bpo-40609: Rewrite how _tracemalloc handles domains (GH-20059)

Rewrite how the _tracemalloc module stores traces of other domains.
Rather than storing the domain inside the key, it now uses a new hash
table with the domain as the key, and the data is a per-domain traces
hash table.

* Add tracemalloc_domain hash table.
* Remove _Py_tracemalloc_config.use_domain.
* Remove pointer_t and related functions.
This commit is contained in:
Victor Stinner 2020-05-13 01:36:47 +02:00 committed by GitHub
parent 3d54211e6e
commit 9e2ca17420
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 179 additions and 165 deletions

View File

@ -88,17 +88,12 @@ struct _PyTraceMalloc_Config {
/* limit of the number of frames in a traceback, 1 by default.
Variable protected by the GIL. */
int max_nframe;
/* use domain in trace key?
Variable protected by the GIL. */
int use_domain;
};
#define _PyTraceMalloc_Config_INIT \
{.initialized = TRACEMALLOC_NOT_INITIALIZED, \
.tracing = 0, \
.max_nframe = 1, \
.use_domain = 0}
.max_nframe = 1}
PyAPI_DATA(struct _PyTraceMalloc_Config) _Py_tracemalloc_config;

View File

@ -47,16 +47,6 @@ static PyThread_type_lock tables_lock;
#define DEFAULT_DOMAIN 0
/* Pack the frame_t structure to reduce the memory footprint. */
typedef struct
#ifdef __GNUC__
__attribute__((packed))
#endif
{
uintptr_t ptr;
unsigned int domain;
} pointer_t;
/* Pack the frame_t structure to reduce the memory footprint on 64-bit
architectures: 12 bytes instead of 16. */
typedef struct
@ -133,6 +123,10 @@ static _Py_hashtable_t *tracemalloc_tracebacks = NULL;
Protected by TABLES_LOCK(). */
static _Py_hashtable_t *tracemalloc_traces = NULL;
/* domain (unsigned int) => traces (_Py_hashtable_t).
Protected by TABLES_LOCK(). */
static _Py_hashtable_t *tracemalloc_domains = NULL;
#ifdef TRACE_DEBUG
static void
@ -235,32 +229,11 @@ hashtable_compare_unicode(_Py_hashtable_t *ht, const void *pkey,
static Py_uhash_t
hashtable_hash_pointer_t(_Py_hashtable_t *ht, const void *pkey)
hashtable_hash_uint(_Py_hashtable_t *ht, const void *pkey)
{
pointer_t ptr;
Py_uhash_t hash;
_Py_HASHTABLE_READ_KEY(ht, pkey, ptr);
hash = (Py_uhash_t)_Py_HashPointer((void*)ptr.ptr);
hash ^= ptr.domain;
return hash;
}
static int
hashtable_compare_pointer_t(_Py_hashtable_t *ht, const void *pkey,
const _Py_hashtable_entry_t *entry)
{
pointer_t ptr1, ptr2;
_Py_HASHTABLE_READ_KEY(ht, pkey, ptr1);
_Py_HASHTABLE_ENTRY_READ_KEY(ht, entry, ptr2);
/* compare pointer before domain, because pointer is more likely to be
different */
return (ptr1.ptr == ptr2.ptr && ptr1.domain == ptr2.domain);
unsigned int key;
_Py_HASHTABLE_READ_KEY(ht, pkey, key);
return (Py_uhash_t)key;
}
@ -501,77 +474,74 @@ traceback_new(void)
}
static int
tracemalloc_use_domain_cb(_Py_hashtable_t *old_traces,
_Py_hashtable_entry_t *entry, void *user_data)
static _Py_hashtable_t*
tracemalloc_create_traces_table(void)
{
uintptr_t ptr;
pointer_t key;
_Py_hashtable_t *new_traces = (_Py_hashtable_t *)user_data;
const void *pdata = _Py_HASHTABLE_ENTRY_PDATA(old_traces, entry);
_Py_HASHTABLE_ENTRY_READ_KEY(old_traces, entry, ptr);
key.ptr = ptr;
key.domain = DEFAULT_DOMAIN;
return _Py_hashtable_set(new_traces,
sizeof(key), &key,
old_traces->data_size, pdata);
return hashtable_new(sizeof(uintptr_t),
sizeof(trace_t),
_Py_hashtable_hash_ptr,
_Py_hashtable_compare_direct);
}
/* Convert tracemalloc_traces from compact key (uintptr_t) to pointer_t key.
* Return 0 on success, -1 on error. */
static int
tracemalloc_use_domain(void)
static _Py_hashtable_t*
tracemalloc_create_domains_table(void)
{
_Py_hashtable_t *new_traces = NULL;
return hashtable_new(sizeof(unsigned int),
sizeof(_Py_hashtable_t *),
hashtable_hash_uint,
_Py_hashtable_compare_direct);
}
assert(!_Py_tracemalloc_config.use_domain);
new_traces = hashtable_new(sizeof(pointer_t),
sizeof(trace_t),
hashtable_hash_pointer_t,
hashtable_compare_pointer_t);
if (new_traces == NULL) {
return -1;
}
if (_Py_hashtable_foreach(tracemalloc_traces, tracemalloc_use_domain_cb,
new_traces) < 0)
{
_Py_hashtable_destroy(new_traces);
return -1;
}
_Py_hashtable_destroy(tracemalloc_traces);
tracemalloc_traces = new_traces;
_Py_tracemalloc_config.use_domain = 1;
static int
tracemalloc_destroy_domains_cb(_Py_hashtable_t *domains,
_Py_hashtable_entry_t *entry,
void *user_data)
{
_Py_hashtable_t *traces;
_Py_HASHTABLE_ENTRY_READ_DATA(domains, entry, traces);
_Py_hashtable_destroy(traces);
return 0;
}
static void
tracemalloc_destroy_domains(_Py_hashtable_t *domains)
{
_Py_hashtable_foreach(domains, tracemalloc_destroy_domains_cb, NULL);
_Py_hashtable_destroy(domains);
}
static _Py_hashtable_t*
tracemalloc_get_traces_table(unsigned int domain)
{
if (domain == DEFAULT_DOMAIN) {
return tracemalloc_traces;
}
else {
_Py_hashtable_t *traces = NULL;
(void)_Py_HASHTABLE_GET(tracemalloc_domains, domain, traces);
return traces;
}
}
static void
tracemalloc_remove_trace(unsigned int domain, uintptr_t ptr)
{
trace_t trace;
int removed;
assert(_Py_tracemalloc_config.tracing);
if (_Py_tracemalloc_config.use_domain) {
pointer_t key = {ptr, domain};
removed = _Py_HASHTABLE_POP(tracemalloc_traces, key, trace);
}
else {
removed = _Py_HASHTABLE_POP(tracemalloc_traces, ptr, trace);
}
if (!removed) {
_Py_hashtable_t *traces = tracemalloc_get_traces_table(domain);
if (!traces) {
return;
}
trace_t trace;
if (!_Py_HASHTABLE_POP(traces, ptr, trace)) {
return;
}
assert(tracemalloc_traced_memory >= trace.size);
tracemalloc_traced_memory -= trace.size;
}
@ -584,54 +554,43 @@ static int
tracemalloc_add_trace(unsigned int domain, uintptr_t ptr,
size_t size)
{
pointer_t key = {ptr, domain};
traceback_t *traceback;
trace_t trace;
_Py_hashtable_entry_t* entry;
int res;
assert(_Py_tracemalloc_config.tracing);
traceback = traceback_new();
traceback_t *traceback = traceback_new();
if (traceback == NULL) {
return -1;
}
if (!_Py_tracemalloc_config.use_domain && domain != DEFAULT_DOMAIN) {
/* first trace using a non-zero domain whereas traces use compact
(uintptr_t) keys: switch to pointer_t keys. */
if (tracemalloc_use_domain() < 0) {
_Py_hashtable_t *traces = tracemalloc_get_traces_table(domain);
if (traces == NULL) {
traces = tracemalloc_create_traces_table();
if (traces == NULL) {
return -1;
}
if (_Py_HASHTABLE_SET(tracemalloc_domains, domain, traces) < 0) {
_Py_hashtable_destroy(traces);
return -1;
}
}
if (_Py_tracemalloc_config.use_domain) {
entry = _Py_HASHTABLE_GET_ENTRY(tracemalloc_traces, key);
}
else {
entry = _Py_HASHTABLE_GET_ENTRY(tracemalloc_traces, ptr);
}
_Py_hashtable_entry_t* entry = _Py_HASHTABLE_GET_ENTRY(traces, ptr);
trace_t trace;
if (entry != NULL) {
/* the memory block is already tracked */
_Py_HASHTABLE_ENTRY_READ_DATA(tracemalloc_traces, entry, trace);
_Py_HASHTABLE_ENTRY_READ_DATA(traces, entry, trace);
assert(tracemalloc_traced_memory >= trace.size);
tracemalloc_traced_memory -= trace.size;
trace.size = size;
trace.traceback = traceback;
_Py_HASHTABLE_ENTRY_WRITE_DATA(tracemalloc_traces, entry, trace);
_Py_HASHTABLE_ENTRY_WRITE_DATA(traces, entry, trace);
}
else {
trace.size = size;
trace.traceback = traceback;
if (_Py_tracemalloc_config.use_domain) {
res = _Py_HASHTABLE_SET(tracemalloc_traces, key, trace);
}
else {
res = _Py_HASHTABLE_SET(tracemalloc_traces, ptr, trace);
}
int res = _Py_HASHTABLE_SET(traces, ptr, trace);
if (res != 0) {
return res;
}
@ -639,8 +598,9 @@ tracemalloc_add_trace(unsigned int domain, uintptr_t ptr,
assert(tracemalloc_traced_memory <= SIZE_MAX - size);
tracemalloc_traced_memory += size;
if (tracemalloc_traced_memory > tracemalloc_peak_traced_memory)
if (tracemalloc_traced_memory > tracemalloc_peak_traced_memory) {
tracemalloc_peak_traced_memory = tracemalloc_traced_memory;
}
return 0;
}
@ -691,7 +651,7 @@ tracemalloc_realloc(void *ctx, void *ptr, size_t new_size)
TABLES_LOCK();
/* tracemalloc_add_trace() updates the trace if there is already
a trace at address (domain, ptr2) */
a trace at address ptr2 */
if (ptr2 != ptr) {
REMOVE_TRACE(ptr);
}
@ -928,6 +888,7 @@ tracemalloc_clear_traces(void)
TABLES_LOCK();
_Py_hashtable_clear(tracemalloc_traces);
_Py_hashtable_clear(tracemalloc_domains);
tracemalloc_traced_memory = 0;
tracemalloc_peak_traced_memory = 0;
TABLES_UNLOCK();
@ -983,21 +944,11 @@ tracemalloc_init(void)
hashtable_hash_traceback,
hashtable_compare_traceback);
if (_Py_tracemalloc_config.use_domain) {
tracemalloc_traces = hashtable_new(sizeof(pointer_t),
sizeof(trace_t),
hashtable_hash_pointer_t,
hashtable_compare_pointer_t);
}
else {
tracemalloc_traces = hashtable_new(sizeof(uintptr_t),
sizeof(trace_t),
_Py_hashtable_hash_ptr,
_Py_hashtable_compare_direct);
}
tracemalloc_traces = tracemalloc_create_traces_table();
tracemalloc_domains = tracemalloc_create_domains_table();
if (tracemalloc_filenames == NULL || tracemalloc_tracebacks == NULL
|| tracemalloc_traces == NULL) {
|| tracemalloc_traces == NULL || tracemalloc_domains == NULL) {
PyErr_NoMemory();
return -1;
}
@ -1029,9 +980,10 @@ tracemalloc_deinit(void)
tracemalloc_stop();
/* destroy hash tables */
tracemalloc_destroy_domains(tracemalloc_domains);
_Py_hashtable_destroy(tracemalloc_traces);
_Py_hashtable_destroy(tracemalloc_tracebacks);
_Py_hashtable_destroy(tracemalloc_filenames);
_Py_hashtable_destroy(tracemalloc_traces);
#if defined(TRACE_RAW_MALLOC)
if (tables_lock != NULL) {
@ -1279,31 +1231,45 @@ trace_to_pyobject(unsigned int domain, trace_t *trace,
typedef struct {
_Py_hashtable_t *traces;
_Py_hashtable_t *domains;
_Py_hashtable_t *tracebacks;
PyObject *list;
unsigned int domain;
} get_traces_t;
static int
tracemalloc_get_traces_copy_domain(_Py_hashtable_t *domains,
_Py_hashtable_entry_t *entry,
void *user_data)
{
get_traces_t *get_traces = user_data;
unsigned int domain;
_Py_HASHTABLE_ENTRY_READ_KEY(domains, entry, domain);
_Py_hashtable_t *traces;
_Py_HASHTABLE_ENTRY_READ_DATA(domains, entry, traces);
_Py_hashtable_t *traces2 = _Py_hashtable_copy(traces);
if (_Py_HASHTABLE_SET(get_traces->domains, domain, traces2) < 0) {
_Py_hashtable_destroy(traces2);
return -1;
}
return 0;
}
static int
tracemalloc_get_traces_fill(_Py_hashtable_t *traces, _Py_hashtable_entry_t *entry,
void *user_data)
{
get_traces_t *get_traces = user_data;
unsigned int domain;
trace_t trace;
PyObject *tracemalloc_obj;
int res;
if (_Py_tracemalloc_config.use_domain) {
pointer_t key;
_Py_HASHTABLE_ENTRY_READ_KEY(traces, entry, key);
domain = key.domain;
}
else {
domain = DEFAULT_DOMAIN;
}
_Py_HASHTABLE_ENTRY_READ_DATA(traces, entry, trace);
tracemalloc_obj = trace_to_pyobject(domain, &trace, get_traces->tracebacks);
tracemalloc_obj = trace_to_pyobject(get_traces->domain, &trace, get_traces->tracebacks);
if (tracemalloc_obj == NULL)
return 1;
@ -1316,6 +1282,25 @@ tracemalloc_get_traces_fill(_Py_hashtable_t *traces, _Py_hashtable_entry_t *entr
}
static int
tracemalloc_get_traces_domain(_Py_hashtable_t *domains,
_Py_hashtable_entry_t *entry,
void *user_data)
{
get_traces_t *get_traces = user_data;
unsigned int domain;
_Py_HASHTABLE_ENTRY_READ_KEY(domains, entry, domain);
_Py_hashtable_t *traces;
_Py_HASHTABLE_ENTRY_READ_DATA(domains, entry, traces);
get_traces->domain = domain;
return _Py_hashtable_foreach(traces,
tracemalloc_get_traces_fill,
get_traces);
}
static int
tracemalloc_pyobject_decref_cb(_Py_hashtable_t *tracebacks,
_Py_hashtable_entry_t *entry,
@ -1345,9 +1330,9 @@ _tracemalloc__get_traces_impl(PyObject *module)
/*[clinic end generated code: output=e9929876ced4b5cc input=6c7d2230b24255aa]*/
{
get_traces_t get_traces;
int err;
get_traces.domain = DEFAULT_DOMAIN;
get_traces.traces = NULL;
get_traces.domains = NULL;
get_traces.tracebacks = NULL;
get_traces.list = PyList_New(0);
if (get_traces.list == NULL)
@ -1363,28 +1348,51 @@ _tracemalloc__get_traces_impl(PyObject *module)
_Py_hashtable_hash_ptr,
_Py_hashtable_compare_direct);
if (get_traces.tracebacks == NULL) {
PyErr_NoMemory();
goto error;
goto no_memory;
}
get_traces.domains = tracemalloc_create_domains_table();
if (get_traces.domains == NULL) {
goto no_memory;
}
int err;
// Copy all traces so tracemalloc_get_traces_fill() doesn't have to disable
// temporarily tracemalloc which would impact other threads and so would
// miss allocations while get_traces() is called.
TABLES_LOCK();
get_traces.traces = _Py_hashtable_copy(tracemalloc_traces);
err = _Py_hashtable_foreach(tracemalloc_domains,
tracemalloc_get_traces_copy_domain,
&get_traces);
TABLES_UNLOCK();
if (get_traces.traces == NULL) {
PyErr_NoMemory();
goto error;
goto no_memory;
}
if (err) {
goto no_memory;
}
// Convert traces to a list of tuples
set_reentrant(1);
err = _Py_hashtable_foreach(get_traces.traces,
tracemalloc_get_traces_fill, &get_traces);
if (!err) {
err = _Py_hashtable_foreach(get_traces.domains,
tracemalloc_get_traces_domain, &get_traces);
}
set_reentrant(0);
if (err)
if (err) {
goto error;
}
goto finally;
no_memory:
PyErr_NoMemory();
error:
Py_CLEAR(get_traces.list);
@ -1397,6 +1405,9 @@ finally:
if (get_traces.traces != NULL) {
_Py_hashtable_destroy(get_traces.traces);
}
if (get_traces.domains != NULL) {
tracemalloc_destroy_domains(get_traces.domains);
}
return get_traces.list;
}
@ -1412,12 +1423,12 @@ tracemalloc_get_traceback(unsigned int domain, uintptr_t ptr)
return NULL;
TABLES_LOCK();
if (_Py_tracemalloc_config.use_domain) {
pointer_t key = {ptr, domain};
found = _Py_HASHTABLE_GET(tracemalloc_traces, key, trace);
_Py_hashtable_t *traces = tracemalloc_get_traces_table(domain);
if (traces) {
found = _Py_HASHTABLE_GET(traces, ptr, trace);
}
else {
found = _Py_HASHTABLE_GET(tracemalloc_traces, ptr, trace);
found = 0;
}
TABLES_UNLOCK();
@ -1564,6 +1575,19 @@ _tracemalloc_get_traceback_limit_impl(PyObject *module)
}
static int
tracemalloc_get_tracemalloc_memory_cb(_Py_hashtable_t *domains,
_Py_hashtable_entry_t *entry,
void *user_data)
{
_Py_hashtable_t *traces;
_Py_HASHTABLE_ENTRY_READ_DATA(domains, entry, traces);
size_t *size = (size_t*)user_data;
*size += _Py_hashtable_size(traces);
return 0;
}
/*[clinic input]
_tracemalloc.get_tracemalloc_memory
@ -1584,6 +1608,8 @@ _tracemalloc_get_tracemalloc_memory_impl(PyObject *module)
TABLES_LOCK();
size += _Py_hashtable_size(tracemalloc_traces);
_Py_hashtable_foreach(tracemalloc_domains,
tracemalloc_get_tracemalloc_memory_cb, &size);
TABLES_UNLOCK();
return PyLong_FromSize_t(size);
@ -1741,18 +1767,11 @@ _PyTraceMalloc_NewReference(PyObject *op)
ptr = (uintptr_t)op;
}
_Py_hashtable_entry_t* entry;
int res = -1;
TABLES_LOCK();
if (_Py_tracemalloc_config.use_domain) {
pointer_t key = {ptr, DEFAULT_DOMAIN};
entry = _Py_HASHTABLE_GET_ENTRY(tracemalloc_traces, key);
}
else {
entry = _Py_HASHTABLE_GET_ENTRY(tracemalloc_traces, ptr);
}
_Py_hashtable_entry_t* entry;
entry = _Py_HASHTABLE_GET_ENTRY(tracemalloc_traces, ptr);
if (entry != NULL) {
/* update the traceback of the memory block */
traceback_t *traceback = traceback_new();