SDL  2.0
SDL_test_memory.c
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "SDL_config.h"
22 #include "SDL_assert.h"
23 #include "SDL_stdinc.h"
24 #include "SDL_log.h"
25 #include "SDL_test_crc32.h"
26 #include "SDL_test_memory.h"
27 
28 #ifdef HAVE_LIBUNWIND_H
29 #include <libunwind.h>
30 #endif
31 
32 /* This is a simple tracking allocator to demonstrate the use of SDL's
33  memory allocation replacement functionality.
34 
35  It gets slow with large numbers of allocations and shouldn't be used
36  for production code.
37 */
38 
39 typedef struct SDL_tracked_allocation
40 {
41  void *mem;
42  size_t size;
44  char stack_names[10][256];
47 
53 static int s_previous_allocations = 0;
55 
56 static unsigned int get_allocation_bucket(void *mem)
57 {
58  CrcUint32 crc_value;
59  unsigned int index;
60  SDLTest_Crc32Calc(&s_crc32_context, (CrcUint8 *)&mem, sizeof(mem), &crc_value);
61  index = (crc_value & (SDL_arraysize(s_tracked_allocations) - 1));
62  return index;
63 }
64 
66 {
68  int index = get_allocation_bucket(mem);
69  for (entry = s_tracked_allocations[index]; entry; entry = entry->next) {
70  if (mem == entry->mem) {
71  return SDL_TRUE;
72  }
73  }
74  return SDL_FALSE;
75 }
76 
77 static void SDL_TrackAllocation(void *mem, size_t size)
78 {
80  int index = get_allocation_bucket(mem);
81 
82  if (SDL_IsAllocationTracked(mem)) {
83  return;
84  }
85  entry = (SDL_tracked_allocation *)SDL_malloc_orig(sizeof(*entry));
86  if (!entry) {
87  return;
88  }
89  entry->mem = mem;
90  entry->size = size;
91 
92  /* Generate the stack trace for the allocation */
93  SDL_zero(entry->stack);
94 #ifdef HAVE_LIBUNWIND_H
95  {
96  int stack_index;
97  unw_cursor_t cursor;
98  unw_context_t context;
99 
100  unw_getcontext(&context);
101  unw_init_local(&cursor, &context);
102 
103  stack_index = 0;
104  while (unw_step(&cursor) > 0) {
105  unw_word_t offset, pc;
106  char sym[256];
107 
108  unw_get_reg(&cursor, UNW_REG_IP, &pc);
109  entry->stack[stack_index] = pc;
110 
111  if (unw_get_proc_name(&cursor, sym, sizeof(sym), &offset) == 0) {
112  snprintf(entry->stack_names[stack_index], sizeof(entry->stack_names[stack_index]), "%s+0x%llx", sym, offset);
113  }
114  ++stack_index;
115 
116  if (stack_index == SDL_arraysize(entry->stack)) {
117  break;
118  }
119  }
120  }
121 #endif /* HAVE_LIBUNWIND_H */
122 
123  entry->next = s_tracked_allocations[index];
124  s_tracked_allocations[index] = entry;
125 }
126 
127 static void SDL_UntrackAllocation(void *mem)
128 {
129  SDL_tracked_allocation *entry, *prev;
130  int index = get_allocation_bucket(mem);
131 
132  prev = NULL;
133  for (entry = s_tracked_allocations[index]; entry; entry = entry->next) {
134  if (mem == entry->mem) {
135  if (prev) {
136  prev->next = entry->next;
137  } else {
138  s_tracked_allocations[index] = entry->next;
139  }
140  SDL_free_orig(entry);
141  return;
142  }
143  prev = entry;
144  }
145 }
146 
147 static void * SDLCALL SDLTest_TrackedMalloc(size_t size)
148 {
149  void *mem;
150 
151  mem = SDL_malloc_orig(size);
152  if (mem) {
153  SDL_TrackAllocation(mem, size);
154  }
155  return mem;
156 }
157 
158 static void * SDLCALL SDLTest_TrackedCalloc(size_t nmemb, size_t size)
159 {
160  void *mem;
161 
162  mem = SDL_calloc_orig(nmemb, size);
163  if (mem) {
164  SDL_TrackAllocation(mem, nmemb * size);
165  }
166  return mem;
167 }
168 
169 static void * SDLCALL SDLTest_TrackedRealloc(void *ptr, size_t size)
170 {
171  void *mem;
172 
173  SDL_assert(!ptr || SDL_IsAllocationTracked(ptr));
174  mem = SDL_realloc_orig(ptr, size);
175  if (mem && mem != ptr) {
176  if (ptr) {
178  }
179  SDL_TrackAllocation(mem, size);
180  }
181  return mem;
182 }
183 
184 static void SDLCALL SDLTest_TrackedFree(void *ptr)
185 {
186  if (!ptr) {
187  return;
188  }
189 
190  if (!s_previous_allocations) {
192  }
194  SDL_free_orig(ptr);
195 }
196 
198 {
199  if (SDL_malloc_orig) {
200  return 0;
201  }
202 
203  SDLTest_Crc32Init(&s_crc32_context);
204 
206  if (s_previous_allocations != 0) {
207  SDL_Log("SDLTest_TrackAllocations(): There are %d previous allocations, disabling free() validation", s_previous_allocations);
208  }
209 
213  &SDL_free_orig);
214 
219  return 0;
220 }
221 
223 {
224  char *message = NULL;
225  size_t message_size = 0;
226  char line[128], *tmp;
227  SDL_tracked_allocation *entry;
228  int index, count, stack_index;
229  Uint64 total_allocated;
230 
231  if (!SDL_malloc_orig) {
232  return;
233  }
234 
235 #define ADD_LINE() \
236  message_size += (SDL_strlen(line) + 1); \
237  tmp = (char *)SDL_realloc_orig(message, message_size); \
238  if (!tmp) { \
239  return; \
240  } \
241  message = tmp; \
242  SDL_strlcat(message, line, message_size)
243 
244  SDL_strlcpy(line, "Memory allocations:\n", sizeof(line));
245  ADD_LINE();
246  SDL_strlcpy(line, "Expect 2 allocations from within SDL_GetErrBuf()\n", sizeof(line));
247  ADD_LINE();
248 
249  count = 0;
250  total_allocated = 0;
251  for (index = 0; index < SDL_arraysize(s_tracked_allocations); ++index) {
252  for (entry = s_tracked_allocations[index]; entry; entry = entry->next) {
253  SDL_snprintf(line, sizeof(line), "Allocation %d: %d bytes\n", count, (int)entry->size);
254  ADD_LINE();
255  /* Start at stack index 1 to skip our tracking functions */
256  for (stack_index = 1; stack_index < SDL_arraysize(entry->stack); ++stack_index) {
257  if (!entry->stack[stack_index]) {
258  break;
259  }
260  SDL_snprintf(line, sizeof(line), "\t0x%"SDL_PRIx64": %s\n", entry->stack[stack_index], entry->stack_names[stack_index]);
261  ADD_LINE();
262  }
263  total_allocated += entry->size;
264  ++count;
265  }
266  }
267  SDL_snprintf(line, sizeof(line), "Total: %.2f Kb in %d allocations\n", (float)total_allocated / 1024, count);
268  ADD_LINE();
269 #undef ADD_LINE
270 
271  SDL_Log("%s", message);
272 }
273 
274 /* vi: set ts=4 sw=4 expandtab: */
void SDLTest_LogAllocations()
Print a log of any outstanding allocations.
static int s_previous_allocations
#define SDL_strlcpy
static SDL_calloc_func SDL_calloc_orig
GLuint GLsizei const GLchar * message
static void SDLTest_TrackedFree(void *ptr)
GLuint GLuint GLsizei count
Definition: SDL_opengl.h:1571
static void SDL_TrackAllocation(void *mem, size_t size)
static unsigned int get_allocation_bucket(void *mem)
static screen_context_t context
Definition: video.c:25
int SDLTest_TrackAllocations()
Start tracking SDL memory allocations.
void *(* SDL_calloc_func)(size_t nmemb, size_t size)
Definition: SDL_stdinc.h:367
GLintptr offset
static void * SDLTest_TrackedMalloc(size_t size)
void(* SDL_free_func)(void *mem)
Definition: SDL_stdinc.h:369
#define SDL_SetMemoryFunctions
static void * SDLTest_TrackedCalloc(size_t nmemb, size_t size)
static SDL_realloc_func SDL_realloc_orig
uint64_t Uint64
Definition: SDL_stdinc.h:194
static SDL_tracked_allocation * s_tracked_allocations[256]
#define ADD_LINE()
#define SDL_Log
void *(* SDL_malloc_func)(size_t size)
Definition: SDL_stdinc.h:366
static void SDL_UntrackAllocation(void *mem)
void *(* SDL_realloc_func)(void *mem, size_t size)
Definition: SDL_stdinc.h:368
#define SDL_zero(x)
Definition: SDL_stdinc.h:416
static SDL_bool SDL_IsAllocationTracked(void *mem)
#define SDL_GetMemoryFunctions
GLsizeiptr size
GLuint index
static SDL_free_func SDL_free_orig
SDL_Cursor * cursor
#define SDL_PRIx64
Definition: SDL_stdinc.h:227
#define SDL_assert(condition)
Definition: SDL_assert.h:169
#define NULL
Definition: begin_code.h:164
SDL_bool
Definition: SDL_stdinc.h:139
int SDLTest_Crc32Init(SDLTest_Crc32Context *crcContext)
Initialize the CRC context.
#define SDL_snprintf
#define SDL_arraysize(array)
Definition: SDL_stdinc.h:93
static SDL_malloc_func SDL_malloc_orig
#define CrcUint32
struct SDL_tracked_allocation * next
#define SDLCALL
Definition: SDL_internal.h:45
#define CrcUint8
int SDLTest_Crc32Calc(SDLTest_Crc32Context *crcContext, CrcUint8 *inBuf, CrcUint32 inLen, CrcUint32 *crc32)
calculate a crc32 from a data block
#define SDL_GetNumAllocations
char stack_names[10][256]
static void * SDLTest_TrackedRealloc(void *ptr, size_t size)
static SDLTest_Crc32Context s_crc32_context