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Added support for poolallocarray and poolmakeunfreeable. The latter is used by the SAFECode project

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7102 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Sumant Kowshik 2003-07-03 17:55:47 +00:00
parent a27028b710
commit af0f37ac49
1 changed files with 193 additions and 25 deletions
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218
runtime/GCCLibraries/libpoolalloc/PoolAllocatorChained.c
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@ -5,11 +5,14 @@
#define assert(X)
#define NODES_PER_SLAB 512
#define NODES_PER_SLAB 65536
typedef struct PoolTy {
void *Data;
unsigned NodeSize;
unsigned FreeablePool; /* Set to false if the memory from this pool cannot be
freed before destroy*/
} PoolTy;
/* PoolSlab Structure - Hold NODES_PER_SLAB objects of the current node type.
@ -20,7 +23,9 @@ typedef struct PoolSlab {
int LastUsed; /* Last allocated node in slab */
struct PoolSlab *Next;
unsigned char AllocatedBitVector[NODES_PER_SLAB/8];
unsigned char StartOfAllocation[NODES_PER_SLAB/8];
char Data[1]; /* Buffer to hold data in this slab... variable sized */
} PoolSlab;
#define NODE_ALLOCATED(POOLSLAB, NODENUM) \
@ -29,21 +34,37 @@ typedef struct PoolSlab {
(POOLSLAB)->AllocatedBitVector[(NODENUM) >> 3] |= 1 << ((NODENUM) & 7)
#define MARK_NODE_FREE(POOLSLAB, NODENUM) \
(POOLSLAB)->AllocatedBitVector[(NODENUM) >> 3] &= ~(1 << ((NODENUM) & 7))
#define ALLOCATION_BEGINS(POOLSLAB, NODENUM) \
((POOLSLAB)->StartOfAllocation[(NODENUM) >> 3] & (1 << ((NODENUM) & 7)))
#define SET_START_BIT(POOLSLAB, NODENUM) \
(POOLSLAB)->StartOfAllocation[(NODENUM) >> 3] |= 1 << ((NODENUM) & 7)
#define CLEAR_START_BIT(POOLSLAB, NODENUM) \
(POOLSLAB)->StartOfAllocation[(NODENUM) >> 3] &= ~(1 << ((NODENUM) & 7))
/* poolinit - Initialize a pool descriptor to empty
*/
void poolinit(PoolTy *Pool, unsigned Size) {
assert(Pool && "Null pool pointer passed in!");
void poolinit(PoolTy *Pool, unsigned NodeSize) {
assert(Pool && "Null pool pointer passed into poolinit!");
Pool->NodeSize = Size;
Pool->NodeSize = NodeSize;
Pool->Data = 0;
Pool->FreeablePool = 1;
}
void poolmakeunfreeable(PoolTy *Pool) {
assert(Pool && "Null pool pointer passed in to poolmakeunfreeable!");
Pool->FreeablePool = 0;
}
/* pooldestroy - Release all memory allocated for a pool
*/
void pooldestroy(PoolTy *Pool) {
PoolSlab *PS = (PoolSlab*)Pool->Data;
PoolSlab *PS;
assert(Pool && "Null pool pointer passed in to pooldestroy!");
PS = (PoolSlab*)Pool->Data;
while (PS) {
PoolSlab *Next = PS->Next;
free(PS);
@ -58,6 +79,7 @@ static void *FindSlabEntry(PoolSlab *PS, unsigned NodeSize) {
if (PS->LastUsed < NODES_PER_SLAB-1) {
/* Mark the returned entry used */
MARK_NODE_ALLOCATED(PS, PS->LastUsed+1);
SET_START_BIT(PS, PS->LastUsed+1);
/* If we are allocating out the first unused field, bump its index also */
if (PS->FirstUnused == PS->LastUsed+1)
@ -73,7 +95,10 @@ static void *FindSlabEntry(PoolSlab *PS, unsigned NodeSize) {
if (PS->FirstUnused < NODES_PER_SLAB) {
/* Successfully allocate out the first unused node */
unsigned Idx = PS->FirstUnused;
MARK_NODE_ALLOCATED(PS, Idx);
SET_START_BIT(PS, Idx);
/* Increment FirstUnused to point to the new first unused value... */
do {
++PS->FirstUnused;
@ -89,20 +114,28 @@ static void *FindSlabEntry(PoolSlab *PS, unsigned NodeSize) {
}
char *poolalloc(PoolTy *Pool) {
unsigned NodeSize = Pool->NodeSize;
PoolSlab *PS = (PoolSlab*)Pool->Data;
unsigned NodeSize;
PoolSlab *PS;
void *Result;
assert(Pool && "Null pool pointer passed in to poolalloc!");
NodeSize = Pool->NodeSize;
PS = (PoolSlab*)Pool->Data;
if ((Result = FindSlabEntry(PS, NodeSize)))
return Result;
/* Otherwise we must allocate a new slab and add it to the list */
PS = (PoolSlab*)malloc(sizeof(PoolSlab)+NodeSize*NODES_PER_SLAB-1);
assert (PS && "Could not allocate memory!");
/* Initialize the slab to indicate that the first element is allocated */
PS->FirstUnused = 1;
PS->LastUsed = 0;
PS->AllocatedBitVector[0] = 1;
MARK_NODE_ALLOCATED(PS, 0);
SET_START_BIT(PS, 0);
/* Add the slab to the list... */
PS->Next = (PoolSlab*)Pool->Data;
@ -111,9 +144,15 @@ char *poolalloc(PoolTy *Pool) {
}
void poolfree(PoolTy *Pool, char *Node) {
unsigned NodeSize = Pool->NodeSize, Idx;
PoolSlab *PS = (PoolSlab*)Pool->Data;
PoolSlab **PPS = (PoolSlab**)&Pool->Data;
unsigned NodeSize, Idx;
PoolSlab *PS;
PoolSlab **PPS;
unsigned idxiter;
assert(Pool && "Null pool pointer passed in to poolfree!");
NodeSize = Pool->NodeSize;
PS = (PoolSlab*)Pool->Data;
PPS = (PoolSlab**)&Pool->Data;
/* Seach for the slab that contains this node... */
while (&PS->Data[0] > Node || &PS->Data[NodeSize*NODES_PER_SLAB] < Node) {
@ -125,18 +164,32 @@ void poolfree(PoolTy *Pool, char *Node) {
Idx = (Node-&PS->Data[0])/NodeSize;
assert(Idx < NODES_PER_SLAB && "Pool slab searching loop broken!");
assert(ALLOCATION_BEGINS(PS, Idx) &&
"Attempt to free middle of allocated array");
/* Free the first node */
CLEAR_START_BIT(PS, Idx);
MARK_NODE_FREE(PS, Idx);
// Free all nodes
idxiter = Idx + 1;
while (idxiter < NODES_PER_SLAB && (!ALLOCATION_BEGINS(PS,idxiter)) &&
(NODE_ALLOCATED(PS, idxiter))) {
MARK_NODE_FREE(PS, idxiter);
}
/* Update the first free field if this node is below the free node line */
if (Idx < PS->FirstUnused) PS->FirstUnused = Idx;
/* If we are not freeing the last element in a slab... */
if (Idx != PS->LastUsed) {
MARK_NODE_FREE(PS, Idx);
if (idxiter - 1 != PS->LastUsed) {
return;
}
}
/* Otherwise we are freeing the last element in a slab... shrink the
* LastUsed marker down to last used node.
*/
PS->LastUsed = Idx;
do {
--PS->LastUsed;
/* Fixme, this should scan the allocated array an entire byte at a time for
@ -151,16 +204,131 @@ void poolfree(PoolTy *Pool, char *Node) {
* it to the head of the list, or free it, depending on whether or not there
* is already an empty slab at the head of the list.
*/
if (PS->LastUsed == -1) { /* Empty slab? */
PoolSlab *HeadSlab;
*PPS = PS->Next; /* Unlink from the list of slabs... */
HeadSlab = (PoolSlab*)Pool->Data;
if (HeadSlab && HeadSlab->LastUsed == -1){/* List already has empty slab? */
free(PS); /* Free memory for slab */
} else {
PS->Next = HeadSlab; /* No empty slab yet, add this */
Pool->Data = PS; /* one to the head of the list */
/* Do this only if the pool is freeable */
if (Pool->FreeablePool) {
if (PS->LastUsed == -1) { /* Empty slab? */
PoolSlab *HeadSlab;
*PPS = PS->Next; /* Unlink from the list of slabs... */
HeadSlab = (PoolSlab*)Pool->Data;
if (HeadSlab && HeadSlab->LastUsed == -1){/* List already has empty slab? */
free(PS); /* Free memory for slab */
} else {
PS->Next = HeadSlab; /* No empty slab yet, add this */
Pool->Data = PS; /* one to the head of the list */
}
}
} else {
/* Pool is not freeable for safety reasons */
/* Leave it in the list of PoolSlabs as an empty PoolSlab */
if (PS->LastUsed == -1) {
PS->FirstUnused = 0;
/* Do not free the pool, but move it to the head of the list if there is no
empty slab there already */
PoolSlab *HeadSlab;
HeadSlab = (PoolSlab*)Pool->Data;
if (HeadSlab && HeadSlab->LastUsed != -1) {
PS->Next = HeadSlab;
Pool->Data = PS;
}
}
}
}
/* The poolallocarray version of FindSlabEntry */
static void *FindSlabEntryArray(PoolSlab *PS, unsigned NodeSize,
unsigned Size) {
unsigned i;
/* Loop through all of the slabs looking for one with an opening */
for (; PS; PS = PS->Next) {
/* Check to see if there are empty entries at the end of the slab... */
if (PS->LastUsed < NODES_PER_SLAB-Size) {
/* Mark the returned entry used and set the start bit*/
SET_START_BIT(PS, PS->LastUsed + 1);
for (i = PS->LastUsed + 1; i <= PS->LastUsed + Size; ++i)
MARK_NODE_ALLOCATED(PS, i);
/* If we are allocating out the first unused field, bump its index also */
if (PS->FirstUnused == PS->LastUsed+1)
PS->FirstUnused += Size;
/* Increment LastUsed */
PS->LastUsed += Size;
/* Return the entry */
return &PS->Data[0] + (PS->LastUsed - Size + 1) * NodeSize;
}
/* If not, check to see if this node has a declared "FirstUnused" value
* starting which Size nodes can be allocated
*/
if (PS->FirstUnused < NODES_PER_SLAB - Size + 1 &&
(PS->LastUsed < PS->FirstUnused ||
PS->LastUsed - PS->FirstUnused >= Size)) {
unsigned Idx = PS->FirstUnused, foundArray;
/* Check if there is a continuous array of Size nodes starting
FirstUnused */
foundArray = 1;
for (i = Idx; (i < Idx + Size) && foundArray; ++i)
if (NODE_ALLOCATED(PS, i))
foundArray = 0;
if (foundArray) {
/* Successfully allocate out the first unused node */
SET_START_BIT(PS, Idx);
for (i = Idx; i < Idx + Size; ++i)
MARK_NODE_ALLOCATED(PS, i);
PS->FirstUnused += Size;
while (PS->FirstUnused < NODES_PER_SLAB &&
NODE_ALLOCATED(PS, PS->FirstUnused)) {
++PS->FirstUnused;
}
return &PS->Data[0] + Idx*NodeSize;
}
}
}
/* No empty nodes available, must grow # slabs! */
return 0;
}
char* poolallocarray(PoolTy* Pool, unsigned Size) {
unsigned NodeSize;
PoolSlab *PS;
void *Result;
unsigned i;
assert(Pool && "Null pool pointer passed in to poolallocarray!");
NodeSize = Pool->NodeSize;
PS = (PoolSlab*)Pool->Data;
assert(Size <= NODES_PER_SLAB &&
"Exceeded the maximum size of an individual malloc");
if ((Result = FindSlabEntryArray(PS, NodeSize,Size)))
return Result;
/* Otherwise we must allocate a new slab and add it to the list */
PS = (PoolSlab*)malloc(sizeof(PoolSlab)+NodeSize*NODES_PER_SLAB-1);
assert (PS && "Could not allocate memory!");
/* Initialize the slab to indicate that the first element is allocated */
PS->FirstUnused = Size;
PS->LastUsed = Size - 1;
SET_START_BIT(PS, 0);
for (i = 0; i < Size; ++i) {
MARK_NODE_ALLOCATED(PS, i);
}
/* Add the slab to the list... */
PS->Next = (PoolSlab*)Pool->Data;
Pool->Data = PS;
return &PS->Data[0];
}