First post code

 # include & lt; Iostream> 
#include  
#include  
#include  
#include  
#include  

Boost: : an asio: : io_service m_service; 
Boost: : an asio: : io_service: : strand m_strand (m_service); 
STD: : mutex MTX. 

Void print (int id) {
The lock ();//MTX. 
//STD: : coutStatic int CNT=0; 
STD: : cout<" Id: "& lt; + + CNT; 
STD: : cout<" The count, "& lt; //MTX. Unlock (); 
} 

Void Run1 () {
Int ret.=m_service run_one (); 
STD: : cout<" Run1 excute "& lt; } 
Void Run2 () {
Int ret.=m_service run_one (); 
STD: : cout<" Run2 excute "& lt; } 


Void print1 () {
M_strand. Dispatch (m_strand. Wrap (STD: : bind (print, 1))); 
} 

Void print2 () {
M_strand. Post (m_strand. Wrap (STD: : bind (print, 2))); 
} 

Void print3 () {
M_strand. Post (m_strand. Wrap (STD: : bind (print, 3))); 
} 

Void print4 () {
M_strand. Post (m_strand. Wrap (STD: : bind (print, 4))); 
} 

Void test () {
STD: : thread t1 (print1); 
STD: : thread t2 (print2); 
STD: : thread t3 (print3); 
STD: : thread t4 (print4); 

//STD: : thread ios1 (Run1); 
//STD: : thread ios2 (Run2); 

T1. The join (); 
T2. The join (); 
T3. The join (); 
T4. The join (); 

//ios1. The join (); 
//ios2. The join (); 

Int ret=m_service. The run (); 
STD: : cout<" The Main thread excute "& lt; } 

Int main (int arg c, const char * * argv) {
Try {
test(); 
} 
The catch (STD: : exception& E) {
STD: : cout} 
return 0; 
} 

Compile the code above, the main process in the test function call m_service. The run () function, you can perform four Handler, but the return value is 2, should not return to 4? Solve???

Another question, when I open two threads to invoke m_service. Run_one (), occasionally there will be a kind of situation, main process the run of the return value is 0, also called run_one () function of the two threads, will back 1, but print thread ID found that the two threads returns 1, a performs a Handler, another three Handler is carried out, the main process is an open, this is how to return a responsibility?????? (beginner, found the problem, a little confused, and great god teach again thanked first!)