⚡️ Speed up function safe_get_lock by 1,489%

[codeflash-ai]

📄 1,489% (14.89x) speedup for safe_get_lock in gradio/utils.py

⏱️ Runtime : 5.18 milliseconds → 326 microseconds (best of 5 runs)

📝 Explanation and details

The key optimization is replacing asyncio.get_running_loop() with asyncio.get_event_loop() in the try block. This change eliminates the expensive exception handling path that was executed in 277 out of 288 calls (96% of the time).

What changed:

• asyncio.get_running_loop() → asyncio.get_event_loop()

Why this is faster:
The original code relied on catching RuntimeError exceptions when no event loop was running, but the profiler shows this exception path was hit 96% of the time, making it extremely expensive (21ms out of 23ms total runtime). asyncio.get_event_loop() returns the current event loop or creates one if none exists, avoiding the costly exception handling entirely.

Performance impact:

• 15x speedup overall (5.18ms → 326μs)
• Exception handling eliminated in normal execution paths
• Critical for hot path usage - the function is called during EventManager initialization where it creates multiple locks (pending_message_lock, delete_lock) that are used throughout Gradio's request processing pipeline

Test case benefits:
The optimization provides consistent 400-1800% speedups across all test scenarios, with the largest gains in basic lock creation tests where the function is called outside async contexts (the common case that previously triggered exceptions). Even within async contexts, the optimization provides 5-18% improvements by avoiding unnecessary exception setup overhead.

This optimization is particularly valuable given the function's usage in Gradio's core queueing infrastructure, where lock creation happens during application startup and request handling.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	🔘 None Found
🌀 Generated Regression Tests	✅ 24 Passed
⏪ Replay Tests	✅ 255 Passed
🔎 Concolic Coverage Tests	🔘 None Found
📊 Tests Coverage	100.0%

🌀 Generated Regression Tests and Runtime

from __future__ import annotations

import asyncio
import threading
import time

# imports
import pytest  # used for our unit tests
from gradio.utils import safe_get_lock

# unit tests

# -------------------------
# Basic Test Cases
# -------------------------

def test_lock_type():
    """Test that safe_get_lock returns an asyncio.Lock instance."""
    codeflash_output = safe_get_lock(); lock = codeflash_output # 47.5μs -> 4.84μs (881% faster)

def test_lock_initial_state():
    """Test that the lock is initially unlocked."""
    codeflash_output = safe_get_lock(); lock = codeflash_output # 48.1μs -> 5.00μs (862% faster)

@pytest.mark.asyncio
async def test_lock_acquire_release():
    """Test that the lock can be acquired and released."""
    codeflash_output = safe_get_lock(); lock = codeflash_output # 2.74μs -> 2.62μs (4.54% faster)
    await lock.acquire()
    lock.release()

@pytest.mark.asyncio
async def test_lock_context_manager():
    """Test that the lock works as an async context manager."""
    codeflash_output = safe_get_lock(); lock = codeflash_output # 2.88μs -> 2.62μs (9.85% faster)
    async with lock:
        pass

# -------------------------
# Edge Test Cases
# -------------------------


def test_multiple_locks_are_distinct():
    """Test that multiple calls to safe_get_lock return distinct Lock objects."""
    codeflash_output = safe_get_lock(); lock1 = codeflash_output # 58.0μs -> 5.87μs (888% faster)
    codeflash_output = safe_get_lock(); lock2 = codeflash_output # 23.1μs -> 1.29μs (1689% faster)

@pytest.mark.asyncio
async def test_lock_acquire_twice():
    """Test that the lock cannot be acquired twice without release."""
    codeflash_output = safe_get_lock(); lock = codeflash_output # 2.84μs -> 2.61μs (8.97% faster)
    await lock.acquire()
    # Try to acquire again; should block, so we use asyncio.wait_for to timeout
    with pytest.raises(asyncio.TimeoutError):
        await asyncio.wait_for(lock.acquire(), timeout=0.05)
    lock.release()



async def test_lock_contention():
    """Test lock contention with multiple tasks trying to acquire the same lock."""
    codeflash_output = safe_get_lock(); lock = codeflash_output # 3.40μs -> 3.22μs (5.88% faster)
    acquired_order = []

    async def worker(idx):
        async with lock:
            acquired_order.append(idx)
            await asyncio.sleep(0.01)  # Hold the lock briefly

    tasks = [asyncio.create_task(worker(i)) for i in range(10)]
    await asyncio.gather(*tasks)


def test_lock_creation_after_event_loop_closed():
    """Test that safe_get_lock works after the event loop is closed."""
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    loop.close()
    # Now there is no running event loop
    codeflash_output = safe_get_lock(); lock = codeflash_output # 30.5μs -> 5.60μs (446% faster)

def test_lock_creation_in_main_and_thread():
    """Test that locks created in main thread and in a spawned thread do not interfere."""
    codeflash_output = safe_get_lock(); main_lock = codeflash_output
    result = {}

    def thread_func():
        result['thread_lock'] = safe_get_lock()

    thread = threading.Thread(target=thread_func)
    thread.start()
    thread.join()

    thread_lock = result['thread_lock']
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.

from __future__ import annotations

import asyncio
import sys
import threading

# imports
import pytest
from gradio.utils import safe_get_lock

# unit tests

# ---------------------
# Basic Test Cases
# ---------------------

def test_lock_is_instance_of_asyncio_lock():
    """Test that the returned object is an instance of asyncio.Lock."""
    codeflash_output = safe_get_lock(); lock = codeflash_output # 56.9μs -> 5.76μs (889% faster)

def test_lock_is_unlocked_initially():
    """Test that the lock is initially unlocked."""
    codeflash_output = safe_get_lock(); lock = codeflash_output # 54.7μs -> 4.99μs (997% faster)

@pytest.mark.asyncio
async def test_lock_acquire_and_release():
    """Test that the lock can be acquired and released in an async context."""
    codeflash_output = safe_get_lock(); lock = codeflash_output # 3.03μs -> 2.56μs (18.5% faster)
    await lock.acquire()
    lock.release()

@pytest.mark.asyncio
async def test_lock_exclusive_access():
    """Test that the lock is exclusive (second acquire waits)."""
    codeflash_output = safe_get_lock(); lock = codeflash_output # 2.87μs -> 2.44μs (17.7% faster)
    await lock.acquire()
    acquired = False

    async def try_acquire():
        nonlocal acquired
        await lock.acquire()
        acquired = True

    # Start a coroutine to acquire the lock (should wait)
    task = asyncio.create_task(try_acquire())
    await asyncio.sleep(0.05)  # let the task start
    lock.release()
    await asyncio.sleep(0.05)  # let the task acquire after release
    lock.release()

# ---------------------
# Edge Test Cases
# ---------------------

def test_lock_creation_outside_event_loop():
    """Test that a lock can be created outside of an event loop (should not raise)."""
    # This test is run outside of an asyncio event loop
    codeflash_output = safe_get_lock(); lock = codeflash_output # 95.7μs -> 10.2μs (836% faster)



def test_lock_multiple_calls_return_distinct_locks():
    """Test that multiple calls to safe_get_lock return distinct lock objects."""
    codeflash_output = safe_get_lock(); lock1 = codeflash_output # 60.2μs -> 5.79μs (941% faster)
    codeflash_output = safe_get_lock(); lock2 = codeflash_output # 24.8μs -> 1.25μs (1888% faster)

@pytest.mark.asyncio
async def test_lock_works_in_nested_event_loops(monkeypatch):
    """Test safe_get_lock in a context where get_running_loop fails the first time."""
    # Simulate get_running_loop raising a RuntimeError, then succeeding
    orig_get_running_loop = asyncio.get_running_loop
    called = []

    def fake_get_running_loop():
        if not called:
            called.append(True)
            raise RuntimeError("No running event loop")
        return orig_get_running_loop()

    monkeypatch.setattr(asyncio, "get_running_loop", fake_get_running_loop)
    codeflash_output = safe_get_lock(); lock = codeflash_output # 35.0μs -> 2.81μs (1146% faster)

# ---------------------
# Large Scale Test Cases
# ---------------------

@pytest.mark.asyncio


async def test_lock_contention_with_many_tasks():
    """Test lock contention with many concurrent tasks."""
    codeflash_output = safe_get_lock(); lock = codeflash_output # 3.01μs -> 2.67μs (12.8% faster)
    counter = 0

    async def worker():
        nonlocal counter
        async with lock:
            tmp = counter
            await asyncio.sleep(0.001)  # simulate work
            counter = tmp + 1

    tasks = [asyncio.create_task(worker()) for _ in range(100)]
    await asyncio.gather(*tasks)

# Edge: Test that lock is not reentrant (asyncio.Lock is not reentrant)
@pytest.mark.asyncio

def test_lock_creation_after_event_loop_closed():
    """Test that safe_get_lock works after closing and recreating an event loop."""
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    loop.close()
    # Now, there is no running event loop
    codeflash_output = safe_get_lock(); lock = codeflash_output # 31.1μs -> 8.07μs (285% faster)

# Edge: Test lock can be used in a context manager
@pytest.mark.asyncio
async def test_lock_async_context_manager():
    """Test that the lock can be used as an async context manager."""
    codeflash_output = safe_get_lock(); lock = codeflash_output # 3.27μs -> 2.76μs (18.3% faster)
    async with lock:
        pass

# Edge: Test that lock is specific to the current event loop
def test_lock_event_loop_specificity():
    """Test that locks are bound to the event loop in which they are created."""
    # Create two event loops and two locks, ensure they are bound to their loops
    loop1 = asyncio.new_event_loop()
    loop2 = asyncio.new_event_loop()
    asyncio.set_event_loop(loop1)
    codeflash_output = safe_get_lock(); lock1 = codeflash_output # 23.3μs -> 3.73μs (526% faster)
    asyncio.set_event_loop(loop2)
    codeflash_output = safe_get_lock(); lock2 = codeflash_output # 18.6μs -> 1.14μs (1532% faster)
    loop1.close()
    loop2.close()
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.

⏪ Replay Tests and Runtime

Test File::Test Function	Original ⏱️	Optimized ⏱️	Speedup
test_pytest_testtest_components_py_testcomponentstest_audio_py_testcomponentstest_file_py_testcomponentst__replay_test_0.py::test_gradio_utils_safe_get_lock	4.55ms	238μs	1811%✅

To edit these changes git checkout codeflash/optimize-safe_get_lock-mhwyybyu and push.