Description

This is a ThreadPool with C++ language.

Support some features:

• Maintain a pool to automatic create,run,destroy a thread.
• Dynamic increase/descrease the thread pool's thread nums
• Support adjust the thread's CPU and I/O priority
• Expand your environment with inherit Class Env

There is a chinese blog to describe the implementation of this threadpool which is written by me. A industrial threadpool's implementation

Compile

compile os: centos7.3.1611 gcc: 5.3

• for lib and static lib: make all
• for example test:

  cd example
  make all

  Before you compile the example, the libthreadpool.so must be produced in the first step.

API

Create ThreadPool

auto* thread_pool = new ThreadPoolImpl();

The interface will produce a PosixEnv to init multi threadpools with LOW/HIGH/USER .etc.

Schedule thread

void Schedule(void (*function)(void* arg1), void* arg, Priority pri = LOW,
            void* tag = nullptr,
            void (*unschedFunction)(void* arg) = nullptr) override;

• function is thread func

• arg is thread func's args, it's better to choose a struct

• pri Env support seperate threads with different tag

  • LOW
  • HIGH

  With these tags, you can set a convinient cpu or I/O priority to these threads

Priority thread

void LowerThreadPoolIOPriority(Priority pool = LOW);

Set threads' number limits

void SetBackgroundThreads(int num, Priority pri);

You can set the threads' num with identity tag, eg: env->SetBackgroundThreads(10, Env::Priority::LOW) Means that the 'LOW' threadpool has less than 10 threads.

Example

For the detail ,you can see the example/threadpool_test.cc

std::atomic<int> last_id(0);

auto* thread_pool1 = new ThreadPoolImpl();
auto* thread_pool2 = new ThreadPoolImpl();

// Set the background threads in threadpool
// threadpool1 have 3 threads and with lower IO priority
// threadpool2 have 7 threads and with lower CPU priority
thread_pool1->SetBackgroundThreads(3);
thread_pool2->SetBackgroundThreads(7);

thread_pool1->LowerIOPriority();
thread_pool2->LowerCPUPriority();

for (int i = 0, j = 0;i < 10; j++,i ++) {
    Cxt cxt_i(&last_id, i);
    Cxt cxt_j(&last_id, j);
    if (i % 2 == 0 ) {
        thread_pool1->Schedule(&Thread1, &cxt_i, &cxt_i, &finish1);
    } else {
        thread_pool2->Schedule(&Thread2, &cxt_j, &cxt_j, &finish1);
    }
}

Cxt cxt_us(&last_id, 1);
thread_pool1->UnSchedule(&cxt_us);
thread_pool2->UnSchedule(&cxt_us);