PlatformThread: add support for detached threads.
The change introduces support for detachable PlatformThreads, for which
the Stop() call doesn't wait until the thread has finished executing.
The change also introduces rtc::ThreadAttributes that carries priority
and detachability thread attributes. It additionally refactors all
known use to use the new semantics.
Bug: b:181572711, webrtc:12659
Change-Id: Id96e87c2a0dafabc8047767d241fd5da4505d14c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/214704
Reviewed-by: Tommi <tommi@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Markus Handell <handellm@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33796}
diff --git a/rtc_base/platform_thread.cc b/rtc_base/platform_thread.cc
index 8a5f2c9..c5f3bc3 100644
--- a/rtc_base/platform_thread.cc
+++ b/rtc_base/platform_thread.cc
@@ -10,6 +10,8 @@
#include "rtc_base/platform_thread.h"
+#include <memory>
+
#if !defined(WEBRTC_WIN)
#include <sched.h>
#endif
@@ -18,123 +20,22 @@
#include <algorithm>
+#include "absl/memory/memory.h"
#include "rtc_base/checks.h"
namespace rtc {
+
namespace {
-#if !defined(WEBRTC_WIN)
-struct ThreadAttributes {
- ThreadAttributes() { pthread_attr_init(&attr); }
- ~ThreadAttributes() { pthread_attr_destroy(&attr); }
- pthread_attr_t* operator&() { return &attr; }
- pthread_attr_t attr;
+struct ThreadStartData {
+ ThreadRunFunction run_function;
+ void* obj;
+ std::string thread_name;
+ ThreadPriority priority;
};
-#endif // defined(WEBRTC_WIN)
-} // namespace
-PlatformThread::PlatformThread(ThreadRunFunction func,
- void* obj,
- absl::string_view thread_name,
- ThreadPriority priority /*= kNormalPriority*/)
- : run_function_(func), priority_(priority), obj_(obj), name_(thread_name) {
- RTC_DCHECK(func);
- RTC_DCHECK(!name_.empty());
- // TODO(tommi): Consider lowering the limit to 15 (limit on Linux).
- RTC_DCHECK(name_.length() < 64);
- spawned_thread_checker_.Detach();
-}
-
-PlatformThread::~PlatformThread() {
- RTC_DCHECK(thread_checker_.IsCurrent());
+bool SetPriority(ThreadPriority priority) {
#if defined(WEBRTC_WIN)
- RTC_DCHECK(!thread_);
- RTC_DCHECK(!thread_id_);
-#endif // defined(WEBRTC_WIN)
-}
-
-#if defined(WEBRTC_WIN)
-DWORD WINAPI PlatformThread::StartThread(void* param) {
- // The GetLastError() function only returns valid results when it is called
- // after a Win32 API function that returns a "failed" result. A crash dump
- // contains the result from GetLastError() and to make sure it does not
- // falsely report a Windows error we call SetLastError here.
- ::SetLastError(ERROR_SUCCESS);
- static_cast<PlatformThread*>(param)->Run();
- return 0;
-}
-#else
-void* PlatformThread::StartThread(void* param) {
- static_cast<PlatformThread*>(param)->Run();
- return 0;
-}
-#endif // defined(WEBRTC_WIN)
-
-void PlatformThread::Start() {
- RTC_DCHECK(thread_checker_.IsCurrent());
- RTC_DCHECK(!thread_) << "Thread already started?";
-#if defined(WEBRTC_WIN)
- // See bug 2902 for background on STACK_SIZE_PARAM_IS_A_RESERVATION.
- // Set the reserved stack stack size to 1M, which is the default on Windows
- // and Linux.
- thread_ = ::CreateThread(nullptr, 1024 * 1024, &StartThread, this,
- STACK_SIZE_PARAM_IS_A_RESERVATION, &thread_id_);
- RTC_CHECK(thread_) << "CreateThread failed";
- RTC_DCHECK(thread_id_);
-#else
- ThreadAttributes attr;
- // Set the stack stack size to 1M.
- pthread_attr_setstacksize(&attr, 1024 * 1024);
- RTC_CHECK_EQ(0, pthread_create(&thread_, &attr, &StartThread, this));
-#endif // defined(WEBRTC_WIN)
-}
-
-bool PlatformThread::IsRunning() const {
- RTC_DCHECK(thread_checker_.IsCurrent());
-#if defined(WEBRTC_WIN)
- return thread_ != nullptr;
-#else
- return thread_ != 0;
-#endif // defined(WEBRTC_WIN)
-}
-
-PlatformThreadRef PlatformThread::GetThreadRef() const {
-#if defined(WEBRTC_WIN)
- return thread_id_;
-#else
- return thread_;
-#endif // defined(WEBRTC_WIN)
-}
-
-void PlatformThread::Stop() {
- RTC_DCHECK(thread_checker_.IsCurrent());
- if (!IsRunning())
- return;
-
-#if defined(WEBRTC_WIN)
- WaitForSingleObject(thread_, INFINITE);
- CloseHandle(thread_);
- thread_ = nullptr;
- thread_id_ = 0;
-#else
- RTC_CHECK_EQ(0, pthread_join(thread_, nullptr));
- thread_ = 0;
-#endif // defined(WEBRTC_WIN)
- spawned_thread_checker_.Detach();
-}
-
-void PlatformThread::Run() {
- // Attach the worker thread checker to this thread.
- RTC_DCHECK(spawned_thread_checker_.IsCurrent());
- rtc::SetCurrentThreadName(name_.c_str());
- SetPriority(priority_);
- run_function_(obj_);
-}
-
-bool PlatformThread::SetPriority(ThreadPriority priority) {
- RTC_DCHECK(spawned_thread_checker_.IsCurrent());
-
-#if defined(WEBRTC_WIN)
- return SetThreadPriority(thread_, priority) != FALSE;
+ return SetThreadPriority(GetCurrentThread(), priority) != FALSE;
#elif defined(__native_client__) || defined(WEBRTC_FUCHSIA)
// Setting thread priorities is not supported in NaCl or Fuchsia.
return true;
@@ -176,13 +77,124 @@
param.sched_priority = top_prio;
break;
}
- return pthread_setschedparam(thread_, policy, ¶m) == 0;
+ return pthread_setschedparam(pthread_self(), policy, ¶m) == 0;
+#endif // defined(WEBRTC_WIN)
+}
+
+void RunPlatformThread(std::unique_ptr<ThreadStartData> data) {
+ rtc::SetCurrentThreadName(data->thread_name.c_str());
+ data->thread_name.clear();
+ SetPriority(data->priority);
+ data->run_function(data->obj);
+}
+
+#if defined(WEBRTC_WIN)
+DWORD WINAPI StartThread(void* param) {
+ // The GetLastError() function only returns valid results when it is called
+ // after a Win32 API function that returns a "failed" result. A crash dump
+ // contains the result from GetLastError() and to make sure it does not
+ // falsely report a Windows error we call SetLastError here.
+ ::SetLastError(ERROR_SUCCESS);
+ RunPlatformThread(absl::WrapUnique(static_cast<ThreadStartData*>(param)));
+ return 0;
+}
+#else
+void* StartThread(void* param) {
+ RunPlatformThread(absl::WrapUnique(static_cast<ThreadStartData*>(param)));
+ return 0;
+}
+#endif // defined(WEBRTC_WIN)
+
+} // namespace
+
+PlatformThread::PlatformThread(ThreadRunFunction func,
+ void* obj,
+ absl::string_view thread_name,
+ ThreadAttributes attributes)
+ : run_function_(func),
+ attributes_(attributes),
+ obj_(obj),
+ name_(thread_name) {
+ RTC_DCHECK(func);
+ RTC_DCHECK(!name_.empty());
+ // TODO(tommi): Consider lowering the limit to 15 (limit on Linux).
+ RTC_DCHECK(name_.length() < 64);
+}
+
+PlatformThread::~PlatformThread() {
+ RTC_DCHECK_RUN_ON(&thread_checker_);
+ RTC_DCHECK(!thread_);
+#if defined(WEBRTC_WIN)
+ RTC_DCHECK(!thread_id_);
+#endif // defined(WEBRTC_WIN)
+}
+
+void PlatformThread::Start() {
+ RTC_DCHECK_RUN_ON(&thread_checker_);
+ RTC_DCHECK(!thread_) << "Thread already started?";
+ ThreadStartData* data =
+ new ThreadStartData{run_function_, obj_, name_, attributes_.priority};
+#if defined(WEBRTC_WIN)
+ // See bug 2902 for background on STACK_SIZE_PARAM_IS_A_RESERVATION.
+ // Set the reserved stack stack size to 1M, which is the default on Windows
+ // and Linux.
+ thread_ = ::CreateThread(nullptr, 1024 * 1024, &StartThread, data,
+ STACK_SIZE_PARAM_IS_A_RESERVATION, &thread_id_);
+ RTC_CHECK(thread_) << "CreateThread failed";
+ RTC_DCHECK(thread_id_);
+#else
+ pthread_attr_t attr;
+ pthread_attr_init(&attr);
+ // Set the stack stack size to 1M.
+ pthread_attr_setstacksize(&attr, 1024 * 1024);
+ pthread_attr_setdetachstate(&attr, attributes_.joinable
+ ? PTHREAD_CREATE_JOINABLE
+ : PTHREAD_CREATE_DETACHED);
+ RTC_CHECK_EQ(0, pthread_create(&thread_, &attr, &StartThread, data));
+ pthread_attr_destroy(&attr);
+#endif // defined(WEBRTC_WIN)
+}
+
+bool PlatformThread::IsRunning() const {
+ RTC_DCHECK_RUN_ON(&thread_checker_);
+#if defined(WEBRTC_WIN)
+ return thread_ != nullptr;
+#else
+ return thread_ != 0;
+#endif // defined(WEBRTC_WIN)
+}
+
+PlatformThreadRef PlatformThread::GetThreadRef() const {
+#if defined(WEBRTC_WIN)
+ return thread_id_;
+#else
+ return thread_;
+#endif // defined(WEBRTC_WIN)
+}
+
+void PlatformThread::Stop() {
+ RTC_DCHECK_RUN_ON(&thread_checker_);
+ if (!IsRunning())
+ return;
+
+#if defined(WEBRTC_WIN)
+ if (attributes_.joinable) {
+ WaitForSingleObject(thread_, INFINITE);
+ }
+ CloseHandle(thread_);
+ thread_ = nullptr;
+ thread_id_ = 0;
+#else
+ if (attributes_.joinable) {
+ RTC_CHECK_EQ(0, pthread_join(thread_, nullptr));
+ }
+ thread_ = 0;
#endif // defined(WEBRTC_WIN)
}
#if defined(WEBRTC_WIN)
bool PlatformThread::QueueAPC(PAPCFUNC function, ULONG_PTR data) {
- RTC_DCHECK(thread_checker_.IsCurrent());
+ RTC_DCHECK_RUN_ON(&thread_checker_);
RTC_DCHECK(IsRunning());
return QueueUserAPC(function, thread_, data) != FALSE;