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/*
* lighty memory profiler
* prints a backtrace for every object not free()d at exit()
*
*/
#include <lighttpd/settings.h>
#include <lighttpd/profiler.h>
#include <lighttpd/utils.h>
#include <fcntl.h>
#ifdef HAVE_EXECINFO_H
# include <execinfo.h>
#endif
#if defined(LIGHTY_OS_MACOSX)
# include <malloc/malloc.h>
#elif defined(LIGHTY_OS_LINUX)
# include <malloc.h>
#endif
#define PROFILER_HASHTABLE_SIZE 65521
#define PROFILER_STACKFRAMES 36
typedef struct profiler_block profiler_block;
struct profiler_block {
gpointer addr;
gsize size;
profiler_block *next;
void *stackframes[PROFILER_STACKFRAMES];
gint stackframes_num;
};
typedef struct profiler_stackframe profiler_stackframe;
struct profiler_stackframe {
gpointer addr;
gsize size;
guint blocks;
gchar *symbol;
profiler_stackframe *next;
profiler_stackframe *children;
};
static void profiler_free(gpointer addr);
static GStaticMutex profiler_mutex = G_STATIC_MUTEX_INIT;
static profiler_block *block_free_list = NULL;
static profiler_block **profiler_hashtable = NULL;
static gint profiler_output_fd = 0;
static gpointer profiler_heap_base = NULL;
gboolean li_profiler_enabled = FALSE;
static guint profiler_hash(gpointer addr) {
return ((uintptr_t)addr * 2654435761); /* ~ golden ratio of 2^32 */
}
static profiler_block *profiler_block_new(void) {
profiler_block *block;
if (!block_free_list) {
/* page_free_list exhausted */
block = malloc(sizeof(profiler_block));
} else {
block = block_free_list;
block_free_list = block_free_list->next;
}
block->addr = NULL;
block->size = 0;
block->next = NULL;
block->stackframes_num = 0;
return block;
}
static void profiler_block_free(profiler_block *block) {
/* push onto free list */
block->next = block_free_list;
block_free_list = block;
}
static gpointer profiler_try_malloc(gsize n_bytes) {
gsize *p;
p = malloc(n_bytes);
if (p) {
#if defined(LIGHTY_OS_MACOSX)
n_bytes = malloc_size(p);
#elif defined(LIGHTY_OS_LINUX)
n_bytes = malloc_usable_size(p);
#endif
li_profiler_hashtable_insert(p, n_bytes);
}
return p;
}
static gpointer profiler_malloc(gsize n_bytes) {
gpointer p = profiler_try_malloc(n_bytes);
LI_FORCE_ASSERT(p);
return p;
}
static gpointer profiler_try_realloc(gpointer mem, gsize n_bytes) {
gsize *p;
if (!mem)
return profiler_try_malloc(n_bytes);
if (!n_bytes) {
profiler_free(mem);
return NULL;
}
p = realloc(mem, n_bytes);
if (p) {
li_profiler_hashtable_remove(mem);
#if defined(LIGHTY_OS_MACOSX)
n_bytes = malloc_size(p);
#elif defined(LIGHTY_OS_LINUX)
n_bytes = malloc_usable_size(p);
#endif
li_profiler_hashtable_insert(p, n_bytes);
}
return p;
}
static gpointer profiler_realloc(gpointer mem, gsize n_bytes) {
gpointer p = profiler_try_realloc(mem, n_bytes);
LI_FORCE_ASSERT(p);
return p;
}
static gpointer profiler_calloc(gsize n_blocks, gsize n_bytes) {
gsize *p;
gsize size = n_blocks * n_bytes;
p = calloc(1, size);
if (p) {
#if defined(LIGHTY_OS_MACOSX)
n_bytes = malloc_size(p);
#elif defined(LIGHTY_OS_LINUX)
n_bytes = malloc_usable_size(p);
#endif
li_profiler_hashtable_insert(p, n_bytes);
}
LI_FORCE_ASSERT(p);
return p;
}
static void profiler_free(gpointer mem) {
LI_FORCE_ASSERT(mem);
li_profiler_hashtable_remove(mem);
free(mem);
}
static void profiler_write(gchar *str, gint len) {
gint res;
gint written = 0;
while (len) {
res = write(profiler_output_fd, str + written, len);
if (-1 == res) {
fputs("error writing to profiler output file\n", stderr);
fflush(stderr);
abort();
}
written += res;
len -= res;
}
}
#ifdef HAVE_EXECINFO_H
static void profiler_dump_frame(guint level, profiler_stackframe *frame, gsize minsize) {
gchar str[1024];
gint len;
gboolean swapped;
profiler_stackframe *f;
/* sort this tree level according to total allocated size. yes, bubblesort. */
do {
profiler_stackframe *f1, *f2;
swapped = FALSE;
for (f1 = frame, f2 = frame->next; f1 != NULL && f2 != NULL; f1 = f2, f2 = f2->next) {
if (f2->size > f1->size) {
profiler_stackframe tmp = *f1;
f1->addr = f2->addr;
f1->blocks = f2->blocks;
f1->size = f2->size;
f1->children = f2->children;
f1->symbol = f2->symbol;
f2->addr = tmp.addr;
f2->blocks = tmp.blocks;
f2->size = tmp.size;
f2->children = tmp.children;
f2->symbol = tmp.symbol;
swapped = TRUE;
}
}
} while (swapped);
while (frame) {
if (frame->size >= minsize) {
/* indention */
memset(str, ' ', level*4);
profiler_write(str, level*4);
len = sprintf(str,
"%"G_GSIZE_FORMAT" %s in %u blocks @ %p %s\n",
(frame->size > 1024) ? frame->size / 1024 : frame->size,
(frame->size > 1024) ? "kilobytes" : "bytes",
frame->blocks,
frame->addr, frame->symbol
);
profiler_write(str, len);
}
if (frame->children)
profiler_dump_frame(level+1, frame->children, minsize);
f = frame->next;
free(frame->symbol);
free(frame);
frame = f;
}
}
#endif
/* public functions */
void li_profiler_enable(gchar *output_path) {
GMemVTable t;
/* force allocation of mutex data; newer glib versions allocate extra data */
g_static_mutex_lock(&profiler_mutex);
g_static_mutex_unlock(&profiler_mutex);
profiler_heap_base = sbrk(0);
if (g_str_equal(output_path, "stdout")) {
profiler_output_fd = STDOUT_FILENO;
} else if (g_str_equal(output_path, "stderr")) {
profiler_output_fd = STDERR_FILENO;
} else {
profiler_output_fd = open(output_path, O_WRONLY | O_CREAT | O_TRUNC, 0600);
if (-1 == profiler_output_fd) {
fputs("error opening profiler output file\n", stderr);
fflush(stderr);
abort();
}
}
block_free_list = profiler_block_new();
profiler_hashtable = calloc(sizeof(profiler_block), PROFILER_HASHTABLE_SIZE);
t.malloc = profiler_malloc;
t.realloc = profiler_realloc;
t.free = profiler_free;
t.calloc = profiler_calloc;
t.try_malloc = profiler_try_malloc;
t.try_realloc = profiler_try_realloc;
g_mem_set_vtable(&t);
li_profiler_enabled = TRUE;
}
void li_profiler_finish(void) {
guint i;
profiler_block *block, *block_tmp;
for (i = 0; i < PROFILER_HASHTABLE_SIZE; i++) {
for (block = profiler_hashtable[i]; block != NULL;) {
block_tmp = block->next;
free(block);
block = block_tmp;
}
}
for (block = block_free_list; block != NULL;) {
block_tmp = block->next;
free(block);
block = block_tmp;
}
free(profiler_hashtable);
}
void li_profiler_dump(gint minsize) {
profiler_stackframe *tree_cur, *frame;
gchar **symbols;
gint i, j, len;
profiler_block *block;
struct stat st;
gchar str[1024];
gsize total_size = 0;
guint total_blocks = 0;
profiler_stackframe *tree = calloc(1, sizeof(profiler_stackframe));
g_static_mutex_lock(&profiler_mutex);
fstat(profiler_output_fd, &st);
lseek(profiler_output_fd, st.st_size, SEEK_SET);
len = sprintf(str, "--------------- memory profiler dump @ %ju ---------------\n", time(NULL));
profiler_write(str, len);
for (i = 0; i < PROFILER_HASHTABLE_SIZE; i++) {
for (block = profiler_hashtable[i]; block != NULL; block = block->next) {
total_size += block->size;
total_blocks++;
#ifdef HAVE_EXECINFO_H
/* resolve all symbols */
symbols = backtrace_symbols(block->stackframes, block->stackframes_num);
tree_cur = tree;
for (j = block->stackframes_num-1; j >= 0; j--) {
for (frame = tree_cur->children; frame != NULL; frame = frame->next) {
if (block->stackframes[j] == frame->addr) {
frame->blocks++;
frame->size += block->size;
break;
}
}
if (!frame) {
frame = malloc(sizeof(profiler_stackframe));
frame->addr = block->stackframes[j];
frame->blocks = 1;
frame->size = block->size;
frame->symbol = strdup(symbols[j]);
frame->children = NULL;
frame->next = tree_cur->children;
tree_cur->children = frame;
}
tree_cur = frame;
}
free(symbols);
#endif
}
}
#ifdef HAVE_EXECINFO_H
profiler_dump_frame(0, tree->children, minsize);
#endif
len = sprintf(str,
"--------------- memory profiler summary ---------------\n"
"total blocks: %u\n"
"total size: %"G_GSIZE_FORMAT" %s\n"
"heap base / break / size: %p / %p / %"G_GSIZE_FORMAT"\n",
total_blocks,
(total_size > 1024) ? total_size / 1024 : total_size,
(total_size > 1024) ? "kilobytes" : "bytes",
profiler_heap_base, sbrk(0), (guintptr)sbrk(0) - (guintptr)profiler_heap_base
);
profiler_write(str, len);
len = sprintf(str, "--------------- memory profiler dump end ---------------\n");
free(tree);
profiler_write(str, len);
g_static_mutex_unlock(&profiler_mutex);
}
void li_profiler_hashtable_insert(const gpointer addr, gsize size) {
profiler_block *block;
guint hash;
g_static_mutex_lock(&profiler_mutex);
hash = profiler_hash(addr);
block = profiler_block_new();
block->addr = addr;
block->size = size;
#ifdef HAVE_EXECINFO_H
block->stackframes_num = backtrace(block->stackframes, PROFILER_STACKFRAMES);
#endif
block->next = profiler_hashtable[hash % PROFILER_HASHTABLE_SIZE];
profiler_hashtable[hash % PROFILER_HASHTABLE_SIZE] = block;
g_static_mutex_unlock(&profiler_mutex);
}
void li_profiler_hashtable_remove(const gpointer addr) {
profiler_block *block, *block_prev;
guint hash;
g_static_mutex_lock(&profiler_mutex);
hash = profiler_hash(addr);
block = profiler_hashtable[hash % PROFILER_HASHTABLE_SIZE];
if (block->addr == addr) {
profiler_hashtable[hash % PROFILER_HASHTABLE_SIZE] = block->next;
profiler_block_free(block);
g_static_mutex_unlock(&profiler_mutex);
return;
}
block_prev = block;
for (block = block->next; block != NULL; block = block->next) {
if (block->addr == addr) {
block_prev->next = block->next;
profiler_block_free(block);
g_static_mutex_unlock(&profiler_mutex);
return;
}
block_prev = block;
}
g_static_mutex_unlock(&profiler_mutex);
}