1 //===-- ThreadLauncher.cpp ------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // lldb Includes
10 #include "lldb/Host/ThreadLauncher.h"
11 #include "lldb/Host/HostNativeThread.h"
12 #include "lldb/Host/HostThread.h"
13 #include "lldb/Utility/Log.h"
14 
15 #if defined(_WIN32)
16 #include "lldb/Host/windows/windows.h"
17 #endif
18 
19 #include "llvm/Support/WindowsError.h"
20 
21 using namespace lldb;
22 using namespace lldb_private;
23 
24 llvm::Expected<HostThread>
25 ThreadLauncher::LaunchThread(llvm::StringRef name,
26                              std::function<thread_result_t()> impl,
27                              size_t min_stack_byte_size) {
28   // Host::ThreadCreateTrampoline will take ownership if thread creation is
29   // successful.
30   auto info_up = std::make_unique<HostThreadCreateInfo>(name.str(), impl);
31   lldb::thread_t thread;
32 #ifdef _WIN32
33   thread = (lldb::thread_t)::_beginthreadex(
34       0, (unsigned)min_stack_byte_size,
35       HostNativeThread::ThreadCreateTrampoline, info_up.get(), 0, NULL);
36   if (thread == LLDB_INVALID_HOST_THREAD)
37     return llvm::errorCodeToError(llvm::mapWindowsError(GetLastError()));
38 #else
39 
40 // ASAN instrumentation adds a lot of bookkeeping overhead on stack frames.
41 #if __has_feature(address_sanitizer)
42   const size_t eight_megabytes = 8 * 1024 * 1024;
43   if (min_stack_byte_size < eight_megabytes) {
44     min_stack_byte_size += eight_megabytes;
45   }
46 #endif
47 
48   pthread_attr_t *thread_attr_ptr = nullptr;
49   pthread_attr_t thread_attr;
50   bool destroy_attr = false;
51   if (min_stack_byte_size > 0) {
52     if (::pthread_attr_init(&thread_attr) == 0) {
53       destroy_attr = true;
54       size_t default_min_stack_byte_size = 0;
55       if (::pthread_attr_getstacksize(&thread_attr,
56                                       &default_min_stack_byte_size) == 0) {
57         if (default_min_stack_byte_size < min_stack_byte_size) {
58           if (::pthread_attr_setstacksize(&thread_attr, min_stack_byte_size) ==
59               0)
60             thread_attr_ptr = &thread_attr;
61         }
62       }
63     }
64   }
65   int err =
66       ::pthread_create(&thread, thread_attr_ptr,
67                        HostNativeThread::ThreadCreateTrampoline, info_up.get());
68 
69   if (destroy_attr)
70     ::pthread_attr_destroy(&thread_attr);
71 
72   if (err)
73     return llvm::errorCodeToError(
74         std::error_code(err, std::generic_category()));
75 #endif
76 
77   info_up.release();
78   return HostThread(thread);
79 }
80