Multithreaded Programming (3)-from CreateThread [continued]

function CreateThread(
　lpThreadAttributes: Pointer;
　dwStackSize: DWORD;
　lpStartAddress: TFNThreadStartRoutine;
　lpParameter: Pointer;
　dwCreationFlags: DWORD; {启动选项}
　var lpThreadId: DWORD
): THandle; stdcall;

CreateThread's penultimate parameter dwcreationflags (startup option) has two optional values:

0: Execute the entry function immediately after the thread is established;

Create_suspended: The thread is set up to suspend the wait.

The available ResumeThread function is the operation of the recovery thread; Use SuspendThread to suspend the thread again.

The arguments for both functions are thread handles, and the return value is the pending count before execution.

What is a hang count?

SuspendThread will give this number +1; ResumeThread will give this number-1; But the smallest number is 0.

When this number = 0 o'clock, the thread will run; > 0 o'clock will hang up.

If you are suspendthread multiple times, you also need to resumethread multiple times to restore the thread's operation.

In the following example, a new thread keeps assigning random values to a global variable;

The Timer control on the form then writes the variable to the form title every 1/10 seconds;

In this process, ResumeThread, suspendthread two functions were demonstrated.

Run Effect chart: