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// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/apple/dispatch_source.h"
#include "base/apple/scoped_dispatch_object.h"
namespace base::apple {
struct DispatchSource::Storage {
// The dispatch queue used to service the source_.
ScopedDispatchObject<dispatch_queue_t> queue;
// Dispatch source type, either DISPATCH_SOURCE_TYPE_MACH_RECV,
// DISPATCH_SOURCE_TYPE_READ or DISPATCH_SOURCE_TYPE_WRITE.
ScopedDispatchObject<dispatch_source_t> source;
// Semaphore used to wait on the |source_|'s cancellation in the destructor.
ScopedDispatchObject<dispatch_semaphore_t> source_canceled;
};
DispatchSource::DispatchSource(const char* name,
mach_port_t port,
void (^event_handler)())
: DispatchSource(dispatch_queue_create(name, DISPATCH_QUEUE_SERIAL),
port,
event_handler) {
// Since the queue was created above in the delegated constructor, and it was
// subsequently retained, release it here.
dispatch_release(storage_->queue.get());
}
DispatchSource::DispatchSource(dispatch_queue_t queue,
int fd,
dispatch_source_type_t type,
void (^event_handler)())
: storage_(std::make_unique<Storage>()) {
DCHECK(type == DISPATCH_SOURCE_TYPE_READ ||
type == DISPATCH_SOURCE_TYPE_WRITE);
storage_->queue.reset(queue, base::scoped_policy::RETAIN);
storage_->source.reset(dispatch_source_create(
type, static_cast<uintptr_t>(fd), 0, storage_->queue.get()));
storage_->source_canceled.reset(dispatch_semaphore_create(0));
dispatch_source_set_event_handler(storage_->source.get(), event_handler);
dispatch_source_set_cancel_handler(storage_->source.get(), ^{
dispatch_semaphore_signal(storage_->source_canceled.get());
});
}
DispatchSource::DispatchSource(dispatch_queue_t queue,
mach_port_t port,
void (^event_handler)())
: storage_(std::make_unique<Storage>()) {
storage_->queue.reset(queue, base::scoped_policy::RETAIN);
storage_->source.reset(dispatch_source_create(
DISPATCH_SOURCE_TYPE_MACH_RECV, port, 0, storage_->queue.get()));
storage_->source_canceled.reset(dispatch_semaphore_create(0));
dispatch_source_set_event_handler(storage_->source.get(), event_handler);
dispatch_source_set_cancel_handler(storage_->source.get(), ^{
dispatch_semaphore_signal(storage_->source_canceled.get());
});
}
DispatchSource::~DispatchSource() {
if (suspended_) {
Resume();
}
// Cancel the source and wait for the semaphore to be signaled. This will
// ensure the source managed by this class is not used after it is freed.
dispatch_source_cancel(storage_->source.get());
storage_->source.reset();
dispatch_semaphore_wait(storage_->source_canceled.get(),
DISPATCH_TIME_FOREVER);
}
void DispatchSource::Resume() {
if (!suspended_) {
return;
}
suspended_ = false;
dispatch_resume(storage_->source.get());
}
void DispatchSource::Suspend() {
if (suspended_) {
return;
}
suspended_ = true;
dispatch_suspend(storage_->source.get());
}
dispatch_queue_t DispatchSource::Queue() const {
return storage_->queue.get();
}
} // namespace base::apple
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