Return NotFound when converting profiles collected with sampling disabled.

tcmalloc/internal/BUILD

@@ -1255,6 +1255,7 @@ cc_test(
         ":residency",
         "//tcmalloc:malloc_extension",
         "//tcmalloc/internal:profile_cc_proto",
+        "//tcmalloc/testing:testutil",
         "@com_google_absl//absl/base",
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/container:flat_hash_set",

tcmalloc/internal/CMakeLists.txt

@@ -1288,6 +1288,7 @@ tcmalloc_cc_test(
     "tcmalloc::internal_residency"
     "tcmalloc::malloc_extension"
     "tcmalloc::tcmalloc"
+    "tcmalloc::testing_testutil"
 )
 
 tcmalloc_cc_test(

tcmalloc/internal/profile_builder.cc

@@ -30,6 +30,7 @@
 #include "absl/types/span.h"
 #include "tcmalloc/internal/compressibility.h"
 #include "tcmalloc/internal/pageflags.h"
+#include "tcmalloc/internal_malloc_extension.h"
 #include "tcmalloc/malloc_extension.h"
 
 #if defined(__linux__)
@@ -882,6 +883,9 @@ absl::StatusOr<std::unique_ptr<perftools::profiles::Profile>> MakeProfileProto(
     const ::tcmalloc::Profile& profile, PageFlagsBase* pageflags,
     Residency* residency) {
   if (profile.Type() == ProfileType::kDoNotUse) {
+    if (MallocExtension::GetProfileSamplingInterval() == 0) {
+      return absl::NotFoundError("Profile sampling is disabled");
+    }
 #if defined(ABSL_HAVE_ADDRESS_SANITIZER) || \
     defined(ABSL_HAVE_LEAK_SANITIZER) ||    \
     defined(ABSL_HAVE_MEMORY_SANITIZER) || defined(ABSL_HAVE_THREAD_SANITIZER)

tcmalloc/internal/profile_builder_test.cc

@@ -55,6 +55,7 @@
 #include "tcmalloc/internal/residency.h"
 #include "tcmalloc/internal_malloc_extension.h"
 #include "tcmalloc/malloc_extension.h"
+#include "tcmalloc/testing/testutil.h"
 
 namespace tcmalloc {
 namespace tcmalloc_internal {
@@ -1658,6 +1659,23 @@ TEST(BuildId, ZeroOneAndCorruptAlignment) {
   EXPECT_EQ(GetBuildId(&info), "");
 }
 
+TEST(ProfileBuilderTest, DisabledSamplingReturnsNotFound) {
+  if (MallocExtension::GetProfileSamplingInterval() < 0) {
+    GTEST_SKIP() << "TCMalloc is not linked in this build configuration";
+  }
+  ScopedProfileSamplingInterval scoped_interval(0);
+
+  Profile heap_profile = MallocExtension::SnapshotCurrent(ProfileType::kHeap);
+  EXPECT_EQ(heap_profile.Type(), ProfileType::kDoNotUse);
+  EXPECT_EQ(MakeProfileProto(heap_profile).status().code(),
+            absl::StatusCode::kNotFound);
+
+  Profile alloc_profile = MallocExtension::StartAllocationProfiling().Stop();
+  EXPECT_EQ(alloc_profile.Type(), ProfileType::kDoNotUse);
+  EXPECT_EQ(MakeProfileProto(alloc_profile).status().code(),
+            absl::StatusCode::kNotFound);
+}
+
 }  // namespace
 }  // namespace tcmalloc_internal
 }  // namespace tcmalloc

tcmalloc/tcmalloc.cc

@@ -290,6 +290,9 @@ extern "C" size_t TCMalloc_Internal_GetStats(char* buffer,
 
 extern "C" const ProfileBase* MallocExtension_Internal_SnapshotCurrent(
     ProfileType type) {
+  if (Parameters::profile_sampling_interval() <= 0) {
+    return nullptr;
+  }
   switch (type) {
     case ProfileType::kHeap:
       return DumpHeapProfile(tc_globals).release();
@@ -302,17 +305,26 @@ extern "C" const ProfileBase* MallocExtension_Internal_SnapshotCurrent(
 
 extern "C" AllocationProfilingTokenBase*
 MallocExtension_Internal_StartAllocationProfiling() {
+  if (Parameters::profile_sampling_interval() <= 0) {
+    return nullptr;
+  }
   return new AllocationSample(&tc_globals.allocation_samples, absl::Now());
 }
 
 extern "C" tcmalloc_internal::AllocationProfilingTokenBase*
 MallocExtension_Internal_StartLifetimeProfiling() {
+  if (Parameters::profile_sampling_interval() <= 0) {
+    return nullptr;
+  }
   return new deallocationz::DeallocationSample(&tc_globals.deallocation_samples,
                                                deallocationz::Mode::kLifetimes);
 }
 
 extern "C" tcmalloc_internal::AllocationProfilingTokenBase*
 MallocExtension_Internal_StartEventTracing() {
+  if (Parameters::profile_sampling_interval() <= 0) {
+    return nullptr;
+  }
   return new deallocationz::DeallocationSample(
       &tc_globals.deallocation_samples, deallocationz::Mode::kEventTrace);
 }