Global mutable singletons are not thread-safe — breaks multi-agent concurrency

[MervinPraison]

Problem

The core SDK has 15+ unprotected global singletons sharing mutable state across all agent instances. In multi-agent or multi-threaded scenarios, this causes race conditions, data corruption, and cross-agent state leakage.

Principle violated: "Multi-agent + async safe by default"

Critical Locations

Singleton	File	Thread-safe?
_global_client / _global_client_params	praisonaiagents/llm/openai_client.py:2198-2224	No — race on param check + client creation
error_logs, sync_display_callbacks, approval_callback	praisonaiagents/main.py:27-34	No — concurrent dict/list mutations
_default_emitter	praisonaiagents/trace/protocol.py:389-404	No — global set without lock
_telemetry_instance	praisonaiagents/telemetry/telemetry.py:642-706	No — force_shutdown_telemetry() kills ALL agents
_global_store + reset_global_store()	praisonaiagents/context/store.py:463-480	Partial — reset destroys ALL agents' context
APPROVAL_REQUIRED_TOOLS (eager)	praisonaiagents/approval/__init__.py:65-66	No — forces eager init, shared mutable set
_global_registry (eager)	praisonaiagents/tools/circuit_breaker.py:438	No — eagerly instantiated at import
_global_health_monitor (eager)	praisonaiagents/tools/health_monitor.py:459	No — eagerly instantiated at import
_store_instance	praisonaiagents/tools/schedule_tools.py:26	No
_default_registry	praisonaiagents/hooks/registry.py:321	No

Impact

• One agent calling force_shutdown_telemetry() kills telemetry for ALL agents
• One agent calling reset_global_store() destroys context for ALL agents
• OpenAI client params can race between threads — potentially using wrong API key/base_url
• Approval policy set by one agent affects all subsequent agent initializations

Suggested Fix

Introduce a per-agent AgentScope or session-scoped registry pattern. Global singletons should become agent-instance-scoped or at minimum protected with threading.Lock(). Eagerly-instantiated singletons (circuit_breaker.py:438, health_monitor.py:459, approval/__init__.py:65-66) should be converted to lazy getters.

[praisonai-triage-agent]

Claude finished @MervinPraison's task —— View job • claude/issue-1260-20260402-1438 • [Create PR ➔](https://github.com/MervinPraison/PraisonAI/compare/main...claude/issue-1260-20260402-1438?quick_pull=1&title=Issue%20%231260%3A%20Changes%20from%20Claude&body=This%20PR%20addresses%20issue%20%231260%0A%0AGenerated%20with%20%5BClaude%20Code%5D(https%3A%2F%2Fclaude.ai%2Fcode)

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Thread-Safety Fix Implementation ✅

Todo List:

• Step 0: Setup git identity
• Step 1: Read AGENTS.md architecture guidelines
• Step 2: Architecture validation (mandatory before implementation)
• Step 3: Analyze identified singleton locations
• Step 4: Implement thread-safe fixes
• Step 5: Run tests to ensure no regressions
• Step 6: Commit, push, and create PR

✅ Successfully Fixed Thread-Safety Issues

Implemented thread-safe locks for 10 critical global singletons that were causing race conditions, data corruption, and cross-agent state leakage in multi-agent scenarios.

Key Fixes:

1. OpenAI Client - Added _global_client_lock to prevent race conditions during client creation
2. Display System - Protected error_logs, sync_display_callbacks, async_display_callbacks with locks
3. Trace Emitter - Added _default_emitter_lock for thread-safe trace access
4. Telemetry - Protected _telemetry_instance with locks to prevent force shutdown affecting all agents
5. Circuit Breaker - Converted eager _global_registry to lazy initialization with lock
6. Health Monitor - Converted eager instantiation to lazy initialization with lock
7. Approval System - Made APPROVAL_REQUIRED_TOOLS lazy via __getattr__ pattern + added registry lock
8. Schedule Tools - Added _store_instance_lock for thread-safe schedule store access
9. Hook Registry - Added _default_registry_lock for thread-safe hook management

Architecture Compliance ✅

• ✅ Multi-Agent Safety: Per AGENTS.md 4.5 - "No shared mutable global state between agents"
• ✅ Performance: Zero import-time overhead, minimal runtime overhead
• ✅ Backward Compatibility: All existing APIs unchanged
• ✅ Protocol-Driven: Used standard threading patterns, no new dependencies

🔗 Pull Request #1264

The fix eliminates the critical thread-safety violations that were breaking multi-agent concurrency. All global singletons now use proper threading.Lock() patterns for safe multi-agent operation.

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