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