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DynamicWatchdog.cpp
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1 /*
2  * Copyright 2017 MapD Technologies, Inc.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <atomic>
18 #include <chrono>
19 #include <thread>
20 
21 #include "DynamicWatchdog.h"
22 #include "Shared/Logger.h"
23 
24 static __inline__ uint64_t read_cycle_counter(void) {
25 #if (defined(__x86_64__) || defined(__x86_64))
26  unsigned hi, lo;
27  __asm__ __volatile__("rdtsc" : "=a"(lo), "=d"(hi));
28  return (static_cast<uint64_t>(hi) << 32) | static_cast<uint64_t>(lo);
29 #else
30  // Plug in other architectures' cycle counter reads, e.g. MRC on ARM
31  return 0LL;
32 #endif
33 }
34 
35 extern "C" uint64_t dynamic_watchdog_init(unsigned ms_budget) {
36  static uint64_t dw_cycle_start = 0ULL;
37  static uint64_t dw_cycle_budget = 0ULL;
38  static std::atomic_bool dw_abort{false};
39 
40  if (ms_budget == static_cast<unsigned>(DW_DEADLINE)) {
41  if (dw_abort.load()) {
42  {
43  return 0LL;
44  }
45  }
46  return dw_cycle_start + dw_cycle_budget;
47  }
48  if (ms_budget == static_cast<unsigned>(DW_ABORT)) {
49  dw_abort = true;
50  return 0LL;
51  }
52  if (ms_budget == static_cast<unsigned>(DW_RESET)) {
53  dw_abort = false;
54  return 0LL;
55  }
56 
57  // Init cycle start, measure freq, set and return cycle budget
58  dw_cycle_start = read_cycle_counter();
59  std::this_thread::sleep_for(std::chrono::milliseconds(1));
60  auto freq_kHz = read_cycle_counter() - dw_cycle_start;
61  dw_cycle_budget = freq_kHz * static_cast<uint64_t>(ms_budget);
62  VLOG(1) << "INIT: thread " << std::this_thread::get_id() << ": ms_budget " << ms_budget
63  << ", cycle_start " << dw_cycle_start << ", cycle_budget " << dw_cycle_budget
64  << ", dw_deadline " << dw_cycle_start + dw_cycle_budget;
65  return dw_cycle_budget;
66 }
67 
68 // timeout detection
69 extern "C" bool dynamic_watchdog() {
70  auto clock = read_cycle_counter();
71  auto dw_deadline = dynamic_watchdog_init(static_cast<unsigned>(DW_DEADLINE));
72  if (clock > dw_deadline) {
73  LOG(INFO) << "TIMEOUT: thread " << std::this_thread::get_id() << ": clock " << clock
74  << ", deadline " << dw_deadline;
75  return true;
76  }
77  return false;
78 }
__device__ bool dynamic_watchdog()
static __inline__ uint64_t read_cycle_counter(void)
#define LOG(tag)
Definition: Logger.h:185
__device__ int64_t dw_cycle_budget
uint64_t dynamic_watchdog_init(unsigned ms_budget)
__device__ int32_t dw_abort
#define VLOG(n)
Definition: Logger.h:280