[12] | 1 | /* |
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| 2 | * Revision Control Information |
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| 3 | * |
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| 4 | * $Id: safe_mem.c,v 1.1.1.1 2008-11-14 20:40:10 hhkim Exp $ |
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| 5 | * |
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| 6 | */ |
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| 7 | /* LINTLIBRARY */ |
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| 8 | |
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| 9 | #include "util.h" |
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| 10 | |
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| 11 | /* |
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| 12 | * These are interface routines to be placed between a program and the |
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| 13 | * system memory allocator. |
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| 14 | * |
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| 15 | * It forces well-defined semantics for several 'borderline' cases: |
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| 16 | * |
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| 17 | * malloc() of a 0 size object is guaranteed to return something |
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| 18 | * which is not 0, and can safely be freed (but not dereferenced) |
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| 19 | * free() accepts (silently) an 0 pointer |
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| 20 | * realloc of a 0 pointer is allowed, and is equiv. to malloc() |
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| 21 | * For the IBM/PC it forces no object > 64K; note that the size argument |
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| 22 | * to malloc/realloc is a 'long' to catch this condition |
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| 23 | * |
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| 24 | * The function pointer MMoutOfMemory() contains a vector to handle a |
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| 25 | * 'out-of-memory' error (which, by default, points at a simple wrap-up |
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| 26 | * and exit routine). |
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| 27 | */ |
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| 28 | |
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| 29 | void (*MMoutOfMemory)(unsigned long) = MMout_of_memory; |
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| 30 | |
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| 31 | |
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| 32 | /* MMout_of_memory -- out of memory for lazy people, flush and exit */ |
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| 33 | void |
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| 34 | MMout_of_memory(unsigned long size) |
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| 35 | { |
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| 36 | (void) fflush(stdout); |
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| 37 | (void) fprintf(stderr, "\nout of memory allocating %lu bytes\n", size); |
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| 38 | exit(1); |
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| 39 | } |
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| 40 | |
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| 41 | |
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| 42 | void * |
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| 43 | MMalloc(unsigned long size) |
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| 44 | { |
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| 45 | void *p; |
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| 46 | |
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| 47 | #ifdef IBMPC |
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| 48 | if (size > 65000L) { |
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| 49 | if (MMoutOfMemory != (void (*)(unsigned long)) 0) (*MMoutOfMemory)(size); |
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| 50 | return NIL(void); |
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| 51 | } |
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| 52 | #endif |
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| 53 | if (size == 0) size = sizeof(long); |
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| 54 | if ((p = malloc(size)) == NIL(void)) { |
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| 55 | if (MMoutOfMemory != (void (*)(unsigned long)) 0) (*MMoutOfMemory)(size); |
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| 56 | return NIL(void); |
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| 57 | } |
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| 58 | return p; |
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| 59 | } |
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| 60 | |
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| 61 | |
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| 62 | void * |
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| 63 | MMrealloc(void *obj, unsigned long size) |
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| 64 | { |
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| 65 | void *p; |
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| 66 | |
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| 67 | #ifdef IBMPC |
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| 68 | if (size > 65000L) { |
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| 69 | if (MMoutOfMemory != (void (*)(unsigned long)) 0) (*MMoutOfMemory)(size); |
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| 70 | return NIL(void); |
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| 71 | } |
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| 72 | #endif |
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| 73 | if (obj == NIL(void)) return MMalloc(size); |
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| 74 | if (size <= 0) size = sizeof(long); |
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| 75 | if ((p = realloc(obj, size)) == NIL(void)) { |
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| 76 | if (MMoutOfMemory != (void (*)(unsigned long)) 0) (*MMoutOfMemory)(size); |
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| 77 | return NIL(void); |
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| 78 | } |
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| 79 | return p; |
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| 80 | } |
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| 81 | |
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| 82 | |
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| 83 | void |
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| 84 | MMfree(void *obj) |
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| 85 | { |
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| 86 | if (obj != 0) { |
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| 87 | free(obj); |
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| 88 | } |
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| 89 | } |
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