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39 lines
1.2 KiB
39 lines
1.2 KiB
// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: t -*- |
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/// @file AP_Semaphore.h |
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/// @brief class to ensure conflicts over shared resources are avoided |
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#ifndef __AP_SEMAPHORE_H__ |
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#define __AP_SEMAPHORE_H__ |
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#include <FastSerial.h> |
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#include <AP_Common.h> |
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#include <AP_Math.h> // ArduPilot Mega Vector/Matrix math Library |
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// the callback type for call_on_release. They are passed in a pointer to the semaphore |
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typedef void (*ap_semaphore_callback)(); |
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/// @class AP_Semaphore |
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class AP_Semaphore { |
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public: |
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// Constructor |
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AP_Semaphore(); |
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// get - to claim ownership of the semaphore |
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virtual bool get(void* caller); |
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// release - to give up ownership of the semaphore |
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virtual bool release(void* caller); |
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// call_on_release - returns true if caller successfully added to the queue to be called back |
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virtual bool call_on_release(void* caller, ap_semaphore_callback callback_fn); |
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protected: |
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bool _taken; |
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void* _owner; |
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void* _waiting_owner; |
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ap_semaphore_callback _waiting_callback; // call back procedure of process waiting for sempahore |
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}; |
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#endif // __AP_SEMAPHORE_H__
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