/GT (Support Fiber-Safe Thread-Local Storage)

/GT

This option supports fiber safety for data allocated using static thread-local storage, that is, data allocated with __declspec(thread).

Data declared with __declspec(thread) is referenced through a thread-local storage (TLS) array. The TLS array is an array of addresses that the system maintains for each thread. Each address in this array gives the location of thread-local storage data.

A fiber is a lightweight object that consists of a stack and a register context and can be scheduled on various threads. A fiber can run on any thread. Because a fiber may get swapped out and restarted later on a different thread, the address of the TLS array must not be cached or optimized as a common subexpression across a function call (see the /Og option for details). /GT prevents such optimizations.

To set this compiler option in the Visual Studio development environment

1. Open the project's Property Pages dialog box. For details, see Setting Visual C++ Project Properties.
2. Click the C/C++ folder.
3. Click the Optimization property page.
4. Modify the Enable Fiber-safe Optimizations property.

To set this compiler option programmatically

See EnableFiberSafeOptimizations Property.

See Also

Compiler Options | Setting Compiler Options