thread.c

 
#include <winpr/config.h>
 
#include <winpr/winpr.h>
#include <winpr/assert.h>
 
#include <winpr/handle.h>
 
#include <winpr/thread.h>
 
#if defined(__FreeBSD__)
#include <pthread_np.h>
#elif defined(__linux__)
#include <sys/syscall.h>
#endif
 
#ifndef MIN
#define MIN(x, y) (((x) < (y)) ? (x) : (y))
#endif
 
#ifndef MAX
#define MAX(x, y) (((x) > (y)) ? (x) : (y))
#endif
 
#ifndef _WIN32
 
#include <pthread.h>
#include <winpr/crt.h>
#include <winpr/platform.h>
 
#include <string.h>
#ifdef WINPR_HAVE_UNISTD_H
#include <unistd.h>
#endif
 
#ifdef WINPR_HAVE_SYS_EVENTFD_H
#include <sys/eventfd.h>
#endif
 
#include <winpr/debug.h>
 
#include <errno.h>
#include <fcntl.h>
 
#include <winpr/collections.h>
 
#include "thread.h"
#include "apc.h"
 
#include "../handle/handle.h"
#include "../log.h"
#define TAG WINPR_TAG("thread")
 
static WINPR_THREAD mainThread;
 
#if defined(WITH_THREAD_LIST)
static wListDictionary* thread_list = nullptr;
#endif
 
static BOOL ThreadCloseHandle(HANDLE handle);
static void cleanup_handle(void* obj);
 
static BOOL ThreadIsHandled(HANDLE handle)
{
  return WINPR_HANDLE_IS_HANDLED(handle, HANDLE_TYPE_THREAD, FALSE);
}
 
static int ThreadGetFd(HANDLE handle)
{
  WINPR_THREAD* pThread = (WINPR_THREAD*)handle;
 
  if (!ThreadIsHandled(handle))
    return -1;
 
  return pThread->event.fds[0];
}
 
#define run_mutex_init(fkt, mux, arg) run_mutex_init_(fkt, #fkt, mux, arg)
static BOOL run_mutex_init_(int (*fkt)(pthread_mutex_t*, const pthread_mutexattr_t*),
                            const char* name, pthread_mutex_t* mutex,
                            const pthread_mutexattr_t* mutexattr)
{
  int rc = 0;
 
  WINPR_ASSERT(fkt);
  WINPR_ASSERT(mutex);
 
  rc = fkt(mutex, mutexattr);
  if (rc != 0)
  {
    char ebuffer[256] = WINPR_C_ARRAY_INIT;
    WLog_WARN(TAG, "[%s] failed with [%s]", name, winpr_strerror(rc, ebuffer, sizeof(ebuffer)));
  }
  return rc == 0;
}
 
#define run_mutex_fkt(fkt, mux) run_mutex_fkt_(fkt, #fkt, mux)
static BOOL run_mutex_fkt_(int (*fkt)(pthread_mutex_t* mux), const char* name,
                           pthread_mutex_t* mutex)
{
  int rc = 0;
 
  WINPR_ASSERT(fkt);
  WINPR_ASSERT(mutex);
 
  rc = fkt(mutex);
  if (rc != 0)
  {
    char ebuffer[256] = WINPR_C_ARRAY_INIT;
    WLog_WARN(TAG, "[%s] failed with [%s]", name, winpr_strerror(rc, ebuffer, sizeof(ebuffer)));
  }
  return rc == 0;
}
 
#define run_cond_init(fkt, cond, arg) run_cond_init_(fkt, #fkt, cond, arg)
static BOOL run_cond_init_(int (*fkt)(pthread_cond_t*, const pthread_condattr_t*), const char* name,
                           pthread_cond_t* condition, const pthread_condattr_t* conditionattr)
{
  int rc = 0;
 
  WINPR_ASSERT(fkt);
  WINPR_ASSERT(condition);
 
  rc = fkt(condition, conditionattr);
  if (rc != 0)
  {
    char ebuffer[256] = WINPR_C_ARRAY_INIT;
    WLog_WARN(TAG, "[%s] failed with [%s]", name, winpr_strerror(rc, ebuffer, sizeof(ebuffer)));
  }
  return rc == 0;
}
 
#define run_cond_fkt(fkt, cond) run_cond_fkt_(fkt, #fkt, cond)
static BOOL run_cond_fkt_(int (*fkt)(pthread_cond_t* mux), const char* name,
                          pthread_cond_t* condition)
{
  int rc = 0;
 
  WINPR_ASSERT(fkt);
  WINPR_ASSERT(condition);
 
  rc = fkt(condition);
  if (rc != 0)
  {
    char ebuffer[256] = WINPR_C_ARRAY_INIT;
    WLog_WARN(TAG, "[%s] failed with [%s]", name, winpr_strerror(rc, ebuffer, sizeof(ebuffer)));
  }
  return rc == 0;
}
 
static int pthread_mutex_checked_unlock(pthread_mutex_t* mutex)
{
  WINPR_ASSERT(mutex);
  WINPR_ASSERT(pthread_mutex_trylock(mutex) == EBUSY);
  return pthread_mutex_unlock(mutex);
}
 
static BOOL mux_condition_bundle_init(mux_condition_bundle* bundle)
{
  WINPR_ASSERT(bundle);
 
  bundle->val = FALSE;
  if (!run_mutex_init(pthread_mutex_init, &bundle->mux, nullptr))
    return FALSE;
 
  if (!run_cond_init(pthread_cond_init, &bundle->cond, nullptr))
    return FALSE;
  return TRUE;
}
 
static void mux_condition_bundle_uninit(mux_condition_bundle* bundle)
{
  mux_condition_bundle empty = WINPR_C_ARRAY_INIT;
 
  WINPR_ASSERT(bundle);
 
  run_cond_fkt(pthread_cond_destroy, &bundle->cond);
  run_mutex_fkt(pthread_mutex_destroy, &bundle->mux);
  *bundle = empty;
}
 
static BOOL mux_condition_bundle_signal(mux_condition_bundle* bundle)
{
  BOOL rc = TRUE;
  WINPR_ASSERT(bundle);
 
  if (!run_mutex_fkt(pthread_mutex_lock, &bundle->mux))
    return FALSE;
  bundle->val = TRUE;
  if (!run_cond_fkt(pthread_cond_signal, &bundle->cond))
    rc = FALSE;
  if (!run_mutex_fkt(pthread_mutex_checked_unlock, &bundle->mux))
    rc = FALSE;
  return rc;
}
 
static BOOL mux_condition_bundle_lock(mux_condition_bundle* bundle)
{
  WINPR_ASSERT(bundle);
  return run_mutex_fkt(pthread_mutex_lock, &bundle->mux);
}
 
static BOOL mux_condition_bundle_unlock(mux_condition_bundle* bundle)
{
  WINPR_ASSERT(bundle);
  return run_mutex_fkt(pthread_mutex_checked_unlock, &bundle->mux);
}
 
static BOOL mux_condition_bundle_wait(mux_condition_bundle* bundle, const char* name)
{
  BOOL rc = FALSE;
 
  WINPR_ASSERT(bundle);
  WINPR_ASSERT(name);
  WINPR_ASSERT(pthread_mutex_trylock(&bundle->mux) == EBUSY);
 
  while (!bundle->val)
  {
    int r = pthread_cond_wait(&bundle->cond, &bundle->mux);
    if (r != 0)
    {
      char ebuffer[256] = WINPR_C_ARRAY_INIT;
      WLog_ERR(TAG, "failed to wait for %s [%s]", name,
               winpr_strerror(r, ebuffer, sizeof(ebuffer)));
      switch (r)
      {
        case ENOTRECOVERABLE:
        case EPERM:
        case ETIMEDOUT:
        case EINVAL:
          goto fail;
 
        default:
          break;
      }
    }
  }
 
  rc = bundle->val;
 
fail:
  return rc;
}
 
static BOOL signal_thread_ready(WINPR_THREAD* thread)
{
  WINPR_ASSERT(thread);
 
  return mux_condition_bundle_signal(&thread->isCreated);
}
 
static BOOL signal_thread_is_running(WINPR_THREAD* thread)
{
  WINPR_ASSERT(thread);
 
  return mux_condition_bundle_signal(&thread->isRunning);
}
 
static DWORD ThreadCleanupHandle(HANDLE handle)
{
  DWORD status = WAIT_FAILED;
  WINPR_THREAD* thread = (WINPR_THREAD*)handle;
 
  if (!ThreadIsHandled(handle))
    return WAIT_FAILED;
 
  if (!run_mutex_fkt(pthread_mutex_lock, &thread->mutex))
    return WAIT_FAILED;
 
  if (!thread->joined)
  {
    int rc = pthread_join(thread->thread, nullptr);
 
    if (rc != 0)
    {
      char ebuffer[256] = WINPR_C_ARRAY_INIT;
      WLog_ERR(TAG, "pthread_join failure: [%d] %s", rc,
               winpr_strerror(rc, ebuffer, sizeof(ebuffer)));
      goto fail;
    }
    else
      thread->joined = TRUE;
  }
 
  status = WAIT_OBJECT_0;
 
fail:
  if (!run_mutex_fkt(pthread_mutex_checked_unlock, &thread->mutex))
    return WAIT_FAILED;
 
  return status;
}
 
static HANDLE_OPS ops = { ThreadIsHandled, ThreadCloseHandle, ThreadGetFd, ThreadCleanupHandle,
                        nullptr,         nullptr,           nullptr,     nullptr,
                        nullptr,         nullptr,           nullptr,     nullptr,
                        nullptr,         nullptr,           nullptr,     nullptr,
                        nullptr,         nullptr,           nullptr,     nullptr,
                        nullptr };
 
static void dump_thread(WINPR_THREAD* thread)
{
#if defined(WITH_DEBUG_THREADS)
  void* stack = winpr_backtrace(20);
  char** msg = nullptr;
  size_t used = 0;
  WLog_DBG(TAG, "Called from:");
  msg = winpr_backtrace_symbols(stack, &used);
 
  for (size_t i = 0; i < used; i++)
    WLog_DBG(TAG, "[%" PRIuz "]: %s", i, msg[i]);
 
  free((void*)msg);
  winpr_backtrace_free(stack);
  WLog_DBG(TAG, "Thread handle created still not closed!");
  msg = winpr_backtrace_symbols(thread->create_stack, &used);
 
  for (size_t i = 0; i < used; i++)
    WLog_DBG(TAG, "[%" PRIuz "]: %s", i, msg[i]);
 
  free((void*)msg);
 
  if (thread->started)
  {
    WLog_DBG(TAG, "Thread still running!");
  }
  else if (!thread->exit_stack)
  {
    WLog_DBG(TAG, "Thread suspended.");
  }
  else
  {
    WLog_DBG(TAG, "Thread exited at:");
    msg = winpr_backtrace_symbols(thread->exit_stack, &used);
 
    for (size_t i = 0; i < used; i++)
      WLog_DBG(TAG, "[%" PRIuz "]: %s", i, msg[i]);
 
    free((void*)msg);
  }
#else
  WINPR_UNUSED(thread);
#endif
}
 
static BOOL set_event(WINPR_THREAD* thread)
{
  return winpr_event_set(&thread->event);
}
 
static BOOL reset_event(WINPR_THREAD* thread)
{
  return winpr_event_reset(&thread->event);
}
 
#if defined(WITH_THREAD_LIST)
static BOOL thread_compare(const void* a, const void* b)
{
  const pthread_t* p1 = a;
  const pthread_t* p2 = b;
  BOOL rc = pthread_equal(*p1, *p2);
  return rc;
}
#endif
 
static INIT_ONCE threads_InitOnce = INIT_ONCE_STATIC_INIT;
static pthread_t mainThreadId;
static pthread_key_t currentThreadTlsIndex = 0;
 
static BOOL initializeThreads(WINPR_ATTR_UNUSED PINIT_ONCE InitOnce,
                              WINPR_ATTR_UNUSED PVOID Parameter, WINPR_ATTR_UNUSED PVOID* Context)
{
  if (!apc_init(&mainThread.apc))
  {
    WLog_ERR(TAG, "failed to initialize APC");
    goto out;
  }
 
  mainThread.common.Type = HANDLE_TYPE_THREAD;
  mainThreadId = pthread_self();
 
  const int res = pthread_key_create(&currentThreadTlsIndex, nullptr);
  if (res != 0)
  {
    WLog_ERR(TAG, "Major bug, unable to allocate a TLS value for currentThread");
    return FALSE;
  }
 
#if defined(WITH_THREAD_LIST)
  thread_list = ListDictionary_New(TRUE);
 
  if (!thread_list)
  {
    WLog_ERR(TAG, "Couldn't create global thread list");
    goto error_thread_list;
  }
 
  thread_list->objectKey.fnObjectEquals = thread_compare;
#endif
 
out:
  return TRUE;
}
 
static BOOL signal_and_wait_for_ready(WINPR_THREAD* thread)
{
  BOOL res = FALSE;
 
  WINPR_ASSERT(thread);
 
  if (!mux_condition_bundle_lock(&thread->isRunning))
    return FALSE;
 
  if (!signal_thread_ready(thread))
    goto fail;
 
  if (!mux_condition_bundle_wait(&thread->isRunning, "threadIsRunning"))
    goto fail;
 
#if defined(WITH_THREAD_LIST)
  if (!ListDictionary_Contains(thread_list, &thread->thread))
  {
    WLog_ERR(TAG, "Thread not in thread_list, startup failed!");
    goto fail;
  }
#endif
 
  res = TRUE;
 
fail:
  if (!mux_condition_bundle_unlock(&thread->isRunning))
    return FALSE;
 
  return res;
}
 
/* Thread launcher function responsible for registering
 * cleanup handlers and calling pthread_exit, if not done
 * in thread function. */
static void* thread_launcher(void* arg)
{
  DWORD rc = 0;
  WINPR_THREAD* thread = (WINPR_THREAD*)arg;
  LPTHREAD_START_ROUTINE fkt = nullptr;
 
  if (!thread)
  {
    WLog_ERR(TAG, "Called with invalid argument %p", arg);
    goto exit;
  }
 
  const int res = pthread_setspecific(currentThreadTlsIndex, thread);
  if (res != 0)
  {
    WLog_ERR(TAG, "thread %" PRIu64 ", unable to set current thread value",
             WINPR_CXX_COMPAT_CAST(uint64_t, pthread_self()));
    goto exit;
  }
 
  if (!(fkt = thread->lpStartAddress))
  {
    union
    {
      LPTHREAD_START_ROUTINE fkt;
      void* pv;
    } cnv;
    cnv.fkt = fkt;
    WLog_ERR(TAG, "Thread function argument is %p", cnv.pv);
    goto exit;
  }
 
  if (!signal_and_wait_for_ready(thread))
    goto exit;
 
  rc = fkt(thread->lpParameter);
exit:
 
  if (thread)
  {
    apc_cleanupThread(thread);
 
    if (!thread->exited)
      thread->dwExitCode = rc;
 
    set_event(thread);
 
    (void)signal_thread_ready(thread);
 
    if (thread->detached || !thread->started)
      cleanup_handle(thread);
  }
 
  return nullptr;
}
 
static BOOL winpr_StartThread(WINPR_THREAD* thread)
{
  BOOL rc = FALSE;
  BOOL locked = FALSE;
  pthread_attr_t attr = WINPR_C_ARRAY_INIT;
 
  if (!mux_condition_bundle_lock(&thread->isCreated))
    return FALSE;
  locked = TRUE;
 
  pthread_attr_init(&attr);
  pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
 
  if (thread->dwStackSize > 0)
    pthread_attr_setstacksize(&attr, thread->dwStackSize);
 
  thread->started = TRUE;
  reset_event(thread);
 
#if defined(WITH_THREAD_LIST)
  if (!ListDictionary_Add(thread_list, &thread->thread, thread))
  {
    WLog_ERR(TAG, "failed to add the thread to the thread list");
    goto error;
  }
#endif
 
  if (pthread_create(&thread->thread, &attr, thread_launcher, thread))
    goto error;
 
  if (!mux_condition_bundle_wait(&thread->isCreated, "threadIsCreated"))
    goto error;
 
  locked = FALSE;
  if (!mux_condition_bundle_unlock(&thread->isCreated))
    goto error;
 
  if (!signal_thread_is_running(thread))
  {
    WLog_ERR(TAG, "failed to signal the thread was ready");
    goto error;
  }
 
  rc = TRUE;
error:
  if (locked)
  {
    if (!mux_condition_bundle_unlock(&thread->isCreated))
      rc = FALSE;
  }
 
  pthread_attr_destroy(&attr);
 
  if (rc)
    dump_thread(thread);
 
  return rc;
}
 
BOOL SetThreadPriority(HANDLE hThread, int nPriority)
{
  ULONG Type = 0;
  WINPR_HANDLE* Object = nullptr;
 
  if (!winpr_Handle_GetInfo(hThread, &Type, &Object) || Object->Type != HANDLE_TYPE_THREAD)
    return FALSE;
 
  const int min = 19;
  const int max = 0;
  const int diff = (max - min);
  const int normal = min + diff / 2;
  const int off = MIN(1, diff / 4);
  int sched_priority = -1;
 
  switch (nPriority & ~(THREAD_MODE_BACKGROUND_BEGIN | THREAD_MODE_BACKGROUND_END))
  {
    case THREAD_PRIORITY_ABOVE_NORMAL:
      sched_priority = MIN(normal + off, max);
      break;
    case THREAD_PRIORITY_BELOW_NORMAL:
      sched_priority = MAX(normal - off, min);
      break;
    case THREAD_PRIORITY_HIGHEST:
      sched_priority = max;
      break;
    case THREAD_PRIORITY_IDLE:
      sched_priority = min;
      break;
    case THREAD_PRIORITY_LOWEST:
      sched_priority = min;
      break;
    case THREAD_PRIORITY_TIME_CRITICAL:
      sched_priority = max;
      break;
    default:
    case THREAD_PRIORITY_NORMAL:
      sched_priority = normal;
      break;
  }
#if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE >= 200809L) && defined(PTHREAD_SETSCHEDPRIO)
  WINPR_THREAD* thread = (WINPR_THREAD*)Object;
  const int rc = pthread_setschedprio(thread->thread, sched_priority);
  if (rc != 0)
  {
    char buffer[256] = WINPR_C_ARRAY_INIT;
    WLog_ERR(TAG, "pthread_setschedprio(%d) %s [%d]", sched_priority,
             winpr_strerror(rc, buffer, sizeof(buffer)), rc);
  }
  return rc == 0;
#else
  WLog_WARN(TAG, "pthread_setschedprio(%d) not implemented, requires POSIX 2008 or later",
            sched_priority);
  return TRUE;
#endif
}
 
HANDLE CreateThread(LPSECURITY_ATTRIBUTES lpThreadAttributes, size_t dwStackSize,
                    LPTHREAD_START_ROUTINE lpStartAddress, LPVOID lpParameter,
                    DWORD dwCreationFlags, WINPR_ATTR_UNUSED LPDWORD lpThreadId)
{
  HANDLE handle = nullptr;
  WINPR_THREAD* thread = (WINPR_THREAD*)calloc(1, sizeof(WINPR_THREAD));
 
  if (!thread)
    return nullptr;
 
  thread->dwStackSize = dwStackSize;
  thread->lpParameter = lpParameter;
  thread->lpStartAddress = lpStartAddress;
  thread->lpThreadAttributes = lpThreadAttributes;
  thread->common.ops = &ops;
#if defined(WITH_DEBUG_THREADS)
  thread->create_stack = winpr_backtrace(20);
  dump_thread(thread);
#endif
 
  if (!winpr_event_init(&thread->event))
  {
    WLog_ERR(TAG, "failed to create event");
    goto fail;
  }
 
  if (!run_mutex_init(pthread_mutex_init, &thread->mutex, nullptr))
  {
    WLog_ERR(TAG, "failed to initialize thread mutex");
    goto fail;
  }
 
  if (!apc_init(&thread->apc))
  {
    WLog_ERR(TAG, "failed to initialize APC");
    goto fail;
  }
 
  if (!mux_condition_bundle_init(&thread->isCreated))
    goto fail;
  if (!mux_condition_bundle_init(&thread->isRunning))
    goto fail;
 
  WINPR_HANDLE_SET_TYPE_AND_MODE(thread, HANDLE_TYPE_THREAD, WINPR_FD_READ);
  handle = (HANDLE)thread;
 
  if (!InitOnceExecuteOnce(&threads_InitOnce, initializeThreads, nullptr, nullptr))
    goto fail;
 
  if (!(dwCreationFlags & CREATE_SUSPENDED))
  {
    if (!winpr_StartThread(thread))
      goto fail;
  }
  else
  {
    if (!set_event(thread))
      goto fail;
  }
 
  return handle;
fail:
  cleanup_handle(thread);
  return nullptr;
}
 
void cleanup_handle(void* obj)
{
  WINPR_THREAD* thread = (WINPR_THREAD*)obj;
  if (!thread)
    return;
 
  if (!apc_uninit(&thread->apc))
    WLog_ERR(TAG, "failed to destroy APC");
 
  mux_condition_bundle_uninit(&thread->isCreated);
  mux_condition_bundle_uninit(&thread->isRunning);
  run_mutex_fkt(pthread_mutex_destroy, &thread->mutex);
 
  winpr_event_uninit(&thread->event);
 
#if defined(WITH_THREAD_LIST)
  ListDictionary_Remove(thread_list, &thread->thread);
#endif
#if defined(WITH_DEBUG_THREADS)
 
  if (thread->create_stack)
    winpr_backtrace_free(thread->create_stack);
 
  if (thread->exit_stack)
    winpr_backtrace_free(thread->exit_stack);
 
#endif
  free(thread);
}
 
BOOL ThreadCloseHandle(HANDLE handle)
{
  WINPR_THREAD* thread = (WINPR_THREAD*)handle;
 
#if defined(WITH_THREAD_LIST)
  if (!thread_list)
  {
    WLog_ERR(TAG, "Thread list does not exist, check call!");
    dump_thread(thread);
  }
  else if (!ListDictionary_Contains(thread_list, &thread->thread))
  {
    WLog_ERR(TAG, "Thread list does not contain this thread! check call!");
    dump_thread(thread);
  }
  else
  {
    ListDictionary_Lock(thread_list);
#endif
    dump_thread(thread);
 
    if ((thread->started) && (WaitForSingleObject(thread, 0) != WAIT_OBJECT_0))
    {
      WLog_DBG(TAG, "Thread running, setting to detached state!");
      thread->detached = TRUE;
      pthread_detach(thread->thread);
    }
    else
    {
      cleanup_handle(thread);
    }
 
#if defined(WITH_THREAD_LIST)
    ListDictionary_Unlock(thread_list);
  }
#endif
 
  return TRUE;
}
 
HANDLE CreateRemoteThread(WINPR_ATTR_UNUSED HANDLE hProcess,
                          WINPR_ATTR_UNUSED LPSECURITY_ATTRIBUTES lpThreadAttributes,
                          WINPR_ATTR_UNUSED size_t dwStackSize,
                          WINPR_ATTR_UNUSED LPTHREAD_START_ROUTINE lpStartAddress,
                          WINPR_ATTR_UNUSED LPVOID lpParameter,
                          WINPR_ATTR_UNUSED DWORD dwCreationFlags,
                          WINPR_ATTR_UNUSED LPDWORD lpThreadId)
{
  WLog_ERR(TAG, "not implemented");
  SetLastError(ERROR_CALL_NOT_IMPLEMENTED);
  return nullptr;
}
 
VOID ExitThread(DWORD dwExitCode)
{
#if defined(WITH_THREAD_LIST)
  DWORD rc;
  pthread_t tid = pthread_self();
 
  if (!thread_list)
  {
    WLog_ERR(TAG, "function called without existing thread list!");
#if defined(WITH_DEBUG_THREADS)
    DumpThreadHandles();
#endif
    pthread_exit(0);
  }
  else if (!ListDictionary_Contains(thread_list, &tid))
  {
    WLog_ERR(TAG, "function called, but no matching entry in thread list!");
#if defined(WITH_DEBUG_THREADS)
    DumpThreadHandles();
#endif
    pthread_exit(0);
  }
  else
  {
    WINPR_THREAD* thread;
    ListDictionary_Lock(thread_list);
    thread = ListDictionary_GetItemValue(thread_list, &tid);
    WINPR_ASSERT(thread);
    thread->exited = TRUE;
    thread->dwExitCode = dwExitCode;
#if defined(WITH_DEBUG_THREADS)
    thread->exit_stack = winpr_backtrace(20);
#endif
    ListDictionary_Unlock(thread_list);
    set_event(thread);
    rc = thread->dwExitCode;
 
    if (thread->detached || !thread->started)
      cleanup_handle(thread);
 
    pthread_exit((void*)(size_t)rc);
  }
#else
  WINPR_UNUSED(dwExitCode);
#endif
}
 
BOOL GetExitCodeThread(HANDLE hThread, LPDWORD lpExitCode)
{
  ULONG Type = 0;
  WINPR_HANDLE* Object = nullptr;
  WINPR_THREAD* thread = nullptr;
 
  if (!winpr_Handle_GetInfo(hThread, &Type, &Object) || Object->Type != HANDLE_TYPE_THREAD)
  {
    WLog_ERR(TAG, "hThread is not a thread");
    SetLastError(ERROR_INVALID_PARAMETER);
    return FALSE;
  }
 
  thread = (WINPR_THREAD*)Object;
  *lpExitCode = thread->dwExitCode;
  return TRUE;
}
 
WINPR_THREAD* winpr_GetCurrentThread(VOID)
{
  WINPR_THREAD* ret = nullptr;
 
  if (!InitOnceExecuteOnce(&threads_InitOnce, initializeThreads, nullptr, nullptr))
    return nullptr;
  if (mainThreadId == pthread_self())
    return (HANDLE)&mainThread;
 
  ret = pthread_getspecific(currentThreadTlsIndex);
  return ret;
}
 
HANDLE _GetCurrentThread(VOID)
{
  return (HANDLE)winpr_GetCurrentThread();
}
 
DWORD GetCurrentThreadId(VOID)
{
#if defined(__FreeBSD__)
  return WINPR_CXX_COMPAT_CAST(DWORD, pthread_getthreadid_np());
#elif defined(__OpenBSD__)
  return WINPR_CXX_COMPAT_CAST(DWORD, getthrid());
#elif defined(__linux__)
  return WINPR_CXX_COMPAT_CAST(DWORD, syscall(SYS_gettid));
#else
  pthread_t tid = pthread_self();
  /* Since pthread_t can be 64-bits on some systems, take just the    */
  /* lower 32-bits of it for the thread ID returned by this function. */
  uintptr_t ptid = WINPR_REINTERPRET_CAST(tid, pthread_t, uintptr_t);
#if UINTPTR_MAX > UINT32_MAX
  return (ptid & UINT32_MAX) ^ (ptid >> 32);
#else
  /* A 32-bit pthread_t already fits. Shifting it by 32 is undefined behaviour and
   * WebAssembly masks the shift count to 0, so the expression above returned
   * ptid ^ ptid == 0 for every thread, and critical sections took any thread for
   * the owner. */
  return WINPR_CXX_COMPAT_CAST(DWORD, ptid);
#endif
#endif
}
 
typedef struct
{
  WINPR_APC_ITEM apc;
  PAPCFUNC completion;
  ULONG_PTR completionArg;
} UserApcItem;
 
static void userAPC(LPVOID arg)
{
  UserApcItem* userApc = (UserApcItem*)arg;
 
  userApc->completion(userApc->completionArg);
 
  userApc->apc.markedForRemove = TRUE;
}
 
DWORD QueueUserAPC(PAPCFUNC pfnAPC, HANDLE hThread, ULONG_PTR dwData)
{
  ULONG Type = 0;
  WINPR_HANDLE* Object = nullptr;
  WINPR_APC_ITEM* apc = nullptr;
  UserApcItem* apcItem = nullptr;
 
  if (!pfnAPC)
    return 1;
 
  if (!winpr_Handle_GetInfo(hThread, &Type, &Object) || Object->Type != HANDLE_TYPE_THREAD)
  {
    WLog_ERR(TAG, "hThread is not a thread");
    SetLastError(ERROR_INVALID_PARAMETER);
    return (DWORD)0;
  }
 
  apcItem = calloc(1, sizeof(*apcItem));
  if (!apcItem)
  {
    SetLastError(ERROR_INVALID_PARAMETER);
    return (DWORD)0;
  }
 
  apc = &apcItem->apc;
  apc->type = APC_TYPE_USER;
  apc->markedForFree = TRUE;
  apc->alwaysSignaled = TRUE;
  apc->completion = userAPC;
  apc->completionArgs = apc;
  apcItem->completion = pfnAPC;
  apcItem->completionArg = dwData;
  apc_register(hThread, apc);
  return 1;
}
 
DWORD ResumeThread(HANDLE hThread)
{
  ULONG Type = 0;
  WINPR_HANDLE* Object = nullptr;
  WINPR_THREAD* thread = nullptr;
 
  if (!winpr_Handle_GetInfo(hThread, &Type, &Object) || Object->Type != HANDLE_TYPE_THREAD)
  {
    WLog_ERR(TAG, "hThread is not a thread");
    SetLastError(ERROR_INVALID_PARAMETER);
    return (DWORD)-1;
  }
 
  thread = (WINPR_THREAD*)Object;
 
  if (!run_mutex_fkt(pthread_mutex_lock, &thread->mutex))
    return (DWORD)-1;
 
  if (!thread->started)
  {
    if (!winpr_StartThread(thread))
    {
      run_mutex_fkt(pthread_mutex_checked_unlock, &thread->mutex);
      return (DWORD)-1;
    }
  }
  else
    WLog_WARN(TAG, "Thread already started!");
 
  if (!run_mutex_fkt(pthread_mutex_checked_unlock, &thread->mutex))
    return (DWORD)-1;
 
  return 0;
}
 
DWORD SuspendThread(WINPR_ATTR_UNUSED HANDLE hThread)
{
  WLog_ERR(TAG, "not implemented");
  SetLastError(ERROR_CALL_NOT_IMPLEMENTED);
  return (DWORD)-1;
}
 
BOOL SwitchToThread(VOID)
{
  if (sched_yield() != 0)
    usleep(1);
 
  return TRUE;
}
 
BOOL TerminateThread(HANDLE hThread, DWORD dwExitCode)
{
  ULONG Type = 0;
  WINPR_HANDLE* Object = nullptr;
  WINPR_THREAD* thread = nullptr;
 
  if (!winpr_Handle_GetInfo(hThread, &Type, &Object) || Object->Type != HANDLE_TYPE_THREAD)
    return FALSE;
 
  thread = (WINPR_THREAD*)Object;
  thread->exited = TRUE;
  thread->dwExitCode = dwExitCode;
 
  if (!run_mutex_fkt(pthread_mutex_lock, &thread->mutex))
    return FALSE;
 
#ifndef ANDROID
  pthread_cancel(thread->thread);
#else
  WLog_ERR(TAG, "Function not supported on this platform!");
#endif
 
  if (!run_mutex_fkt(pthread_mutex_checked_unlock, &thread->mutex))
    return FALSE;
 
  set_event(thread);
  return TRUE;
}
 
VOID DumpThreadHandles(void)
{
#if defined(WITH_DEBUG_THREADS)
  char** msg = nullptr;
  size_t used = 0;
  void* stack = winpr_backtrace(20);
  WLog_DBG(TAG, "---------------- Called from ----------------------------");
  msg = winpr_backtrace_symbols(stack, &used);
 
  for (size_t i = 0; i < used; i++)
  {
    WLog_DBG(TAG, "[%" PRIuz "]: %s", i, msg[i]);
  }
 
  free((void*)msg);
  winpr_backtrace_free(stack);
  WLog_DBG(TAG, "---------------- Start Dumping thread handles -----------");
 
#if defined(WITH_THREAD_LIST)
  if (!thread_list)
  {
    WLog_DBG(TAG, "All threads properly shut down and disposed of.");
  }
  else
  {
    ULONG_PTR* keys = nullptr;
    ListDictionary_Lock(thread_list);
    int x, count = ListDictionary_GetKeys(thread_list, &keys);
    WLog_DBG(TAG, "Dumping %d elements", count);
 
    for (size_t x = 0; x < count; x++)
    {
      WINPR_THREAD* thread = ListDictionary_GetItemValue(thread_list, (void*)keys[x]);
      WLog_DBG(TAG, "Thread [%d] handle created still not closed!", x);
      msg = winpr_backtrace_symbols(thread->create_stack, &used);
 
      for (size_t i = 0; i < used; i++)
      {
        WLog_DBG(TAG, "[%" PRIdz "]: %s", i, msg[i]);
      }
 
      free(msg);
 
      if (thread->started)
      {
        WLog_DBG(TAG, "Thread [%d] still running!", x);
      }
      else
      {
        WLog_DBG(TAG, "Thread [%d] exited at:", x);
        msg = winpr_backtrace_symbols(thread->exit_stack, &used);
 
        for (size_t i = 0; i < used; i++)
          WLog_DBG(TAG, "[%" PRIdz "]: %s", i, msg[i]);
 
        free(msg);
      }
    }
 
    free(keys);
    ListDictionary_Unlock(thread_list);
  }
#endif
 
  WLog_DBG(TAG, "---------------- End Dumping thread handles -------------");
#endif
}
#endif