In my project I need to mock a blocking function that runs on a thread, I need it to release the thread few times during the tests with my control, on my command, I want it to be blocked most of the time as the read func is in while loop.
class BlockFuncsIf {
public:
virtual bool Write(const Msg& msg) = 0;
virtual bool Read(Msg* msg) = 0;
};
class BlockFuncs: public BlockFuncsIf {
public:
MOCK_METHOD1(Write, bool(const Msg&));
MOCK_METHOD1(Read, bool(Msg* msg));
};
class TestedClass {
public:
MSG msg;
std::condition_variable cv;
bool success;
...
bool expectRead() {
success = true;
while(success) {
success = Read(&msg);
cv.notify_all();
}
}
...
};
The solution I found is to wrap the mocked functions and add a semaphore to control the blocking. In this solution I control the semaphore (sem_init, sem_post) from the tests.
Note: I wanted to use
std::semaphore
but it is available only onc++20
so I usedsemaphore.h
insted, there some other implementation for cpp semaphore avallible if needed: cpp semaphore implementation.
class BlockFuncsIf {
public:
virtual bool Write(const Msg& msg) = 0;
virtual bool Read(Msg* msg) = 0;
};
class BlockFuncsMock: public BlockFuncsIf {
public:
MOCK_METHOD1(Write, bool(const Msg&));
MOCK_METHOD1(Read, bool(Msg* msg));
static std::shared_ptr<BlockFuncsMock> _blockFuncsMockObj;
};
std::shared_ptr<BlockFuncsMock> BlockFuncsMock::_blockFuncsMockObj = std::make_shared< BlockFuncsMock >();
class BlockFuncs {
public:
bool Write(const Msg& msg){
sem_wait(&SemWriteMutex);
return BlockFuncsMock::_blockFuncsMockObj->Write(msg);
}
bool Read(Msg* msg){
sem_wait(&SemReadMutex);
return BlockFuncsMock::_blockFuncsMockObj->Read(msg);
}
sem_t SemWriteMutex;
sem_t SemReadMutex;
};