mirror of https://github.com/ArduPilot/ardupilot
42 lines
1.2 KiB
C
42 lines
1.2 KiB
C
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// -*- 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
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#define AP_SEMAPHORE
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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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// some global semaphores
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extern AP_Semaphore AP_Semaphore_spi3;
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#endif // AP_SEMAPHORE
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