Initial checkin of gRPC to third_party/

third_party/grpc/src/core/support/time_posix.c

Index: third_party/grpc/src/core/support/time_posix.c
diff --git a/third_party/grpc/src/core/support/time_posix.c b/third_party/grpc/src/core/support/time_posix.c
new file mode 100644
index 0000000000000000000000000000000000000000..36d75e7da2fbfa1b63051fbcf90509729107e269
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+++ b/third_party/grpc/src/core/support/time_posix.c
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+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+#include <src/core/support/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/log.h>
+#include <grpc/support/time.h>
+#include "src/core/support/block_annotate.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
+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(); }
+
+gpr_timespec gpr_now(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 <sys/time.h>
+#include <mach/mach.h>
+#include <mach/mach_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();
+}
+
+gpr_timespec gpr_now(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, NULL);
+      now.tv_sec = now_tv.tv_sec;
+      now.tv_nsec = now_tv.tv_usec * 1000;
+      break;
+    case GPR_CLOCK_MONOTONIC:
+      now_dbl = (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
+
+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);
+    GRPC_SCHEDULING_START_BLOCKING_REGION;
+    ns_result = nanosleep(&delta_ts, NULL);
+    GRPC_SCHEDULING_END_BLOCKING_REGION;
+    if (ns_result == 0) {
+      break;
+    }
+  }
+}
+
+#endif /* GPR_POSIX_TIME */