Add timeouts to ThreadPoolExecutor result() calls to prevent indefinite hangs

[Copilot]

ThreadPoolExecutor .result() calls were blocking indefinitely when background tasks failed or took too long, causing the application to hang.

Changes

• Added timeout handling helper: get_future_result_with_timeout() wraps .result() calls with timeout and returns default values on timeout
• Applied 10s timeout to all index route futures: Created priority bugs, open bugs, completed issues, PR reviews, and authored PRs now timeout gracefully
• Added timeout constants: INDEX_FUTURE_TIMEOUT = 10 for concurrent index operations, distinguished from EXECUTOR_TIMEOUT_SECONDS = 30 for individual route operations
• Graceful degradation: Returns empty lists/dicts on timeout rather than failing, allowing partial page rendering

def get_future_result_with_timeout(
    future: Future[T],
    default_value: T,
    timeout: int = INDEX_FUTURE_TIMEOUT
) -> T:
    try:
        return future.result(timeout=timeout)
    except TimeoutError:
        return default_value

# Applied throughout _build_index_context()
created_priority_bugs = get_future_result_with_timeout(created_priority_future, [])
merged_reviews = get_future_result_with_timeout(reviews_future, {})

Minor: Removed redundant "for debugging" from logging comments.

Original prompt

Please apply the following diffs and create a pull request.
Once the PR is ready, give it a title based on the messages of the fixes being applied.

[{"message":"ThreadPoolExecutor results are accessed without timeout, which could cause the application to hang indefinitely if the underlying operations fail or take too long. Add timeout parameter to all .result() calls.","fixFiles":[{"filePath":"app.py","diff":"diff --git a/app.py b/app.py\n--- a/app.py\n+++ b/app.py\n@@ -1,6 +1,6 @@\n import re\n import time\n-from concurrent.futures import ThreadPoolExecutor\n+from concurrent.futures import ThreadPoolExecutor, TimeoutError\n from datetime import datetime\n from functools import lru_cache\n from typing import TypedDict\n@@ -30,6 +30,9 @@\n \n app = Flask(__name__)\n \n+# Maximum time in seconds to wait for background tasks in the index context.\n+INDEX_FUTURE_TIMEOUT = 10\n+\n # Configuration constants\n # Timeout in seconds for ThreadPoolExecutor result() calls\n EXECUTOR_TIMEOUT_SECONDS = 30\n@@ -146,25 +149,37 @@\n         reviews_future = executor.submit(merged_prs_by_reviewer, days)\n         authored_prs_future = executor.submit(merged_prs_by_author, days)\n \n-    created_priority_bugs = created_priority_future.result()\n-    open_priority_bugs = open_priority_future.result()\n+    try:\n+        created_priority_bugs = created_priority_future.result(timeout=INDEX_FUTURE_TIMEOUT)\n+        open_priority_bugs = open_priority_future.result(timeout=INDEX_FUTURE_TIMEOUT)\n \n-    # Only include non-project issues in the index summary\n-    completed_priority_bugs = [\n-        issue\n-        for issue in completed_priority_future.result()\n-        if not issue.get(\"project\")\n-    ]\n-    completed_bugs = [\n-        issue\n-        for issue in completed_bugs_future.result()\n-        if not issue.get(\"project\")\n-    ]\n-    completed_new_features = [\n-        issue\n-        for issue in completed_new_features_future.result()\n-        if not issue.get(\"project\")\n-    ]\n+        # Only include non-project issues in the index summary\n+        completed_priority_bugs = [\n+            issue\n+            for issue in completed_priority_future.result(timeout=INDEX_FUTURE_TIMEOUT)\n+            if not issue.get(\"project\")\n+        ]\n+        completed_bugs = [\n+            issue\n+            for issue in completed_bugs_future.result(timeout=INDEX_FUTURE_TIMEOUT)\n+            if not issue.get(\"project\")\n+        ]\n+        completed_new_features = [\n+            issue\n+            for issue in completed_new_features_future.result(timeout=INDEX_FUTURE_TIMEOUT)\n+            if not issue.get(\"project\")\n+        ]\n+        # completed_technical_changes_future, open_bugs_future, open_new_features_future,\n+        # open_technical_changes_future, reviews_future, and authored_prs_future\n+        # should also be consumed with timeouts wherever their .result() values are used.\n+        completed_technical_changes = completed_technical_changes_future.result(timeout=INDEX_FUTURE_TIMEOUT)\n+        open_bugs = open_bugs_future.result(timeout=INDEX_FUTURE_TIMEOUT)\n+        open_new_features = open_new_features_future.result(timeout=INDEX_FUTURE_TIMEOUT)\n+        open_technical_changes = open_technical_changes_future.result(timeout=INDEX_FUTURE_TIMEOUT)\n+        reviews = reviews_future.result(timeout=INDEX_FUTURE_TIMEOUT)\n+        authored_prs = authored_prs_future.result(timeout=INDEX_FUTURE_TIMEOUT)\n+    except TimeoutError:\n+        abort(504, description=\"Timed out waiting for background tasks in index context\")\n     completed_technical_changes = [\n         issue\n         for issue in completed_technical_changes_future.result()\n"}]},{"message":"ThreadPoolExecutor results are accessed without timeout, which could cause the application to hang indefinitely if the underlying operations fail or take too long. Add timeout parameter to all .result() calls.","fixFiles":[{"filePath":"app.py","diff":"diff --git a/app.py b/app.py\n--- a/app.py\n+++ b/app.py\n@@ -1,6 +1,6 @@\n import re\n import time\n-from concurrent.futures import ThreadPoolExecutor\n+from concurrent.futures import ThreadPoolExecutor, TimeoutError\n from datetime import datetime\n from functools import lru_cache\n from typing import TypedDict\n@@ -29,6 +29,7 @@\n )\n \n app = Flask(__name__)\n+INDEX_FUTURE_TIMEOUT = 10\n \n # Configuration constants\n # Timeout in seconds for ThreadPoolExecutor result() calls\n@@ -146,34 +147,68 @@\n         reviews_future = executor.submit(merged_prs_by_reviewer, days)\n         authored_prs_future = executor.submit(merged_prs_by_author, days)\n \n-    created_priority_bugs = created_priority_future.result()\n-    open_priority_bugs = open_priority_future.result()\n+    try:\n+        created_priority_bugs = created_priority_future.result(timeout=INDEX_FUTURE_TIMEOUT)\n+    except TimeoutError:\n+        created_priority_bugs = []\n+    try:\n+        open_prior...

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Index future timeouts never take effect

These get_future_result_with_timeout(..., timeout=INDEX_FUTURE_TIMEOUT) calls run only after the surrounding with ThreadPoolExecutor(...) block has exited. The executor context manager calls shutdown(wait=True) before reaching this point, which blocks until all submitted futures finish. As a result, the new 10s timeouts can never fire and a hung get_* call will still hang _build_index_context, so the change does not actually prevent the indefinite waits it is meant to address.

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