Implementation:InternLM Lmdeploy Barrier
| Knowledge Sources | |
|---|---|
| Domains | Synchronization, Multi_Threading |
| Last Updated | 2026-02-07 15:00 GMT |
Overview
Provides a cross-platform thread barrier synchronization primitive with platform-specific implementations for MSVC and POSIX systems.
Description
The Barrier class implements a reusable thread barrier that blocks all participating threads until a specified number have called arrive_and_wait(). On POSIX platforms (Linux, macOS with GCC/Clang), it wraps pthread_barrier_t for efficient native barrier support. On MSVC (without Clang), it provides a fallback implementation using std::mutex, std::condition_variable, and a phase counter to achieve the same semantics. The barrier is initialized with a count parameter and can be reused across multiple synchronization rounds.
Usage
Used internally by thread-based communication infrastructure (e.g., ThreadCommImpl) to synchronize multiple worker threads at specific coordination points during collective operations.
Code Reference
Source Location
- Repository: InternLM_Lmdeploy
- File: src/turbomind/comm/barrier.h
- Lines: 1-72
Signature
namespace turbomind::comm {
class Barrier {
public:
explicit Barrier(int count);
~Barrier();
void arrive_and_wait();
};
} // namespace turbomind::comm
Import
#include "src/turbomind/comm/barrier.h"
I/O Contract
Inputs
| Name | Type | Required | Description |
|---|---|---|---|
| count | int | Yes | Number of threads that must call arrive_and_wait() before any are released |
Outputs
| Name | Type | Description |
|---|---|---|
| (none) | void | All threads are released once the count is reached |
Usage Examples
#include "src/turbomind/comm/barrier.h"
turbomind::comm::Barrier barrier(4); // 4 threads must synchronize
// In each thread:
barrier.arrive_and_wait(); // blocks until all 4 threads arrive
// ... proceed after synchronization ...