//===-- HostThreadFreeBSD.cpp -----------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// lldb Includes
#include "lldb/Host/freebsd/HostThreadFreeBSD.h"
#include "lldb/Host/Host.h"

// C includes
#include <errno.h>
#include <pthread.h>
#if defined(__FreeBSD__)
#include <pthread_np.h>
#endif
#include <stdlib.h>
#include <sys/sysctl.h>
#include <sys/user.h>

// C++ includes
#include <string>

using namespace lldb_private;

HostThreadFreeBSD::HostThreadFreeBSD() {}

HostThreadFreeBSD::HostThreadFreeBSD(lldb::thread_t thread)
    : HostThreadPosix(thread) {}

void HostThreadFreeBSD::GetName(lldb::tid_t tid,
                                llvm::SmallVectorImpl<char> &name) {
  name.clear();
  int pid = Host::GetCurrentProcessID();

  struct kinfo_proc *kp = nullptr, *nkp;
  size_t len = 0;
  int error;
  int ctl[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PID | KERN_PROC_INC_THREAD,
                (int)pid};

  while (1) {
    error = sysctl(ctl, 4, kp, &len, nullptr, 0);
    if (kp == nullptr || (error != 0 && errno == ENOMEM)) {
      // Add extra space in case threads are added before next call.
      len += sizeof(*kp) + len / 10;
      nkp = (struct kinfo_proc *)realloc(kp, len);
      if (nkp == nullptr) {
        free(kp);
        return;
      }
      kp = nkp;
      continue;
    }
    if (error != 0)
      len = 0;
    break;
  }

  for (size_t i = 0; i < len / sizeof(*kp); i++) {
    if (kp[i].ki_tid == (lwpid_t)tid) {
      name.append(kp[i].ki_tdname, kp[i].ki_tdname + strlen(kp[i].ki_tdname));
      break;
    }
  }
  free(kp);
}
