Wake the PC from standby or hibernation

I thank you for giving us a well designed and documented working example. I've studied this and other programs like it (particularly this one). Comparing both source codes show they are derived from the same source but it's not obvious who came first. I've massaged a C code version attempting to replicate the code Mr DiSarli gave us (shown below, built using Vis Studio 2022, pay attention to build configs at top of file). My program DOES NOT WORK when my computer is asleep (works fine when not asleep). DiSarli's code does indeed work regardless of the sleep state and I can't explain why. Can anyone enlighten me? Is it because of the implicit windows message loop running in the DiSarli code? If so, why?

C++

#include <stdio.h>
#include <stdlib.h>

#include <windows.h>

#define	USE_CALLBACK
#define	SET_EVENT_IN_CALLBACK

#define COUNTS_PER_SECOND 10000000

int gNumSeconds = 0;

int gEvidenceCallbackRan = FALSE;

/////////////////////////////////////////////////////////////////////////////
VOID CALLBACK TimerAPCProc(LPVOID lpArg,DWORD dwTimerLowValue,DWORD dwTimerHighValue)
{
	SetThreadExecutionState(ES_CONTINUOUS | ES_SYSTEM_REQUIRED | ES_AWAYMODE_REQUIRED);

	MessageBeep(0);

	HANDLE hWoke = *(HANDLE *)(lpArg);

#ifdef SET_EVENT_IN_CALLBACK
	BOOL success = SetEvent(hWoke);
	if(!success)
	{
		printf("SetEvent failed with error %d\n",GetLastError());
	}
#endif

	gEvidenceCallbackRan = TRUE;
}

/////////////////////////////////////////////////////////////////////////////
DWORD CALLBACK MyThread(LPVOID p)
{
	HANDLE hTimer;
	BOOL bSuccess;
	__int64 qwDueTime;
	LARGE_INTEGER liDueTime;

	printf("Start thread\n");

	HANDLE hWoke = *(HANDLE *)(p);

	hTimer = CreateWaitableTimer(	NULL,					// Default security attributes
									FALSE,					// Create auto-reset timer
									"SpethWARE_MyTimer");	// Name of waitable timer
	if(!hTimer)
	{
		printf("CreateWaitableTimer failed with error %d\n",GetLastError());
		return 0;
	}

	// Create an integer that will be used to signal the timer N seconds from now.(negative indicates relative time from "now")
	qwDueTime = -gNumSeconds * COUNTS_PER_SECOND;

	// Copy the relative time into a LARGE_INTEGER.
	liDueTime.LowPart  = (DWORD)(qwDueTime & 0xFFFFFFFF);
	liDueTime.HighPart = (LONG) (qwDueTime >> 32);

	bSuccess = SetWaitableTimer(	hTimer,			// Handle to the timer object
									&liDueTime,		// When timer will become signaled
									0,				// One shot timer (0 means one shot)
#ifdef USE_CALLBACK
									TimerAPCProc,	// Completion routine
#else
									NULL,			// Completion routine (none specified)
#endif
									&hWoke,			// Argument sent to the completion routine
									TRUE);			// Restore a suspended system
	if(!bSuccess)
	{
		printf("SetWaitableTimer failed with error %d\n",GetLastError());
		CloseHandle(hTimer);
		return 0;
	}

	// Wait forever but put the thread in an alertable state so it can return
#ifdef USE_CALLBACK
	// NOTE: Callback will be called - intended
	SleepEx(INFINITE,TRUE);
#else
	// NOTE: Callback will not be called - UNEXPECTED
	DWORD error = WaitForSingleObjectEx(hTimer,INFINITE,TRUE);
	if(error)
	{
		printf("WaitForSingleObjectEx failed with error %d\n",GetLastError());
		CloseHandle(hTimer);
		return 0;
	}
#endif

	CloseHandle(hTimer);

#ifdef SET_EVENT_IN_THREAD
	BOOL success = SetEvent(hWoke);
	if(!success)
	{
		printf("SetEvent failed with error %d\n",GetLastError());
		return 0;
	}
#endif

	printf("Done thread\n");

    return 0;
}

/////////////////////////////////////////////////////////////////////////////
int main(int argc,char *argv[])
{
	if(argc != 2)
	{
		printf("Command line error\n");
		return;
	}

	gNumSeconds = atoi(argv[1]);
	if(gNumSeconds <= 0)
	{
		printf("gNumSeconds range error (%d)\n",gNumSeconds);
		return 0;
	}

	printf("Start main to wait for %d seconds\n",gNumSeconds);

	HANDLE hWoke = CreateEvent(NULL,FALSE,FALSE,NULL);
    if(!hWoke)
    {
		printf("CreateEvent error\n");
        return 0;
    }

    HANDLE hThread = CreateThread(NULL,0,MyThread,&hWoke,0,NULL);
    if(!hThread)
    {
		printf("CreateThread error\n");
        return 0;
    }

	printf("Waiting for hWoke\n");
    DWORD error1 = WaitForSingleObjectEx(hWoke,INFINITE,TRUE);
	if(error1)
	{
		printf("WaitForSingleObjectEx(hWoke) failed with error %d\n",GetLastError());
        return 0;
	}
	printf("Got hWoke\n");

    DWORD error2 = WaitForSingleObjectEx(hThread,INFINITE,TRUE);
	if(error2)
	{
		printf("WaitForSingleObjectEx(hThread) failed with error %d\n",GetLastError());
        return 0;
	}

	CloseHandle(hWoke);

	printf("Callback %s run\n",gEvidenceCallbackRan ? "DID" : "did not");

	printf("Done main\n");

	return 0;
}

JJS

After some research, I've discovered there is a minimum time the computer is required to sleep before it can be automatically woken from a waitable timer. I was using 20 seconds and it never worked. When I went to 120 seconds, everything worked as intended. Below is my final C code console app that automatically wakes the computer after some programmable amount of time. Note that no callback function nor user code thread is needed. All my code runs in the "main" thread.

C++

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

/////////////////////////////////////////////////////////////////////////////
int main(int argc,char *argv[])
{
	int seconds = argc >= 2 ? atoi(argv[1]) : 0;
	if(seconds <= 0) seconds = 120;

	printf("Wait for %d seconds\n",seconds);

	HANDLE hTimer = CreateWaitableTimer(NULL,FALSE,NULL);
	assert(hTimer);

	// Create an integer that will be used to signal the timer N seconds from now
	#define COUNTS_PER_SECOND 10000000
	__int64 qwDueTime = -seconds * COUNTS_PER_SECOND;

	// Copy the relative time into a LARGE_INTEGER.
	LARGE_INTEGER liDueTime;
	liDueTime.LowPart  = (DWORD)(qwDueTime & 0xFFFFFFFF);
	liDueTime.HighPart = (LONG) (qwDueTime >> 32);

	BOOL bSuccess = SetWaitableTimer(hTimer,&liDueTime,0,NULL,NULL,TRUE);
	assert(bSuccess);

	// Wait forever but put the thread in an alertable state so it can return
	DWORD error = WaitForSingleObjectEx(hTimer,INFINITE,TRUE);
	assert(error == 0);

	CloseHandle(hTimer);

	// Indicate the full system and display needs to come on and stay on
	SetThreadExecutionState(ES_DISPLAY_REQUIRED | ES_SYSTEM_REQUIRED);

	printf("Done\n");

	return 0;
}

JJS

The program as listed works well as a standalone process (Windows 11). But I want to be able to issue wake up timers from a service. When I do this from a service the timer appears in powercfg /waketimers. Everything looks the same except that it now says "Timer set by [SERVICE]". And now the wake timer will not wake the system from either standby or hibernation. Both of these modes work 100% of the time from the sample above. Does anybody have any idea why this might be so?

Your solution does not work in win 10.

See c# - Why Isn't My Windows 10 PC Waking Up after a SetWaitableTimer() Call? - Stack Overflow. Windows 10 has been revised to not allow this by default. The "Allow Wake Timers" must be enabled. I have not tried that yet.

Also the ACPI specification says that wake ups from sleeping state S4 (hibernate) is optional so it won't work in all systems.

I have noticed that when we wakeup our system after a specific time it does not wakeup monitor ,there is any api aur example why which i can understand how to automattically active our monitor screen at the time of wake programmatically.

Nice!!!!!

C#

[DllImport("user32.dll")]
static extern void mouse_event(Int32 dwFlags, Int32 dx, Int32 dy, Int32 dwData, UIntPtr dwExtraInfo);

private const int MOUSEEVENTF_MOVE = 0x0001;

                            mouse_event(MOUSEEVENTF_MOVE, 0, 1, 0, UIntPtr.Zero);
                            Thread.Sleep(40);
                            mouse_event(MOUSEEVENTF_MOVE, 0, -1, 0, UIntPtr.Zero);

Daniele mi puoi mandare exe file?

ale44ko

Works great, thanks!
Easy to add to as well.
Pete

_

When I specify a time on the same date the code works fine but when I specify a future date it doesn't work can anyone help me?

Hi, Thanks for a beautifully simple solution.

I am using WINXP Pro SP2. The code works error-free but...
1. The monitor stays in standby mode and I need to use mouse/keyboard to wake it up
2. The Woken date/time is correctly displayed, which indicates that the system did wake up at the correct time.
3. I tried the SetExecutionSate solution given, but after I introduced that in the code, the computer did not wake up at all and I had to do a cold boot.

I don't know C#, but manage to read and understand C# code.

I have put the entire code here (in vb.net 2005) for others to use, and give me a pointer to the error (or better still, the solution itself Smile | :)

)

Thanks in advance

This is the code for the Form:

VB

Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Text
Imports System.Windows.Forms
Public Class frmWakeUp
    Dim wup As MyWakeUpTimer.WakeUP

    Private Sub timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles timer1.Tick
        lblNow.Text = String.Format("Now: {0}", DateTime.Now.ToShortDateString() + " " + DateTime.Now.ToLongTimeString())
    End Sub
    Private Sub button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button1.Click
        Dim wup As New MyWakeUpTimer.WakeUP()
        AddHandler wup.Woken, AddressOf WakeUP_Woken
        wup.SetWakeUpTime(DateTimePicker1.Value)

    End Sub
    Private Sub WakeUP_Woken(ByVal sender As Object, ByVal e As EventArgs)
        lblWoken.Text = String.Format("Woken: {0}", (DateTime.Now.ToShortDateString + (" " + DateTime.Now.ToLongTimeString)))
    End Sub
    Private Sub button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button2.Click
        'Application.SetSuspendState(PowerState.Hibernate, false, false)
        Application.SetSuspendState(PowerState.Suspend, False, False)
    End Sub

End Class

This is the code for the Class

VB

Imports System
Imports System.Text
Imports System.Runtime.InteropServices
Imports Microsoft.Win32.SafeHandles
Imports System.ComponentModel
Imports System.Threading

Class WakeUP
    'Public Enum EXECUTION_STATE As UInteger
    '    ES_CONTINUOUS = &H80000000L
    '    ES_DISPLAY_REQUIRED = &H2
    '    ES_SYSTEM_REQUIRED = &H1
    '    ES_AWAYMODE_REQUIRED = &H40
    'End Enum

    'Private Const VK_NONAME As Integer = &HFC
    'Private Const KEYEVENTF_SILENT As Byte = &H4

    '<DllImport("Kernel32.DLL", CharSet:=CharSet.Auto, SetLastError:=True)> _
    'Protected Shared Function SetThreadExecutionState(ByVal state As EXECUTION_STATE) As EXECUTION_STATE
    'End Function

    '<DllImport("user32.dll")> _
    'Private Shared Sub keybd_event(ByVal bVk As Byte, ByVal bScan As Byte, ByVal dwFlags As UInteger, _
    '                                ByVal dwExtraInfo As Integer)
    'End Sub

    <DllImport("kernel32.dll")> Private Shared Function CreateWaitableTimer( _
    ByVal lpTimerAttributes As IntPtr, _
    ByVal bManualReset As Boolean, _
    ByVal lpTimerName As String) As SafeWaitHandle 'IntPtr
    End Function
    'Public Declare Function CreateWaitableTimer Lib "kernel32.dll" (ByVal lpTimerAttributes As IntPtr, ByVal bManualReset As Boolean, ByVal lpTimerName As String) As SafeWaitHandle

    <DllImport("kernel32.dll")> Private Shared Function SetWaitableTimer( _
    ByVal hTimer As SafeWaitHandle, _
    ByRef pDueTime As Long, _
    ByVal lPeriod As Integer, _
    ByVal pfnCompletionRoutine As IntPtr, _
    ByVal lpArgToCompletionRoutine As IntPtr, _
    ByVal fResume As Boolean) As Boolean
    End Function
    'Public Declare Function SetWaitableTimer Lib "kernel32.dll" (ByVal hTimer As SafeWaitHandle, ByRef pDueTime As Long, ByVal lPeriod As Integer, ByVal pfnCompletionRoutine As IntPtr, ByVal lpArgToCompletionRoutine As IntPtr, ByVal fResume As Boolean) As Boolean

    Public Event Woken As EventHandler

    Private bgWorker As New BackgroundWorker()

    Public Sub New()
        AddHandler bgWorker.DoWork, AddressOf bgWorker_DoWork
        AddHandler bgWorker.RunWorkerCompleted, AddressOf bgWorker_RunWorkerCompleted
    End Sub

    Public Sub SetWakeUpTime(ByVal time As DateTime)
        bgWorker.RunWorkerAsync(time.ToFileTime())
    End Sub

    Private Sub bgWorker_RunWorkerCompleted(ByVal sender As Object, ByVal e As RunWorkerCompletedEventArgs)
        RaiseEvent Woken(Me, New EventArgs())
    End Sub

    Private Sub bgWorker_DoWork(ByVal sender As Object, ByVal e As DoWorkEventArgs)
        Dim waketime As Long = CLng(e.Argument)

        Using handle As SafeWaitHandle = CreateWaitableTimer(IntPtr.Zero, True, Me.[GetType]().Assembly.GetName().Name.ToString() + "Timer")
            If SetWaitableTimer(handle, waketime, 0, IntPtr.Zero, IntPtr.Zero, True) Then
                Using wh As New EventWaitHandle(False, EventResetMode.AutoReset)
                    wh.SafeWaitHandle = handle
                    wh.WaitOne()
                End Using
            Else
                Throw New Win32Exception(Marshal.GetLastWin32Error())
            End If
        End Using
        '' 27/01/2011
        'SetThreadExecutionState(EXECUTION_STATE.ES_SYSTEM_REQUIRED Or EXECUTION_STATE.ES_CONTINUOUS)
        'SetThreadExecutionState(EXECUTION_STATE.ES_DISPLAY_REQUIRED)

        '' keyboard event
        'keybd_event(VK_NONAME, 0, KEYEVENTF_SILENT, 0)

    End Sub

End Class

Just a note to users reading this:

1. Application.SetSuspendState does not work. Instead use

VB

Private Declare Function SetSuspendState Lib "Powrprof" (ByVal Hibernate As Boolean, ByVal ForceCritical As Boolean, ByVal DisableWakeEvent As Boolean) As Boolean

In the code, use

VB

SetSuspendState(1, 0, 0)

2. This works only for Hibernate status. Standby still gives the same error.

Anyone able to explain this?

Thanks in advance

Great R&D..

I updated the code like this:
//invoke wakeup
private void btnSwitch_Click(object sender, EventArgs e)
{
WakeUP wup = new WakeUP();
long delay = 30;
wup.SetWakeUpDelay(-1 * delay * 10000000);
RunCmd("rundll32 powrprof.dll,SetSuspendState");
}
//wakeup class
public void SetWakeUpDelay(long nsec)
{
bgWorker.RunWorkerAsync(nsec);
}

if delay >= 50, it works well;
if delay < 50, it's always waken up just in 53 ms.
Can you help me? thanks!

OS: win7 32b

This code is very useful for me, but i don't know C#, Could you code it using vc++? Smile | :)

Hello, I would like to make the app wake the computer at a specified time daily instead of using the current datetimepicker where a date needs to be specified. How can I do so? Am new to C# programming and its components by the way, still learning the way around

On any of our DELL Desktop PCs, setting a resume date / time to, say tomorrow + 1 hour, actually resumes in 1 hour.

Any thoughts.

Hmm sorry, I can't reproduce this behavior. Can you make sure that your hardware clock time is correct?

Thanks Danielle!

I used your code and incorporated it into a cgi script on my server. I can now turn the server off or *more excitingly* put it to sleep overnight using my mobile phone, having it wake at a time of my choosing in the morning. [mutters slowly to self] M u s t . n o t . p l a y . f u n n y . b u g g e r s . w i t h . f r i e n d ' s . s e r v e r s.... Big Grin | :-D

I login by user of administrator group then it done, also by standard user then PC slept but not wake up. Can you help me, pls ?

modified 13-Nov-11 22:30pm.

What operating system are you using?

I use windows 7 Enterprise 32 bit.

modified 16-Nov-11 23:29pm.

Wake the PC from standby or hibernation

Introduction

Background

Using the Code

Troubleshooting

Points of Interest

History

License

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