1 files changed, 166 insertions, 0 deletions
diff --git a/src/core/lib/gpr/time_posix.cc b/src/core/lib/gpr/time_posix.cc
new file mode 100644
index 0000000000..9c7e86b080
--- /dev/null
+++ b/src/core/lib/gpr/time_posix.cc
@@ -0,0 +1,166 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * 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.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+#include "src/core/lib/gpr/time_precise.h"
+
+#ifdef GPR_POSIX_TIME
+
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+#ifdef __linux__
+#include <sys/syscall.h>
+#endif
+#include <grpc/support/atm.h>
+#include <grpc/support/log.h>
+#include <grpc/support/time.h>
+
+static struct timespec timespec_from_gpr(gpr_timespec gts) {
+  struct timespec rv;
+  if (sizeof(time_t) < sizeof(int64_t)) {
+    /* fine to assert, as this is only used in gpr_sleep_until */
+    GPR_ASSERT(gts.tv_sec <= INT32_MAX && gts.tv_sec >= INT32_MIN);
+  }
+  rv.tv_sec = (time_t)gts.tv_sec;
+  rv.tv_nsec = gts.tv_nsec;
+  return rv;
+}
+
+#if _POSIX_TIMERS > 0 || defined(__OpenBSD__)
+static gpr_timespec gpr_from_timespec(struct timespec ts,
+                                      gpr_clock_type clock_type) {
+  /*
+   * timespec.tv_sec can have smaller size than gpr_timespec.tv_sec,
+   * but we are only using this function to implement gpr_now
+   * so there's no need to handle "infinity" values.
+   */
+  gpr_timespec rv;
+  rv.tv_sec = ts.tv_sec;
+  rv.tv_nsec = (int32_t)ts.tv_nsec;
+  rv.clock_type = clock_type;
+  return rv;
+}
+
+/** maps gpr_clock_type --> clockid_t for clock_gettime */
+static const clockid_t clockid_for_gpr_clock[] = {CLOCK_MONOTONIC,
+                                                  CLOCK_REALTIME};
+
+void gpr_time_init(void) { gpr_precise_clock_init(); }
+
+static gpr_timespec now_impl(gpr_clock_type clock_type) {
+  struct timespec now;
+  GPR_ASSERT(clock_type != GPR_TIMESPAN);
+  if (clock_type == GPR_CLOCK_PRECISE) {
+    gpr_timespec ret;
+    gpr_precise_clock_now(&ret);
+    return ret;
+  } else {
+#if defined(GPR_BACKWARDS_COMPATIBILITY_MODE) && defined(__linux__)
+    /* avoid ABI problems by invoking syscalls directly */
+    syscall(SYS_clock_gettime, clockid_for_gpr_clock[clock_type], &now);
+#else
+    clock_gettime(clockid_for_gpr_clock[clock_type], &now);
+#endif
+    return gpr_from_timespec(now, clock_type);
+  }
+}
+#else
+  /* For some reason Apple's OSes haven't implemented clock_gettime. */
+
+#include <mach/mach.h>
+#include <mach/mach_time.h>
+#include <sys/time.h>
+
+static double g_time_scale;
+static uint64_t g_time_start;
+
+void gpr_time_init(void) {
+  mach_timebase_info_data_t tb = {0, 1};
+  gpr_precise_clock_init();
+  mach_timebase_info(&tb);
+  g_time_scale = tb.numer;
+  g_time_scale /= tb.denom;
+  g_time_start = mach_absolute_time();
+}
+
+static gpr_timespec now_impl(gpr_clock_type clock) {
+  gpr_timespec now;
+  struct timeval now_tv;
+  double now_dbl;
+
+  now.clock_type = clock;
+  switch (clock) {
+    case GPR_CLOCK_REALTIME:
+      gettimeofday(&now_tv, nullptr);
+      now.tv_sec = now_tv.tv_sec;
+      now.tv_nsec = now_tv.tv_usec * 1000;
+      break;
+    case GPR_CLOCK_MONOTONIC:
+      now_dbl = ((double)(mach_absolute_time() - g_time_start)) * g_time_scale;
+      now.tv_sec = (int64_t)(now_dbl * 1e-9);
+      now.tv_nsec = (int32_t)(now_dbl - ((double)now.tv_sec) * 1e9);
+      break;
+    case GPR_CLOCK_PRECISE:
+      gpr_precise_clock_now(&now);
+      break;
+    case GPR_TIMESPAN:
+      abort();
+  }
+
+  return now;
+}
+#endif
+
+gpr_timespec (*gpr_now_impl)(gpr_clock_type clock_type) = now_impl;
+
+#ifdef GPR_LOW_LEVEL_COUNTERS
+gpr_atm gpr_now_call_count;
+#endif
+
+gpr_timespec gpr_now(gpr_clock_type clock_type) {
+#ifdef GPR_LOW_LEVEL_COUNTERS
+  __atomic_fetch_add(&gpr_now_call_count, 1, __ATOMIC_RELAXED);
+#endif
+  return gpr_now_impl(clock_type);
+}
+
+void gpr_sleep_until(gpr_timespec until) {
+  gpr_timespec now;
+  gpr_timespec delta;
+  struct timespec delta_ts;
+  int ns_result;
+
+  for (;;) {
+    /* We could simplify by using clock_nanosleep instead, but it might be
+     * slightly less portable. */
+    now = gpr_now(until.clock_type);
+    if (gpr_time_cmp(until, now) <= 0) {
+      return;
+    }
+
+    delta = gpr_time_sub(until, now);
+    delta_ts = timespec_from_gpr(delta);
+    ns_result = nanosleep(&delta_ts, nullptr);
+    if (ns_result == 0) {
+      break;
+    }
+  }
+}
+
+#endif /* GPR_POSIX_TIME */