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/*
* include/common/hathreads.h
* definitions, macros and inline functions about threads.
*
* Copyright (C) 2017 Christopher Fauet - cfaulet@haproxy.com
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation, version 2.1
* exclusively.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _COMMON_HATHREADS_H
#define _COMMON_HATHREADS_H
#include <common/config.h>
#define MAX_THREADS_MASK ((unsigned long)-1)
extern THREAD_LOCAL unsigned int tid; /* The thread id */
extern THREAD_LOCAL unsigned long tid_bit; /* The bit corresponding to the thread id */
#ifndef USE_THREAD
#define MAX_THREADS 1
#define __decl_hathreads(decl)
#define HA_ATOMIC_CAS(val, old, new) ({((*val) == (*old)) ? (*(val) = (new) , 1) : (*(old) = *(val), 0);})
#define HA_ATOMIC_ADD(val, i) ({*(val) += (i);})
#define HA_ATOMIC_SUB(val, i) ({*(val) -= (i);})
#define HA_ATOMIC_AND(val, flags) ({*(val) &= (flags);})
#define HA_ATOMIC_OR(val, flags) ({*(val) |= (flags);})
#define HA_ATOMIC_XCHG(val, new) \
({ \
typeof(*(val)) __old = *(val); \
*(val) = new; \
__old; \
})
#define HA_ATOMIC_STORE(val, new) ({*(val) = new;})
#define HA_ATOMIC_UPDATE_MAX(val, new) \
({ \
typeof(*(val)) __new = (new); \
\
if (*(val) < __new) \
*(val) = __new; \
*(val); \
})
#define HA_ATOMIC_UPDATE_MIN(val, new) \
({ \
typeof(*(val)) __new = (new); \
\
if (*(val) > __new) \
*(val) = __new; \
*(val); \
})
#define HA_BARRIER() do { } while (0)
#define THREAD_SYNC_INIT(m) do { /* do nothing */ } while(0)
#define THREAD_SYNC_ENABLE() do { /* do nothing */ } while(0)
#define THREAD_WANT_SYNC() do { /* do nothing */ } while(0)
#define THREAD_ENTER_SYNC() do { /* do nothing */ } while(0)
#define THREAD_EXIT_SYNC() do { /* do nothing */ } while(0)
#define THREAD_NO_SYNC() ({ 0; })
#define THREAD_NEED_SYNC() ({ 1; })
#define HA_SPIN_INIT(l) do { /* do nothing */ } while(0)
#define HA_SPIN_DESTROY(l) do { /* do nothing */ } while(0)
#define HA_SPIN_LOCK(lbl, l) do { /* do nothing */ } while(0)
#define HA_SPIN_TRYLOCK(lbl, l) ({ 0; })
#define HA_SPIN_UNLOCK(lbl, l) do { /* do nothing */ } while(0)
#define HA_RWLOCK_INIT(l) do { /* do nothing */ } while(0)
#define HA_RWLOCK_DESTROY(l) do { /* do nothing */ } while(0)
#define HA_RWLOCK_WRLOCK(lbl, l) do { /* do nothing */ } while(0)
#define HA_RWLOCK_TRYWRLOCK(lbl, l) ({ 0; })
#define HA_RWLOCK_WRUNLOCK(lbl, l) do { /* do nothing */ } while(0)
#define HA_RWLOCK_RDLOCK(lbl, l) do { /* do nothing */ } while(0)
#define HA_RWLOCK_TRYRDLOCK(lbl, l) ({ 0; })
#define HA_RWLOCK_RDUNLOCK(lbl, l) do { /* do nothing */ } while(0)
#else /* USE_THREAD */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <import/plock.h>
#define MAX_THREADS LONGBITS
#define __decl_hathreads(decl) decl
/* TODO: thread: For now, we rely on GCC builtins but it could be a good idea to
* have a header file regrouping all functions dealing with threads. */
#if defined(__GNUC__) && (__GNUC__ < 4 || __GNUC__ == 4 && __GNUC_MINOR__ < 7) && !defined(__clang__)
/* gcc < 4.7 */
#define HA_ATOMIC_ADD(val, i) __sync_add_and_fetch(val, i)
#define HA_ATOMIC_SUB(val, i) __sync_sub_and_fetch(val, i)
#define HA_ATOMIC_AND(val, flags) __sync_and_and_fetch(val, flags)
#define HA_ATOMIC_OR(val, flags) __sync_or_and_fetch(val, flags)
/* the CAS is a bit complicated. The older API doesn't support returning the
* value and the swap's result at the same time. So here we take what looks
* like the safest route, consisting in using the boolean version guaranteeing
* that the operation was performed or not, and we snoop a previous value. If
* the compare succeeds, we return. If it fails, we return the previous value,
* but only if it differs from the expected one. If it's the same it's a race
* thus we try again to avoid confusing a possibly sensitive caller.
*/
#define HA_ATOMIC_CAS(val, old, new) \
({ \
typeof((val)) __val = (val); \
typeof((old)) __oldp = (old); \
typeof(*(old)) __oldv; \
typeof((new)) __new = (new); \
int __ret; \
do { \
__oldv = *__val; \
__ret = __sync_bool_compare_and_swap(__val, *__oldp, __new); \
} while (!__ret && *__oldp == __oldv); \
if (!__ret) \
*__oldp = __oldv; \
__ret; \
})
#define HA_ATOMIC_XCHG(val, new) \
({ \
typeof((val)) __val = (val); \
typeof(*(val)) __old; \
typeof((new)) __new = (new); \
do { __old = *__val; \
} while (!__sync_bool_compare_and_swap(__val, __old, __new)); \
__old; \
})
#define HA_ATOMIC_STORE(val, new) \
({ \
typeof((val)) __val = (val); \
typeof(*(val)) __old; \
typeof((new)) __new = (new); \
do { __old = *__val; \
} while (!__sync_bool_compare_and_swap(__val, __old, __new)); \
})
#else
/* gcc >= 4.7 */
#define HA_ATOMIC_CAS(val, old, new) __atomic_compare_exchange_n(val, old, new, 0, 0, 0)
#define HA_ATOMIC_ADD(val, i) __atomic_add_fetch(val, i, 0)
#define HA_ATOMIC_SUB(val, i) __atomic_sub_fetch(val, i, 0)
#define HA_ATOMIC_AND(val, flags) __atomic_and_fetch(val, flags, 0)
#define HA_ATOMIC_OR(val, flags) __atomic_or_fetch(val, flags, 0)
#define HA_ATOMIC_XCHG(val, new) __atomic_exchange_n(val, new, 0)
#define HA_ATOMIC_STORE(val, new) __atomic_store_n(val, new, 0)
#endif
#define HA_ATOMIC_UPDATE_MAX(val, new) \
({ \
typeof(*(val)) __old = *(val); \
typeof(*(val)) __new = (new); \
\
while (__old < __new && !HA_ATOMIC_CAS(val, &__old, __new)); \
(*val); \
})
#define HA_ATOMIC_UPDATE_MIN(val, new) \
({ \
typeof((*val)) __old = *(val); \
typeof((*val)) __new = (new); \
\
while (__old > __new && !HA_ATOMIC_CAS(val, &__old, __new)); \
(*val); \
})
#define HA_BARRIER() pl_barrier()
#define THREAD_SYNC_INIT(m) thread_sync_init(m)
#define THREAD_SYNC_ENABLE() thread_sync_enable()
#define THREAD_WANT_SYNC() thread_want_sync()
#define THREAD_ENTER_SYNC() thread_enter_sync()
#define THREAD_EXIT_SYNC() thread_exit_sync()
#define THREAD_NO_SYNC() thread_no_sync()
#define THREAD_NEED_SYNC() thread_need_sync()
int thread_sync_init(unsigned long mask);
void thread_sync_enable(void);
void thread_want_sync(void);
void thread_enter_sync(void);
void thread_exit_sync(void);
int thread_no_sync(void);
int thread_need_sync(void);
#if defined(DEBUG_THREAD) || defined(DEBUG_FULL)
enum lock_label {
THREAD_SYNC_LOCK = 0,
FDTAB_LOCK,
FDCACHE_LOCK,
FD_LOCK,
POLL_LOCK,
TASK_RQ_LOCK,
TASK_WQ_LOCK,
POOL_LOCK,
LISTENER_LOCK,
LISTENER_QUEUE_LOCK,
PROXY_LOCK,
SERVER_LOCK,
UPDATED_SERVERS_LOCK,
LBPRM_LOCK,
SIGNALS_LOCK,
STK_TABLE_LOCK,
STK_SESS_LOCK,
APPLETS_LOCK,
PEER_LOCK,
BUF_WQ_LOCK,
STRMS_LOCK,
SSL_LOCK,
SSL_GEN_CERTS_LOCK,
PATREF_LOCK,
PATEXP_LOCK,
PATLRU_LOCK,
VARS_LOCK,
COMP_POOL_LOCK,
LUA_LOCK,
NOTIF_LOCK,
SPOE_APPLET_LOCK,
DNS_LOCK,
PID_LIST_LOCK,
EMAIL_ALERTS_LOCK,
PIPES_LOCK,
START_LOCK,
LOCK_LABELS
};
struct lock_stat {
uint64_t nsec_wait_for_write;
uint64_t nsec_wait_for_read;
uint64_t num_write_locked;
uint64_t num_write_unlocked;
uint64_t num_read_locked;
uint64_t num_read_unlocked;
};
extern struct lock_stat lock_stats[LOCK_LABELS];
#define __HA_SPINLOCK_T unsigned long
#define __SPIN_INIT(l) ({ (*l) = 0; })
#define __SPIN_DESTROY(l) ({ (*l) = 0; })
#define __SPIN_LOCK(l) pl_take_s(l)
#define __SPIN_TRYLOCK(l) !pl_try_s(l)
#define __SPIN_UNLOCK(l) pl_drop_s(l)
#define __HA_RWLOCK_T unsigned long
#define __RWLOCK_INIT(l) ({ (*l) = 0; })
#define __RWLOCK_DESTROY(l) ({ (*l) = 0; })
#define __RWLOCK_WRLOCK(l) pl_take_w(l)
#define __RWLOCK_TRYWRLOCK(l) !pl_try_w(l)
#define __RWLOCK_WRUNLOCK(l) pl_drop_w(l)
#define __RWLOCK_RDLOCK(l) pl_take_r(l)
#define __RWLOCK_TRYRDLOCK(l) !pl_try_r(l)
#define __RWLOCK_RDUNLOCK(l) pl_drop_r(l)
#define HA_SPINLOCK_T struct ha_spinlock
#define HA_SPIN_INIT(l) __spin_init(l)
#define HA_SPIN_DESTROY(l) __spin_destroy(l)
#define HA_SPIN_LOCK(lbl, l) __spin_lock(lbl, l, __func__, __FILE__, __LINE__)
#define HA_SPIN_TRYLOCK(lbl, l) __spin_trylock(lbl, l, __func__, __FILE__, __LINE__)
#define HA_SPIN_UNLOCK(lbl, l) __spin_unlock(lbl, l, __func__, __FILE__, __LINE__)
#define HA_RWLOCK_T struct ha_rwlock
#define HA_RWLOCK_INIT(l) __ha_rwlock_init((l))
#define HA_RWLOCK_DESTROY(l) __ha_rwlock_destroy((l))
#define HA_RWLOCK_WRLOCK(lbl,l) __ha_rwlock_wrlock(lbl, l, __func__, __FILE__, __LINE__)
#define HA_RWLOCK_TRYWRLOCK(lbl,l) __ha_rwlock_trywrlock(lbl, l, __func__, __FILE__, __LINE__)
#define HA_RWLOCK_WRUNLOCK(lbl,l) __ha_rwlock_wrunlock(lbl, l, __func__, __FILE__, __LINE__)
#define HA_RWLOCK_RDLOCK(lbl,l) __ha_rwlock_rdlock(lbl, l)
#define HA_RWLOCK_TRYRDLOCK(lbl,l) __ha_rwlock_tryrdlock(lbl, l)
#define HA_RWLOCK_RDUNLOCK(lbl,l) __ha_rwlock_rdunlock(lbl, l)
struct ha_spinlock {
__HA_SPINLOCK_T lock;
struct {
unsigned long owner; /* a bit is set to 1 << tid for the lock owner */
unsigned long waiters; /* a bit is set to 1 << tid for waiting threads */
struct {
const char *function;
const char *file;
int line;
} last_location; /* location of the last owner */
} info;
};
struct ha_rwlock {
__HA_RWLOCK_T lock;
struct {
unsigned long cur_writer; /* a bit is set to 1 << tid for the lock owner */
unsigned long wait_writers; /* a bit is set to 1 << tid for waiting writers */
unsigned long cur_readers; /* a bit is set to 1 << tid for current readers */
unsigned long wait_readers; /* a bit is set to 1 << tid for waiting waiters */
struct {
const char *function;
const char *file;
int line;
} last_location; /* location of the last write owner */
} info;
};
static inline void show_lock_stats()
{
const char *labels[LOCK_LABELS] = {"THREAD_SYNC", "FDTAB", "FDCACHE", "FD", "POLL",
"TASK_RQ", "TASK_WQ", "POOL",
"LISTENER", "LISTENER_QUEUE", "PROXY", "SERVER",
"UPDATED_SERVERS", "LBPRM", "SIGNALS", "STK_TABLE", "STK_SESS",
"APPLETS", "PEER", "BUF_WQ", "STREAMS", "SSL", "SSL_GEN_CERTS",
"PATREF", "PATEXP", "PATLRU", "VARS", "COMP_POOL", "LUA",
"NOTIF", "SPOE_APPLET", "DNS", "PID_LIST", "EMAIL_ALERTS",
"PIPES" };
int lbl;
for (lbl = 0; lbl < LOCK_LABELS; lbl++) {
fprintf(stderr,
"Stats about Lock %s: \n"
"\t # write lock : %lu\n"
"\t # write unlock: %lu (%ld)\n"
"\t # wait time for write : %.3f msec\n"
"\t # wait time for write/lock: %.3f nsec\n"
"\t # read lock : %lu\n"
"\t # read unlock : %lu (%ld)\n"
"\t # wait time for read : %.3f msec\n"
"\t # wait time for read/lock : %.3f nsec\n",
labels[lbl],
lock_stats[lbl].num_write_locked,
lock_stats[lbl].num_write_unlocked,
lock_stats[lbl].num_write_unlocked - lock_stats[lbl].num_write_locked,
(double)lock_stats[lbl].nsec_wait_for_write / 1000000.0,
lock_stats[lbl].num_write_locked ? ((double)lock_stats[lbl].nsec_wait_for_write / (double)lock_stats[lbl].num_write_locked) : 0,
lock_stats[lbl].num_read_locked,
lock_stats[lbl].num_read_unlocked,
lock_stats[lbl].num_read_unlocked - lock_stats[lbl].num_read_locked,
(double)lock_stats[lbl].nsec_wait_for_read / 1000000.0,
lock_stats[lbl].num_read_locked ? ((double)lock_stats[lbl].nsec_wait_for_read / (double)lock_stats[lbl].num_read_locked) : 0);
}
}
/* Following functions are used to collect some stats about locks. We wrap
* pthread functions to known how much time we wait in a lock. */
static uint64_t nsec_now(void) {
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return ((uint64_t) ts.tv_sec * 1000000000ULL +
(uint64_t) ts.tv_nsec);
}
static inline void __ha_rwlock_init(struct ha_rwlock *l)
{
memset(l, 0, sizeof(struct ha_rwlock));
__RWLOCK_INIT(&l->lock);
}
static inline void __ha_rwlock_destroy(struct ha_rwlock *l)
{
__RWLOCK_DESTROY(&l->lock);
memset(l, 0, sizeof(struct ha_rwlock));
}
static inline void __ha_rwlock_wrlock(enum lock_label lbl, struct ha_rwlock *l,
const char *func, const char *file, int line)
{
uint64_t start_time;
if (unlikely(l->info.cur_writer & tid_bit)) {
/* the thread is already owning the lock for write */
abort();
}
if (unlikely(l->info.cur_readers & tid_bit)) {
/* the thread is already owning the lock for read */
abort();
}
HA_ATOMIC_OR(&l->info.wait_writers, tid_bit);
start_time = nsec_now();
__RWLOCK_WRLOCK(&l->lock);
HA_ATOMIC_ADD(&lock_stats[lbl].nsec_wait_for_write, (nsec_now() - start_time));
HA_ATOMIC_ADD(&lock_stats[lbl].num_write_locked, 1);
l->info.cur_writer = tid_bit;
l->info.last_location.function = func;
l->info.last_location.file = file;
l->info.last_location.line = line;
HA_ATOMIC_AND(&l->info.wait_writers, ~tid_bit);
}
static inline int __ha_rwlock_trywrlock(enum lock_label lbl, struct ha_rwlock *l,
const char *func, const char *file, int line)
{
uint64_t start_time;
int r;
if (unlikely(l->info.cur_writer & tid_bit)) {
/* the thread is already owning the lock for write */
abort();
}
if (unlikely(l->info.cur_readers & tid_bit)) {
/* the thread is already owning the lock for read */
abort();
}
/* We set waiting writer because trywrlock could wait for readers to quit */
HA_ATOMIC_OR(&l->info.wait_writers, tid_bit);
start_time = nsec_now();
r = __RWLOCK_TRYWRLOCK(&l->lock);
HA_ATOMIC_ADD(&lock_stats[lbl].nsec_wait_for_write, (nsec_now() - start_time));
if (unlikely(r)) {
HA_ATOMIC_AND(&l->info.wait_writers, ~tid_bit);
return r;
}
HA_ATOMIC_ADD(&lock_stats[lbl].num_write_locked, 1);
l->info.cur_writer = tid_bit;
l->info.last_location.function = func;
l->info.last_location.file = file;
l->info.last_location.line = line;
HA_ATOMIC_AND(&l->info.wait_writers, ~tid_bit);
return 0;
}
static inline void __ha_rwlock_wrunlock(enum lock_label lbl,struct ha_rwlock *l,
const char *func, const char *file, int line)
{
if (unlikely(!(l->info.cur_writer & tid_bit))) {
/* the thread is not owning the lock for write */
abort();
}
l->info.cur_writer = 0;
l->info.last_location.function = func;
l->info.last_location.file = file;
l->info.last_location.line = line;
__RWLOCK_WRUNLOCK(&l->lock);
HA_ATOMIC_ADD(&lock_stats[lbl].num_write_unlocked, 1);
}
static inline void __ha_rwlock_rdlock(enum lock_label lbl,struct ha_rwlock *l)
{
uint64_t start_time;
if (unlikely(l->info.cur_writer & tid_bit)) {
/* the thread is already owning the lock for write */
abort();
}
if (unlikely(l->info.cur_readers & tid_bit)) {
/* the thread is already owning the lock for read */
abort();
}
HA_ATOMIC_OR(&l->info.wait_readers, tid_bit);
start_time = nsec_now();
__RWLOCK_RDLOCK(&l->lock);
HA_ATOMIC_ADD(&lock_stats[lbl].nsec_wait_for_read, (nsec_now() - start_time));
HA_ATOMIC_ADD(&lock_stats[lbl].num_read_locked, 1);
HA_ATOMIC_OR(&l->info.cur_readers, tid_bit);
HA_ATOMIC_AND(&l->info.wait_readers, ~tid_bit);
}
static inline int __ha_rwlock_tryrdlock(enum lock_label lbl,struct ha_rwlock *l)
{
int r;
if (unlikely(l->info.cur_writer & tid_bit)) {
/* the thread is already owning the lock for write */
abort();
}
if (unlikely(l->info.cur_readers & tid_bit)) {
/* the thread is already owning the lock for read */
abort();
}
/* try read should never wait */
r = __RWLOCK_TRYRDLOCK(&l->lock);
if (unlikely(r))
return r;
HA_ATOMIC_ADD(&lock_stats[lbl].num_read_locked, 1);
HA_ATOMIC_OR(&l->info.cur_readers, tid_bit);
return 0;
}
static inline void __ha_rwlock_rdunlock(enum lock_label lbl,struct ha_rwlock *l)
{
if (unlikely(!(l->info.cur_readers & tid_bit))) {
/* the thread is not owning the lock for read */
abort();
}
HA_ATOMIC_AND(&l->info.cur_readers, ~tid_bit);
__RWLOCK_RDUNLOCK(&l->lock);
HA_ATOMIC_ADD(&lock_stats[lbl].num_read_unlocked, 1);
}
static inline void __spin_init(struct ha_spinlock *l)
{
memset(l, 0, sizeof(struct ha_spinlock));
__SPIN_INIT(&l->lock);
}
static inline void __spin_destroy(struct ha_spinlock *l)
{
__SPIN_DESTROY(&l->lock);
memset(l, 0, sizeof(struct ha_spinlock));
}
static inline void __spin_lock(enum lock_label lbl, struct ha_spinlock *l,
const char *func, const char *file, int line)
{
uint64_t start_time;
if (unlikely(l->info.owner & tid_bit)) {
/* the thread is already owning the lock */
abort();
}
HA_ATOMIC_OR(&l->info.waiters, tid_bit);
start_time = nsec_now();
__SPIN_LOCK(&l->lock);
HA_ATOMIC_ADD(&lock_stats[lbl].nsec_wait_for_write, (nsec_now() - start_time));
HA_ATOMIC_ADD(&lock_stats[lbl].num_write_locked, 1);
l->info.owner = tid_bit;
l->info.last_location.function = func;
l->info.last_location.file = file;
l->info.last_location.line = line;
HA_ATOMIC_AND(&l->info.waiters, ~tid_bit);
}
static inline int __spin_trylock(enum lock_label lbl, struct ha_spinlock *l,
const char *func, const char *file, int line)
{
int r;
if (unlikely(l->info.owner & tid_bit)) {
/* the thread is already owning the lock */
abort();
}
/* try read should never wait */
r = __SPIN_TRYLOCK(&l->lock);
if (unlikely(r))
return r;
HA_ATOMIC_ADD(&lock_stats[lbl].num_write_locked, 1);
l->info.owner = tid_bit;
l->info.last_location.function = func;
l->info.last_location.file = file;
l->info.last_location.line = line;
return 0;
}
static inline void __spin_unlock(enum lock_label lbl, struct ha_spinlock *l,
const char *func, const char *file, int line)
{
if (unlikely(!(l->info.owner & tid_bit))) {
/* the thread is not owning the lock */
abort();
}
l->info.owner = 0;
l->info.last_location.function = func;
l->info.last_location.file = file;
l->info.last_location.line = line;
__SPIN_UNLOCK(&l->lock);
HA_ATOMIC_ADD(&lock_stats[lbl].num_write_unlocked, 1);
}
#else /* DEBUG_THREAD */
#define HA_SPINLOCK_T unsigned long
#define HA_SPIN_INIT(l) ({ (*l) = 0; })
#define HA_SPIN_DESTROY(l) ({ (*l) = 0; })
#define HA_SPIN_LOCK(lbl, l) pl_take_s(l)
#define HA_SPIN_TRYLOCK(lbl, l) !pl_try_s(l)
#define HA_SPIN_UNLOCK(lbl, l) pl_drop_s(l)
#define HA_RWLOCK_T unsigned long
#define HA_RWLOCK_INIT(l) ({ (*l) = 0; })
#define HA_RWLOCK_DESTROY(l) ({ (*l) = 0; })
#define HA_RWLOCK_WRLOCK(lbl,l) pl_take_w(l)
#define HA_RWLOCK_TRYWRLOCK(lbl,l) !pl_try_w(l)
#define HA_RWLOCK_WRUNLOCK(lbl,l) pl_drop_w(l)
#define HA_RWLOCK_RDLOCK(lbl,l) pl_take_r(l)
#define HA_RWLOCK_TRYRDLOCK(lbl,l) !pl_try_r(l)
#define HA_RWLOCK_RDUNLOCK(lbl,l) pl_drop_r(l)
#endif /* DEBUG_THREAD */
#endif /* USE_THREAD */
#endif /* _COMMON_HATHREADS_H */