Imported Upstream version 5.18.0.225

Former-commit-id: 10196d987d5fc5564b9d3b33b1fdf13190f4d0b5

external/llvm/lib/Support/Unix/Threading.inc

@@ -0,0 +1,215 @@
+//===- Unix/Threading.inc - Unix Threading Implementation ----- -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides the Unix specific implementation of Threading functions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/Twine.h"
+
+#if defined(__APPLE__)
+#include <mach/mach_init.h>
+#include <mach/mach_port.h>
+#endif
+
+#include <pthread.h>
+
+#if defined(__FreeBSD__)
+#include <pthread_np.h> // For pthread_getthreadid_np()
+#endif
+
+#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+#include <errno.h>
+#include <sys/sysctl.h>
+#include <sys/user.h>
+#include <unistd.h>
+#endif
+
+#if defined(__NetBSD__)
+#include <lwp.h> // For _lwp_self()
+#endif
+
+#if defined(__linux__)
+#include <sys/syscall.h> // For syscall codes
+#include <unistd.h>      // For syscall()
+#endif
+
+namespace {
+  struct ThreadInfo {
+    void(*UserFn)(void *);
+    void *UserData;
+  };
+}
+
+static void *ExecuteOnThread_Dispatch(void *Arg) {
+  ThreadInfo *TI = reinterpret_cast<ThreadInfo*>(Arg);
+  TI->UserFn(TI->UserData);
+  return nullptr;
+}
+
+void llvm::llvm_execute_on_thread(void(*Fn)(void*), void *UserData,
+  unsigned RequestedStackSize) {
+  ThreadInfo Info = { Fn, UserData };
+  pthread_attr_t Attr;
+  pthread_t Thread;
+
+  // Construct the attributes object.
+  if (::pthread_attr_init(&Attr) != 0)
+    return;
+
+  // Set the requested stack size, if given.
+  if (RequestedStackSize != 0) {
+    if (::pthread_attr_setstacksize(&Attr, RequestedStackSize) != 0)
+      goto error;
+  }
+
+  // Construct and execute the thread.
+  if (::pthread_create(&Thread, &Attr, ExecuteOnThread_Dispatch, &Info) != 0)
+    goto error;
+
+  // Wait for the thread and clean up.
+  ::pthread_join(Thread, nullptr);
+
+error:
+  ::pthread_attr_destroy(&Attr);
+}
+
+
+uint64_t llvm::get_threadid() {
+#if defined(__APPLE__)
+  // Calling "mach_thread_self()" bumps the reference count on the thread
+  // port, so we need to deallocate it. mach_task_self() doesn't bump the ref
+  // count.
+  thread_port_t Self = mach_thread_self();
+  mach_port_deallocate(mach_task_self(), Self);
+  return Self;
+#elif defined(__FreeBSD__)
+  return uint64_t(pthread_getthreadid_np());
+#elif defined(__NetBSD__)
+  return uint64_t(_lwp_self());
+#elif defined(__ANDROID__)
+  return uint64_t(gettid());
+#elif defined(__linux__)
+  return uint64_t(syscall(SYS_gettid));
+#elif defined(LLVM_ON_WIN32)
+  return uint64_t(::GetCurrentThreadId());
+#else
+  return uint64_t(pthread_self());
+#endif
+}
+
+
+static constexpr uint32_t get_max_thread_name_length_impl() {
+#if defined(__NetBSD__)
+  return PTHREAD_MAX_NAMELEN_NP;
+#elif defined(__APPLE__)
+  return 64;
+#elif defined(__linux__)
+#if HAVE_PTHREAD_SETNAME_NP
+  return 16;
+#else
+  return 0;
+#endif
+#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+  return 16;
+#else
+  return 0;
+#endif
+}
+
+uint32_t llvm::get_max_thread_name_length() {
+  return get_max_thread_name_length_impl();
+}
+
+void llvm::set_thread_name(const Twine &Name) {
+  // Make sure the input is null terminated.
+  SmallString<64> Storage;
+  StringRef NameStr = Name.toNullTerminatedStringRef(Storage);
+
+  // Truncate from the beginning, not the end, if the specified name is too
+  // long.  For one, this ensures that the resulting string is still null
+  // terminated, but additionally the end of a long thread name will usually
+  // be more unique than the beginning, since a common pattern is for similar
+  // threads to share a common prefix.
+  if (get_max_thread_name_length() > 0)
+    NameStr = NameStr.take_back(get_max_thread_name_length());
+  (void)NameStr;
+#if defined(__linux__)
+#if (defined(__GLIBC__) && defined(_GNU_SOURCE)) || defined(__ANDROID__)
+#if HAVE_PTHREAD_SETNAME_NP
+  ::pthread_setname_np(::pthread_self(), NameStr.data());
+#endif
+#endif
+#elif defined(__FreeBSD__)
+  ::pthread_set_name_np(::pthread_self(), NameStr.data());
+#elif defined(__NetBSD__)
+  ::pthread_setname_np(::pthread_self(), "%s",
+    const_cast<char *>(NameStr.data()));
+#elif defined(__APPLE__)
+  ::pthread_setname_np(NameStr.data());
+#endif
+}
+
+void llvm::get_thread_name(SmallVectorImpl<char> &Name) {
+  Name.clear();
+
+#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+  int pid = ::getpid();
+  uint64_t tid = get_threadid();
+
+  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);
+  return;
+#elif defined(__NetBSD__)
+  constexpr uint32_t len = get_max_thread_name_length_impl();
+  char buf[len];
+  ::pthread_getname_np(::pthread_self(), buf, len);
+
+  Name.append(buf, buf + strlen(buf));
+#elif defined(__linux__)
+#if (defined(__GLIBC__) && defined(_GNU_SOURCE)) || defined(__ANDROID__)
+#if HAVE_PTHREAD_GETNAME_NP
+  constexpr uint32_t len = get_max_thread_name_length_impl();
+  char Buffer[len] = {'\0'};  // FIXME: working around MSan false positive.
+  if (0 == ::pthread_getname_np(::pthread_self(), Buffer, len))
+    Name.append(Buffer, Buffer + strlen(Buffer));
+#endif
+#endif
+#endif
+}