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module.c
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1852 lines (1575 loc) · 59.1 KB
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/******************************************************************************
* Remote Debugging Module - Main Module Implementation
*
* This file contains the main module initialization, the RemoteUnwinder
* class implementation, and utility functions.
******************************************************************************/
#include "_remote_debugging.h"
#include "binary_io.h"
/* Forward declarations for clinic-generated code */
typedef struct {
PyObject_HEAD
BinaryWriter *writer;
uint32_t cached_total_samples; /* Preserved after finalize */
} BinaryWriterObject;
typedef struct {
PyObject_HEAD
BinaryReader *reader;
} BinaryReaderObject;
#include "clinic/module.c.h"
/* ============================================================================
* STRUCTSEQ TYPE DEFINITIONS
* ============================================================================ */
// TaskInfo structseq type
static PyStructSequence_Field TaskInfo_fields[] = {
{"task_id", "Task ID (memory address)"},
{"task_name", "Task name"},
{"coroutine_stack", "Coroutine call stack"},
{"awaited_by", "Tasks awaiting this task"},
{NULL}
};
PyStructSequence_Desc TaskInfo_desc = {
"_remote_debugging.TaskInfo",
"Information about an asyncio task",
TaskInfo_fields,
4
};
// LocationInfo structseq type
static PyStructSequence_Field LocationInfo_fields[] = {
{"lineno", "Line number"},
{"end_lineno", "End line number"},
{"col_offset", "Column offset"},
{"end_col_offset", "End column offset"},
{NULL}
};
PyStructSequence_Desc LocationInfo_desc = {
"_remote_debugging.LocationInfo",
"Source location information: (lineno, end_lineno, col_offset, end_col_offset)",
LocationInfo_fields,
4
};
// FrameInfo structseq type
static PyStructSequence_Field FrameInfo_fields[] = {
{"filename", "Source code filename"},
{"location", "LocationInfo structseq or None for synthetic frames"},
{"funcname", "Function name"},
{"opcode", "Opcode being executed (None if not gathered)"},
{NULL}
};
PyStructSequence_Desc FrameInfo_desc = {
"_remote_debugging.FrameInfo",
"Information about a frame",
FrameInfo_fields,
4
};
// CoroInfo structseq type
static PyStructSequence_Field CoroInfo_fields[] = {
{"call_stack", "Coroutine call stack"},
{"task_name", "Task name"},
{NULL}
};
PyStructSequence_Desc CoroInfo_desc = {
"_remote_debugging.CoroInfo",
"Information about a coroutine",
CoroInfo_fields,
2
};
// ThreadInfo structseq type
static PyStructSequence_Field ThreadInfo_fields[] = {
{"thread_id", "Thread ID"},
{"status", "Thread status (flags: HAS_GIL, ON_CPU, UNKNOWN or legacy enum)"},
{"frame_info", "Frame information"},
{NULL}
};
PyStructSequence_Desc ThreadInfo_desc = {
"_remote_debugging.ThreadInfo",
"Information about a thread",
ThreadInfo_fields,
3
};
// InterpreterInfo structseq type
static PyStructSequence_Field InterpreterInfo_fields[] = {
{"interpreter_id", "Interpreter ID"},
{"threads", "List of threads in this interpreter"},
{NULL}
};
PyStructSequence_Desc InterpreterInfo_desc = {
"_remote_debugging.InterpreterInfo",
"Information about an interpreter",
InterpreterInfo_fields,
2
};
// AwaitedInfo structseq type
static PyStructSequence_Field AwaitedInfo_fields[] = {
{"thread_id", "Thread ID"},
{"awaited_by", "List of tasks awaited by this thread"},
{NULL}
};
PyStructSequence_Desc AwaitedInfo_desc = {
"_remote_debugging.AwaitedInfo",
"Information about what a thread is awaiting",
AwaitedInfo_fields,
2
};
/* ============================================================================
* UTILITY FUNCTIONS
* ============================================================================ */
void
cached_code_metadata_destroy(void *ptr)
{
CachedCodeMetadata *meta = (CachedCodeMetadata *)ptr;
Py_DECREF(meta->func_name);
Py_DECREF(meta->file_name);
Py_DECREF(meta->linetable);
PyMem_RawFree(meta);
}
RemoteDebuggingState *
RemoteDebugging_GetState(PyObject *module)
{
void *state = _PyModule_GetState(module);
assert(state != NULL);
return (RemoteDebuggingState *)state;
}
RemoteDebuggingState *
RemoteDebugging_GetStateFromType(PyTypeObject *type)
{
PyObject *module = PyType_GetModule(type);
assert(module != NULL);
return RemoteDebugging_GetState(module);
}
RemoteDebuggingState *
RemoteDebugging_GetStateFromObject(PyObject *obj)
{
RemoteUnwinderObject *unwinder = (RemoteUnwinderObject *)obj;
if (unwinder->cached_state == NULL) {
unwinder->cached_state = RemoteDebugging_GetStateFromType(Py_TYPE(obj));
}
return unwinder->cached_state;
}
int
RemoteDebugging_InitState(RemoteDebuggingState *st)
{
return 0;
}
int
is_prerelease_version(uint64_t version)
{
return (version & 0xF0) != 0xF0;
}
int
validate_debug_offsets(struct _Py_DebugOffsets *debug_offsets)
{
if (memcmp(debug_offsets->cookie, _Py_Debug_Cookie, sizeof(debug_offsets->cookie)) != 0) {
// The remote is probably running a Python version predating debug offsets.
PyErr_SetString(
PyExc_RuntimeError,
"Can't determine the Python version of the remote process");
return -1;
}
// Assume debug offsets could change from one pre-release version to another,
// or one minor version to another, but are stable across patch versions.
if (is_prerelease_version(Py_Version) && Py_Version != debug_offsets->version) {
PyErr_SetString(
PyExc_RuntimeError,
"Can't attach from a pre-release Python interpreter"
" to a process running a different Python version");
return -1;
}
if (is_prerelease_version(debug_offsets->version) && Py_Version != debug_offsets->version) {
PyErr_SetString(
PyExc_RuntimeError,
"Can't attach to a pre-release Python interpreter"
" from a process running a different Python version");
return -1;
}
unsigned int remote_major = (debug_offsets->version >> 24) & 0xFF;
unsigned int remote_minor = (debug_offsets->version >> 16) & 0xFF;
if (PY_MAJOR_VERSION != remote_major || PY_MINOR_VERSION != remote_minor) {
PyErr_Format(
PyExc_RuntimeError,
"Can't attach from a Python %d.%d process to a Python %d.%d process",
PY_MAJOR_VERSION, PY_MINOR_VERSION, remote_major, remote_minor);
return -1;
}
// The debug offsets differ between free threaded and non-free threaded builds.
if (_Py_Debug_Free_Threaded && !debug_offsets->free_threaded) {
PyErr_SetString(
PyExc_RuntimeError,
"Cannot attach from a free-threaded Python process"
" to a process running a non-free-threaded version");
return -1;
}
if (!_Py_Debug_Free_Threaded && debug_offsets->free_threaded) {
PyErr_SetString(
PyExc_RuntimeError,
"Cannot attach to a free-threaded Python process"
" from a process running a non-free-threaded version");
return -1;
}
return 0;
}
/* ============================================================================
* REMOTEUNWINDER CLASS IMPLEMENTATION
* ============================================================================ */
/*[clinic input]
module _remote_debugging
class _remote_debugging.RemoteUnwinder "RemoteUnwinderObject *" "&RemoteUnwinder_Type"
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=12b4dce200381115]*/
/*[clinic input]
@permit_long_summary
@permit_long_docstring_body
_remote_debugging.RemoteUnwinder.__init__
pid: int
*
all_threads: bool = False
only_active_thread: bool = False
mode: int = 0
debug: bool = False
skip_non_matching_threads: bool = True
native: bool = False
gc: bool = False
opcodes: bool = False
cache_frames: bool = False
stats: bool = False
Initialize a new RemoteUnwinder object for debugging a remote Python process.
Args:
pid: Process ID of the target Python process to debug
all_threads: If True, initialize state for all threads in the process.
If False, only initialize for the main thread.
only_active_thread: If True, only sample the thread holding the GIL.
mode: Profiling mode: 0=WALL (wall-time), 1=CPU (cpu-time), 2=GIL (gil-time).
Cannot be used together with all_threads=True.
debug: If True, chain exceptions to explain the sequence of events that
lead to the exception.
skip_non_matching_threads: If True, skip threads that don't match the selected mode.
If False, include all threads regardless of mode.
native: If True, include artificial "<native>" frames to denote calls to
non-Python code.
gc: If True, include artificial "<GC>" frames to denote active garbage
collection.
opcodes: If True, gather bytecode opcode information for instruction-level
profiling.
cache_frames: If True, enable frame caching optimization to avoid re-reading
unchanged parent frames between samples.
stats: If True, collect statistics about cache hits, memory reads, etc.
Use get_stats() to retrieve the collected statistics.
The RemoteUnwinder provides functionality to inspect and debug a running Python
process, including examining thread states, stack frames and other runtime data.
Raises:
PermissionError: If access to the target process is denied
OSError: If unable to attach to the target process or access its memory
RuntimeError: If unable to read debug information from the target process
ValueError: If both all_threads and only_active_thread are True
[clinic start generated code]*/
static int
_remote_debugging_RemoteUnwinder___init___impl(RemoteUnwinderObject *self,
int pid, int all_threads,
int only_active_thread,
int mode, int debug,
int skip_non_matching_threads,
int native, int gc,
int opcodes, int cache_frames,
int stats)
/*[clinic end generated code: output=0031f743f4b9ad52 input=8fb61b24102dec6e]*/
{
// Validate that all_threads and only_active_thread are not both True
if (all_threads && only_active_thread) {
PyErr_SetString(PyExc_ValueError,
"all_threads and only_active_thread cannot both be True");
return -1;
}
#ifdef Py_GIL_DISABLED
if (only_active_thread) {
PyErr_SetString(PyExc_ValueError,
"only_active_thread is not supported in free-threaded builds");
return -1;
}
#endif
self->native = native;
self->gc = gc;
self->opcodes = opcodes;
self->cache_frames = cache_frames;
self->collect_stats = stats;
self->stale_invalidation_counter = 0;
self->debug = debug;
self->only_active_thread = only_active_thread;
self->mode = mode;
self->skip_non_matching_threads = skip_non_matching_threads;
self->cached_state = NULL;
self->frame_cache = NULL;
#ifdef Py_REMOTE_DEBUG_SUPPORTS_BLOCKING
self->threads_stopped = 0;
#endif
// Initialize stats to zero
memset(&self->stats, 0, sizeof(self->stats));
if (_Py_RemoteDebug_InitProcHandle(&self->handle, pid) < 0) {
set_exception_cause(self, PyExc_RuntimeError, "Failed to initialize process handle");
return -1;
}
self->runtime_start_address = _Py_RemoteDebug_GetPyRuntimeAddress(&self->handle);
if (self->runtime_start_address == 0) {
set_exception_cause(self, PyExc_RuntimeError, "Failed to get Python runtime address");
return -1;
}
if (_Py_RemoteDebug_ReadDebugOffsets(&self->handle,
&self->runtime_start_address,
&self->debug_offsets) < 0)
{
set_exception_cause(self, PyExc_RuntimeError, "Failed to read debug offsets");
return -1;
}
// Validate that the debug offsets are valid
if (validate_debug_offsets(&self->debug_offsets) == -1) {
set_exception_cause(self, PyExc_RuntimeError, "Invalid debug offsets found");
return -1;
}
// Try to read async debug offsets, but don't fail if they're not available
self->async_debug_offsets_available = 1;
if (read_async_debug(self) < 0) {
PyErr_Clear();
memset(&self->async_debug_offsets, 0, sizeof(self->async_debug_offsets));
self->async_debug_offsets_available = 0;
}
if (populate_initial_state_data(all_threads, self, self->runtime_start_address,
&self->interpreter_addr ,&self->tstate_addr) < 0)
{
set_exception_cause(self, PyExc_RuntimeError, "Failed to populate initial state data");
return -1;
}
self->code_object_cache = _Py_hashtable_new_full(
_Py_hashtable_hash_ptr,
_Py_hashtable_compare_direct,
NULL, // keys are stable pointers, don't destroy
cached_code_metadata_destroy,
NULL
);
if (self->code_object_cache == NULL) {
PyErr_NoMemory();
set_exception_cause(self, PyExc_MemoryError, "Failed to create code object cache");
return -1;
}
#ifdef Py_GIL_DISABLED
// Initialize TLBC cache
self->tlbc_generation = 0;
self->tlbc_cache = _Py_hashtable_new_full(
_Py_hashtable_hash_ptr,
_Py_hashtable_compare_direct,
NULL, // keys are stable pointers, don't destroy
tlbc_cache_entry_destroy,
NULL
);
if (self->tlbc_cache == NULL) {
_Py_hashtable_destroy(self->code_object_cache);
PyErr_NoMemory();
set_exception_cause(self, PyExc_MemoryError, "Failed to create TLBC cache");
return -1;
}
#endif
#if defined(__APPLE__)
self->thread_id_offset = 0;
#endif
#ifdef MS_WINDOWS
self->win_process_buffer = NULL;
self->win_process_buffer_size = 0;
#endif
#ifdef __linux__
self->thread_tids = NULL;
self->thread_tids_capacity = 0;
#endif
if (cache_frames && frame_cache_init(self) < 0) {
return -1;
}
// Clear stale last_profiled_frame values from previous profilers
// This prevents us from stopping frame walking early due to stale values
if (cache_frames) {
clear_last_profiled_frames(self);
}
return 0;
}
/*[clinic input]
@permit_long_docstring_body
@critical_section
_remote_debugging.RemoteUnwinder.get_stack_trace
Returns stack traces for all interpreters and threads in process.
Each element in the returned list is a tuple of (interpreter_id, thread_list), where:
- interpreter_id is the interpreter identifier
- thread_list is a list of tuples (thread_id, frame_list) for threads in that interpreter
- thread_id is the OS thread identifier
- frame_list is a list of tuples (function_name, filename, line_number) representing
the Python stack frames for that thread, ordered from most recent to oldest
The threads returned depend on the initialization parameters:
- If only_active_thread was True: returns only the thread holding the GIL across all interpreters
- If all_threads was True: returns all threads across all interpreters
- Otherwise: returns only the main thread of each interpreter
Example:
[
(0, [ # Main interpreter
(1234, [
('process_data', 'worker.py', 127),
('run_worker', 'worker.py', 45),
('main', 'app.py', 23)
]),
(1235, [
('handle_request', 'server.py', 89),
('serve_forever', 'server.py', 52)
])
]),
(1, [ # Sub-interpreter
(1236, [
('sub_worker', 'sub.py', 15)
])
])
]
Raises:
RuntimeError: If there is an error copying memory from the target process
OSError: If there is an error accessing the target process
PermissionError: If access to the target process is denied
UnicodeDecodeError: If there is an error decoding strings from the target process
[clinic start generated code]*/
static PyObject *
_remote_debugging_RemoteUnwinder_get_stack_trace_impl(RemoteUnwinderObject *self)
/*[clinic end generated code: output=666192b90c69d567 input=bcff01c73cccc1c0]*/
{
STATS_INC(self, total_samples);
PyObject* result = PyList_New(0);
if (!result) {
set_exception_cause(self, PyExc_MemoryError, "Failed to create stack trace result list");
return NULL;
}
// Iterate over all interpreters
uintptr_t current_interpreter = self->interpreter_addr;
while (current_interpreter != 0) {
// Read interpreter state to get the interpreter ID
char interp_state_buffer[INTERP_STATE_BUFFER_SIZE];
if (_Py_RemoteDebug_PagedReadRemoteMemory(
&self->handle,
current_interpreter,
INTERP_STATE_BUFFER_SIZE,
interp_state_buffer) < 0) {
set_exception_cause(self, PyExc_RuntimeError, "Failed to read interpreter state buffer");
Py_CLEAR(result);
goto exit;
}
uintptr_t gc_frame = 0;
if (self->gc) {
gc_frame = GET_MEMBER(uintptr_t, interp_state_buffer,
self->debug_offsets.interpreter_state.gc
+ self->debug_offsets.gc.frame);
}
int64_t interpreter_id = GET_MEMBER(int64_t, interp_state_buffer,
self->debug_offsets.interpreter_state.id);
// Get code object generation from buffer
uint64_t code_object_generation = GET_MEMBER(uint64_t, interp_state_buffer,
self->debug_offsets.interpreter_state.code_object_generation);
if (code_object_generation != self->code_object_generation) {
self->code_object_generation = code_object_generation;
_Py_hashtable_clear(self->code_object_cache);
}
#ifdef Py_GIL_DISABLED
// Check TLBC generation and invalidate cache if needed
uint32_t current_tlbc_generation = GET_MEMBER(uint32_t, interp_state_buffer,
self->debug_offsets.interpreter_state.tlbc_generation);
if (current_tlbc_generation != self->tlbc_generation) {
self->tlbc_generation = current_tlbc_generation;
_Py_hashtable_clear(self->tlbc_cache);
}
#endif
// Create a list to hold threads for this interpreter
PyObject *interpreter_threads = PyList_New(0);
if (!interpreter_threads) {
set_exception_cause(self, PyExc_MemoryError, "Failed to create interpreter threads list");
Py_CLEAR(result);
goto exit;
}
// Get the GIL holder for this interpreter (needed for GIL_WAIT logic)
uintptr_t gil_holder_tstate = 0;
int gil_locked = GET_MEMBER(int, interp_state_buffer,
self->debug_offsets.interpreter_state.gil_runtime_state_locked);
if (gil_locked) {
gil_holder_tstate = (uintptr_t)GET_MEMBER(PyThreadState*, interp_state_buffer,
self->debug_offsets.interpreter_state.gil_runtime_state_holder);
}
uintptr_t current_tstate;
if (self->only_active_thread) {
// Find the GIL holder for THIS interpreter
if (!gil_locked) {
// This interpreter's GIL is not locked, skip it
Py_DECREF(interpreter_threads);
goto next_interpreter;
}
current_tstate = gil_holder_tstate;
} else if (self->tstate_addr == 0) {
// Get all threads for this interpreter
current_tstate = GET_MEMBER(uintptr_t, interp_state_buffer,
self->debug_offsets.interpreter_state.threads_head);
} else {
// Target specific thread (only process first interpreter)
current_tstate = self->tstate_addr;
}
while (current_tstate != 0) {
uintptr_t prev_tstate = current_tstate;
PyObject* frame_info = unwind_stack_for_thread(self, ¤t_tstate,
gil_holder_tstate,
gc_frame);
if (!frame_info) {
// Check if this was an intentional skip due to mode-based filtering
if ((self->mode == PROFILING_MODE_CPU || self->mode == PROFILING_MODE_GIL ||
self->mode == PROFILING_MODE_EXCEPTION) && !PyErr_Occurred()) {
// Detect cycle: if current_tstate didn't advance, we have corrupted data
if (current_tstate == prev_tstate) {
Py_DECREF(interpreter_threads);
set_exception_cause(self, PyExc_RuntimeError,
"Thread list cycle detected (corrupted remote memory)");
Py_CLEAR(result);
goto exit;
}
// Thread was skipped due to mode filtering, continue to next thread
continue;
}
// This was an actual error
Py_DECREF(interpreter_threads);
set_exception_cause(self, PyExc_RuntimeError, "Failed to unwind stack for thread");
Py_CLEAR(result);
goto exit;
}
if (PyList_Append(interpreter_threads, frame_info) == -1) {
Py_DECREF(frame_info);
Py_DECREF(interpreter_threads);
set_exception_cause(self, PyExc_RuntimeError, "Failed to append thread frame info");
Py_CLEAR(result);
goto exit;
}
Py_DECREF(frame_info);
// If targeting specific thread or only active thread, process just one
if (self->tstate_addr || self->only_active_thread) {
break;
}
}
// Create the InterpreterInfo StructSequence
RemoteDebuggingState *state = RemoteDebugging_GetStateFromObject((PyObject*)self);
PyObject *interpreter_info = PyStructSequence_New(state->InterpreterInfo_Type);
if (!interpreter_info) {
Py_DECREF(interpreter_threads);
set_exception_cause(self, PyExc_MemoryError, "Failed to create InterpreterInfo");
Py_CLEAR(result);
goto exit;
}
PyObject *interp_id = PyLong_FromLongLong(interpreter_id);
if (!interp_id) {
Py_DECREF(interpreter_threads);
Py_DECREF(interpreter_info);
set_exception_cause(self, PyExc_MemoryError, "Failed to create interpreter ID");
Py_CLEAR(result);
goto exit;
}
PyStructSequence_SetItem(interpreter_info, 0, interp_id); // steals reference
PyStructSequence_SetItem(interpreter_info, 1, interpreter_threads); // steals reference
// Add this interpreter to the result list
if (PyList_Append(result, interpreter_info) == -1) {
Py_DECREF(interpreter_info);
set_exception_cause(self, PyExc_RuntimeError, "Failed to append interpreter info");
Py_CLEAR(result);
goto exit;
}
Py_DECREF(interpreter_info);
next_interpreter:
// Get the next interpreter address
current_interpreter = GET_MEMBER(uintptr_t, interp_state_buffer,
self->debug_offsets.interpreter_state.next);
// If we're targeting a specific thread, stop after first interpreter
if (self->tstate_addr != 0) {
break;
}
}
exit:
// Invalidate cache entries for threads not seen in this sample.
// Only do this every 1024 iterations to avoid performance overhead.
if (self->cache_frames && result) {
if (++self->stale_invalidation_counter >= 1024) {
self->stale_invalidation_counter = 0;
frame_cache_invalidate_stale(self, result);
}
}
_Py_RemoteDebug_ClearCache(&self->handle);
return result;
}
/*[clinic input]
@permit_long_summary
@permit_long_docstring_body
@critical_section
_remote_debugging.RemoteUnwinder.get_all_awaited_by
Get all tasks and their awaited_by relationships from the remote process.
This provides a tree structure showing which tasks are waiting for other tasks.
For each task, returns:
1. The call stack frames leading to where the task is currently executing
2. The name of the task
3. A list of tasks that this task is waiting for, with their own frames/names/etc
Returns a list of [frames, task_name, subtasks] where:
- frames: List of (func_name, filename, lineno) showing the call stack
- task_name: String identifier for the task
- subtasks: List of tasks being awaited by this task, in same format
Raises:
RuntimeError: If AsyncioDebug section is not available in the remote process
MemoryError: If memory allocation fails
OSError: If reading from the remote process fails
Example output:
[
# Task c2_root waiting for two subtasks
[
# Call stack of c2_root
[("c5", "script.py", 10), ("c4", "script.py", 14)],
"c2_root",
[
# First subtask (sub_main_2) and what it's waiting for
[
[("c1", "script.py", 23)],
"sub_main_2",
[...]
],
# Second subtask and its waiters
[...]
]
]
]
[clinic start generated code]*/
static PyObject *
_remote_debugging_RemoteUnwinder_get_all_awaited_by_impl(RemoteUnwinderObject *self)
/*[clinic end generated code: output=6a49cd345e8aec53 input=307f754cbe38250c]*/
{
if (ensure_async_debug_offsets(self) < 0) {
return NULL;
}
PyObject *result = PyList_New(0);
if (result == NULL) {
set_exception_cause(self, PyExc_MemoryError, "Failed to create awaited_by result list");
goto result_err;
}
// Process all threads
if (iterate_threads(self, process_thread_for_awaited_by, result) < 0) {
goto result_err;
}
uintptr_t head_addr = self->interpreter_addr
+ (uintptr_t)self->async_debug_offsets.asyncio_interpreter_state.asyncio_tasks_head;
// On top of a per-thread task lists used by default by asyncio to avoid
// contention, there is also a fallback per-interpreter list of tasks;
// any tasks still pending when a thread is destroyed will be moved to the
// per-interpreter task list. It's unlikely we'll find anything here, but
// interesting for debugging.
if (append_awaited_by(self, 0, head_addr, result))
{
set_exception_cause(self, PyExc_RuntimeError, "Failed to append interpreter awaited_by in get_all_awaited_by");
goto result_err;
}
_Py_RemoteDebug_ClearCache(&self->handle);
return result;
result_err:
_Py_RemoteDebug_ClearCache(&self->handle);
Py_XDECREF(result);
return NULL;
}
/*[clinic input]
@permit_long_summary
@permit_long_docstring_body
@critical_section
_remote_debugging.RemoteUnwinder.get_async_stack_trace
Get the currently running async tasks and their dependency graphs from the remote process.
This returns information about running tasks and all tasks that are waiting for them,
forming a complete dependency graph for each thread's active task.
For each thread with a running task, returns the running task plus all tasks that
transitively depend on it (tasks waiting for the running task, tasks waiting for
those tasks, etc.).
Returns a list of per-thread results, where each thread result contains:
- Thread ID
- List of task information for the running task and all its waiters
Each task info contains:
- Task ID (memory address)
- Task name
- Call stack frames: List of (func_name, filename, lineno)
- List of tasks waiting for this task (recursive structure)
Raises:
RuntimeError: If AsyncioDebug section is not available in the target process
MemoryError: If memory allocation fails
OSError: If reading from the remote process fails
Example output (similar structure to get_all_awaited_by but only for running tasks):
[
# Thread 140234 results
(140234, [
# Running task and its complete waiter dependency graph
(4345585712, 'main_task',
[("run_server", "server.py", 127), ("main", "app.py", 23)],
[
# Tasks waiting for main_task
(4345585800, 'worker_1', [...], [...]),
(4345585900, 'worker_2', [...], [...])
])
])
]
[clinic start generated code]*/
static PyObject *
_remote_debugging_RemoteUnwinder_get_async_stack_trace_impl(RemoteUnwinderObject *self)
/*[clinic end generated code: output=6433d52b55e87bbe input=6129b7d509a887c9]*/
{
if (ensure_async_debug_offsets(self) < 0) {
return NULL;
}
PyObject *result = PyList_New(0);
if (result == NULL) {
set_exception_cause(self, PyExc_MemoryError, "Failed to create result list in get_async_stack_trace");
return NULL;
}
// Process all threads
if (iterate_threads(self, process_thread_for_async_stack_trace, result) < 0) {
goto result_err;
}
_Py_RemoteDebug_ClearCache(&self->handle);
return result;
result_err:
_Py_RemoteDebug_ClearCache(&self->handle);
Py_XDECREF(result);
return NULL;
}
/*[clinic input]
@permit_long_docstring_body
@critical_section
_remote_debugging.RemoteUnwinder.get_stats
Get collected statistics about profiling performance.
Returns a dictionary containing statistics about cache performance,
memory reads, and other profiling metrics. Only available if the
RemoteUnwinder was created with stats=True.
Returns:
dict: A dictionary containing:
- total_samples: Total number of get_stack_trace calls
- frame_cache_hits: Full cache hits (entire stack unchanged)
- frame_cache_misses: Cache misses requiring full walk
- frame_cache_partial_hits: Partial hits (stopped at cached frame)
- frames_read_from_cache: Total frames retrieved from cache
- frames_read_from_memory: Total frames read from remote memory
- memory_reads: Total remote memory read operations
- memory_bytes_read: Total bytes read from remote memory
- code_object_cache_hits: Code object cache hits
- code_object_cache_misses: Code object cache misses
- stale_cache_invalidations: Times stale cache entries were cleared
- frame_cache_hit_rate: Percentage of samples that hit the cache
- code_object_cache_hit_rate: Percentage of code object lookups that hit cache
Raises:
RuntimeError: If stats collection was not enabled (stats=False)
[clinic start generated code]*/
static PyObject *
_remote_debugging_RemoteUnwinder_get_stats_impl(RemoteUnwinderObject *self)
/*[clinic end generated code: output=21e36477122be2a0 input=75fef4134c12a8c9]*/
{
if (!self->collect_stats) {
PyErr_SetString(PyExc_RuntimeError,
"Statistics collection was not enabled. "
"Create RemoteUnwinder with stats=True to collect statistics.");
return NULL;
}
PyObject *result = PyDict_New();
if (!result) {
return NULL;
}
#define ADD_STAT(name) do { \
PyObject *val = PyLong_FromUnsignedLongLong(self->stats.name); \
if (!val || PyDict_SetItemString(result, #name, val) < 0) { \
Py_XDECREF(val); \
Py_DECREF(result); \
return NULL; \
} \
Py_DECREF(val); \
} while(0)
ADD_STAT(total_samples);
ADD_STAT(frame_cache_hits);
ADD_STAT(frame_cache_misses);
ADD_STAT(frame_cache_partial_hits);
ADD_STAT(frames_read_from_cache);
ADD_STAT(frames_read_from_memory);
ADD_STAT(memory_reads);
ADD_STAT(memory_bytes_read);
ADD_STAT(code_object_cache_hits);
ADD_STAT(code_object_cache_misses);
ADD_STAT(stale_cache_invalidations);
#undef ADD_STAT
// Calculate and add derived statistics
// Hit rate is calculated as (hits + partial_hits) / total_cache_lookups
double frame_cache_hit_rate = 0.0;
uint64_t total_cache_lookups = self->stats.frame_cache_hits + self->stats.frame_cache_partial_hits + self->stats.frame_cache_misses;
if (total_cache_lookups > 0) {
frame_cache_hit_rate = 100.0 * (double)(self->stats.frame_cache_hits + self->stats.frame_cache_partial_hits)
/ (double)total_cache_lookups;
}
PyObject *hit_rate = PyFloat_FromDouble(frame_cache_hit_rate);
if (!hit_rate || PyDict_SetItemString(result, "frame_cache_hit_rate", hit_rate) < 0) {
Py_XDECREF(hit_rate);
Py_DECREF(result);
return NULL;
}
Py_DECREF(hit_rate);
double code_object_hit_rate = 0.0;
uint64_t total_code_lookups = self->stats.code_object_cache_hits + self->stats.code_object_cache_misses;
if (total_code_lookups > 0) {
code_object_hit_rate = 100.0 * (double)self->stats.code_object_cache_hits / (double)total_code_lookups;
}
PyObject *code_hit_rate = PyFloat_FromDouble(code_object_hit_rate);
if (!code_hit_rate || PyDict_SetItemString(result, "code_object_cache_hit_rate", code_hit_rate) < 0) {
Py_XDECREF(code_hit_rate);
Py_DECREF(result);
return NULL;
}
Py_DECREF(code_hit_rate);
return result;
}
/*[clinic input]
@permit_long_docstring_body
@critical_section
_remote_debugging.RemoteUnwinder.pause_threads
Pause all threads in the target process.
This stops all threads in the target process to allow for consistent
memory reads during sampling. Must be paired with a call to resume_threads().
Returns True if threads were successfully paused, False if they were already paused.
Raises:
RuntimeError: If there is an error stopping the threads
[clinic start generated code]*/
static PyObject *
_remote_debugging_RemoteUnwinder_pause_threads_impl(RemoteUnwinderObject *self)
/*[clinic end generated code: output=aaf2bdc0a725750c input=d8a266f19a81c67e]*/
{
#ifdef Py_REMOTE_DEBUG_SUPPORTS_BLOCKING
if (self->threads_stopped) {
Py_RETURN_FALSE;
}
_Py_RemoteDebug_InitThreadsState(self, &self->threads_state);
if (_Py_RemoteDebug_StopAllThreads(self, &self->threads_state) < 0) {
return NULL;
}
self->threads_stopped = 1;
Py_RETURN_TRUE;
#else
PyErr_SetString(PyExc_NotImplementedError,
"pause_threads is not supported on this platform");
return NULL;
#endif
}
/*[clinic input]
@permit_long_docstring_body
@critical_section
_remote_debugging.RemoteUnwinder.resume_threads
Resume all threads in the target process.
This resumes threads that were previously paused with pause_threads().
Returns True if threads were successfully resumed, False if they were not paused.
[clinic start generated code]*/
static PyObject *