Core: fixed a race resulting in extra sem_post()'s. The mtx->wait counter was not decremented if we were able to obtain the lock right after incrementing it. This resulted in unneeded sem_post() calls, eventually leading to EOVERFLOW errors being logged, "sem_post() failed while wake shmtx (75: Value too large for defined data type)". To close the race, mtx->wait is now decremented if we obtain the lock right after incrementing it in ngx_shmtx_lock(). The result can become -1 if a concurrent ngx_shmtx_unlock() decrements mtx->wait before the added code does. However, that only leads to one extra iteration in the next call of ngx_shmtx_lock().

// stub module to test header files' C++ compatibility

extern "C" {
  #include <ngx_config.h>
  #include <ngx_core.h>
  #include <ngx_event.h>
  #include <ngx_event_connect.h>
  #include <ngx_event_pipe.h>

  #include <ngx_http.h>

  #include <ngx_mail.h>
  #include <ngx_mail_pop3_module.h>
  #include <ngx_mail_imap_module.h>
  #include <ngx_mail_smtp_module.h>
}

// nginx header files should go before other, because they define 64-bit off_t
// #include <string>


void ngx_cpp_test_handler(void *data);

void
ngx_cpp_test_handler(void *data)
{
    return;
}