Condition.hpp

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// ======================================================================
// \title Os/Condition.hpp
// \brief common function definitions for Os::ConditionVariables
// ======================================================================
#include "Os/Mutex.hpp"
#include "Os/Os.hpp"

#ifndef OS_CONDITION_HPP_
#define OS_CONDITION_HPP_

namespace Os {

class ConditionVariableHandle {};

class ConditionVariableInterface {
  public:
    enum Status {
        OP_OK,                  
        ERROR_MUTEX_NOT_HELD,   
        ERROR_DIFFERENT_MUTEX,  
        ERROR_NOT_IMPLEMENTED,  
        NOT_SUPPORTED,          
        ERROR_OTHER             
    };

    ConditionVariableInterface() = default;
    virtual ~ConditionVariableInterface() = default;

    ConditionVariableInterface(const ConditionVariableInterface& other) = delete;

    virtual ConditionVariableInterface& operator=(const ConditionVariableInterface& other) = delete;

    virtual Status pend(Os::Mutex& mutex) = 0;

    virtual void notify() = 0;

    virtual void notifyAll() = 0;

    virtual ConditionVariableHandle* getHandle() = 0;

    static ConditionVariableInterface* getDelegate(ConditionVariableHandleStorage& aligned_new_memory);
};

class ConditionVariable final : public ConditionVariableInterface {
  public:
    ConditionVariable();

    ~ConditionVariable() final;

    ConditionVariable(const ConditionVariableInterface& other) = delete;

    ConditionVariable(const ConditionVariableInterface* other) = delete;

    ConditionVariableInterface& operator=(const ConditionVariableInterface& other) override = delete;

    Status pend(Os::Mutex& mutex) override;

    void wait(Os::Mutex& mutex);

    void notify() override;

    void notifyAll() override;

    ConditionVariableHandle* getHandle() override;

  private:
    Os::Mutex* m_lock = nullptr;

    // This section is used to store the implementation-defined file handle. To Os::File and fprime, this type is
    // opaque and thus normal allocation cannot be done. Instead, we allow the implementor to store then handle in
    // the byte-array here and set `handle` to that address for storage.
    alignas(FW_HANDLE_ALIGNMENT)
        ConditionVariableHandleStorage m_handle_storage;  
    ConditionVariableInterface& m_delegate;               
};
}  // namespace Os
#endif  // OS_CONDITION_HPP_