[Clank SSM]: Inject Unwinder in StackSampler.

Add Unwinder as optional param in StackSampler that's used if present.
This is necessary for follow up NativeUnwinderAndroid that doesn't have
a default constructor.

Late creation of StackSampler in StackSamplingProfiler is also removed
because this won't be possible with NativeUnwinderAndroid. Instead, StackSampler
is always created in constructor or injected.

Bug: 989102
Change-Id: Ib90416659f28d7139baed8d7adba62836337b13e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2095372
Commit-Queue: Etienne Pierre-Doray <etiennep@chromium.org>
Reviewed-by: oysteine <oysteine@chromium.org>
Reviewed-by: Mike Wittman <wittman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755046}

base/profiler/stack_sampler.h

@@ -33,7 +33,8 @@ class BASE_EXPORT StackSampler {
   static std::unique_ptr<StackSampler> Create(
       SamplingProfilerThreadToken thread_token,
       ModuleCache* module_cache,
-      StackSamplerTestDelegate* test_delegate);
+      StackSamplerTestDelegate* test_delegate,
+      std::unique_ptr<Unwinder> native_unwinder = nullptr);
 
   // Gets the required size of the stack buffer.
   static size_t GetStackBufferSize();

base/profiler/stack_sampler_android.cc

@@ -6,10 +6,10 @@
 
 #include <pthread.h>
 
-#include "base/profiler/native_unwinder_android.h"
 #include "base/profiler/stack_copier_signal.h"
 #include "base/profiler/stack_sampler_impl.h"
 #include "base/profiler/thread_delegate_posix.h"
+#include "base/profiler/unwinder.h"
 #include "base/threading/platform_thread.h"
 
 namespace base {
@@ -17,11 +17,12 @@ namespace base {
 std::unique_ptr<StackSampler> StackSampler::Create(
     SamplingProfilerThreadToken thread_token,
     ModuleCache* module_cache,
-    StackSamplerTestDelegate* test_delegate) {
+    StackSamplerTestDelegate* test_delegate,
+    std::unique_ptr<Unwinder> native_unwinder) {
   return std::make_unique<StackSamplerImpl>(
       std::make_unique<StackCopierSignal>(
           std::make_unique<ThreadDelegatePosix>(thread_token)),
-      std::make_unique<NativeUnwinderAndroid>(), module_cache, test_delegate);
+      std::move(native_unwinder), module_cache, test_delegate);
 }
 
 size_t StackSampler::GetStackBufferSize() {

base/profiler/stack_sampler_ios.cc

@@ -13,7 +13,8 @@ namespace base {
 std::unique_ptr<StackSampler> StackSampler::Create(
     SamplingProfilerThreadToken thread_token,
     ModuleCache* module_cache,
-    StackSamplerTestDelegate* test_delegate) {
+    StackSamplerTestDelegate* test_delegate,
+    std::unique_ptr<Unwinder> native_unwinder) {
   return nullptr;
 }
 

base/profiler/stack_sampler_mac.cc

@@ -15,7 +15,9 @@ namespace base {
 std::unique_ptr<StackSampler> StackSampler::Create(
     SamplingProfilerThreadToken thread_token,
     ModuleCache* module_cache,
-    StackSamplerTestDelegate* test_delegate) {
+    StackSamplerTestDelegate* test_delegate,
+    std::unique_ptr<Unwinder> native_unwinder) {
+  DCHECK(!native_unwinder);
   return std::make_unique<StackSamplerImpl>(
       std::make_unique<StackCopierSuspend>(
           std::make_unique<SuspendableThreadDelegateMac>(thread_token)),

base/profiler/stack_sampler_posix.cc

@@ -14,7 +14,8 @@ namespace base {
 std::unique_ptr<StackSampler> StackSampler::Create(
     SamplingProfilerThreadToken thread_token,
     ModuleCache* module_cache,
-    StackSamplerTestDelegate* test_delegate) {
+    StackSamplerTestDelegate* test_delegate,
+    std::unique_ptr<Unwinder> native_unwinder) {
   return nullptr;
 }
 

base/profiler/stack_sampler_win.cc

@@ -16,7 +16,9 @@ namespace base {
 std::unique_ptr<StackSampler> StackSampler::Create(
     SamplingProfilerThreadToken thread_token,
     ModuleCache* module_cache,
-    StackSamplerTestDelegate* test_delegate) {
+    StackSamplerTestDelegate* test_delegate,
+    std::unique_ptr<Unwinder> native_unwinder) {
+  DCHECK(!native_unwinder);
 #if defined(ARCH_CPU_X86_64) || defined(ARCH_CPU_ARM64)
   return std::make_unique<StackSamplerImpl>(
       std::make_unique<StackCopierSuspend>(

base/profiler/stack_sampling_profiler.cc

@@ -694,27 +694,22 @@ StackSamplingProfiler::StackSamplingProfiler(
     const SamplingParams& params,
     std::unique_ptr<ProfileBuilder> profile_builder,
     StackSamplerTestDelegate* test_delegate)
-    : StackSamplingProfiler(thread_token,
-                            params,
-                            std::move(profile_builder),
-                            nullptr,
-                            test_delegate) {}
+    : StackSamplingProfiler(params, std::move(profile_builder), nullptr) {
+  sampler_ = StackSampler::Create(
+      thread_token, profile_builder_->GetModuleCache(), test_delegate);
+}
 
 StackSamplingProfiler::StackSamplingProfiler(
-    SamplingProfilerThreadToken thread_token,
     const SamplingParams& params,
     std::unique_ptr<ProfileBuilder> profile_builder,
-    std::unique_ptr<StackSampler> sampler,
-    StackSamplerTestDelegate* test_delegate)
-    : thread_token_(thread_token),
-      params_(params),
+    std::unique_ptr<StackSampler> sampler)
+    : params_(params),
       profile_builder_(std::move(profile_builder)),
       sampler_(std::move(sampler)),
       // The event starts "signaled" so code knows it's safe to start thread
       // and "manual" so that it can be waited in multiple places.
       profiling_inactive_(kResetPolicy, WaitableEvent::InitialState::SIGNALED),
-      profiler_id_(kNullProfilerId),
-      test_delegate_(test_delegate) {
+      profiler_id_(kNullProfilerId) {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("cpu_profiler"),
                "StackSamplingProfiler::StackSamplingProfiler");
   DCHECK(profile_builder_);
@@ -751,10 +746,8 @@ void StackSamplingProfiler::Start() {
   // already.
   DCHECK(profile_builder_);
 
-  if (!sampler_)
-    sampler_ = StackSampler::Create(
-        thread_token_, profile_builder_->GetModuleCache(), test_delegate_);
-
+  // |sampler_| will be null if sampling isn't supported on the current
+  // platform.
   if (!sampler_)
     return;
 

base/profiler/stack_sampling_profiler.h

@@ -95,11 +95,9 @@ class BASE_EXPORT StackSamplingProfiler {
 
   // Same as above function, with custom |sampler| implementation. The sampler
   // on Android is not implemented in base.
-  StackSamplingProfiler(SamplingProfilerThreadToken thread_token,
-                        const SamplingParams& params,
+  StackSamplingProfiler(const SamplingParams& params,
                         std::unique_ptr<ProfileBuilder> profile_builder,
-                        std::unique_ptr<StackSampler> sampler,
-                        StackSamplerTestDelegate* test_delegate = nullptr);
+                        std::unique_ptr<StackSampler> sampler);
 
   // Stops any profiling currently taking place before destroying the profiler.
   // This will block until profile_builder_'s OnProfileCompleted function has
@@ -202,9 +200,6 @@ class BASE_EXPORT StackSamplingProfiler {
   // will be an internal "null" value when no collection has been started.
   int profiler_id_;
 
-  // Stored until it can be passed to the StackSampler created in Start().
-  StackSamplerTestDelegate* const test_delegate_;
-
   DISALLOW_COPY_AND_ASSIGN(StackSamplingProfiler);
 };
 

services/tracing/public/cpp/stack_sampling/tracing_sampler_profiler.cc

@@ -571,7 +571,7 @@ void TracingSamplerProfiler::StartTracing(
 #if BUILDFLAG(CAN_UNWIND_WITH_CFI_TABLE) && defined(OFFICIAL_BUILD)
   auto* module_cache = profile_builder->GetModuleCache();
   profiler_ = std::make_unique<base::StackSamplingProfiler>(
-      sampled_thread_token_, params, std::move(profile_builder),
+      params, std::move(profile_builder),
       std::make_unique<StackSamplerAndroid>(sampled_thread_token_,
                                             module_cache));
   profiler_->Start();