7b98814d02
unix implementation of uv_async_t has been wasting cpu cycles for nothing since 1.29.0 release implement efficient callback scheduling for linux
79 lines
1.4 KiB
C++
79 lines
1.4 KiB
C++
#include "base/io/Async.h"
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#if defined(XMRIG_UV_PERFORMANCE_BUG)
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#include <sys/eventfd.h>
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#include <sys/poll.h>
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#include <unistd.h>
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#include <cstdlib>
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namespace xmrig {
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uv_async_t::~uv_async_t()
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{
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close(m_fd);
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}
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static void on_schedule(uv_poll_t *handle, int status, int events)
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{
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static uint64_t val;
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uv_async_t *async = reinterpret_cast<uv_async_t *>(handle);
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for (;;) {
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int r = read(async->m_fd, &val, sizeof(val));
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if (r == sizeof(val))
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continue;
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if (r != -1)
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break;
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if (errno == EAGAIN || errno == EWOULDBLOCK)
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break;
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if (errno == EINTR)
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continue;
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abort();
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}
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if (async->m_cb) {
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(*async->m_cb)(async);
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}
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}
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int uv_async_init(uv_loop_t *loop, uv_async_t *async, uv_async_cb cb)
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{
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int fd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
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if (fd < 0) {
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return uv_translate_sys_error(errno);
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}
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uv_poll_init(loop, (uv_poll_t *)async, fd);
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uv_poll_start((uv_poll_t *)async, POLLIN, on_schedule);
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async->m_cb = cb;
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async->m_fd = fd;
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return 0;
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}
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int uv_async_send(uv_async_t *async)
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{
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static const uint64_t val = 1;
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int r;
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do {
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r = write(async->m_fd, &val, sizeof(val));
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}
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while (r == -1 && errno == EINTR);
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if (r == sizeof(val) || (r == 1 && (errno == EAGAIN || errno == EWOULDBLOCK))) {
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return 0;
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}
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abort();
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}
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} // namespace xmrig
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#endif
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