//===-- MICmnThreadMgrStd.h -------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#pragma once

// Third party headers:
#include <vector>

// In-house headers:
#include "MICmnBase.h"
#include "MIUtilThreadBaseStd.h"
#include "MICmnResources.h"
#include "MIUtilSingletonBase.h"

//++ ============================================================================
// Details: MI's worker thread (active thread) manager.
//          The manager creates threads and behalf of clients. Client are
//          responsible for their threads and can delete them when necessary.
//          This manager will stop and delete all threads on *this manager's
//          shutdown.
//          Singleton class.
// Gotchas: None.
// Authors: Aidan Dodds 12/03/2014.
// Changes: None.
//--
class CMICmnThreadMgrStd : public CMICmnBase, public MI::ISingleton<CMICmnThreadMgrStd>
{
    friend MI::ISingleton<CMICmnThreadMgrStd>;

    // Methods:
  public:
    bool Initialize(void);
    bool Shutdown(void);
    bool
    ThreadAllTerminate(void); // Ask all threads to stop (caution)
    template <typename T>     // Ask the thread manager to start and stop threads on our behalf
    bool ThreadStart(T &vrwObject);

    // Typedef:
  private:
    typedef std::vector<CMIUtilThreadActiveObjBase *> ThreadList_t;

    // Methods:
  private:
    /* ctor */ CMICmnThreadMgrStd(void);
    /* ctor */ CMICmnThreadMgrStd(const CMICmnThreadMgrStd &);
    void operator=(const CMICmnThreadMgrStd &);
    //
    bool
    AddThread(const CMIUtilThreadActiveObjBase &vrObj); // Add a thread for monitoring by the threadmanager

    // Overridden:
  private:
    // From CMICmnBase
    /* dtor */ virtual ~CMICmnThreadMgrStd(void);

    // Attributes:
  private:
    CMIUtilThreadMutex m_mutex;
    ThreadList_t m_threadList;
};

//++ ------------------------------------------------------------------------------------
// Details: Given a thread object start its (worker) thread to do work. The object is
//          added to the *this manager for housekeeping and deletion of all thread objects.
// Type:    Template method.
// Args:    vrwThreadObj      - (RW) A CMIUtilThreadActiveObjBase derived object.
// Return:  MIstatus::success - Functional succeeded.
//          MIstatus::failure - Functional failed.
// Throws:  None.
//--
template <typename T>
bool
CMICmnThreadMgrStd::ThreadStart(T &vrwThreadObj)
{
    bool bOk = MIstatus::success;

    // Grab a reference to the base object type
    CMIUtilThreadActiveObjBase &rObj = static_cast<CMIUtilThreadActiveObjBase &>(vrwThreadObj);

    // Add to the thread managers internal database
    bOk &= AddThread(rObj);
    if (!bOk)
    {
        const CMIUtilString errMsg(
            CMIUtilString::Format(MIRSRC(IDS_THREADMGR_ERR_THREAD_FAIL_CREATE), vrwThreadObj.ThreadGetName().c_str()));
        SetErrorDescription(errMsg);
        return MIstatus::failure;
    }

    // Grab a reference on behalf of the caller
    bOk &= vrwThreadObj.Acquire();
    if (!bOk)
    {
        const CMIUtilString errMsg(
            CMIUtilString::Format(MIRSRC(IDS_THREADMGR_ERR_THREAD_FAIL_CREATE), vrwThreadObj.ThreadGetName().c_str()));
        SetErrorDescription(errMsg);
        return MIstatus::failure;
    }

    // Thread is already started
    // This call must come after the reference count increment
    if (vrwThreadObj.ThreadIsActive())
    {
        // Early exit on thread already running condition
        return MIstatus::success;
    }

    // Start the thread running
    bOk &= vrwThreadObj.ThreadExecute();
    if (!bOk)
    {
        const CMIUtilString errMsg(
            CMIUtilString::Format(MIRSRC(IDS_THREADMGR_ERR_THREAD_FAIL_CREATE), vrwThreadObj.ThreadGetName().c_str()));
        SetErrorDescription(errMsg);
        return MIstatus::failure;
    }

    return MIstatus::success;
}
