1 files changed, 227 insertions, 0 deletions
diff --git a/mozglue/baseprofiler/public/BaseProfilerUtils.h b/mozglue/baseprofiler/public/BaseProfilerUtils.h
new file mode 100644
index 0000000000..ab02e03b95
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilerUtils.h
@@ -0,0 +1,227 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BaseProfilerUtils_h
+#define BaseProfilerUtils_h
+
+// This header contains most process- and thread-related functions.
+// It is safe to include unconditionally.
+
+// --------------------------------------------- WASI process & thread ids
+#if defined(__wasi__)
+
+namespace mozilla::baseprofiler::detail {
+using ProcessIdType = unsigned;
+using ThreadIdType = unsigned;
+}  // namespace mozilla::baseprofiler::detail
+
+// --------------------------------------------- Windows process & thread ids
+#elif defined(XP_WIN)
+
+namespace mozilla::baseprofiler::detail {
+using ProcessIdType = int;
+using ThreadIdType = unsigned long;
+}  // namespace mozilla::baseprofiler::detail
+
+// --------------------------------------------- Non-Windows process id
+#else
+// All non-Windows platforms are assumed to be POSIX, which has getpid().
+
+#  include <unistd.h>
+namespace mozilla::baseprofiler::detail {
+using ProcessIdType = decltype(getpid());
+}  // namespace mozilla::baseprofiler::detail
+
+// --------------------------------------------- Non-Windows thread id
+// ------------------------------------------------------- macOS
+#  if defined(XP_MACOSX)
+
+namespace mozilla::baseprofiler::detail {
+using ThreadIdType = uint64_t;
+}  // namespace mozilla::baseprofiler::detail
+
+// ------------------------------------------------------- Android
+// Test Android before Linux, because Linux includes Android.
+#  elif defined(__ANDROID__) || defined(ANDROID)
+
+#    include <sys/types.h>
+namespace mozilla::baseprofiler::detail {
+using ThreadIdType = decltype(gettid());
+}  // namespace mozilla::baseprofiler::detail
+
+// ------------------------------------------------------- Linux
+#  elif defined(XP_LINUX)
+
+namespace mozilla::baseprofiler::detail {
+using ThreadIdType = long;
+}  // namespace mozilla::baseprofiler::detail
+
+// ------------------------------------------------------- FreeBSD
+#  elif defined(XP_FREEBSD)
+
+namespace mozilla::baseprofiler::detail {
+using ThreadIdType = long;
+}  // namespace mozilla::baseprofiler::detail
+
+// ------------------------------------------------------- Others
+#  else
+
+#    include <thread>
+
+namespace mozilla::baseprofiler::detail {
+using ThreadIdType = std::thread::id;
+}  // namespace mozilla::baseprofiler::detail
+
+#  endif
+#endif  // End of non-XP_WIN.
+
+#include <stdint.h>
+#include <string.h>
+#include <type_traits>
+
+namespace mozilla::baseprofiler {
+
+// Trivially-copyable class containing a process id. It may be left unspecified.
+class BaseProfilerProcessId {
+ public:
+  using NativeType = detail::ProcessIdType;
+
+  using NumberType =
+      std::conditional_t<(sizeof(NativeType) <= 4), uint32_t, uint64_t>;
+  static_assert(sizeof(NativeType) <= sizeof(NumberType));
+
+  // Unspecified process id.
+  constexpr BaseProfilerProcessId() = default;
+
+  [[nodiscard]] constexpr bool IsSpecified() const {
+    return mProcessId != scUnspecified;
+  }
+
+  // Construct from a native type.
+  [[nodiscard]] static BaseProfilerProcessId FromNativeId(
+      const NativeType& aNativeProcessId) {
+    BaseProfilerProcessId id;
+    // Convert trivially-copyable native id by copying its bits.
+    static_assert(std::is_trivially_copyable_v<NativeType>);
+    memcpy(&id.mProcessId, &aNativeProcessId, sizeof(NativeType));
+    return id;
+  }
+
+  // Get the process id as a number, which may be unspecified.
+  // This should only be used for serialization or logging.
+  [[nodiscard]] constexpr NumberType ToNumber() const { return mProcessId; }
+
+  // BaseProfilerProcessId from given number (which may be unspecified).
+  constexpr static BaseProfilerProcessId FromNumber(
+      const NumberType& aProcessId) {
+    BaseProfilerProcessId id;
+    id.mProcessId = aProcessId;
+    return id;
+  }
+
+  [[nodiscard]] constexpr bool operator==(
+      const BaseProfilerProcessId& aOther) const {
+    return mProcessId == aOther.mProcessId;
+  }
+  [[nodiscard]] constexpr bool operator!=(
+      const BaseProfilerProcessId& aOther) const {
+    return mProcessId != aOther.mProcessId;
+  }
+
+ private:
+  static constexpr NumberType scUnspecified = 0;
+  NumberType mProcessId = scUnspecified;
+};
+
+// Check traits. These should satisfy usage in std::atomic.
+static_assert(std::is_trivially_copyable_v<BaseProfilerProcessId>);
+static_assert(std::is_copy_constructible_v<BaseProfilerProcessId>);
+static_assert(std::is_move_constructible_v<BaseProfilerProcessId>);
+static_assert(std::is_copy_assignable_v<BaseProfilerProcessId>);
+static_assert(std::is_move_assignable_v<BaseProfilerProcessId>);
+
+// Trivially-copyable class containing a thread id. It may be left unspecified.
+class BaseProfilerThreadId {
+ public:
+  using NativeType = detail::ThreadIdType;
+
+  using NumberType =
+      std::conditional_t<(sizeof(NativeType) <= 4), uint32_t, uint64_t>;
+  static_assert(sizeof(NativeType) <= sizeof(NumberType));
+
+  // Unspecified thread id.
+  constexpr BaseProfilerThreadId() = default;
+
+  [[nodiscard]] constexpr bool IsSpecified() const {
+    return mThreadId != scUnspecified;
+  }
+
+  // Construct from a native type.
+  [[nodiscard]] static BaseProfilerThreadId FromNativeId(
+      const NativeType& aNativeThreadId) {
+    BaseProfilerThreadId id;
+    // Convert trivially-copyable native id by copying its bits.
+    static_assert(std::is_trivially_copyable_v<NativeType>);
+    memcpy(&id.mThreadId, &aNativeThreadId, sizeof(NativeType));
+    return id;
+  }
+
+  // Get the thread id as a number, which may be unspecified.
+  // This should only be used for serialization or logging.
+  [[nodiscard]] constexpr NumberType ToNumber() const { return mThreadId; }
+
+  // BaseProfilerThreadId from given number (which may be unspecified).
+  constexpr static BaseProfilerThreadId FromNumber(
+      const NumberType& aThreadId) {
+    BaseProfilerThreadId id;
+    id.mThreadId = aThreadId;
+    return id;
+  }
+
+  [[nodiscard]] constexpr bool operator==(
+      const BaseProfilerThreadId& aOther) const {
+    return mThreadId == aOther.mThreadId;
+  }
+  [[nodiscard]] constexpr bool operator!=(
+      const BaseProfilerThreadId& aOther) const {
+    return mThreadId != aOther.mThreadId;
+  }
+
+ private:
+  static constexpr NumberType scUnspecified = 0;
+  NumberType mThreadId = scUnspecified;
+};
+
+// Check traits. These should satisfy usage in std::atomic.
+static_assert(std::is_trivially_copyable_v<BaseProfilerThreadId>);
+static_assert(std::is_copy_constructible_v<BaseProfilerThreadId>);
+static_assert(std::is_move_constructible_v<BaseProfilerThreadId>);
+static_assert(std::is_copy_assignable_v<BaseProfilerThreadId>);
+static_assert(std::is_move_assignable_v<BaseProfilerThreadId>);
+
+}  // namespace mozilla::baseprofiler
+
+#include "mozilla/Types.h"
+
+namespace mozilla::baseprofiler {
+
+// Get the current process's ID.
+[[nodiscard]] MFBT_API BaseProfilerProcessId profiler_current_process_id();
+
+// Get the current thread's ID.
+[[nodiscard]] MFBT_API BaseProfilerThreadId profiler_current_thread_id();
+
+// Must be called at least once from the main thread, before any other main-
+// thread id function.
+MFBT_API void profiler_init_main_thread_id();
+
+[[nodiscard]] MFBT_API BaseProfilerThreadId profiler_main_thread_id();
+
+[[nodiscard]] MFBT_API bool profiler_is_main_thread();
+
+}  // namespace mozilla::baseprofiler
+
+#endif  // BaseProfilerUtils_h