[Sampling profiler] Add ThreadDelegate::GetThreadId()

This interface will be used for POSIX stack copying in a following CL.

Bug: 988579
Change-Id: Iefd9c14031ef34f88587de4615b58faa8a58dd9a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1860150
Commit-Queue: Mike Wittman <wittman@chromium.org>
Reviewed-by: Charlie Andrews <charliea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708345}

base/profiler/stack_copier_suspend_unittest.cc

@@ -63,6 +63,8 @@ class TestSuspendableThreadDelegate : public SuspendableThreadDelegate {
     return true;
   }
 
+  PlatformThreadId GetThreadId() const override { return PlatformThreadId(); }
+
   uintptr_t GetStackBaseAddress() const override {
     return reinterpret_cast<uintptr_t>(&fake_stack_[0] + fake_stack_.size());
   }

base/profiler/suspendable_thread_delegate_mac.cc

@@ -78,6 +78,10 @@ SuspendableThreadDelegateMac::CreateScopedSuspendThread() {
   return std::make_unique<ScopedSuspendThread>(thread_port_);
 }
 
+PlatformThreadId SuspendableThreadDelegateMac::GetThreadId() const {
+  return thread_port_;
+}
+
 // NO HEAP ALLOCATIONS.
 bool SuspendableThreadDelegateMac::GetThreadContext(
     x86_thread_state64_t* thread_context) {

base/profiler/suspendable_thread_delegate_mac.h

@@ -46,6 +46,7 @@ class BASE_EXPORT SuspendableThreadDelegateMac
   std::unique_ptr<SuspendableThreadDelegate::ScopedSuspendThread>
   CreateScopedSuspendThread() override;
   bool GetThreadContext(x86_thread_state64_t* thread_context) override;
+  PlatformThreadId GetThreadId() const override;
   uintptr_t GetStackBaseAddress() const override;
   bool CanCopyStack(uintptr_t stack_pointer) override;
   std::vector<uintptr_t*> GetRegistersToRewrite(
@@ -53,7 +54,7 @@ class BASE_EXPORT SuspendableThreadDelegateMac
 
  private:
   // Weak reference: Mach port for thread being profiled.
-  mach_port_t thread_port_;
+  const mach_port_t thread_port_;
 
   // The stack base address corresponding to |thread_port_|.
   const uintptr_t thread_stack_base_address_;

base/profiler/suspendable_thread_delegate_win.cc

@@ -173,7 +173,8 @@ bool SuspendableThreadDelegateWin::ScopedSuspendThread::WasSuccessful() const {
 
 SuspendableThreadDelegateWin::SuspendableThreadDelegateWin(
     PlatformThreadId thread_id)
-    : thread_handle_(GetThreadHandle(thread_id)),
+    : thread_id_(thread_id),
+      thread_handle_(GetThreadHandle(thread_id)),
       thread_stack_base_address_(reinterpret_cast<uintptr_t>(
           GetThreadEnvironmentBlock(thread_handle_.Get())->Tib.StackBase)) {}
 
@@ -184,6 +185,10 @@ SuspendableThreadDelegateWin::CreateScopedSuspendThread() {
   return std::make_unique<ScopedSuspendThread>(thread_handle_.Get());
 }
 
+PlatformThreadId SuspendableThreadDelegateWin::GetThreadId() const {
+  return thread_id_;
+}
+
 // NO HEAP ALLOCATIONS.
 bool SuspendableThreadDelegateWin::GetThreadContext(CONTEXT* thread_context) {
   *thread_context = {0};

base/profiler/suspendable_thread_delegate_win.h

@@ -45,12 +45,14 @@ class BASE_EXPORT SuspendableThreadDelegateWin
   std::unique_ptr<SuspendableThreadDelegate::ScopedSuspendThread>
   CreateScopedSuspendThread() override;
   bool GetThreadContext(CONTEXT* thread_context) override;
+  PlatformThreadId GetThreadId() const override;
   uintptr_t GetStackBaseAddress() const override;
   bool CanCopyStack(uintptr_t stack_pointer) override;
   std::vector<uintptr_t*> GetRegistersToRewrite(
       CONTEXT* thread_context) override;
 
  private:
+  const PlatformThreadId thread_id_;
   win::ScopedHandle thread_handle_;
   const uintptr_t thread_stack_base_address_;
 };

base/profiler/thread_delegate.h

@@ -9,6 +9,7 @@
 
 #include "base/base_export.h"
 #include "base/profiler/register_context.h"
+#include "base/threading/platform_thread.h"
 
 namespace base {
 
@@ -24,6 +25,9 @@ class BASE_EXPORT ThreadDelegate {
   ThreadDelegate(const ThreadDelegate&) = delete;
   ThreadDelegate& operator=(const ThreadDelegate&) = delete;
 
+  // Gets the platform-specific id for the thread.
+  virtual PlatformThreadId GetThreadId() const = 0;
+
   // Gets the base address of the thread's stack.
   virtual uintptr_t GetStackBaseAddress() const = 0;
 

base/profiler/thread_delegate_posix.cc

@@ -24,7 +24,12 @@ uintptr_t GetThreadStackBaseAddress(PlatformThreadId thread_id) {
 }  // namespace
 
 ThreadDelegatePosix::ThreadDelegatePosix(PlatformThreadId thread_id)
-    : thread_stack_base_address_(GetThreadStackBaseAddress(thread_id)) {}
+    : thread_id_(thread_id),
+      thread_stack_base_address_(GetThreadStackBaseAddress(thread_id)) {}
+
+PlatformThreadId ThreadDelegatePosix::GetThreadId() const {
+  return thread_id_;
+}
 
 uintptr_t ThreadDelegatePosix::GetStackBaseAddress() const {
   return thread_stack_base_address_;

base/profiler/thread_delegate_posix.h

@@ -21,11 +21,13 @@ class BASE_EXPORT ThreadDelegatePosix : public ThreadDelegate {
   ThreadDelegatePosix& operator=(const ThreadDelegatePosix&) = delete;
 
   // ThreadDelegate
+  PlatformThreadId GetThreadId() const override;
   uintptr_t GetStackBaseAddress() const override;
   std::vector<uintptr_t*> GetRegistersToRewrite(
       RegisterContext* thread_context) override;
 
  private:
+  const PlatformThreadId thread_id_;
   const uintptr_t thread_stack_base_address_;
 };