wake_host.h

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#pragma once
 
#include "esphome/core/defines.h"
 
#ifdef USE_HOST
 
#include "esphome/core/hal.h"
 
#include <sys/select.h>
#include <sys/socket.h>
 
namespace esphome {
 
void wake_loop_threadsafe();
void wake_scheduler_threadsafe();
 
bool wake_register_fd(int fd);
 
void wake_unregister_fd(int fd);
 
void wake_setup();
 
inline void wake_loop_any_context() { wake_loop_threadsafe(); }
 
namespace internal {
void wakeable_delay(uint32_t ms);
 
// File-scope state owned by wake_host.cpp. Accessed inline by
// wake_drain_notifications() and wake_fd_ready() so the hot path stays in the header.
// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
extern int g_wake_socket_fd;
// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
extern fd_set g_read_fds;
}  // namespace internal
 
inline bool ESPHOME_ALWAYS_INLINE wake_fd_ready(int fd) { return FD_ISSET(fd, &internal::g_read_fds); }
 
// Small buffer for draining wake notification bytes (1 byte sent per wake).
// Sized to drain multiple notifications per recvfrom() without wasting stack.
inline constexpr size_t WAKE_NOTIFY_DRAIN_BUFFER_SIZE = 16;
 
inline void ESPHOME_ALWAYS_INLINE wake_drain_notifications() {
  // Called from main loop to drain any pending wake notifications.
  // Must check wake_fd_ready() to avoid blocking on empty socket.
  if (internal::g_wake_socket_fd >= 0 && wake_fd_ready(internal::g_wake_socket_fd)) {
    char buffer[WAKE_NOTIFY_DRAIN_BUFFER_SIZE];
    // Drain all pending notifications with non-blocking reads. Multiple wake events
    // may have triggered multiple writes, so drain until EWOULDBLOCK. We control
    // both ends of this loopback socket (always 1 byte per wake), so no error
    // checking — any error indicates catastrophic system failure.
    while (::recvfrom(internal::g_wake_socket_fd, buffer, sizeof(buffer), 0, nullptr, nullptr) > 0) {
    }
  }
}
 
}  // namespace esphome
 
#endif  // USE_HOST