runtime/objc-auto-dump.m

   1 /*
   2  * Copyright (c) 2008 Apple Inc.  All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #include "objc-auto.h"
  25
  26 #ifndef OBJC_NO_GC
  27
  28 #include <auto_zone.h>
  29 #include <objc/objc.h>
  30 #include <objc/runtime.h>
  31 #include "objc-auto-dump.h"
  32 #include "objc-private.h"
  33 #include <strings.h>
  34
  35 /*
  36  * Utilities
  37  */
  38
  39 static char myType() {
  40     char type = 0;
  41     if (sizeof(void *) == 8) type |= SixtyFour;
  42 #if __LITTLE_ENDIAN__
  43     type |= Little;
  44 #endif
  45     return type;
  46 }
  47
  48 /*
  49  *  Sigh, a mutable set.
  50  */
  51
  52 typedef struct {
  53     long *items;
  54     long count;
  55     long capacity;
  56 } pointer_set_t;
  57
  58 static pointer_set_t *new_pointer_set() {
  59     pointer_set_t *result = malloc_zone_malloc(_objc_internal_zone(), sizeof(pointer_set_t));
  60     result->items = calloc(64, sizeof(long));
  61     result->count = 0;
  62     result->capacity = 63;  // last valid ptr, also mask
  63     return result;
  64 }
  65
  66 static void pointer_set_grow(pointer_set_t *set);
  67
  68 static void pointer_set_add(pointer_set_t *set, long ptr) {
  69     long hash = ptr & set->capacity;
  70     while (1) {
  71         if (!set->items[hash]) {
  72             set->items[hash] = ptr;
  73             ++set->count;
  74             if (set->count*3 > set->capacity*2)
  75                 pointer_set_grow(set);
  76             return;
  77         }
  78         if (set->items[hash] == ptr) return;
  79         hash = (hash + 1) & set->capacity;
  80     }
  81 }
  82
  83 static void pointer_set_grow(pointer_set_t *set) {
  84     long oldCapacity = set->capacity;
  85     long *oldItems = set->items;
  86     long i;
  87     set->count = 0;
  88     set->capacity = 2*(oldCapacity+1)-1;
  89     set->items = malloc_zone_calloc(_objc_internal_zone(), 2*(oldCapacity+1), sizeof(long));
  90     for (i = 0; i < oldCapacity; ++i)
  91         if (oldItems[i]) pointer_set_add(set, oldItems[i]);
  92     free(oldItems);
  93 }
  94
  95 static void pointer_set_iterate(pointer_set_t *set, void (^block)(long item)) {
  96     long i;
  97     for (i = 0; i < set->capacity; ++i)
  98         if (set->items[i]) block(set->items[i]);
  99 }
 100
 101 static void pointer_set_dispose(pointer_set_t *set) {
 102     free(set->items);
 103     free(set);
 104 }
 105
 106 /*
 107    Quickly dump heap to a named file in a pretty raw format.
 108  */
 109 BOOL _objc_dumpHeap(auto_zone_t *zone, const char *filename) {
 110     // just write interesting info to disk
 111     int fd = secure_open(filename, O_WRONLY|O_CREAT, geteuid());
 112     if (fd < 0) return NO;
 113     FILE *fp = fdopen(fd, "w");
 114     if (fp == NULL) {
 115         return NO;
 116     }
 117
 118     fwrite(HEADER, strlen(HEADER), 1, fp);
 119     char type2 = myType();
 120     fwrite(&type2, 1, 1, fp);
 121
 122     // for each thread...
 123
 124     // do registers first
 125     auto_zone_register_dump dump_registers = ^(const void *base, unsigned long byte_size) {
 126         char type = REGISTER;
 127         fwrite(&type, 1, 1, fp);
 128         //fwrite(REGISTER, strlen(REGISTER), 1, fp);
 129         fwrite(&byte_size, sizeof(byte_size), 1, fp);
 130         fwrite(base, byte_size, 1, fp);
 131     };
 132
 133     // then stacks
 134     auto_zone_stack_dump dump_stack = ^(const void *base, unsigned long byte_size) {
 135         char type = THREAD;
 136         fwrite(&type, 1, 1, fp);
 137         //fwrite(THREAD, strlen(THREAD), 1, fp);
 138         fwrite(&byte_size, sizeof(byte_size), 1, fp);
 139         fwrite(base, byte_size, 1, fp);
 140     };
 141
 142     // then locals
 143     void (^dump_local)(const void *, unsigned long, unsigned int, unsigned long) =
 144         ^(const void *address, unsigned long size, unsigned int layout, unsigned long refcount) {
 145             // just write the value - rely on it showing up again as a node later
 146             char type = LOCAL;
 147             fwrite(&type, 1, 1, fp);
 148             fwrite(&address, sizeof(address), 1, fp);
 149     };
 150
 151
 152
 153     // roots
 154     auto_zone_root_dump dump_root = ^(const void **address) {
 155         char type = ROOT;
 156         fwrite(&type, 1, 1, fp);
 157         // write the address so that we can catch misregistered globals
 158         fwrite(&address, sizeof(address), 1, fp);
 159         // write content, even (?) if zero
 160         fwrite(address, sizeof(*address), 1, fp);
 161     };
 162
 163     // the nodes
 164     pointer_set_t *classes = new_pointer_set();
 165     auto_zone_node_dump dump_node = ^(const void *address, unsigned long size, unsigned int layout, unsigned long refcount) {
 166         char type = NODE;
 167         fwrite(&type, 1, 1, fp);
 168         fwrite(&address, sizeof(address), 1, fp);
 169         fwrite(&size, sizeof(size), 1, fp);
 170         fwrite(&layout, sizeof(layout), 1, fp);
 171         fwrite(&refcount, sizeof(refcount), 1, fp);
 172         if ((layout & AUTO_UNSCANNED) != AUTO_UNSCANNED) {
 173             // now the nodes unfiltered content
 174             fwrite(address, size, 1, fp);
 175         }
 176         if ((layout & AUTO_OBJECT) == AUTO_OBJECT) {
 177             long theClass = *(long *)address;
 178             if (theClass) pointer_set_add(classes, theClass);
 179         }
 180     };
 181
 182     // weak
 183     auto_zone_weak_dump dump_weak = ^(const void **address, const void *item) {
 184         char type = WEAK;
 185         fwrite(&type, 1, 1, fp);
 186         fwrite(&address, sizeof(address), 1, fp);
 187         fwrite(&item, sizeof(item), 1, fp);
 188     };
 189
 190     auto_zone_dump(zone, dump_stack, dump_registers, dump_local, dump_root, dump_node, dump_weak);
 191
 192     pointer_set_iterate(classes, ^(long class) {
 193         char type = CLASS;
 194         fwrite(&type, 1, 1, fp);
 195         fwrite(&class, sizeof(class), 1, fp);   // write address so that we can map it from node isa's
 196         // classname (for grins)
 197         const char *className = class_getName((Class)class);
 198         unsigned int length = (int)strlen(className);
 199         fwrite(&length, sizeof(length), 1, fp);      // n
 200         fwrite(className, length, 1, fp);          // n bytes
 201         // strong layout
 202         const uint8_t *layout = class_getIvarLayout((Class)class);
 203         length = layout ? (int)strlen((char *)layout)+1 : 0; // format is <skipnibble><count nibble> ending with <0><0>
 204         fwrite(&length, sizeof(length), 1, fp);      // n
 205         fwrite(layout, length, 1, fp);            // n bytes
 206         // weak layout
 207         layout = class_getWeakIvarLayout((Class)class);
 208         length = layout ? (int)strlen((char *)layout)+1 : 0; // format is <skipnibble><count nibble> ending with <0><0>
 209         fwrite(&length, sizeof(length), 1, fp);      // n
 210         fwrite(layout, length, 1, fp);             // n bytes
 211     });
 212
 213     {
 214         // end
 215         char type = END;
 216         fwrite(&type, 1, 1, fp);
 217         fclose(fp);
 218         pointer_set_dispose(classes);
 219     }
 220     return YES;
 221 }
 222
 223 #endif