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Synchronous Shared Memory

• When a PE wants to write, it sends a parallel signal and waits for a barrier
• If a PE sees a signal pending (by polling or hardware interrupt), it joins the barrier
• Once all PEs have joined, the PEs vote on who wants to write
• In turn, each writer broadcasts to all PEs
• If a writer sees overlapping data, it adjusts its write request to preserve atomicity in resolving the race