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31 lines
679 B
C++
31 lines
679 B
C++
#include "./semaphore.h"
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#include "../interrupt/guard.h"
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#include "../thread/scheduler.h"
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uint8_t counter;
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Queue<Thread> waiting;
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Semaphore::Semaphore(unsigned c) {
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counter=c;
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}
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void Semaphore::p(Vault &vault) {
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//resource is frei, läuft direkt weiter
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if (vault.counter > 0)
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vault.counter--;
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else
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//thread block, zu aktueller queue hinzufügen und
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waiting.enqueue(*vault.sch.active()); //was is der calling thread
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//
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}
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//release
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void Semaphore::v(Vault &vault) {
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Thread* first = waiting.dequeue();
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if (first != nullptr)
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vault.sch.ready(first); //wakeup "first" thread
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else
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vault.counter++;
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}
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