TlsGetValue retrieves the value in the calling thread's thread local storage (TLS) slot for a specified TLS index. Each thread of a process has its own slot for each TLS index.
Syntax
LPVOID TlsGetValue(
DWORD TlsIndex
);Parameters
TlsIndex
The TLS index that was allocated by TlsAlloc.
Return Value
If the function succeeds, it returns the value stored in the calling thread's TLS slot associated with the specified index. If the function fails, it returns 0 (zero).
To get extended error information, call GetLastError.
Note: The data stored in a TLS slot can have a value of zero. In this case, the return value is zero and GetLastError returns NO_ERROR.
Remarks
TLS indexes are typically allocated by TlsAlloc during process or RTDLL initialization. Once allocated, each thread of the process can use a TLS index to access its own TLS storage slot for that index. The storage slot for each thread is initialized to NULL. A thread specifies a TLS index in a call to TlsSetValue, to store a value in its slot. The thread specifies the same index in a subsequent call to TlsGetValue, to retrieve the stored value.
TlsSetValue and TlsGetValue were implemented with speed as the primary goal. These functions perform minimal parameter validation and error checking. In particular, this function succeeds if TlsIndex is in the range 0 through (TLS_MINIMUM_AVAILABLE - 1). It is up to the programmer to ensure that the index is valid.
TlsGetValue calls SetLastError to clear a thread's last error when it succeeds. That allows checking for the error-free retrieval of NULL values.
Requirements
| Minimum supported version | Header | Library |
|---|---|---|
|
eRTOS 1.0 SDK |
windows.h | rtkrnl.lib |
See Also:
