1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
/*------------------------------------------------------------------------*/
/*--- A simple pool (memory) allocator implementation. m_poolalloc.c --- */
/*------------------------------------------------------------------------*/
/*
This file is part of Valgrind, a dynamic binary instrumentation
framework.
Copyright (C) 2011-2017 OpenWorks LLP info@open-works.co.uk,
Philippe Waroquiers philippe.waroquiers@skynet.be
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
The GNU General Public License is contained in the file COPYING.
*/
#include "pub_core_basics.h"
#include "pub_core_libcbase.h"
#include "pub_core_libcassert.h"
#include "pub_core_xarray.h"
#include "pub_core_poolalloc.h" /* self */
struct _PoolAlloc {
UWord nrRef; /* nr reference to this pool allocator */
UWord elemSzB; /* element size */
UWord nPerPool; /* # elems per pool */
Alloc_Fn_t alloc_fn; /* pool allocator */
const HChar* cc; /* pool allocator's cost centre */
Free_Fn_t free_fn; /* pool allocator's free-er */
/* XArray of void* (pointers to pools). The pools themselves.
Each element is a pointer to a block of size (elemSzB *
nPerPool) bytes. */
XArray* pools;
/* next free element. Is a pointer to an element in one of the
pools pointed to by .pools */
void* nextFree;
};
PoolAlloc* VG_(newPA) ( UWord elemSzB,
UWord nPerPool,
Alloc_Fn_t alloc_fn,
const HChar* cc,
Free_Fn_t free_fn )
{
PoolAlloc* pa;
vg_assert(0 == (elemSzB % sizeof(UWord)));
vg_assert(elemSzB >= sizeof(UWord));
vg_assert(nPerPool >= 100); /* let's say */
vg_assert(alloc_fn);
vg_assert(cc);
vg_assert(free_fn);
pa = alloc_fn(cc, sizeof(*pa));
VG_(memset)(pa, 0, sizeof(*pa));
pa->nrRef = 0;
pa->elemSzB = elemSzB;
pa->nPerPool = nPerPool;
pa->pools = NULL;
pa->alloc_fn = alloc_fn;
pa->cc = cc;
pa->free_fn = free_fn;
pa->pools = VG_(newXA)( alloc_fn, cc, free_fn, sizeof(void*) );
pa->nextFree = NULL;
return pa;
}
void VG_(deletePA) ( PoolAlloc* pa)
{
Word i;
vg_assert(pa->nrRef == 0);
for (i = 0; i < VG_(sizeXA) (pa->pools); i++)
pa->free_fn (*(UWord **)VG_(indexXA) ( pa->pools, i ));
VG_(deleteXA) (pa->pools);
pa->free_fn (pa);
}
/* The freelist is empty. Allocate a new pool and put all the new
elements in it onto the freelist. */
__attribute__((noinline))
static void pal_add_new_pool ( PoolAlloc* pa )
{
Word i;
UWord* pool;
vg_assert(pa);
vg_assert(pa->nextFree == NULL);
pool = pa->alloc_fn( pa->cc, pa->elemSzB * pa->nPerPool );
/* extend the freelist through the new pool. Place the freelist
pointer in the first word of each element. That's why the
element size must be at least one word. */
for (i = pa->nPerPool-1; i >= 0; i--) {
UChar* elemC = ((UChar*)pool) + i * pa->elemSzB;
UWord* elem = (UWord*)elemC;
vg_assert(0 == (((UWord)elem) % sizeof(UWord)));
*elem = (UWord)pa->nextFree;
pa->nextFree = elem;
}
/* and add to our collection of pools */
VG_(addToXA)( pa->pools, &pool );
}
UWord VG_(sizePA) ( PoolAlloc* pa)
{
vg_assert(pa);
return pa->nPerPool * VG_(sizeXA) (pa->pools);
}
void* VG_(allocEltPA) ( PoolAlloc* pa)
{
UWord* elem;
if (UNLIKELY(pa->nextFree == NULL)) {
pal_add_new_pool(pa);
}
elem = pa->nextFree;
pa->nextFree = (void*)*elem;
*elem = 0; /* unnecessary, but just to be on the safe side */
return elem;
}
void VG_(freeEltPA) ( PoolAlloc* pa, void* p)
{
UWord* elem = (UWord*)p;
*elem = (UWord)pa->nextFree;
pa->nextFree = elem;
}
void VG_(addRefPA) ( PoolAlloc* pa)
{
pa->nrRef++;
}
UWord VG_(releasePA)(PoolAlloc* pa)
{
UWord nrRef;
vg_assert(pa->nrRef > 0);
nrRef = --pa->nrRef;
if (nrRef == 0)
VG_(deletePA)(pa);
return nrRef;
}
|
