From 6ed8b4e290489b154a660f1ab0a890da10c67ee3 Mon Sep 17 00:00:00 2001
From: Nicholas Junge <nicho.junge@gmail.com>
Date: Mon, 19 Oct 2026 13:16:19 +0200
Subject: [PATCH 1/3] Use `clock_gettime` on all MacOS after 10.11

`clock_gettime` is available on macOS since 10.12 (September 2016), and
noticeably faster than mach's `thread_info`, so use it whenever available.

Assisted-By: Codex
---
 src/timers.cc | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/timers.cc b/src/timers.cc
index 53cf4875e1..01d1d421f4 100644
--- a/src/timers.cc
+++ b/src/timers.cc
@@ -35,6 +35,7 @@
 #include <sys/sysctl.h>
 #endif
 #if defined(BENCHMARK_OS_MACOSX)
+#include <Availability.h>
 #include <mach/mach_init.h>
 #include <mach/mach_port.h>
 #include <mach/thread_act.h>
@@ -150,9 +151,7 @@ double ProcessCPUUsage() {
            (static_cast<double>(ts.tv_nsec) * 1e-9);
   }
   DiagnoseAndExit("clock_gettime(CLOCK_MONOTONIC, ...) failed");
-#elif defined(CLOCK_PROCESS_CPUTIME_ID) && !defined(BENCHMARK_OS_MACOSX)
-  // FIXME We want to use clock_gettime, but its not available in MacOS 10.11.
-  // See https://github.com/google/benchmark/pull/292
+#elif defined(CLOCK_PROCESS_CPUTIME_ID)
   struct timespec spec {};
   if (clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &spec) == 0) {
     return MakeTime(spec);
@@ -183,9 +182,11 @@ double ThreadCPUUsage() {
   return static_cast<double>(
              qurt_timer_timetick_to_us(qurt_sysclock_get_hw_ticks())) *
          1.0e-6;
-#elif defined(BENCHMARK_OS_MACOSX)
-  // FIXME We want to use clock_gettime, but its not available in MacOS 10.11.
-  // See https://github.com/google/benchmark/pull/292
+#elif defined(BENCHMARK_OS_MACOSX) &&             \
+    (!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) || \
+     __MAC_OS_X_VERSION_MIN_REQUIRED < 101200)
+  // clock_gettime is available since macOS 10.12, older deployment targets
+  // and other Apple platforms read mach's thread_info, which is slower.
   mach_msg_type_number_t count = THREAD_BASIC_INFO_COUNT;
   thread_basic_info_data_t info;
   mach_port_t thread = pthread_mach_thread_np(pthread_self());

From e7332a3acd6b976d317e32a010544fdc10bf1693 Mon Sep 17 00:00:00 2001
From: Nicholas Junge <nicho.junge@gmail.com>
Date: Mon, 19 Oct 2026 15:02:30 +0200
Subject: [PATCH 2/3] Drop ThreadCPUUsage() branch for macOS<10.12

---
 src/timers.cc | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/src/timers.cc b/src/timers.cc
index 01d1d421f4..13ea270783 100644
--- a/src/timers.cc
+++ b/src/timers.cc
@@ -182,20 +182,6 @@ double ThreadCPUUsage() {
   return static_cast<double>(
              qurt_timer_timetick_to_us(qurt_sysclock_get_hw_ticks())) *
          1.0e-6;
-#elif defined(BENCHMARK_OS_MACOSX) &&             \
-    (!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) || \
-     __MAC_OS_X_VERSION_MIN_REQUIRED < 101200)
-  // clock_gettime is available since macOS 10.12, older deployment targets
-  // and other Apple platforms read mach's thread_info, which is slower.
-  mach_msg_type_number_t count = THREAD_BASIC_INFO_COUNT;
-  thread_basic_info_data_t info;
-  mach_port_t thread = pthread_mach_thread_np(pthread_self());
-  if (thread_info(thread, THREAD_BASIC_INFO,
-                  reinterpret_cast<thread_info_t>(&info),
-                  &count) == KERN_SUCCESS) {
-    return MakeTime(info);
-  }
-  DiagnoseAndExit("ThreadCPUUsage() failed when evaluating thread_info");
 #elif defined(BENCHMARK_OS_EMSCRIPTEN)
   // Emscripten doesn't support traditional threads
   return ProcessCPUUsage();

From e566a104008942e94f7793d28989739daa019cfd Mon Sep 17 00:00:00 2001
From: Nicholas Junge <nicho.junge@gmail.com>
Date: Mon, 19 Oct 2026 19:52:07 +0200
Subject: [PATCH 3/3] Remove macOS-specific includes, mach-specific MakeTime()
 overload

Since we assume that we can access `clock_gettime()` on all supported macOS
versions, we can remove the mach thread-info route entirely.
---
 src/timers.cc | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/src/timers.cc b/src/timers.cc
index 13ea270783..d029dfbb25 100644
--- a/src/timers.cc
+++ b/src/timers.cc
@@ -34,12 +34,6 @@
     defined BENCHMARK_OS_MACOSX
 #include <sys/sysctl.h>
 #endif
-#if defined(BENCHMARK_OS_MACOSX)
-#include <Availability.h>
-#include <mach/mach_init.h>
-#include <mach/mach_port.h>
-#include <mach/thread_act.h>
-#endif
 #if defined(BENCHMARK_OS_QURT)
 #include <qurt.h>
 #endif
@@ -95,14 +89,6 @@ double MakeTime(struct rusage const& ru) {
           static_cast<double>(ru.ru_stime.tv_usec) * 1e-6);
 }
 #endif
-#if defined(BENCHMARK_OS_MACOSX)
-double MakeTime(thread_basic_info_data_t const& info) {
-  return (static_cast<double>(info.user_time.seconds) +
-          static_cast<double>(info.user_time.microseconds) * 1e-6 +
-          static_cast<double>(info.system_time.seconds) +
-          static_cast<double>(info.system_time.microseconds) * 1e-6);
-}
-#endif
 #if defined(CLOCK_PROCESS_CPUTIME_ID) || defined(CLOCK_THREAD_CPUTIME_ID)
 double MakeTime(struct timespec const& ts) {
   return static_cast<double>(ts.tv_sec) +