Synchronization Overview

Introduction

Synchronization primitives are essential for coordinating access to shared resources in multithreaded Windows applications. This overview covers the most commonly used kernel‑level synchronization objects and their typical use‑cases.

Kernel‑Level Primitives

Mutex – Mutual exclusion across processes.
Semaphore – Controls a pool of resources.
Event – Signaling between threads.
Critical Section – Fast intra‑process mutual exclusion.
Slim Reader‑Writer (SRW) Lock – Efficient read/write synchronization.

Sample Code: Using a Mutex

#include <windows.h>
#include <stdio.h>

int main() {
    HANDLE hMutex = CreateMutex(NULL, FALSE, L"MyAppMutex");
    if (hMutex == NULL) {
        printf("CreateMutex failed: %lu\n", GetLastError());
        return 1;
    }

    // Wait for ownership
    WaitForSingleObject(hMutex, INFINITE);
    printf("Mutex acquired!\n");

    // Critical section work here...

    ReleaseMutex(hMutex);
    CloseHandle(hMutex);
    return 0;
}

For more examples, see the Mutex topic.

Best Practices

Prefer SRW locks over critical sections when possible.
Use events for simple signaling; avoid busy‑waiting.
Keep the scope of synchronization objects as small as practical.
Never hold a kernel object while performing I/O that may block.
Always release ownership in a finally‑style block to avoid deadlocks.