1 files changed, 125 insertions, 0 deletions
diff --git a/darwin/PlatformHelpers.c b/darwin/PlatformHelpers.c
new file mode 100644
index 0000000..a4ea82b
--- /dev/null
+++ b/darwin/PlatformHelpers.c
@@ -0,0 +1,125 @@
+/*
+htop - darwin/PlatformHelpers.c
+(C) 2018 Pierre Malhaire, 2020-2021 htop dev team, 2021 Alexander Momchilov
+Released under the GNU GPLv2+, see the COPYING file
+in the source distribution for its full text.
+*/
+
+#include "darwin/PlatformHelpers.h"
+
+#include <errno.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/sysctl.h>
+
+#include "CRT.h"
+
+#ifdef HAVE_MACH_MACH_TIME_H
+#include <mach/mach_time.h>
+#endif
+
+
+void Platform_GetKernelVersion(KernelVersion* k) {
+   static KernelVersion cachedKernelVersion;
+
+   if (!cachedKernelVersion.major) {
+      // just in case it fails someday
+      cachedKernelVersion = (KernelVersion) { -1, -1, -1 };
+      char str[256] = {0};
+      size_t size = sizeof(str);
+      int ret = sysctlbyname("kern.osrelease", str, &size, NULL, 0);
+      if (ret == 0) {
+         sscanf(str, "%hd.%hd.%hd", &cachedKernelVersion.major, &cachedKernelVersion.minor, &cachedKernelVersion.patch);
+      }
+   }
+   memcpy(k, &cachedKernelVersion, sizeof(cachedKernelVersion));
+}
+
+int Platform_CompareKernelVersion(KernelVersion v) {
+   struct KernelVersion actualVersion;
+   Platform_GetKernelVersion(&actualVersion);
+
+   if (actualVersion.major != v.major) {
+      return actualVersion.major - v.major;
+   }
+   if (actualVersion.minor != v.minor) {
+      return actualVersion.minor - v.minor;
+   }
+   if (actualVersion.patch != v.patch) {
+      return actualVersion.patch - v.patch;
+   }
+
+   return 0;
+}
+
+bool Platform_KernelVersionIsBetween(KernelVersion lowerBound, KernelVersion upperBound) {
+   return 0 <= Platform_CompareKernelVersion(lowerBound)
+      && Platform_CompareKernelVersion(upperBound) < 0;
+}
+
+void Platform_getCPUBrandString(char* cpuBrandString, size_t cpuBrandStringSize) {
+   if (sysctlbyname("machdep.cpu.brand_string", cpuBrandString, &cpuBrandStringSize, NULL, 0) == -1) {
+      fprintf(stderr,
+         "WARN: Unable to determine the CPU brand string.\n"
+         "errno: %i, %s\n", errno, strerror(errno));
+
+      String_safeStrncpy(cpuBrandString, "UNKNOWN!", cpuBrandStringSize);
+   }
+}
+
+// Adapted from https://developer.apple.com/documentation/apple-silicon/about-the-rosetta-translation-environment
+bool Platform_isRunningTranslated(void) {
+   int ret = 0;
+   size_t size = sizeof(ret);
+   errno = 0;
+   if (sysctlbyname("sysctl.proc_translated", &ret, &size, NULL, 0) == -1) {
+      if (errno == ENOENT)
+         return false;
+
+      fprintf(stderr,
+         "WARN: Could not determine if this process was running in a translation environment like Rosetta 2.\n"
+         "Assuming that we're not.\n"
+         "errno: %i, %s\n", errno, strerror(errno));
+
+      return false;
+   }
+   return ret;
+}
+
+double Platform_calculateNanosecondsPerMachTick(void) {
+   // Check if we can determine the timebase used on this system.
+   // If the API is unavailable assume we get our timebase in nanoseconds.
+#ifndef HAVE_MACH_TIMEBASE_INFO
+   return 1.0;
+#else
+   mach_timebase_info_data_t info;
+
+   /* WORKAROUND for `mach_timebase_info` giving incorrect values on M1 under Rosetta 2.
+    *    rdar://FB9546856 https://openradar.appspot.com/radar?id=5055988478509056
+    *
+    *    We don't know exactly what feature/attribute of the M1 chip causes this mistake under Rosetta 2.
+    *    Until we have more Apple ARM chips to compare against, the best we can do is special-case
+    *    the "Apple M1" chip specifically when running under Rosetta 2.
+    */
+
+   char cpuBrandString[1024] = "";
+   Platform_getCPUBrandString(cpuBrandString, sizeof(cpuBrandString));
+
+   bool isRunningUnderRosetta2 = Platform_isRunningTranslated();
+
+   // Kernel version 20.0.0 is macOS 11.0 (Big Sur)
+   bool isBuggedVersion = Platform_KernelVersionIsBetween((KernelVersion) {20, 0, 0}, (KernelVersion) {999, 999, 999});
+
+   if (isRunningUnderRosetta2 && String_eq(cpuBrandString, "Apple M1") && isBuggedVersion) {
+      // In this case `mach_timebase_info` provides the wrong value, so we hard-code the correct factor,
+      // as determined from `mach_timebase_info` when the process running natively.
+      info = (mach_timebase_info_data_t) { .numer = 125, .denom = 3 };
+   } else {
+      // No workarounds needed, use the OS-provided value.
+      mach_timebase_info(&info);
+   }
+
+   return (double)info.numer / (double)info.denom;
+#endif
+}