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//===-- PThreadEvent.cpp ----------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Created by Greg Clayton on 6/16/07.
//
//===----------------------------------------------------------------------===//
#include "PThreadEvent.h"
#include "DNBLog.h"
#include <cerrno>
PThreadEvent::PThreadEvent(uint32_t bits, uint32_t validBits)
: m_mutex(), m_set_condition(), m_bits(bits), m_validBits(validBits),
m_reset_ack_mask(0) {
// DNBLogThreadedIf(LOG_EVENTS, "%p PThreadEvent::%s (0x%8.8x, 0x%8.8x)",
// this, __FUNCTION__, bits, validBits);
}
PThreadEvent::~PThreadEvent() {
// DNBLogThreadedIf(LOG_EVENTS, "%p %s", this, LLVM_PRETTY_FUNCTION);
}
uint32_t PThreadEvent::NewEventBit() {
// DNBLogThreadedIf(LOG_EVENTS, "%p %s", this, LLVM_PRETTY_FUNCTION);
std::lock_guard<std::mutex> guard(m_mutex);
uint32_t mask = 1;
while (mask & m_validBits)
mask <<= 1;
m_validBits |= mask;
return mask;
}
void PThreadEvent::FreeEventBits(const uint32_t mask) {
// DNBLogThreadedIf(LOG_EVENTS, "%p PThreadEvent::%s (0x%8.8x)", this,
// __FUNCTION__, mask);
if (mask) {
std::lock_guard<std::mutex> guard(m_mutex);
m_bits &= ~mask;
m_validBits &= ~mask;
}
}
uint32_t PThreadEvent::GetEventBits() const {
// DNBLogThreadedIf(LOG_EVENTS, "%p %s", this, LLVM_PRETTY_FUNCTION);
std::lock_guard<std::mutex> guard(m_mutex);
uint32_t bits = m_bits;
return bits;
}
// Replace the event bits with a new bitmask value
void PThreadEvent::ReplaceEventBits(const uint32_t bits) {
// DNBLogThreadedIf(LOG_EVENTS, "%p PThreadEvent::%s (0x%8.8x)", this,
// __FUNCTION__, bits);
std::lock_guard<std::mutex> guard(m_mutex);
// Make sure we have some bits and that they aren't already set...
if (m_bits != bits) {
// Figure out which bits are changing
uint32_t changed_bits = m_bits ^ bits;
// Set the new bit values
m_bits = bits;
// If any new bits are set, then broadcast
if (changed_bits & m_bits)
m_set_condition.notify_all();
}
}
// Set one or more event bits and broadcast if any new event bits get set
// that weren't already set.
void PThreadEvent::SetEvents(const uint32_t mask) {
// DNBLogThreadedIf(LOG_EVENTS, "%p PThreadEvent::%s (0x%8.8x)", this,
// __FUNCTION__, mask);
// Make sure we have some bits to set
if (mask) {
std::lock_guard<std::mutex> guard(m_mutex);
// Save the old event bit state so we can tell if things change
uint32_t old = m_bits;
// Set the all event bits that are set in 'mask'
m_bits |= mask;
// Broadcast only if any extra bits got set.
if (old != m_bits)
m_set_condition.notify_all();
}
}
// Reset one or more event bits
void PThreadEvent::ResetEvents(const uint32_t mask) {
// DNBLogThreadedIf(LOG_EVENTS, "%p PThreadEvent::%s (0x%8.8x)", this,
// __FUNCTION__, mask);
if (mask) {
std::lock_guard<std::mutex> guard(m_mutex);
// Clear the all event bits that are set in 'mask'
m_bits &= ~mask;
}
}
static std::chrono::nanoseconds ToDuration(timespec ts) {
auto duration =
std::chrono::seconds{ts.tv_sec} + std::chrono::nanoseconds{ts.tv_nsec};
return std::chrono::duration_cast<std::chrono::nanoseconds>(duration);
}
static std::chrono::time_point<std::chrono::system_clock,
std::chrono::nanoseconds>
ToTimePoint(timespec ts) {
return std::chrono::time_point<std::chrono::system_clock,
std::chrono::nanoseconds>{
std::chrono::duration_cast<std::chrono::system_clock::duration>(
ToDuration(ts))};
}
// Wait until 'timeout_abstime' for any events that are set in
// 'mask'. If 'timeout_abstime' is NULL, then wait forever.
uint32_t
PThreadEvent::WaitForEventsImpl(const uint32_t mask,
const struct timespec *timeout_abstime,
std::function<bool()> predicate) const {
// DNBLogThreadedIf(LOG_EVENTS, "%p PThreadEvent::%s (0x%8.8x, %p)", this,
// __FUNCTION__, mask, timeout_abstime);
std::unique_lock<std::mutex> lock(m_mutex);
if (timeout_abstime) {
// Wait for condition to get broadcast, or for a timeout. If we get
// a timeout we will drop out of the loop on the next iteration and we
// will recompute the mask in case of a race between the condition and the
// timeout.
m_set_condition.wait_until(lock, ToTimePoint(*timeout_abstime), predicate);
} else {
// Wait for condition to get broadcast.
m_set_condition.wait(lock, predicate);
}
// Either the predicate passed, we hit the specified timeout (ETIMEDOUT) or we
// encountered an unrecoverable error (EINVAL, EPERM). Regardless of how we
// got here, recompute and return the mask indicating which bits (if any) are
// set.
return GetBitsMasked(mask);
}
uint32_t
PThreadEvent::WaitForSetEvents(const uint32_t mask,
const struct timespec *timeout_abstime) const {
auto predicate = [&]() -> uint32_t { return GetBitsMasked(mask) != 0; };
return WaitForEventsImpl(mask, timeout_abstime, predicate);
}
uint32_t PThreadEvent::WaitForEventsToReset(
const uint32_t mask, const struct timespec *timeout_abstime) const {
auto predicate = [&]() -> uint32_t { return GetBitsMasked(mask) == 0; };
return WaitForEventsImpl(mask, timeout_abstime, predicate);
}
uint32_t
PThreadEvent::WaitForResetAck(const uint32_t mask,
const struct timespec *timeout_abstime) const {
if (mask & m_reset_ack_mask) {
// DNBLogThreadedIf(LOG_EVENTS, "%p PThreadEvent::%s (0x%8.8x, %p)", this,
// __FUNCTION__, mask, timeout_abstime);
return WaitForEventsToReset(mask & m_reset_ack_mask, timeout_abstime);
}
return 0;
}
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