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#ifndef THR_COND_INCLUDED
#define THR_COND_INCLUDED
/* Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
/**
MySQL condition variable implementation.
There are three "layers":
1) native_cond_*()
Functions that map directly down to OS primitives.
Windows - ConditionVariable
Other OSes - pthread
2) my_cond_*()
Functions that use SAFE_MUTEX (default for debug).
Otherwise native_cond_*() is used.
3) mysql_cond*()
Functions that include Performance Schema instrumentation.
See include/mysql/psi/mysql_thread.h
*/
#include "my_thread.h"
#include "thr_mutex.h"
C_MODE_START
#ifdef _WIN32
typedef CONDITION_VARIABLE native_cond_t;
#else
typedef pthread_cond_t native_cond_t;
#endif
#ifdef _WIN32
/**
Convert abstime to milliseconds
*/
static DWORD get_milliseconds(const struct timespec *abstime)
{
#ifndef HAVE_STRUCT_TIMESPEC
long long millis;
union ft64 now;
if (abstime == NULL)
return INFINITE;
GetSystemTimeAsFileTime(&now.ft);
/*
Calculate time left to abstime
- subtract start time from current time(values are in 100ns units)
- convert to millisec by dividing with 10000
*/
millis= (abstime->tv.i64 - now.i64) / 10000;
/* Don't allow the timeout to be negative */
if (millis < 0)
return 0;
/*
Make sure the calculated timeout does not exceed original timeout
value which could cause "wait for ever" if system time changes
*/
if (millis > abstime->max_timeout_msec)
millis= abstime->max_timeout_msec;
if (millis > UINT_MAX)
millis= UINT_MAX;
return (DWORD)millis;
#else
/*
Convert timespec to millis and subtract current time.
my_getsystime() returns time in 100 ns units.
*/
ulonglong future= abstime->tv_sec * 1000 + abstime->tv_nsec / 1000000;
ulonglong now= my_getsystime() / 10000;
/* Don't allow the timeout to be negative. */
if (future < now)
return 0;
return (DWORD)(future - now);
#endif
}
#endif /* _WIN32 */
static inline int native_cond_init(native_cond_t *cond)
{
#ifdef _WIN32
InitializeConditionVariable(cond);
return 0;
#else
/* pthread_condattr_t is not used in MySQL */
return pthread_cond_init(cond, NULL);
#endif
}
static inline int native_cond_destroy(native_cond_t *cond)
{
#ifdef _WIN32
return 0; /* no destroy function */
#else
return pthread_cond_destroy(cond);
#endif
}
static inline int native_cond_timedwait(native_cond_t *cond,
native_mutex_t *mutex,
const struct timespec *abstime)
{
#ifdef _WIN32
DWORD timeout= get_milliseconds(abstime);
if (!SleepConditionVariableCS(cond, mutex, timeout))
return ETIMEDOUT;
return 0;
#else
return pthread_cond_timedwait(cond, mutex, abstime);
#endif
}
static inline int native_cond_wait(native_cond_t *cond, native_mutex_t *mutex)
{
#ifdef _WIN32
if (!SleepConditionVariableCS(cond, mutex, INFINITE))
return ETIMEDOUT;
return 0;
#else
return pthread_cond_wait(cond, mutex);
#endif
}
static inline int native_cond_signal(native_cond_t *cond)
{
#ifdef _WIN32
WakeConditionVariable(cond);
return 0;
#else
return pthread_cond_signal(cond);
#endif
}
static inline int native_cond_broadcast(native_cond_t *cond)
{
#ifdef _WIN32
WakeAllConditionVariable(cond);
return 0;
#else
return pthread_cond_broadcast(cond);
#endif
}
#ifdef SAFE_MUTEX
int safe_cond_wait(native_cond_t *cond, my_mutex_t *mp,
const char *file, uint line);
int safe_cond_timedwait(native_cond_t *cond, my_mutex_t *mp,
const struct timespec *abstime,
const char *file, uint line);
#endif
static inline int my_cond_timedwait(native_cond_t *cond, my_mutex_t *mp,
const struct timespec *abstime
#ifdef SAFE_MUTEX
, const char *file, uint line
#endif
)
{
#ifdef SAFE_MUTEX
return safe_cond_timedwait(cond, mp, abstime, file, line);
#else
return native_cond_timedwait(cond, mp, abstime);
#endif
}
static inline int my_cond_wait(native_cond_t *cond, my_mutex_t *mp
#ifdef SAFE_MUTEX
, const char *file, uint line
#endif
)
{
#ifdef SAFE_MUTEX
return safe_cond_wait(cond, mp, file, line);
#else
return native_cond_wait(cond, mp);
#endif
}
C_MODE_END
#endif /* THR_COND_INCLUDED */
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