issue=1251, use clock_gettime(CLOCK_MONOTONIC) to get current time

bug fix for system time rollback
baidu · May 5, 2017 · 43a6b26 · 43a6b26
1 parent 98b337d
commit 43a6b26
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Showing 8 changed files with 51 additions and 43 deletions.
diff --git a/src/common/mutex.h b/src/common/mutex.h
@@ -120,10 +120,14 @@ class MutexLock {
 class CondVar {
 public:
     explicit CondVar(Mutex* mu) : mu_(mu) {
-        PthreadCall("init condvar", pthread_cond_init(&cond_, NULL));
+        // use monotonic clock
+        PthreadCall("condattr init ", pthread_condattr_init(&attr_));
+        PthreadCall("condattr setclock ", pthread_condattr_setclock(&attr_, CLOCK_MONOTONIC));
+        PthreadCall("condvar init with attr", pthread_cond_init(&cond_, &attr_));
     }
     ~CondVar() {
-        PthreadCall("destroy condvar", pthread_cond_destroy(&cond_));
+        PthreadCall("condvar destroy", pthread_cond_destroy(&cond_));
+        PthreadCall("condattr destroy", pthread_condattr_destroy(&attr_));
     }
     void Wait(const char* msg = NULL) {
         int64_t msg_threshold = mu_->msg_threshold_;
@@ -134,12 +138,13 @@ class CondVar {
     // Time wait in us
     // timeout < 0 would cause ETIMEOUT and return false immediately
     bool TimeWaitInUs(int timeout, const char* msg = NULL) {
-        timespec ts;
-        struct timeval tv;
-        gettimeofday(&tv, NULL);
-        int64_t usec = tv.tv_usec + timeout;
-        ts.tv_sec = tv.tv_sec + usec / 1000000;
-        ts.tv_nsec = (usec % 1000000) * 1000;
+        // ref: http://www.qnx.com/developers/docs/6.5.0SP1.update/com.qnx.doc.neutrino_lib_ref/p/pthread_cond_timedwait.html
+        struct timespec ts;
+        clock_gettime(CLOCK_MONOTONIC, &ts);
+        int64_t nsec = ((int64_t)timeout) * 1000 + ts.tv_nsec;
+        ts.tv_sec += nsec / 1000000000;
+        ts.tv_nsec = nsec % 1000000000;
+
         int64_t msg_threshold = mu_->msg_threshold_;
         mu_->BeforeUnlock();
         int ret = pthread_cond_timedwait(&cond_, &mu_->mu_, &ts);
@@ -163,6 +168,7 @@ class CondVar {
     void operator=(const CondVar&);
     Mutex* mu_;
     pthread_cond_t cond_;
+    pthread_condattr_t attr_;
 };
 }  // namespace common
 

diff --git a/src/common/timer.h b/src/common/timer.h
@@ -27,17 +27,15 @@ static inline std::string get_curtime_str() {
 }
 
 static inline int64_t get_micros() {
-    struct timeval tv;
-    gettimeofday(&tv, NULL);
-    return static_cast<int64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;
+    struct timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return static_cast<int64_t>(ts.tv_sec) * 1000000 + static_cast<int64_t>(ts.tv_nsec) / 1000;
 }
 
 static inline int64_t get_unique_micros(int64_t ref) {
-    struct timeval tv;
     int64_t now;
     do {
-        gettimeofday(&tv, NULL);
-        now = static_cast<int64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;
+        now = get_micros();
     } while (now == ref);
     return now;
 }

diff --git a/src/leveldb/bench/tera_bench.cc b/src/leveldb/bench/tera_bench.cc
@@ -222,8 +222,8 @@ class Benchmark {
       snprintf(msg, sizeof(msg), "(%d ops)", num_entries);
       message_ = msg;
     }
-    char ts[10];
-    snprintf(ts, sizeof(ts), "%d", FLAGS_value_seed);
+    char ts[20];
+    snprintf(ts, sizeof(ts), "%lld", ((long long int)FLAGS_value_seed) * 1000000);
 
     // Write to database
     int i = FLAGS_start_key;

diff --git a/src/leveldb/port/port_posix.cc b/src/leveldb/port/port_posix.cc
@@ -50,32 +50,39 @@ void Mutex::Unlock() { PthreadCall("unlock", pthread_mutex_unlock(&mu_)); }
 
 CondVar::CondVar(Mutex* mu)
     : mu_(mu) {
-    PthreadCall("init cv", pthread_cond_init(&cv_, NULL));
+    // use monotonic clock
+    PthreadCall("condattr init ", pthread_condattr_init(&attr_));
+    PthreadCall("condattr setclock ", pthread_condattr_setclock(&attr_, CLOCK_MONOTONIC));
+    PthreadCall("condvar init with attr", pthread_cond_init(&cond_, &attr_));
 }
 
-CondVar::~CondVar() { PthreadCall("destroy cv", pthread_cond_destroy(&cv_)); }
+CondVar::~CondVar() {
+    PthreadCall("condvar destroy", pthread_cond_destroy(&cond_));
+    PthreadCall("condattr destroy", pthread_condattr_destroy(&attr_));
+}
 
 void CondVar::Wait() {
-  PthreadCall("wait", pthread_cond_wait(&cv_, &mu_->mu_));
+  PthreadCall("condvar wait", pthread_cond_wait(&cond_, &mu_->mu_));
 }
 
+// wait in ms
 bool CondVar::Wait(int64_t wait_millisec) {
   assert(wait_millisec >= 0);
+  // ref: http://www.qnx.com/developers/docs/6.5.0SP1.update/com.qnx.doc.neutrino_lib_ref/p/pthread_cond_timedwait.html
   struct timespec ts;
-  struct timeval tp;
-  gettimeofday(&tp, NULL);
-  uint64_t usec = tp.tv_usec + wait_millisec * 1000;
-  ts.tv_sec = tp.tv_sec + usec / 1000000;
-  ts.tv_nsec = (usec % 1000000) * 1000;
-  return (0 == pthread_cond_timedwait(&cv_, &mu_->mu_, &ts));
+  clock_gettime(CLOCK_MONOTONIC, &ts);
+  int64_t nsec = ((int64_t)wait_millisec) * 1000000 + ts.tv_nsec;
+  ts.tv_sec += nsec / 1000000000;
+  ts.tv_nsec = nsec % 1000000000;
+  return (0 == pthread_cond_timedwait(&cond_, &mu_->mu_, &ts));
 }
 
 void CondVar::Signal() {
-  PthreadCall("signal", pthread_cond_signal(&cv_));
+  PthreadCall("signal", pthread_cond_signal(&cond_));
 }
 
 void CondVar::SignalAll() {
-  PthreadCall("broadcast", pthread_cond_broadcast(&cv_));
+  PthreadCall("broadcast", pthread_cond_broadcast(&cond_));
 }
 
 void InitOnce(OnceType* once, void (*initializer)()) {

diff --git a/src/leveldb/port/port_posix.h b/src/leveldb/port/port_posix.h
@@ -113,7 +113,8 @@ class CondVar {
   void Signal();
   void SignalAll();
  private:
-  pthread_cond_t cv_;
+  pthread_cond_t cond_;
+  pthread_condattr_t attr_;
   Mutex* mu_;
 };
 

diff --git a/src/leveldb/util/env_posix.cc b/src/leveldb/util/env_posix.cc
@@ -809,9 +809,9 @@ class PosixEnv : public Env {
   }
 
   virtual uint64_t NowMicros() {
-    struct timeval tv;
-    gettimeofday(&tv, NULL);
-    return static_cast<uint64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;
+    struct timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return static_cast<int64_t>(ts.tv_sec) * 1000000 + static_cast<int64_t>(ts.tv_nsec) / 1000;
   }
 
   virtual void SleepForMicroseconds(int micros) {

diff --git a/src/leveldb/util/raw_key_operator_test.cc b/src/leveldb/util/raw_key_operator_test.cc
@@ -19,9 +19,9 @@ void print_bytes(const char* str, int len) {
 }
 
 int64_t get_micros() {
-    struct timeval tv;
-    gettimeofday(&tv, NULL);
-    return static_cast<int64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;
+    struct timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return static_cast<int64_t>(ts.tv_sec) * 1000000 + static_cast<int64_t>(ts.tv_nsec) / 1000;
 }
 
 class RawKeyOperatorTest {};

diff --git a/src/utils/timer.h b/src/utils/timer.h
@@ -27,23 +27,19 @@ static inline std::string get_curtime_str_plain() {
 }
 
 static inline int64_t get_micros() {
-    struct timeval tv;
-    gettimeofday(&tv, NULL);
-    return static_cast<int64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;
+    struct timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return static_cast<int64_t>(ts.tv_sec) * 1000000 + static_cast<int64_t>(ts.tv_nsec) / 1000;
 }
 
 static inline int64_t get_millis() {
-    struct timeval tv;
-    gettimeofday(&tv, NULL);
-    return static_cast<int64_t>(tv.tv_sec) * 1000 + tv.tv_usec / 1000;
+    return get_micros() / 1000;
 }
 
 static inline int64_t get_unique_micros(int64_t ref) {
-    struct timeval tv;
     int64_t now;
     do {
-        gettimeofday(&tv, NULL);
-        now = static_cast<int64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;
+        now = get_micros();
     } while (now == ref);
     return now;
 }