1 files changed, 72 insertions, 0 deletions
diff --git a/Foundation/GTMTimeUtils.m b/Foundation/GTMTimeUtils.m
new file mode 100644
index 0000000..2b551e4
--- /dev/null
+++ b/Foundation/GTMTimeUtils.m
@@ -0,0 +1,72 @@
+//
+//  GTMTimeUtils.m
+//
+//  Copyright 2018 Google LLC
+//
+//  Licensed under the Apache License, Version 2.0 (the "License"); you may not
+//  use this file except in compliance with the License.  You may obtain a copy
+//  of the License at
+//
+//  http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+//  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+//  License for the specific language governing permissions and limitations under
+//  the License.
+//
+
+#import "GTMTimeUtils.h"
+
+#include <sys/sysctl.h>
+
+#import "GTMDefines.h"
+
+NSTimeInterval GTMTimeValToNSTimeInterval(struct timeval time) {
+  return time.tv_sec + (time.tv_usec / (double)USEC_PER_SEC);
+}
+
+struct timeval GTMBootTimeRelativeTo1970(void) {
+  struct timeval bootTime = { 0, 0 };
+  int mib[2] = { CTL_KERN, KERN_BOOTTIME };
+  size_t bootTimeSize = sizeof(bootTime);
+  if (sysctl(mib, 2, &bootTime, &bootTimeSize, NULL, 0) != 0) {
+    _GTMDevAssert(errno == 0, @"sysctl error - %d", errno);
+    struct timeval invalid = { 0, 0 };
+    return invalid;
+  }
+  return bootTime;
+}
+
+struct timeval GTMAppLaunchTimeRelativeTo1970(void) {
+  id_t pid = getpid();
+  int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_PID, (int)pid };
+  const size_t mibSize = sizeof(mib) / sizeof(mib[0]);
+  size_t infoSize = 0;
+
+  // Get initial size of KERN_PROC data structure.
+  if (sysctl(mib, mibSize, NULL, &infoSize, NULL, 0) != 0) {
+    _GTMDevAssert(errno == 0, @"sysctl error - %d", errno);
+    struct timeval invalid = { 0, 0 };
+    return invalid;
+  }
+  struct kinfo_proc info;
+  if (sysctl(mib, mibSize, &info, &infoSize, NULL, 0) != 0) {
+    _GTMDevAssert(errno == 0, @"sysctl error - %d", errno);
+    struct timeval invalid = { 0, 0 };
+    return invalid;
+  }
+  return info.kp_proc.p_starttime;
+}
+
+NSDate *GTMAppLaunchDate() {
+  NSTimeInterval ti =
+      GTMTimeValToNSTimeInterval(GTMAppLaunchTimeRelativeTo1970());
+  return [NSDate dateWithTimeIntervalSince1970:ti];
+}
+
+NSDate *GTMBootDate() {
+  NSTimeInterval ti =
+      GTMTimeValToNSTimeInterval(GTMBootTimeRelativeTo1970());
+  return [NSDate dateWithTimeIntervalSince1970:ti];
+}