1 | #ifndef _LOCALMALLOCHEAP_H_ |
---|
2 | #define _LOCALMALLOCHEAP_H_ |
---|
3 | |
---|
4 | #include <dlfcn.h> |
---|
5 | |
---|
6 | #include "ansiwrapper.h" |
---|
7 | #include "sizeheap.h" |
---|
8 | #include "staticheap.h" |
---|
9 | |
---|
10 | extern "C" { |
---|
11 | size_t malloc_usable_size (void *); |
---|
12 | |
---|
13 | typedef void * mallocFunction (size_t); |
---|
14 | typedef void freeFunction (void *); |
---|
15 | typedef size_t msizeFunction (void *); |
---|
16 | |
---|
17 | typedef void exitFunction (int); |
---|
18 | exitFunction * trueExitFunction; |
---|
19 | } |
---|
20 | |
---|
21 | namespace HL { |
---|
22 | |
---|
23 | class LocalMallocHeap { |
---|
24 | public: |
---|
25 | |
---|
26 | LocalMallocHeap (void) |
---|
27 | : freefn (NULL), |
---|
28 | msizefn (NULL), |
---|
29 | mallocfn (NULL), |
---|
30 | firsttime (true) |
---|
31 | {} |
---|
32 | |
---|
33 | inline void * malloc (size_t sz) { |
---|
34 | if (firsttime) { |
---|
35 | |
---|
36 | firsttime = false; |
---|
37 | |
---|
38 | // We haven't initialized anything yet. |
---|
39 | // Initialize all of the malloc shim functions. |
---|
40 | |
---|
41 | freefn = (freeFunction *) dlsym (RTLD_NEXT, "free"); |
---|
42 | msizefn = (msizeFunction *) dlsym (RTLD_NEXT, "malloc_usable_size"); |
---|
43 | trueExitFunction = (exitFunction *) dlsym (RTLD_NEXT, "exit"); |
---|
44 | mallocfn = (mallocFunction *) dlsym (RTLD_NEXT, "malloc"); |
---|
45 | |
---|
46 | if (!(freefn && msizefn && trueExitFunction && mallocfn)) { |
---|
47 | fprintf (stderr, "Serious problem!\n"); |
---|
48 | abort(); |
---|
49 | } |
---|
50 | |
---|
51 | assert (freefn); |
---|
52 | assert (msizefn); |
---|
53 | assert (trueExitFunction); |
---|
54 | assert (mallocfn); |
---|
55 | |
---|
56 | // Go get some memory from malloc! |
---|
57 | return (*mallocfn)(sz); |
---|
58 | } |
---|
59 | |
---|
60 | // Now, once we have mallocfn resolved, we can use it. |
---|
61 | // Otherwise, we're still in dlsym-land, and have to use our local heap. |
---|
62 | |
---|
63 | if (mallocfn) { |
---|
64 | return (*mallocfn)(sz); |
---|
65 | } else { |
---|
66 | void * ptr = localHeap.malloc (sz); |
---|
67 | assert (ptr); |
---|
68 | return ptr; |
---|
69 | } |
---|
70 | } |
---|
71 | |
---|
72 | inline void free (void * ptr) { |
---|
73 | if (mallocfn) { |
---|
74 | if (localHeap.isValid (ptr)) { |
---|
75 | // We got a pointer to the temporary allocation buffer. |
---|
76 | localHeap.free (ptr); |
---|
77 | } else { |
---|
78 | (*freefn)(ptr); |
---|
79 | } |
---|
80 | } |
---|
81 | } |
---|
82 | |
---|
83 | inline size_t getSize (void * ptr) { |
---|
84 | if (localHeap.isValid (ptr)) { |
---|
85 | return localHeap.getSize (ptr); |
---|
86 | } else if (mallocfn) { |
---|
87 | return (*msizefn)(ptr); |
---|
88 | } else { |
---|
89 | // This should never happen. |
---|
90 | return 0; |
---|
91 | } |
---|
92 | } |
---|
93 | |
---|
94 | private: |
---|
95 | |
---|
96 | bool firsttime; /// True iff we haven't initialized the shim functions. |
---|
97 | |
---|
98 | // Shim functions below. |
---|
99 | |
---|
100 | freeFunction * freefn; |
---|
101 | msizeFunction * msizefn; |
---|
102 | mallocFunction * mallocfn; |
---|
103 | |
---|
104 | /// The local heap (for use while we are in dlsym, installing the |
---|
105 | /// shim functions). Hopefully 64K is enough... |
---|
106 | |
---|
107 | ANSIWrapper<SizeHeap<StaticHeap<65536> > > localHeap; |
---|
108 | |
---|
109 | }; |
---|
110 | |
---|
111 | } |
---|
112 | |
---|
113 | #endif |
---|