Index: third_party/sqlite/sqlite-src-3070603/src/mem5.c |
diff --git a/third_party/sqlite/sqlite-src-3070603/src/mem5.c b/third_party/sqlite/sqlite-src-3070603/src/mem5.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..783cef6176c59cbf30914631095a1a54f4e42e08 |
--- /dev/null |
+++ b/third_party/sqlite/sqlite-src-3070603/src/mem5.c |
@@ -0,0 +1,581 @@ |
+/* |
+** 2007 October 14 |
+** |
+** The author disclaims copyright to this source code. In place of |
+** a legal notice, here is a blessing: |
+** |
+** May you do good and not evil. |
+** May you find forgiveness for yourself and forgive others. |
+** May you share freely, never taking more than you give. |
+** |
+************************************************************************* |
+** This file contains the C functions that implement a memory |
+** allocation subsystem for use by SQLite. |
+** |
+** This version of the memory allocation subsystem omits all |
+** use of malloc(). The application gives SQLite a block of memory |
+** before calling sqlite3_initialize() from which allocations |
+** are made and returned by the xMalloc() and xRealloc() |
+** implementations. Once sqlite3_initialize() has been called, |
+** the amount of memory available to SQLite is fixed and cannot |
+** be changed. |
+** |
+** This version of the memory allocation subsystem is included |
+** in the build only if SQLITE_ENABLE_MEMSYS5 is defined. |
+** |
+** This memory allocator uses the following algorithm: |
+** |
+** 1. All memory allocations sizes are rounded up to a power of 2. |
+** |
+** 2. If two adjacent free blocks are the halves of a larger block, |
+** then the two blocks are coalesed into the single larger block. |
+** |
+** 3. New memory is allocated from the first available free block. |
+** |
+** This algorithm is described in: J. M. Robson. "Bounds for Some Functions |
+** Concerning Dynamic Storage Allocation". Journal of the Association for |
+** Computing Machinery, Volume 21, Number 8, July 1974, pages 491-499. |
+** |
+** Let n be the size of the largest allocation divided by the minimum |
+** allocation size (after rounding all sizes up to a power of 2.) Let M |
+** be the maximum amount of memory ever outstanding at one time. Let |
+** N be the total amount of memory available for allocation. Robson |
+** proved that this memory allocator will never breakdown due to |
+** fragmentation as long as the following constraint holds: |
+** |
+** N >= M*(1 + log2(n)/2) - n + 1 |
+** |
+** The sqlite3_status() logic tracks the maximum values of n and M so |
+** that an application can, at any time, verify this constraint. |
+*/ |
+#include "sqliteInt.h" |
+ |
+/* |
+** This version of the memory allocator is used only when |
+** SQLITE_ENABLE_MEMSYS5 is defined. |
+*/ |
+#ifdef SQLITE_ENABLE_MEMSYS5 |
+ |
+/* |
+** A minimum allocation is an instance of the following structure. |
+** Larger allocations are an array of these structures where the |
+** size of the array is a power of 2. |
+** |
+** The size of this object must be a power of two. That fact is |
+** verified in memsys5Init(). |
+*/ |
+typedef struct Mem5Link Mem5Link; |
+struct Mem5Link { |
+ int next; /* Index of next free chunk */ |
+ int prev; /* Index of previous free chunk */ |
+}; |
+ |
+/* |
+** Maximum size of any allocation is ((1<<LOGMAX)*mem5.szAtom). Since |
+** mem5.szAtom is always at least 8 and 32-bit integers are used, |
+** it is not actually possible to reach this limit. |
+*/ |
+#define LOGMAX 30 |
+ |
+/* |
+** Masks used for mem5.aCtrl[] elements. |
+*/ |
+#define CTRL_LOGSIZE 0x1f /* Log2 Size of this block */ |
+#define CTRL_FREE 0x20 /* True if not checked out */ |
+ |
+/* |
+** All of the static variables used by this module are collected |
+** into a single structure named "mem5". This is to keep the |
+** static variables organized and to reduce namespace pollution |
+** when this module is combined with other in the amalgamation. |
+*/ |
+static SQLITE_WSD struct Mem5Global { |
+ /* |
+ ** Memory available for allocation |
+ */ |
+ int szAtom; /* Smallest possible allocation in bytes */ |
+ int nBlock; /* Number of szAtom sized blocks in zPool */ |
+ u8 *zPool; /* Memory available to be allocated */ |
+ |
+ /* |
+ ** Mutex to control access to the memory allocation subsystem. |
+ */ |
+ sqlite3_mutex *mutex; |
+ |
+ /* |
+ ** Performance statistics |
+ */ |
+ u64 nAlloc; /* Total number of calls to malloc */ |
+ u64 totalAlloc; /* Total of all malloc calls - includes internal frag */ |
+ u64 totalExcess; /* Total internal fragmentation */ |
+ u32 currentOut; /* Current checkout, including internal fragmentation */ |
+ u32 currentCount; /* Current number of distinct checkouts */ |
+ u32 maxOut; /* Maximum instantaneous currentOut */ |
+ u32 maxCount; /* Maximum instantaneous currentCount */ |
+ u32 maxRequest; /* Largest allocation (exclusive of internal frag) */ |
+ |
+ /* |
+ ** Lists of free blocks. aiFreelist[0] is a list of free blocks of |
+ ** size mem5.szAtom. aiFreelist[1] holds blocks of size szAtom*2. |
+ ** and so forth. |
+ */ |
+ int aiFreelist[LOGMAX+1]; |
+ |
+ /* |
+ ** Space for tracking which blocks are checked out and the size |
+ ** of each block. One byte per block. |
+ */ |
+ u8 *aCtrl; |
+ |
+} mem5; |
+ |
+/* |
+** Access the static variable through a macro for SQLITE_OMIT_WSD |
+*/ |
+#define mem5 GLOBAL(struct Mem5Global, mem5) |
+ |
+/* |
+** Assuming mem5.zPool is divided up into an array of Mem5Link |
+** structures, return a pointer to the idx-th such lik. |
+*/ |
+#define MEM5LINK(idx) ((Mem5Link *)(&mem5.zPool[(idx)*mem5.szAtom])) |
+ |
+/* |
+** Unlink the chunk at mem5.aPool[i] from list it is currently |
+** on. It should be found on mem5.aiFreelist[iLogsize]. |
+*/ |
+static void memsys5Unlink(int i, int iLogsize){ |
+ int next, prev; |
+ assert( i>=0 && i<mem5.nBlock ); |
+ assert( iLogsize>=0 && iLogsize<=LOGMAX ); |
+ assert( (mem5.aCtrl[i] & CTRL_LOGSIZE)==iLogsize ); |
+ |
+ next = MEM5LINK(i)->next; |
+ prev = MEM5LINK(i)->prev; |
+ if( prev<0 ){ |
+ mem5.aiFreelist[iLogsize] = next; |
+ }else{ |
+ MEM5LINK(prev)->next = next; |
+ } |
+ if( next>=0 ){ |
+ MEM5LINK(next)->prev = prev; |
+ } |
+} |
+ |
+/* |
+** Link the chunk at mem5.aPool[i] so that is on the iLogsize |
+** free list. |
+*/ |
+static void memsys5Link(int i, int iLogsize){ |
+ int x; |
+ assert( sqlite3_mutex_held(mem5.mutex) ); |
+ assert( i>=0 && i<mem5.nBlock ); |
+ assert( iLogsize>=0 && iLogsize<=LOGMAX ); |
+ assert( (mem5.aCtrl[i] & CTRL_LOGSIZE)==iLogsize ); |
+ |
+ x = MEM5LINK(i)->next = mem5.aiFreelist[iLogsize]; |
+ MEM5LINK(i)->prev = -1; |
+ if( x>=0 ){ |
+ assert( x<mem5.nBlock ); |
+ MEM5LINK(x)->prev = i; |
+ } |
+ mem5.aiFreelist[iLogsize] = i; |
+} |
+ |
+/* |
+** If the STATIC_MEM mutex is not already held, obtain it now. The mutex |
+** will already be held (obtained by code in malloc.c) if |
+** sqlite3GlobalConfig.bMemStat is true. |
+*/ |
+static void memsys5Enter(void){ |
+ sqlite3_mutex_enter(mem5.mutex); |
+} |
+static void memsys5Leave(void){ |
+ sqlite3_mutex_leave(mem5.mutex); |
+} |
+ |
+/* |
+** Return the size of an outstanding allocation, in bytes. The |
+** size returned omits the 8-byte header overhead. This only |
+** works for chunks that are currently checked out. |
+*/ |
+static int memsys5Size(void *p){ |
+ int iSize = 0; |
+ if( p ){ |
+ int i = ((u8 *)p-mem5.zPool)/mem5.szAtom; |
+ assert( i>=0 && i<mem5.nBlock ); |
+ iSize = mem5.szAtom * (1 << (mem5.aCtrl[i]&CTRL_LOGSIZE)); |
+ } |
+ return iSize; |
+} |
+ |
+/* |
+** Find the first entry on the freelist iLogsize. Unlink that |
+** entry and return its index. |
+*/ |
+static int memsys5UnlinkFirst(int iLogsize){ |
+ int i; |
+ int iFirst; |
+ |
+ assert( iLogsize>=0 && iLogsize<=LOGMAX ); |
+ i = iFirst = mem5.aiFreelist[iLogsize]; |
+ assert( iFirst>=0 ); |
+ while( i>0 ){ |
+ if( i<iFirst ) iFirst = i; |
+ i = MEM5LINK(i)->next; |
+ } |
+ memsys5Unlink(iFirst, iLogsize); |
+ return iFirst; |
+} |
+ |
+/* |
+** Return a block of memory of at least nBytes in size. |
+** Return NULL if unable. Return NULL if nBytes==0. |
+** |
+** The caller guarantees that nByte positive. |
+** |
+** The caller has obtained a mutex prior to invoking this |
+** routine so there is never any chance that two or more |
+** threads can be in this routine at the same time. |
+*/ |
+static void *memsys5MallocUnsafe(int nByte){ |
+ int i; /* Index of a mem5.aPool[] slot */ |
+ int iBin; /* Index into mem5.aiFreelist[] */ |
+ int iFullSz; /* Size of allocation rounded up to power of 2 */ |
+ int iLogsize; /* Log2 of iFullSz/POW2_MIN */ |
+ |
+ /* nByte must be a positive */ |
+ assert( nByte>0 ); |
+ |
+ /* Keep track of the maximum allocation request. Even unfulfilled |
+ ** requests are counted */ |
+ if( (u32)nByte>mem5.maxRequest ){ |
+ mem5.maxRequest = nByte; |
+ } |
+ |
+ /* Abort if the requested allocation size is larger than the largest |
+ ** power of two that we can represent using 32-bit signed integers. |
+ */ |
+ if( nByte > 0x40000000 ){ |
+ return 0; |
+ } |
+ |
+ /* Round nByte up to the next valid power of two */ |
+ for(iFullSz=mem5.szAtom, iLogsize=0; iFullSz<nByte; iFullSz *= 2, iLogsize++){} |
+ |
+ /* Make sure mem5.aiFreelist[iLogsize] contains at least one free |
+ ** block. If not, then split a block of the next larger power of |
+ ** two in order to create a new free block of size iLogsize. |
+ */ |
+ for(iBin=iLogsize; mem5.aiFreelist[iBin]<0 && iBin<=LOGMAX; iBin++){} |
+ if( iBin>LOGMAX ){ |
+ testcase( sqlite3GlobalConfig.xLog!=0 ); |
+ sqlite3_log(SQLITE_NOMEM, "failed to allocate %u bytes", nByte); |
+ return 0; |
+ } |
+ i = memsys5UnlinkFirst(iBin); |
+ while( iBin>iLogsize ){ |
+ int newSize; |
+ |
+ iBin--; |
+ newSize = 1 << iBin; |
+ mem5.aCtrl[i+newSize] = CTRL_FREE | iBin; |
+ memsys5Link(i+newSize, iBin); |
+ } |
+ mem5.aCtrl[i] = iLogsize; |
+ |
+ /* Update allocator performance statistics. */ |
+ mem5.nAlloc++; |
+ mem5.totalAlloc += iFullSz; |
+ mem5.totalExcess += iFullSz - nByte; |
+ mem5.currentCount++; |
+ mem5.currentOut += iFullSz; |
+ if( mem5.maxCount<mem5.currentCount ) mem5.maxCount = mem5.currentCount; |
+ if( mem5.maxOut<mem5.currentOut ) mem5.maxOut = mem5.currentOut; |
+ |
+ /* Return a pointer to the allocated memory. */ |
+ return (void*)&mem5.zPool[i*mem5.szAtom]; |
+} |
+ |
+/* |
+** Free an outstanding memory allocation. |
+*/ |
+static void memsys5FreeUnsafe(void *pOld){ |
+ u32 size, iLogsize; |
+ int iBlock; |
+ |
+ /* Set iBlock to the index of the block pointed to by pOld in |
+ ** the array of mem5.szAtom byte blocks pointed to by mem5.zPool. |
+ */ |
+ iBlock = ((u8 *)pOld-mem5.zPool)/mem5.szAtom; |
+ |
+ /* Check that the pointer pOld points to a valid, non-free block. */ |
+ assert( iBlock>=0 && iBlock<mem5.nBlock ); |
+ assert( ((u8 *)pOld-mem5.zPool)%mem5.szAtom==0 ); |
+ assert( (mem5.aCtrl[iBlock] & CTRL_FREE)==0 ); |
+ |
+ iLogsize = mem5.aCtrl[iBlock] & CTRL_LOGSIZE; |
+ size = 1<<iLogsize; |
+ assert( iBlock+size-1<(u32)mem5.nBlock ); |
+ |
+ mem5.aCtrl[iBlock] |= CTRL_FREE; |
+ mem5.aCtrl[iBlock+size-1] |= CTRL_FREE; |
+ assert( mem5.currentCount>0 ); |
+ assert( mem5.currentOut>=(size*mem5.szAtom) ); |
+ mem5.currentCount--; |
+ mem5.currentOut -= size*mem5.szAtom; |
+ assert( mem5.currentOut>0 || mem5.currentCount==0 ); |
+ assert( mem5.currentCount>0 || mem5.currentOut==0 ); |
+ |
+ mem5.aCtrl[iBlock] = CTRL_FREE | iLogsize; |
+ while( ALWAYS(iLogsize<LOGMAX) ){ |
+ int iBuddy; |
+ if( (iBlock>>iLogsize) & 1 ){ |
+ iBuddy = iBlock - size; |
+ }else{ |
+ iBuddy = iBlock + size; |
+ } |
+ assert( iBuddy>=0 ); |
+ if( (iBuddy+(1<<iLogsize))>mem5.nBlock ) break; |
+ if( mem5.aCtrl[iBuddy]!=(CTRL_FREE | iLogsize) ) break; |
+ memsys5Unlink(iBuddy, iLogsize); |
+ iLogsize++; |
+ if( iBuddy<iBlock ){ |
+ mem5.aCtrl[iBuddy] = CTRL_FREE | iLogsize; |
+ mem5.aCtrl[iBlock] = 0; |
+ iBlock = iBuddy; |
+ }else{ |
+ mem5.aCtrl[iBlock] = CTRL_FREE | iLogsize; |
+ mem5.aCtrl[iBuddy] = 0; |
+ } |
+ size *= 2; |
+ } |
+ memsys5Link(iBlock, iLogsize); |
+} |
+ |
+/* |
+** Allocate nBytes of memory |
+*/ |
+static void *memsys5Malloc(int nBytes){ |
+ sqlite3_int64 *p = 0; |
+ if( nBytes>0 ){ |
+ memsys5Enter(); |
+ p = memsys5MallocUnsafe(nBytes); |
+ memsys5Leave(); |
+ } |
+ return (void*)p; |
+} |
+ |
+/* |
+** Free memory. |
+** |
+** The outer layer memory allocator prevents this routine from |
+** being called with pPrior==0. |
+*/ |
+static void memsys5Free(void *pPrior){ |
+ assert( pPrior!=0 ); |
+ memsys5Enter(); |
+ memsys5FreeUnsafe(pPrior); |
+ memsys5Leave(); |
+} |
+ |
+/* |
+** Change the size of an existing memory allocation. |
+** |
+** The outer layer memory allocator prevents this routine from |
+** being called with pPrior==0. |
+** |
+** nBytes is always a value obtained from a prior call to |
+** memsys5Round(). Hence nBytes is always a non-negative power |
+** of two. If nBytes==0 that means that an oversize allocation |
+** (an allocation larger than 0x40000000) was requested and this |
+** routine should return 0 without freeing pPrior. |
+*/ |
+static void *memsys5Realloc(void *pPrior, int nBytes){ |
+ int nOld; |
+ void *p; |
+ assert( pPrior!=0 ); |
+ assert( (nBytes&(nBytes-1))==0 ); /* EV: R-46199-30249 */ |
+ assert( nBytes>=0 ); |
+ if( nBytes==0 ){ |
+ return 0; |
+ } |
+ nOld = memsys5Size(pPrior); |
+ if( nBytes<=nOld ){ |
+ return pPrior; |
+ } |
+ memsys5Enter(); |
+ p = memsys5MallocUnsafe(nBytes); |
+ if( p ){ |
+ memcpy(p, pPrior, nOld); |
+ memsys5FreeUnsafe(pPrior); |
+ } |
+ memsys5Leave(); |
+ return p; |
+} |
+ |
+/* |
+** Round up a request size to the next valid allocation size. If |
+** the allocation is too large to be handled by this allocation system, |
+** return 0. |
+** |
+** All allocations must be a power of two and must be expressed by a |
+** 32-bit signed integer. Hence the largest allocation is 0x40000000 |
+** or 1073741824 bytes. |
+*/ |
+static int memsys5Roundup(int n){ |
+ int iFullSz; |
+ if( n > 0x40000000 ) return 0; |
+ for(iFullSz=mem5.szAtom; iFullSz<n; iFullSz *= 2); |
+ return iFullSz; |
+} |
+ |
+/* |
+** Return the ceiling of the logarithm base 2 of iValue. |
+** |
+** Examples: memsys5Log(1) -> 0 |
+** memsys5Log(2) -> 1 |
+** memsys5Log(4) -> 2 |
+** memsys5Log(5) -> 3 |
+** memsys5Log(8) -> 3 |
+** memsys5Log(9) -> 4 |
+*/ |
+static int memsys5Log(int iValue){ |
+ int iLog; |
+ for(iLog=0; (iLog<(int)((sizeof(int)*8)-1)) && (1<<iLog)<iValue; iLog++); |
+ return iLog; |
+} |
+ |
+/* |
+** Initialize the memory allocator. |
+** |
+** This routine is not threadsafe. The caller must be holding a mutex |
+** to prevent multiple threads from entering at the same time. |
+*/ |
+static int memsys5Init(void *NotUsed){ |
+ int ii; /* Loop counter */ |
+ int nByte; /* Number of bytes of memory available to this allocator */ |
+ u8 *zByte; /* Memory usable by this allocator */ |
+ int nMinLog; /* Log base 2 of minimum allocation size in bytes */ |
+ int iOffset; /* An offset into mem5.aCtrl[] */ |
+ |
+ UNUSED_PARAMETER(NotUsed); |
+ |
+ /* For the purposes of this routine, disable the mutex */ |
+ mem5.mutex = 0; |
+ |
+ /* The size of a Mem5Link object must be a power of two. Verify that |
+ ** this is case. |
+ */ |
+ assert( (sizeof(Mem5Link)&(sizeof(Mem5Link)-1))==0 ); |
+ |
+ nByte = sqlite3GlobalConfig.nHeap; |
+ zByte = (u8*)sqlite3GlobalConfig.pHeap; |
+ assert( zByte!=0 ); /* sqlite3_config() does not allow otherwise */ |
+ |
+ /* boundaries on sqlite3GlobalConfig.mnReq are enforced in sqlite3_config() */ |
+ nMinLog = memsys5Log(sqlite3GlobalConfig.mnReq); |
+ mem5.szAtom = (1<<nMinLog); |
+ while( (int)sizeof(Mem5Link)>mem5.szAtom ){ |
+ mem5.szAtom = mem5.szAtom << 1; |
+ } |
+ |
+ mem5.nBlock = (nByte / (mem5.szAtom+sizeof(u8))); |
+ mem5.zPool = zByte; |
+ mem5.aCtrl = (u8 *)&mem5.zPool[mem5.nBlock*mem5.szAtom]; |
+ |
+ for(ii=0; ii<=LOGMAX; ii++){ |
+ mem5.aiFreelist[ii] = -1; |
+ } |
+ |
+ iOffset = 0; |
+ for(ii=LOGMAX; ii>=0; ii--){ |
+ int nAlloc = (1<<ii); |
+ if( (iOffset+nAlloc)<=mem5.nBlock ){ |
+ mem5.aCtrl[iOffset] = ii | CTRL_FREE; |
+ memsys5Link(iOffset, ii); |
+ iOffset += nAlloc; |
+ } |
+ assert((iOffset+nAlloc)>mem5.nBlock); |
+ } |
+ |
+ /* If a mutex is required for normal operation, allocate one */ |
+ if( sqlite3GlobalConfig.bMemstat==0 ){ |
+ mem5.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM); |
+ } |
+ |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** Deinitialize this module. |
+*/ |
+static void memsys5Shutdown(void *NotUsed){ |
+ UNUSED_PARAMETER(NotUsed); |
+ mem5.mutex = 0; |
+ return; |
+} |
+ |
+#ifdef SQLITE_TEST |
+/* |
+** Open the file indicated and write a log of all unfreed memory |
+** allocations into that log. |
+*/ |
+void sqlite3Memsys5Dump(const char *zFilename){ |
+ FILE *out; |
+ int i, j, n; |
+ int nMinLog; |
+ |
+ if( zFilename==0 || zFilename[0]==0 ){ |
+ out = stdout; |
+ }else{ |
+ out = fopen(zFilename, "w"); |
+ if( out==0 ){ |
+ fprintf(stderr, "** Unable to output memory debug output log: %s **\n", |
+ zFilename); |
+ return; |
+ } |
+ } |
+ memsys5Enter(); |
+ nMinLog = memsys5Log(mem5.szAtom); |
+ for(i=0; i<=LOGMAX && i+nMinLog<32; i++){ |
+ for(n=0, j=mem5.aiFreelist[i]; j>=0; j = MEM5LINK(j)->next, n++){} |
+ fprintf(out, "freelist items of size %d: %d\n", mem5.szAtom << i, n); |
+ } |
+ fprintf(out, "mem5.nAlloc = %llu\n", mem5.nAlloc); |
+ fprintf(out, "mem5.totalAlloc = %llu\n", mem5.totalAlloc); |
+ fprintf(out, "mem5.totalExcess = %llu\n", mem5.totalExcess); |
+ fprintf(out, "mem5.currentOut = %u\n", mem5.currentOut); |
+ fprintf(out, "mem5.currentCount = %u\n", mem5.currentCount); |
+ fprintf(out, "mem5.maxOut = %u\n", mem5.maxOut); |
+ fprintf(out, "mem5.maxCount = %u\n", mem5.maxCount); |
+ fprintf(out, "mem5.maxRequest = %u\n", mem5.maxRequest); |
+ memsys5Leave(); |
+ if( out==stdout ){ |
+ fflush(stdout); |
+ }else{ |
+ fclose(out); |
+ } |
+} |
+#endif |
+ |
+/* |
+** This routine is the only routine in this file with external |
+** linkage. It returns a pointer to a static sqlite3_mem_methods |
+** struct populated with the memsys5 methods. |
+*/ |
+const sqlite3_mem_methods *sqlite3MemGetMemsys5(void){ |
+ static const sqlite3_mem_methods memsys5Methods = { |
+ memsys5Malloc, |
+ memsys5Free, |
+ memsys5Realloc, |
+ memsys5Size, |
+ memsys5Roundup, |
+ memsys5Init, |
+ memsys5Shutdown, |
+ 0 |
+ }; |
+ return &memsys5Methods; |
+} |
+ |
+#endif /* SQLITE_ENABLE_MEMSYS5 */ |