You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
298 lines
8.5 KiB
298 lines
8.5 KiB
/*
|
|
* Copyright 2010-2015 Samy Al Bahra.
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. 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.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
|
|
*/
|
|
|
|
#ifndef CK_SPINLOCK_TICKET_H
|
|
#define CK_SPINLOCK_TICKET_H
|
|
|
|
#include <ck_backoff.h>
|
|
#include <ck_cc.h>
|
|
#include <ck_elide.h>
|
|
#include <ck_md.h>
|
|
#include <ck_pr.h>
|
|
#include <stdbool.h>
|
|
|
|
#ifndef CK_F_SPINLOCK_TICKET
|
|
#define CK_F_SPINLOCK_TICKET
|
|
/*
|
|
* If 16-bit or 32-bit increment is supported, implement support for
|
|
* trylock functionality on availability of 32-bit or 64-bit fetch-and-add
|
|
* and compare-and-swap. This code path is only applied to x86*.
|
|
*/
|
|
#if defined(CK_MD_TSO) && (defined(__x86__) || defined(__x86_64__))
|
|
#if defined(CK_F_PR_FAA_32) && defined(CK_F_PR_INC_16) && defined(CK_F_PR_CAS_32)
|
|
#define CK_SPINLOCK_TICKET_TYPE uint32_t
|
|
#define CK_SPINLOCK_TICKET_TYPE_BASE uint16_t
|
|
#define CK_SPINLOCK_TICKET_INC(x) ck_pr_inc_16(x)
|
|
#define CK_SPINLOCK_TICKET_CAS(x, y, z) ck_pr_cas_32(x, y, z)
|
|
#define CK_SPINLOCK_TICKET_FAA(x, y) ck_pr_faa_32(x, y)
|
|
#define CK_SPINLOCK_TICKET_LOAD(x) ck_pr_load_32(x)
|
|
#define CK_SPINLOCK_TICKET_INCREMENT (0x00010000UL)
|
|
#define CK_SPINLOCK_TICKET_MASK (0xFFFFUL)
|
|
#define CK_SPINLOCK_TICKET_SHIFT (16)
|
|
#elif defined(CK_F_PR_FAA_64) && defined(CK_F_PR_INC_32) && defined(CK_F_PR_CAS_64)
|
|
#define CK_SPINLOCK_TICKET_TYPE uint64_t
|
|
#define CK_SPINLOCK_TICKET_TYPE_BASE uint32_t
|
|
#define CK_SPINLOCK_TICKET_INC(x) ck_pr_inc_32(x)
|
|
#define CK_SPINLOCK_TICKET_CAS(x, y, z) ck_pr_cas_64(x, y, z)
|
|
#define CK_SPINLOCK_TICKET_FAA(x, y) ck_pr_faa_64(x, y)
|
|
#define CK_SPINLOCK_TICKET_LOAD(x) ck_pr_load_64(x)
|
|
#define CK_SPINLOCK_TICKET_INCREMENT (0x0000000100000000ULL)
|
|
#define CK_SPINLOCK_TICKET_MASK (0xFFFFFFFFULL)
|
|
#define CK_SPINLOCK_TICKET_SHIFT (32)
|
|
#endif
|
|
#endif /* CK_MD_TSO */
|
|
|
|
#if defined(CK_SPINLOCK_TICKET_TYPE)
|
|
#define CK_F_SPINLOCK_TICKET_TRYLOCK
|
|
|
|
struct ck_spinlock_ticket {
|
|
CK_SPINLOCK_TICKET_TYPE value;
|
|
};
|
|
typedef struct ck_spinlock_ticket ck_spinlock_ticket_t;
|
|
#define CK_SPINLOCK_TICKET_INITIALIZER { .value = 0 }
|
|
|
|
CK_CC_INLINE static void
|
|
ck_spinlock_ticket_init(struct ck_spinlock_ticket *ticket)
|
|
{
|
|
|
|
ticket->value = 0;
|
|
ck_pr_barrier();
|
|
return;
|
|
}
|
|
|
|
CK_CC_INLINE static bool
|
|
ck_spinlock_ticket_locked(struct ck_spinlock_ticket *ticket)
|
|
{
|
|
CK_SPINLOCK_TICKET_TYPE request, position;
|
|
|
|
ck_pr_fence_load();
|
|
|
|
request = CK_SPINLOCK_TICKET_LOAD(&ticket->value);
|
|
position = request & CK_SPINLOCK_TICKET_MASK;
|
|
request >>= CK_SPINLOCK_TICKET_SHIFT;
|
|
|
|
return request != position;
|
|
}
|
|
|
|
CK_CC_INLINE static void
|
|
ck_spinlock_ticket_lock(struct ck_spinlock_ticket *ticket)
|
|
{
|
|
CK_SPINLOCK_TICKET_TYPE request, position;
|
|
|
|
/* Get our ticket number and set next ticket number. */
|
|
request = CK_SPINLOCK_TICKET_FAA(&ticket->value,
|
|
CK_SPINLOCK_TICKET_INCREMENT);
|
|
|
|
position = request & CK_SPINLOCK_TICKET_MASK;
|
|
request >>= CK_SPINLOCK_TICKET_SHIFT;
|
|
|
|
while (request != position) {
|
|
ck_pr_stall();
|
|
position = CK_SPINLOCK_TICKET_LOAD(&ticket->value) &
|
|
CK_SPINLOCK_TICKET_MASK;
|
|
}
|
|
|
|
ck_pr_fence_acquire();
|
|
return;
|
|
}
|
|
|
|
CK_CC_INLINE static void
|
|
ck_spinlock_ticket_lock_pb(struct ck_spinlock_ticket *ticket, unsigned int c)
|
|
{
|
|
CK_SPINLOCK_TICKET_TYPE request, position;
|
|
ck_backoff_t backoff;
|
|
|
|
/* Get our ticket number and set next ticket number. */
|
|
request = CK_SPINLOCK_TICKET_FAA(&ticket->value,
|
|
CK_SPINLOCK_TICKET_INCREMENT);
|
|
|
|
position = request & CK_SPINLOCK_TICKET_MASK;
|
|
request >>= CK_SPINLOCK_TICKET_SHIFT;
|
|
|
|
while (request != position) {
|
|
ck_pr_stall();
|
|
position = CK_SPINLOCK_TICKET_LOAD(&ticket->value) &
|
|
CK_SPINLOCK_TICKET_MASK;
|
|
|
|
backoff = (request - position) & CK_SPINLOCK_TICKET_MASK;
|
|
backoff <<= c;
|
|
ck_backoff_eb(&backoff);
|
|
}
|
|
|
|
ck_pr_fence_acquire();
|
|
return;
|
|
}
|
|
|
|
CK_CC_INLINE static bool
|
|
ck_spinlock_ticket_trylock(struct ck_spinlock_ticket *ticket)
|
|
{
|
|
CK_SPINLOCK_TICKET_TYPE snapshot, request, position;
|
|
|
|
snapshot = CK_SPINLOCK_TICKET_LOAD(&ticket->value);
|
|
position = snapshot & CK_SPINLOCK_TICKET_MASK;
|
|
request = snapshot >> CK_SPINLOCK_TICKET_SHIFT;
|
|
|
|
if (position != request)
|
|
return false;
|
|
|
|
if (CK_SPINLOCK_TICKET_CAS(&ticket->value,
|
|
snapshot, snapshot + CK_SPINLOCK_TICKET_INCREMENT) == false) {
|
|
return false;
|
|
}
|
|
|
|
ck_pr_fence_acquire();
|
|
return true;
|
|
}
|
|
|
|
CK_CC_INLINE static void
|
|
ck_spinlock_ticket_unlock(struct ck_spinlock_ticket *ticket)
|
|
{
|
|
|
|
ck_pr_fence_release();
|
|
CK_SPINLOCK_TICKET_INC((CK_SPINLOCK_TICKET_TYPE_BASE *)(void *)&ticket->value);
|
|
return;
|
|
}
|
|
|
|
#undef CK_SPINLOCK_TICKET_TYPE
|
|
#undef CK_SPINLOCK_TICKET_TYPE_BASE
|
|
#undef CK_SPINLOCK_TICKET_INC
|
|
#undef CK_SPINLOCK_TICKET_FAA
|
|
#undef CK_SPINLOCK_TICKET_LOAD
|
|
#undef CK_SPINLOCK_TICKET_INCREMENT
|
|
#undef CK_SPINLOCK_TICKET_MASK
|
|
#undef CK_SPINLOCK_TICKET_SHIFT
|
|
#else
|
|
/*
|
|
* MESI benefits from cacheline padding between next and current. This avoids
|
|
* invalidation of current from the cache due to incoming lock requests.
|
|
*/
|
|
struct ck_spinlock_ticket {
|
|
unsigned int next;
|
|
unsigned int position;
|
|
};
|
|
typedef struct ck_spinlock_ticket ck_spinlock_ticket_t;
|
|
|
|
#define CK_SPINLOCK_TICKET_INITIALIZER {.next = 0, .position = 0}
|
|
|
|
CK_CC_INLINE static void
|
|
ck_spinlock_ticket_init(struct ck_spinlock_ticket *ticket)
|
|
{
|
|
|
|
ticket->next = 0;
|
|
ticket->position = 0;
|
|
ck_pr_barrier();
|
|
|
|
return;
|
|
}
|
|
|
|
CK_CC_INLINE static bool
|
|
ck_spinlock_ticket_locked(struct ck_spinlock_ticket *ticket)
|
|
{
|
|
unsigned int request;
|
|
|
|
ck_pr_fence_load();
|
|
request = ck_pr_load_uint(&ticket->next);
|
|
ck_pr_fence_load();
|
|
return ck_pr_load_uint(&ticket->position) != request;
|
|
}
|
|
|
|
CK_CC_INLINE static void
|
|
ck_spinlock_ticket_lock(struct ck_spinlock_ticket *ticket)
|
|
{
|
|
unsigned int request;
|
|
|
|
/* Get our ticket number and set next ticket number. */
|
|
request = ck_pr_faa_uint(&ticket->next, 1);
|
|
|
|
/*
|
|
* Busy-wait until our ticket number is current.
|
|
* We can get away without a fence here assuming
|
|
* our position counter does not overflow.
|
|
*/
|
|
while (ck_pr_load_uint(&ticket->position) != request)
|
|
ck_pr_stall();
|
|
|
|
ck_pr_fence_acquire();
|
|
return;
|
|
}
|
|
|
|
CK_CC_INLINE static void
|
|
ck_spinlock_ticket_lock_pb(struct ck_spinlock_ticket *ticket, unsigned int c)
|
|
{
|
|
ck_backoff_t backoff;
|
|
unsigned int request, position;
|
|
|
|
request = ck_pr_faa_uint(&ticket->next, 1);
|
|
|
|
for (;;) {
|
|
position = ck_pr_load_uint(&ticket->position);
|
|
if (position == request)
|
|
break;
|
|
|
|
backoff = request - position;
|
|
backoff <<= c;
|
|
|
|
/*
|
|
* Ideally, back-off from generating cache traffic for at least
|
|
* the amount of time necessary for the number of pending lock
|
|
* acquisition and relinquish operations (assuming an empty
|
|
* critical section).
|
|
*/
|
|
ck_backoff_eb(&backoff);
|
|
}
|
|
|
|
ck_pr_fence_acquire();
|
|
return;
|
|
}
|
|
|
|
CK_CC_INLINE static void
|
|
ck_spinlock_ticket_unlock(struct ck_spinlock_ticket *ticket)
|
|
{
|
|
unsigned int update;
|
|
|
|
ck_pr_fence_release();
|
|
|
|
/*
|
|
* Update current ticket value so next lock request can proceed.
|
|
* Overflow behavior is assumed to be roll-over, in which case,
|
|
* it is only an issue if there are 2^32 pending lock requests.
|
|
*/
|
|
update = ck_pr_load_uint(&ticket->position);
|
|
ck_pr_store_uint(&ticket->position, update + 1);
|
|
return;
|
|
}
|
|
#endif /* !CK_F_SPINLOCK_TICKET_TRYLOCK */
|
|
|
|
CK_ELIDE_PROTOTYPE(ck_spinlock_ticket, ck_spinlock_ticket_t,
|
|
ck_spinlock_ticket_locked, ck_spinlock_ticket_lock,
|
|
ck_spinlock_ticket_locked, ck_spinlock_ticket_unlock)
|
|
|
|
CK_ELIDE_TRYLOCK_PROTOTYPE(ck_spinlock_ticket, ck_spinlock_ticket_t,
|
|
ck_spinlock_ticket_locked, ck_spinlock_ticket_trylock)
|
|
|
|
#endif /* CK_F_SPINLOCK_TICKET */
|
|
#endif /* CK_SPINLOCK_TICKET_H */
|