io.cpp

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/*
 * Zth (libzth), a cooperative userspace multitasking library.
 * Copyright (C) 2019-2022  Jochem Rutgers
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */
 
#include <libzth/config.h>
#include <libzth/io.h>
#include <libzth/poller.h>
#include <libzth/util.h>
#include <libzth/worker.h>
#include <libzth/zmq.h>
 
#if defined(ZTH_HAVE_POLLER) && !defined(ZTH_OS_WINDOWS)
#       include <fcntl.h>
 
namespace zth {
namespace io {
 
ssize_t read(int fd, void* buf, size_t count)
{
        perf_syscall("read()");
 
        int flags = fcntl(fd, F_GETFL);
        if(unlikely(flags == -1))
                return -1; // with errno set
 
        // NOLINTNEXTLINE(hicpp-signed-bitwise)
        if((flags & O_NONBLOCK)) {
                zth_dbg(io, "[%s] read(%d) non-blocking", currentFiber().str().c_str(), fd);
                // Just do the call.
                return ::read(fd, buf, count);
        }
 
        if((errno = zth::poll(PollableFd(fd, Pollable::PollIn), -1)))
                return -1;
 
        // Got data to read.
        zth_dbg(io, "[%s] read(%d)", currentFiber().str().c_str(), fd);
        return ::read(fd, buf, count);
}
 
ssize_t write(int fd, void const* buf, size_t count)
{
        perf_syscall("write()");
 
        int flags = fcntl(fd, F_GETFL);
        if(unlikely(flags == -1))
                return -1; // with errno set
 
        // NOLINTNEXTLINE(hicpp-signed-bitwise)
        if((flags & O_NONBLOCK)) {
                zth_dbg(io, "[%s] write(%d) non-blocking", currentFiber().str().c_str(), fd);
                // Just do the call.
                return ::write(fd, buf, count);
        }
 
        if((errno = zth::poll(PollableFd(fd, Pollable::PollOut), -1)))
                return -1;
 
        // Go write the data.
        zth_dbg(io, "[%s] write(%d)", currentFiber().str().c_str(), fd);
        return ::write(fd, buf, count);
}
 
} // namespace io
} // namespace zth
#else
static int no_io __attribute__((unused));
#endif // ZTH_HAVE_POLLER