ThreadDescription.c File Reference

#include "k32_vista.h"

Include dependency graph for ThreadDescription.c:

Go to the source code of this file.

Functions
HRESULT WINAPI DECLSPEC_HOTPATCH	GetThreadDescription (_In_ HANDLE hThread, _Outptr_result_z_ PWSTR *ppszThreadDescription)
HRESULT WINAPI DECLSPEC_HOTPATCH	SetThreadDescription (_In_ HANDLE hThread, _In_ PCWSTR lpThreadDescription)

Function Documentation

GetThreadDescription()

HRESULT WINAPI DECLSPEC_HOTPATCH GetThreadDescription	(	_In_ HANDLE	hThread,
		_Outptr_result_z_ PWSTR *	ppszThreadDescription
	)

Definition at line 13 of file ThreadDescription.c.

{
    PTHREAD_NAME_INFORMATION NameInfo = NULL;
    PVOID ptr;
    NTSTATUS Status;
    ULONG Length;
 
    *ppszThreadDescription = NULL;
 
    /* Since there may be concurrent SetThreadDescription() invocations being
     * executed, we need to loop over the buffer allocation size until we can
     * successfully capture the thread name. */
    Length = 0;
    Status = NtQueryInformationThread(hThread, ThreadNameInformation, NULL, 0, &Length);
    if (Status != STATUS_BUFFER_TOO_SMALL)
        return HRESULT_FROM_NT(Status);
 
    /* Loop again only if we get buffer-too-small types of errors;
     * otherwise, break the loop: any error will be handled below. */
    while (Status == STATUS_INFO_LENGTH_MISMATCH ||
           Status == STATUS_BUFFER_TOO_SMALL)
    {
        /* (Re-)allocate the information buffer */
        ptr = (NameInfo ? LocalReAlloc(NameInfo, Length, LMEM_MOVEABLE)
                        : LocalAlloc(LMEM_FIXED, Length));
        if (!ptr)
        {
            Status = STATUS_NO_MEMORY;
            break;
        }
        NameInfo = ptr;
        Status = NtQueryInformationThread(hThread, ThreadNameInformation,
                                          NameInfo, Length, &Length);
    }
    if (!NT_SUCCESS(Status))
    {
        LocalFree(NameInfo);
        return HRESULT_FROM_NT(Status);
    }
 
    /*
     * We already have a suitable memory buffer, containing a UNICODE_STRING
     * followed by the actual string data. Just move the string back to the
     * beginning of the buffer and resize it down. Since sizeof(UNICODE_STRING)
     * is larger than sizeof(WCHAR), we also have space for the NUL-terminator.
     */
    *ppszThreadDescription = (PWSTR)NameInfo;
    Length = NameInfo->ThreadName.Length;
    if (Length)
        RtlMoveMemory(*ppszThreadDescription, NameInfo->ThreadName.Buffer, Length);
    (*ppszThreadDescription)[Length / sizeof(WCHAR)] = UNICODE_NULL;
 
    /* Resize down the buffer. If the call fails, the old buffer
     * is still valid, but is larger than what is necessary. */
    ptr = LocalReAlloc(*ppszThreadDescription, Length + sizeof(WCHAR), LMEM_FIXED);
    if (ptr)
        *ppszThreadDescription = ptr;
 
    return HRESULT_FROM_NT(Status);
}

SetThreadDescription()

HRESULT WINAPI DECLSPEC_HOTPATCH SetThreadDescription	(	_In_ HANDLE	hThread,
		_In_ PCWSTR	lpThreadDescription
	)

Definition at line 79 of file ThreadDescription.c.

{
    THREAD_NAME_INFORMATION NameInfo;
    NTSTATUS Status;
 
    Status = RtlInitUnicodeStringEx(&NameInfo.ThreadName, lpThreadDescription);
    if (NT_SUCCESS(Status))
    {
        Status = NtSetInformationThread(hThread, ThreadNameInformation,
                                        &NameInfo, sizeof(NameInfo));
    }
    return HRESULT_FROM_NT(Status);
}

Referenced by rpcrt4_http_timer_thread(), RPCRT4_io_thread(), and RPCRT4_server_thread().