src/dyldNew.cpp

   1 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2004-2008 Apple Inc. All rights reserved.
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   9  * Version 2.0 (the 'License'). You may not use this file except in
  10  * compliance with the License. Please obtain a copy of the License at
  11  * http://www.opensource.apple.com/apsl/ and read it before using this
  12  * file.
  13  *
  14  * The Original Code and all software distributed under the License are
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  24
  25
  26 #include <stdlib.h>
  27 #include <stdint.h>
  28 #include <string.h>
  29 #include <mach/mach.h>
  30
  31 extern "C" void* __dso_handle;
  32
  33 #include "dyld.h"
  34 #include "dyldLibSystemInterface.h"
  35
  36 //
  37 //       dyld initially allocates all memory from a pool inside dyld.
  38 //   Once libSystem.dylib is initialized, dyld uses libSystem's malloc/free.
  39 //
  40
  41 #if __LP64__
  42         // room for about ~1000 initial dylibs
  43         #define DYLD_POOL_CHUNK_SIZE 200*1024
  44 #else
  45         // room for about ~900 initial dylibs
  46         #define DYLD_POOL_CHUNK_SIZE 150*1024
  47 #endif
  48
  49 struct dyld_static_pool {
  50         dyld_static_pool*       previousPool;
  51         uint8_t*                        current;
  52         uint8_t*                        end;
  53         uint8_t                         pool[1];
  54 };
  55
  56 // allocate initial pool independently of pool header to take less space on disk
  57 static uint8_t initialPoolContent[DYLD_POOL_CHUNK_SIZE] __attribute__((__aligned__(16)));
  58 static dyld_static_pool initialPool = { NULL, initialPoolContent, &initialPoolContent[DYLD_POOL_CHUNK_SIZE] };
  59 static dyld_static_pool* currentPool = &initialPool;
  60
  61
  62 void* malloc(size_t size)
  63 {
  64         if ( dyld::gLibSystemHelpers != NULL) {
  65                 void* p = dyld::gLibSystemHelpers->malloc(size);
  66                 //dyld::log("malloc(%lu) => %p from libSystem\n", size, p);
  67                 return p;
  68         }
  69         else {
  70                 size = (size+sizeof(void*)-1) & (-sizeof(void*)); // pointer align
  71                 uint8_t* result = currentPool->current;
  72                 currentPool->current += size;
  73                 if ( currentPool->current > currentPool->end ) {
  74                         vm_address_t addr = 0;
  75                         kern_return_t r = vm_allocate(mach_task_self(), &addr, DYLD_POOL_CHUNK_SIZE, VM_FLAGS_ANYWHERE);
  76                         if ( r != KERN_SUCCESS ) {
  77                                 dyld::log("out of address space for dyld memory pool\n");
  78                                 exit(1);
  79                         }
  80                         dyld_static_pool* newPool = (dyld_static_pool*)addr;
  81                         newPool->previousPool = NULL;
  82                         newPool->current = newPool->pool;
  83                         newPool->end = (uint8_t*)(addr + DYLD_POOL_CHUNK_SIZE);
  84                         newPool->previousPool = currentPool;
  85                         currentPool = newPool;
  86                         if ( (currentPool->current + size) > currentPool->end ) {
  87                                 dyld::log("dyld memory pool exhausted: size=%lu\n", size);
  88                                 exit(1);
  89                         }
  90                         result = currentPool->current;
  91                         currentPool->current += size;
  92                 }
  93                 //dyld::log("%p = malloc(%3lu) from pool %p, free space = %lu\n", result, size, currentPool, (long)(currentPool->end - currentPool->current));
  94                 return result;
  95         }
  96 }
  97
  98
  99 void free(void* ptr)
 100 {
 101         // ignore any pointer within dyld (i.e. stuff from pool or static strings)
 102         if ( (dyld::gLibSystemHelpers != NULL) && ((ptr < &__dso_handle) || (ptr >= &initialPoolContent[DYLD_POOL_CHUNK_SIZE])) ) {
 103                 // ignore stuff in any dynamically alloated dyld pools
 104                 for (dyld_static_pool* p = initialPool.previousPool; p != NULL; p = p->previousPool) {
 105                         if ( (p->pool < ptr) && (ptr < p->end) ) {
 106                                 // do nothing, pool entries can't be reclaimed
 107                                 //dyld::log("free(%p) from dynamic pool\n", ptr);
 108                                 return;
 109                         }
 110                 }
 111
 112                 //dyld::log("free(%p) from libSystem\n", ptr);
 113                 return dyld::gLibSystemHelpers->free(ptr);
 114         }
 115         else {
 116                 // do nothing, pool entries can't be reclaimed
 117                 //dyld::log("free(%p) from static pool\n", ptr);
 118         }
 119 }
 120
 121
 122 void* calloc(size_t count, size_t size)
 123 {
 124         if ( dyld::gLibSystemHelpers != NULL ) {
 125                 void* result = dyld::gLibSystemHelpers->malloc(size*count);
 126                 bzero(result, size*count);
 127                 return result;
 128         }
 129         else {
 130                 return malloc(count*size);
 131         }
 132 }
 133
 134
 135 void* realloc(void *ptr, size_t size)
 136 {
 137         void* result = malloc(size);
 138         memcpy(result, ptr, size);
 139         return result;
 140 }
 141
 142 //     void* reallocf(void *ptr, size_t size);
 143 //     void* valloc(size_t size);
 144
 145 // needed __libc_init()
 146 extern "C" int _malloc_lock;
 147 int _malloc_lock = 0;
 148
 149