolAllocator::~TPoolAllocator()
118 {
119     while (inUseList) {
120         tHeader* next = inUseList->nextPage;
121         inUseList->~tHeader();
122         delete [] reinterpret_cast<char*>(inUseList);
123         inUseList = next;
124     }
125 
126     //
127     // Always delete the free list memory - it can't be being
128     // (correctly) referenced, whether the pool allocator was
129     // global or not.  We should not check the guard blocks
130     // here, because we did it already when the block was
131     // placed into the free list.
132     //
133     while (freeList) {
134         tHeader* next = freeList->nextPage;
135         delete [] reinterpret_cast<char*>(freeList);
136         freeList = next;
137     }
138 }
139 
140 const unsigned char TAllocation::guardBlockBeginVal = 0xfb;
141 const unsigned char TAllocation::guardBlockEndVal   = 0xfe;
142 const unsigned char TAllocation::userDataFill       = 0xcd;
143 
144 #   ifdef GUARD_BLOCKS
145     const size_t TAllocation::guardBlockSize = 16;
146 #   else
147     const size_t TAllocation::guardBlockSize = 0;
148 #   endif
149 
150 //
151 // Check a single guard block for damage
152 //
153 #ifdef GUARD_BLOCKS
checkGuardBlock(unsigned char * blockMem,unsigned char val,const char * locText) const154 void TAllocation::checkGuardBlock(unsigned char* blockMem, unsigned char val, const char* locText) const
155 #else
156 void TAllocation::checkGuardBlock(unsigned char*, unsigned char, const char*) const
157 #endif
158 {
159 #ifdef GUARD_BLOCKS
160     for (size_t x = 0; x < guardBlockSize; x++) {
161         if (blockMem[x] != val) {
162             const int maxSize = 80;
163             char assertMsg[maxSize];
164 
165             // We don't print the assert message.  It's here just to be helpful.
166             snprintf(assertMsg, maxSize, "PoolAlloc: Damage %s %zu byte allocation at 0x%p\n",
167                       locText, size, data());
168             assert(0 && "PoolAlloc: Damage in guard block");
169         }
170     }
171 #else
172     assert(guardBlockSize == 0);
173 #endif
174 }
175 
push()176 void TPoolAllocator::push()
177 {
178     tAllocState state = { currentPageOffset, inUseList };
179 
180     stack.push_back(state);
181 
182     //
183     // Indicate there is no current page to allocate from.
184     //
185     currentPageOffset = pageSize;
186 }
187 
188 //
189 // Do a mass-deallocation of all the individual allocations
190 // that have occurred since the last push(), or since the
191 // last pop(), or since the object's creation.
192 //
193 // The deallocated pages are saved for future allocations.
194 //
pop()195 void TPoolAllocator::pop()
196 {
197     if (stack.size() < 1)
198         return;
199 
200     tHeader* page = stack.back().page;
201     currentPageOffset = stack.back().offset;
202 
203     while (inUseList != page) {
204         tHeader* nextInUse = inUseList->nextPage;
205         size_t pageCount = inUseList->pageCount;
206 
207         // This technically ends the lifetime of the header as C++ object,
208         // but we will still control the memory and reuse it.
209         inUseList->~tHeader(); // currently, just a debug allocation checker
210 
211         if (pageCount > 1) {
212             delete [] reinterpret_cast<char*>(inUseList);
213         } else {
214             inUseList->nextPage = freeList;
215             freeList = inUseList;
216         }
217         inUseList = nextInUse;
218     }
219 
220     stack.pop_back();
221 }
222 
223 //
224 // Do a mass-deallocation of all the individual allocations
225 // that have occurred.
226 //
popAll()227 void TPoolAllocator::popAll()
228 {
229     while (stack.size() > 0)
230         pop();
231 }
232 
allocate(size_t numBytes)233 void* TPoolAllocator::allocate(size_t numBytes)
234 {
235     // If we are using guard blocks, all allocations are bracketed by
236     // them: [guardblock][allocation][guardblock].  numBytes is how
237     // much memory the caller asked for.  allocationSize is the total
238     // size including guard blocks.  In release build,
239     // guardBlockSize=0 and this all gets optimized away.
240     size_t allocationSize = TAllocation::allocationSize(numBytes);
241 
242     //
243     // Just keep some interesting statistics.
244     //
245     ++numCalls;
246     totalBytes += numBytes;
247 
248     //
249     // Do the allocation, most likely case first, for efficiency.
250     // This step could be moved to be inline sometime.
251     //
252     if (currentPageOffset + allocationSize <= pageSize) {
253         //
254         // Safe to allocate from currentPageOffset.
255         //
256         unsigned char* memory = reinterpret_cast<unsigned char*>(inUseList) + currentPageOffset;
257         currentPageOffset += allocationSize;
258         currentPageOffset = (currentPageOffset + alignmentMask) & ~alignmentMask;
259 
260         return initializeAllocation(inUseList, memory, numBytes);
261     }
262 
263     if (allocationSize + headerSkip > pageSize) {
264         //
265         // Do a multi-page allocation.  Don't mix these with the others.
266         // The OS is efficient and allocating and free-ing multiple pages.
267         //
268         size_t numBytesToAlloc = allocationSize + headerSkip;
269         tHeader* memory = reinterpret_cast<tHeader*>(::new char[numBytesToAlloc]);
270         if (memory == 0)
271             return 0;
272 
273         // Use placement-new to initialize header
274         new(memory) tHeader(inUseList, (numBytesToAlloc + pageSize - 1) / pageSize);
275         inUseList = memory;
276 
277         currentPageOffset = pageSize;  // make next allocation come from a new page
278 
279         // No guard blocks for multi-page allocations (yet)
280         return reinterpret_cast<void*>(reinterpret_cast<UINT_PTR>(memory) + headerSkip);
281     }
282 
283     //
284     // Need a simple page to allocate from.
285     //
286     tHeader* memory;
287     if (freeList) {
288         memory = freeList;
289         freeList = freeList->nextPage;
290     } else {
291         memory = reinterpret_cast<tHeader*>(::new char[pageSize]);
292         if (memory == 0)
293             return 0;
294     }
295 
296     // Use placement-new to initialize header
297     new(memory) tHeader(inUseList, 1);
298     inUseList = memory;
299 
300     unsigned char* ret = reinterpret_cast<unsigned char*>(inUseList) + headerSkip;
301     currentPageOffset = (headerSkip + allocationSize + alignmentMask) & ~alignmentMask;
302 
303     return initializeAllocation(inUseList, ret, numBytes);
304 }
305 
306 //
307 // Check all allocations in a list for damage by calling check on each.
308 //
checkAllocList() const309 void TAllocation::checkAllocList() const
310 {
311     for (const TAllocation* alloc = this; alloc != 0; alloc = alloc->prevAlloc)
312         alloc->check();
313 }
314 
315 } // end namespace glslang
316