How to syncronize 2 dll's

[vma]

Hi,
I have 2 dll's in an application. One process, 2 different threads. The 2 dll's are some kind of data sources and they need to start a data cycle at same time. The 3rd dll is a vizualization which has to show up the data. How can I make the 2 data sources start transmiting data at the same time. I tried using 2 mutexes but I end up blocking the entire procees. Can you please guide me to some articles or documentation that could help?
Thank you!

[cilu]

On single cores, there is no "same time". Even though you have multiple threads, they run at different time slots. So when you say "same time" that means most likely "about the same time".

Why don't you explained how you tried to synchronize the two, maybe we can figure what was wrong.

[vma]

so here is what I've done:
1. In Source1 I start Mutex1 and after that I wait for Mutex2
2. In Source2 I wait for Mutex1 and when I got it I start Mutex2.

Here is data source 1:

m_h_ghMutex1 = CreateMutex(NULL, FALSE, TEXT("SignalGenerator1"));
DWORD dwMutexResult;
	do {
		m_h_ghMutex2 = OpenMutex(MUTEX_ALL_ACCESS, FALSE, TEXT("SignalGenerator2")); 
			
		dwMutexResult = WaitForSingleObject(m_h_ghMutex2, 1000L);
	}
	while (dwMutexResult != WAIT_OBJECT_0);
//----start sending data----

In data source 2:

DWORD dwMutexResult;
	do {
		m_h_ghMutex1 = OpenMutex(MUTEX_ALL_ACCESS, FALSE, TEXT("SignalGenerator1")); 
		dwMutexResult = WaitForSingleObject(m_h_ghMutex1, 1000L);
	} while (dwMutexResult != WAIT_OBJECT_0);
	m_h_ghMutex2 = CreateMutex(NULL, FALSE, TEXT("SignalGenerator2"));
//---start sending data---

L.E. I know there is no such thing like "same time" but something unsesizable by human eye would be good enough for me