84 lines
2.1 KiB
C++
84 lines
2.1 KiB
C++
#include "../globals.h"
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/*
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* Conditional variable. Implemented using pthreads condition variables, and
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* using events on windows.
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*/
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#include "condition_variable.h"
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// #define TRACE
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#if defined(__WIN32__)
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condition_variable::condition_variable() {
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_event = CreateEvent(NULL, FALSE, FALSE, NULL);
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}
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#else
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condition_variable::condition_variable() {
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pthread_cond_init(&_cond, NULL);
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pthread_mutex_init(&_mutex, NULL);
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}
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#endif
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condition_variable::~condition_variable() {
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#if defined(__WIN32__)
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CloseHandle(_event);
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#else
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pthread_cond_destroy(&_cond);
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pthread_mutex_destroy(&_mutex);
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#endif
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}
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/**
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* Wait indefinitely until condition is signaled.
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*/
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void condition_variable::wait() {
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timed_wait(0);
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}
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void condition_variable::timed_wait(size_t timeout_in_ns) {
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#ifdef TRACE
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printf("waiting on condition_variable: 0x%" PRIxPTR " for %d ns. \n",
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(uintptr_t) this, (int) timeout_in_ns);
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#endif
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#if defined(__WIN32__)
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WaitForSingleObject(_event, INFINITE);
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#else
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pthread_mutex_lock(&_mutex);
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// wait() automatically releases the mutex while it waits, and acquires
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// it right before exiting. This allows signal() to acquire the mutex
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// when signaling.)
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if (timeout_in_ns == 0) {
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pthread_cond_wait(&_cond, &_mutex);
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} else {
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timeval time_val;
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gettimeofday(&time_val, NULL);
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timespec time_spec;
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time_spec.tv_sec = time_val.tv_sec + 0;
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time_spec.tv_nsec = time_val.tv_usec * 1000 + timeout_in_ns;
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pthread_cond_timedwait(&_cond, &_mutex, &time_spec);
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}
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pthread_mutex_unlock(&_mutex);
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#endif
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#ifdef TRACE
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printf("resumed on condition_variable: 0x%" PRIxPTR "\n",
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(uintptr_t)this);
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#endif
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}
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/**
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* Signal condition, and resume the waiting thread.
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*/
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void condition_variable::signal() {
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#if defined(__WIN32__)
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SetEvent(_event);
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#else
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pthread_mutex_lock(&_mutex);
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pthread_cond_signal(&_cond);
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pthread_mutex_unlock(&_mutex);
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#endif
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#ifdef TRACE
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printf("signal condition_variable: 0x%" PRIxPTR "\n",
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(uintptr_t)this);
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#endif
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}
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