# HG changeset patch
# User mbaesken
# Date 1574327214 -3600
#      Thu Nov 21 10:06:54 2019 +0100
# Node ID a0f01e10daf99a4ffe780bb4736f0b8b38c3689f
# Parent  580fb715b29d82439ab7174d9277b5eeb9d27514
8234397: add OS uptime information to os::print_os_info output

diff --git a/src/hotspot/os/aix/os_aix.cpp b/src/hotspot/os/aix/os_aix.cpp
--- a/src/hotspot/os/aix/os_aix.cpp
+++ b/src/hotspot/os/aix/os_aix.cpp
@@ -1385,6 +1385,8 @@
   st->print_cr("AIX kernel version %u.%u.%u.%u",
                (ver >> 24) & 0xFF, (ver >> 16) & 0xFF, (ver >> 8) & 0xFF, ver & 0xFF);
 
+  os::Posix::print_uptime_info(st);
+
   os::Posix::print_rlimit_info(st);
 
   os::Posix::print_load_average(st);
diff --git a/src/hotspot/os/bsd/os_bsd.cpp b/src/hotspot/os/bsd/os_bsd.cpp
--- a/src/hotspot/os/bsd/os_bsd.cpp
+++ b/src/hotspot/os/bsd/os_bsd.cpp
@@ -169,6 +169,22 @@
   return available;
 }
 
+// for more info see :
+// https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man3/sysctl.3.html
+void os::Bsd::print_uptime_info(outputStream* st) {
+  struct timeval boottime;
+  size_t len = sizeof(boottime);
+  int mib[2];
+  mib[0] = CTL_KERN;
+  mib[1] = KERN_BOOTTIME;
+
+  if (sysctl(mib, 2, &boottime, &len, NULL, 0) >= 0) {
+    time_t bootsec = boottime.tv_sec, currsec = time(NULL);
+    double tdiff = difftime(currsec, bootsec);
+    st->print_cr("OS uptime (in days): %.2lf", tdiff/(60.0*60.0*24.0));
+  }
+}
+
 julong os::physical_memory() {
   return Bsd::physical_memory();
 }
@@ -1570,6 +1586,8 @@
 
   os::Posix::print_uname_info(st);
 
+  os::Bsd::print_uptime_info(st);
+
   os::Posix::print_rlimit_info(st);
 
   os::Posix::print_load_average(st);
diff --git a/src/hotspot/os/bsd/os_bsd.hpp b/src/hotspot/os/bsd/os_bsd.hpp
--- a/src/hotspot/os/bsd/os_bsd.hpp
+++ b/src/hotspot/os/bsd/os_bsd.hpp
@@ -155,6 +155,8 @@
     }
   }
   static int get_node_by_cpu(int cpu_id);
+
+  static void print_uptime_info(outputStream* st);
 };
 
 #endif // OS_BSD_OS_BSD_HPP
diff --git a/src/hotspot/os/linux/os_linux.cpp b/src/hotspot/os/linux/os_linux.cpp
--- a/src/hotspot/os/linux/os_linux.cpp
+++ b/src/hotspot/os/linux/os_linux.cpp
@@ -2120,6 +2120,8 @@
 
   os::Posix::print_uname_info(st);
 
+  os::Linux::print_uptime_info(st);
+
   // Print warning if unsafe chroot environment detected
   if (unsafe_chroot_detected) {
     st->print("WARNING!! ");
@@ -2305,6 +2307,15 @@
   st->cr();
 }
 
+void os::Linux::print_uptime_info(outputStream* st) {
+  struct sysinfo sinfo;
+  int ret = sysinfo(&sinfo);
+  if (ret == 0) {
+    st->print_cr("OS uptime (in days): %.2lf", (double) sinfo.uptime/(60*60*24) );
+  }
+}
+
+
 void os::Linux::print_container_info(outputStream* st) {
   if (!OSContainer::is_containerized()) {
     return;
diff --git a/src/hotspot/os/linux/os_linux.hpp b/src/hotspot/os/linux/os_linux.hpp
--- a/src/hotspot/os/linux/os_linux.hpp
+++ b/src/hotspot/os/linux/os_linux.hpp
@@ -103,6 +103,7 @@
   static void print_libversion_info(outputStream* st);
   static void print_proc_sys_info(outputStream* st);
   static void print_ld_preload_file(outputStream* st);
+  static void print_uptime_info(outputStream* st);
 
  public:
   struct CPUPerfTicks {
diff --git a/src/hotspot/os/posix/os_posix.cpp b/src/hotspot/os/posix/os_posix.cpp
--- a/src/hotspot/os/posix/os_posix.cpp
+++ b/src/hotspot/os/posix/os_posix.cpp
@@ -47,6 +47,7 @@
 #include <sys/utsname.h>
 #include <time.h>
 #include <unistd.h>
+#include <utmpx.h>
 
 // Todo: provide a os::get_max_process_id() or similar. Number of processes
 // may have been configured, can be read more accurately from proc fs etc.
@@ -377,6 +378,27 @@
   st->cr();
 }
 
+// boot/uptime information;
+// unfortunately it does not work on macOS because the utx chain has no entry
+// for reboot at least on my test machines
+void os::Posix::print_uptime_info(outputStream* st) {
+  int bootsec = -1;
+  int currsec = time(NULL);
+  struct utmpx* ent;
+  setutxent();
+  while ((ent = getutxent())) {
+    if (!strcmp("system boot", ent->ut_line)) {
+      bootsec = ent->ut_tv.tv_sec;
+      break;
+    }
+  }
+
+  if (bootsec != -1) {
+    st->print_cr("OS uptime (in days): %.2lf", (double) (currsec-bootsec)/(60*60*24));
+  }
+}
+
+
 void os::Posix::print_rlimit_info(outputStream* st) {
   st->print("rlimit:");
   struct rlimit rlim;
diff --git a/src/hotspot/os/posix/os_posix.hpp b/src/hotspot/os/posix/os_posix.hpp
--- a/src/hotspot/os/posix/os_posix.hpp
+++ b/src/hotspot/os/posix/os_posix.hpp
@@ -41,6 +41,7 @@
   static void print_uname_info(outputStream* st);
   static void print_libversion_info(outputStream* st);
   static void print_load_average(outputStream* st);
+  static void print_uptime_info(outputStream* st);
 
   // Minimum stack size a thread can be created with (allowing
   // the VM to completely create the thread and enter user code).
diff --git a/src/hotspot/os/solaris/os_solaris.cpp b/src/hotspot/os/solaris/os_solaris.cpp
--- a/src/hotspot/os/solaris/os_solaris.cpp
+++ b/src/hotspot/os/solaris/os_solaris.cpp
@@ -1584,6 +1584,8 @@
 
   os::Posix::print_uname_info(st);
 
+  os::Posix::print_uptime_info(st);
+
   os::Solaris::print_libversion_info(st);
 
   os::Posix::print_rlimit_info(st);
diff --git a/src/hotspot/os/windows/os_windows.cpp b/src/hotspot/os/windows/os_windows.cpp
--- a/src/hotspot/os/windows/os_windows.cpp
+++ b/src/hotspot/os/windows/os_windows.cpp
@@ -1604,6 +1604,9 @@
   st->print("OS:");
   os::win32::print_windows_version(st);
 
+  unsigned long long ticks = GetTickCount64();
+  st->print_cr("OS uptime (in days): %.2lf", (double) ((double)ticks/(1000.0*60.0*60.0*24.0)));
+
 #ifdef _LP64
   VM_Version::print_platform_virtualization_info(st);
 #endif