runtime/objc-auto-dump.mm

   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-config.h"
  25
  26 #if SUPPORT_GC
  27
  28 #include "objc-private.h"
  29 #include "objc-auto-dump.h"
  30
  31 #include <auto_zone.h>
  32 #include <objc/objc.h>
  33 #include <objc/runtime.h>
  34 #include <strings.h>
  35
  36 /*
  37  * Utilities
  38  */
  39
  40 static char myType() {
  41     char type = 0;
  42     if (sizeof(void *) == 8) type |= SixtyFour;
  43 #if __LITTLE_ENDIAN__
  44     type |= Little;
  45 #endif
  46     return type;
  47 }
  48
  49 /*
  50  *  Sigh, a mutable set.
  51  */
  52
  53 typedef struct {
  54     long *items;
  55     long count;
  56     long capacity;
  57 } pointer_set_t;
  58
  59 static pointer_set_t *new_pointer_set() {
  60     pointer_set_t *result = (pointer_set_t *)malloc_zone_malloc(_objc_internal_zone(), sizeof(pointer_set_t));
  61     result->items = (long *)calloc(64, sizeof(long));
  62     result->count = 0;
  63     result->capacity = 63;  // last valid ptr, also mask
  64     return result;
  65 }
  66
  67 static void pointer_set_grow(pointer_set_t *set);
  68
  69 static void pointer_set_add(pointer_set_t *set, long ptr) {
  70     long hash = ptr & set->capacity;
  71     while (1) {
  72         if (!set->items[hash]) {
  73             set->items[hash] = ptr;
  74             ++set->count;
  75             if (set->count*3 > set->capacity*2)
  76                 pointer_set_grow(set);
  77             return;
  78         }
  79         if (set->items[hash] == ptr) return;
  80         hash = (hash + 1) & set->capacity;
  81     }
  82 }
  83
  84 static void pointer_set_grow(pointer_set_t *set) {
  85     long oldCapacity = set->capacity;
  86     long *oldItems = set->items;
  87     long i;
  88     set->count = 0;
  89     set->capacity = 2*(oldCapacity+1)-1;
  90     set->items = (long *)malloc_zone_calloc(_objc_internal_zone(), 2*(oldCapacity+1), sizeof(long));
  91     for (i = 0; i < oldCapacity; ++i)
  92         if (oldItems[i]) pointer_set_add(set, oldItems[i]);
  93     free(oldItems);
  94 }
  95
  96 static void pointer_set_iterate(pointer_set_t *set, void (^block)(long item)) {
  97     long i;
  98     for (i = 0; i < set->capacity; ++i)
  99         if (set->items[i]) block(set->items[i]);
 100 }
 101
 102 static void pointer_set_dispose(pointer_set_t *set) {
 103     free(set->items);
 104     free(set);
 105 }
 106
 107 /*
 108    Quickly dump heap to a named file in a pretty raw format.
 109  */
 110 BOOL _objc_dumpHeap(auto_zone_t *zone, const char *filename) {
 111     // just write interesting info to disk
 112     int fd = secure_open(filename, O_WRONLY|O_CREAT, geteuid());
 113     if (fd < 0) return NO;
 114     FILE *fp = fdopen(fd, "w");
 115     if (fp == NULL) {
 116         return NO;
 117     }
 118
 119     fwrite(HEADER, strlen(HEADER), 1, fp);
 120     char type2 = myType();
 121     fwrite(&type2, 1, 1, fp);
 122
 123     // for each thread...
 124
 125     // do registers first
 126     auto_zone_register_dump dump_registers = ^(const void *base, unsigned long byte_size) {
 127         char type = REGISTER;
 128         fwrite(&type, 1, 1, fp);
 129         //fwrite(REGISTER, strlen(REGISTER), 1, fp);
 130         fwrite(&byte_size, sizeof(byte_size), 1, fp);
 131         fwrite(base, byte_size, 1, fp);
 132     };
 133
 134     // then stacks
 135     auto_zone_stack_dump dump_stack = ^(const void *base, unsigned long byte_size) {
 136         char type = THREAD;
 137         fwrite(&type, 1, 1, fp);
 138         //fwrite(THREAD, strlen(THREAD), 1, fp);
 139         fwrite(&byte_size, sizeof(byte_size), 1, fp);
 140         fwrite(base, byte_size, 1, fp);
 141     };
 142
 143     // then locals
 144     void (^dump_local)(const void *, unsigned long, unsigned int, unsigned long) =
 145         ^(const void *address, unsigned long size, unsigned int layout, unsigned long refcount) {
 146             // just write the value - rely on it showing up again as a node later
 147             char type = LOCAL;
 148             fwrite(&type, 1, 1, fp);
 149             fwrite(&address, sizeof(address), 1, fp);
 150     };
 151
 152
 153
 154     // roots
 155     auto_zone_root_dump dump_root = ^(const void **address) {
 156         char type = ROOT;
 157         fwrite(&type, 1, 1, fp);
 158         // write the address so that we can catch misregistered globals
 159         fwrite(&address, sizeof(address), 1, fp);
 160         // write content, even (?) if zero
 161         fwrite(address, sizeof(*address), 1, fp);
 162     };
 163
 164     // the nodes
 165     pointer_set_t *classes = new_pointer_set();
 166     auto_zone_node_dump dump_node = ^(const void *address, unsigned long size, unsigned int layout, unsigned long refcount) {
 167         char type = NODE;
 168         fwrite(&type, 1, 1, fp);
 169         fwrite(&address, sizeof(address), 1, fp);
 170         fwrite(&size, sizeof(size), 1, fp);
 171         fwrite(&layout, sizeof(layout), 1, fp);
 172         fwrite(&refcount, sizeof(refcount), 1, fp);
 173         if ((layout & AUTO_UNSCANNED) != AUTO_UNSCANNED) {
 174             // now the nodes unfiltered content
 175             fwrite(address, size, 1, fp);
 176         }
 177         if ((layout & AUTO_OBJECT) == AUTO_OBJECT) {
 178             long theClass = *(long *)address;
 179             if (theClass) pointer_set_add(classes, theClass);
 180         }
 181     };
 182
 183     // weak
 184     auto_zone_weak_dump dump_weak = ^(const void **address, const void *item) {
 185         char type = WEAK;
 186         fwrite(&type, 1, 1, fp);
 187         fwrite(&address, sizeof(address), 1, fp);
 188         fwrite(&item, sizeof(item), 1, fp);
 189     };
 190
 191     auto_zone_dump(zone, dump_stack, dump_registers, dump_local, dump_root, dump_node, dump_weak);
 192
 193     pointer_set_iterate(classes, ^(long cls) {
 194         char type = CLASS;
 195         fwrite(&type, 1, 1, fp);
 196         fwrite(&cls, sizeof(cls), 1, fp);   // write address so that we can map it from node isa's
 197         // classname (for grins)
 198         const char *className = class_getName((Class)cls);
 199         unsigned int length = (int)strlen(className);
 200         fwrite(&length, sizeof(length), 1, fp);      // n
 201         fwrite(className, length, 1, fp);          // n bytes
 202         // strong layout
 203         const uint8_t *layout = class_getIvarLayout((Class)cls);
 204         length = layout ? (int)strlen((char *)layout)+1 : 0; // format is <skipnibble><count nibble> ending with <0><0>
 205         fwrite(&length, sizeof(length), 1, fp);      // n
 206         fwrite(layout, length, 1, fp);            // n bytes
 207         // weak layout
 208         layout = class_getWeakIvarLayout((Class)cls);
 209         length = layout ? (int)strlen((char *)layout)+1 : 0; // format is <skipnibble><count nibble> ending with <0><0>
 210         fwrite(&length, sizeof(length), 1, fp);      // n
 211         fwrite(layout, length, 1, fp);             // n bytes
 212     });
 213
 214     {
 215         // end
 216         char type = END;
 217         fwrite(&type, 1, 1, fp);
 218         fclose(fp);
 219         pointer_set_dispose(classes);
 220     }
 221     return YES;
 222 }
 223
 224 #endif