*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/include/storage/s_lock.h,v 1.1 1997/09/18 14:20:59 momjian Exp $
- *
- *-------------------------------------------------------------------------
- */
-/*
- * DESCRIPTION
- * The following code fragment should be written (in assembly
- * language) on machines that have a native test-and-set instruction:
- *
- * void
- * S_LOCK(char_address)
- * char *char_address;
- * {
- * while (test_and_set(char_address))
- * ;
- * }
- *
- * If this is not done, POSTGRES will default to using System V
- * semaphores (and take a large performance hit -- around 40% of
- * its time on a DS5000/240 is spent in semop(3)...).
- *
- * NOTES
- * AIX has a test-and-set but the recommended interface is the cs(3)
- * system call. This provides an 8-instruction (plus system call
- * overhead) uninterruptible compare-and-set operation. True
- * spinlocks might be faster but using cs(3) still speeds up the
- * regression test suite by about 25%. I don't have an assembler
- * manual for POWER in any case.
- *
- */
-#ifndef S_LOCK_H
-#define S_LOCK_H
-
-#include "storage/ipc.h"
-
-#if defined(HAS_TEST_AND_SET)
-
-#if defined (nextstep)
-/*
- * NEXTSTEP (mach)
- * slock_t is defined as a struct mutex.
- */
-#define S_LOCK(lock) mutex_lock(lock)
-
-#define S_UNLOCK(lock) mutex_unlock(lock)
-
-#define S_INIT_LOCK(lock) mutex_init(lock)
-
- /* S_LOCK_FREE should return 1 if lock is free; 0 if lock is locked */
-/* For Mach, we have to delve inside the entrails of `struct mutex'. Ick! */
-#define S_LOCK_FREE(alock) ((alock)->lock == 0)
-
-#endif /* next */
-
-
-
-#if defined(irix5)
-/*
- * SGI IRIX 5
- * slock_t is defined as a struct abilock_t, which has a single unsigned long
- * member.
- *
- * This stuff may be supplemented in the future with Masato Kataoka's MIPS-II
- * assembly from his NECEWS SVR4 port, but we probably ought to retain this
- * for the R3000 chips out there.
- */
-#define S_LOCK(lock) do \
- { \
- while (!acquire_lock(lock)) \
- ; \
- } while (0)
-
-#define S_UNLOCK(lock) release_lock(lock)
-
-#define S_INIT_LOCK(lock) init_lock(lock)
-
-/* S_LOCK_FREE should return 1 if lock is free; 0 if lock is locked */
-
-#define S_LOCK_FREE(lock) (stat_lock(lock) == UNLOCKED)
-
-#endif /* irix5 */
-
-
-/*
- * OSF/1 (Alpha AXP)
- *
- * Note that slock_t on the Alpha AXP is msemaphore instead of char
- * (see storage/ipc.h).
- */
-
-#if defined(__alpha__) || defined(__alpha)
-
-#define S_LOCK(lock) do \
- { \
- while (msem_lock((lock), MSEM_IF_NOWAIT) < 0) \
- ; \
- } while (0)
-
-#define S_UNLOCK(lock) msem_unlock((lock), 0)
-
-#define S_INIT_LOCK(lock) msem_init((lock), MSEM_UNLOCKED)
-
-#define S_LOCK_FREE(lock) (!(lock)->msem_state)
-
-#endif /* alpha */
-
-/*
- * Solaris 2
- */
-
-#if defined(i386_solaris) || \
- defined(sparc_solaris)
-/* for xxxxx_solaris, this is defined in port/.../tas.s */
-
-static int tas(slock_t *lock);
-
-#define S_LOCK(lock) do \
- { \
- while (tas(lock)) \
- ; \
- } while (0)
-
-#define S_UNLOCK(lock) (*(lock) = 0)
-
-#define S_INIT_LOCK(lock) S_UNLOCK(lock)
-
-#endif /* i86pc_solaris || sparc_solaris */
-
-/*
- * AIX (POWER)
- *
- * Note that slock_t on POWER/POWER2/PowerPC is int instead of char
- * (see storage/ipc.h).
- */
-
-#if defined(aix)
-
-#define S_LOCK(lock) do \
- { \
- while (cs((int *) (lock), 0, 1)) \
- ; \
- } while (0)
-
-#define S_UNLOCK(lock) (*(lock) = 0)
-
-#define S_INIT_LOCK(lock) S_UNLOCK(lock)
-
-#endif /* aix */
-
-/*
- * HP-UX (PA-RISC)
- *
- * Note that slock_t on PA-RISC is a structure instead of char
- * (see storage/ipc.h).
- */
-
-#if defined(hpux)
-
-/*
-* a "set" slock_t has a single word cleared. a "clear" slock_t has
-* all words set to non-zero.
-*/
-static slock_t clear_lock = {-1, -1, -1, -1};
-
-static int tas(slock_t *lock);
-
-#define S_LOCK(lock) do \
- { \
- while (tas(lock)) \
- ; \
- } while (0)
-
-#define S_UNLOCK(lock) (*(lock) = clear_lock) /* struct assignment */
-
-#define S_INIT_LOCK(lock) S_UNLOCK(lock)
-
-#define S_LOCK_FREE(lock) ( *(int *) (((long) (lock) + 15) & ~15) != 0)
-
-#endif /* hpux */
-
-/*
- * sun3
- */
-
-#if defined(sun3)
-
-static int tas(slock_t *lock);
-
-#define S_LOCK(lock) do \
- { \
- while (tas(lock)) \
- ; \
- } while (0)
-
-#define S_UNLOCK(lock) (*(lock) = 0)
-
-#define S_INIT_LOCK(lock) S_UNLOCK(lock)
-
-#ifdef NOT_USED
-static int
-tas_dummy()
-{
- asm("LLA0:");
- asm(" .data");
- asm(" .text");
- asm("|#PROC# 04");
- asm(" .globl _tas");
- asm("_tas:");
- asm("|#PROLOGUE# 1");
- asm(" movel sp@(0x4),a0");
- asm(" tas a0@");
- asm(" beq LLA1");
- asm(" moveq #-128,d0");
- asm(" rts");
- asm("LLA1:");
- asm(" moveq #0,d0");
- asm(" rts");
- asm(" .data");
-}
-#endif
-
-#endif /* sun3 */
-
-/*
- * sparc machines
- */
-
-#if defined(NEED_SPARC_TAS_ASM)
-
-/* if we're using -ansi w/ gcc, use __asm__ instead of asm */
-#if defined(__STRICT_ANSI__)
-#define asm(x) __asm__(x)
-#endif
-
-static int tas(slock_t *lock);
-
-#ifdef NOT_USED
-static int
-tas_dummy()
-{
- asm(".seg \"data\"");
- asm(".seg \"text\"");
- asm(".global _tas");
- asm("_tas:");
-
- /*
- * Sparc atomic test and set (sparc calls it "atomic load-store")
- */
-
- asm("ldstub [%r8], %r8");
-
- /*
- * Did test and set actually do the set?
- */
-
- asm("tst %r8");
-
- asm("be,a ReturnZero");
-
- /*
- * otherwise, just return.
- */
-
- asm("clr %r8");
- asm("mov 0x1, %r8");
- asm("ReturnZero:");
- asm("retl");
- asm("nop");
-}
-#endif
-
-#define S_LOCK(addr) do \
- { \
- while (tas(addr)) \
- ; \
- } while (0)
-
-/*
- * addr should be as in the above S_LOCK routine
- */
-#define S_UNLOCK(addr) (*(addr) = 0)
-
-#define S_INIT_LOCK(addr) (*(addr) = 0)
-
-#endif /* NEED_SPARC_TAS_ASM */
-
-/*
- * i386 based things
- */
-
-#if defined(NEED_I386_TAS_ASM)
-
-#define S_LOCK(lock) do \
- { \
- slock_t res; \
- do \
- { \
- __asm__("xchgb %0,%1": "=q"(res), "=m"(*lock):"0"(0x1)); \
- } while (res != 0); \
- } while (0)
-
-#define S_UNLOCK(lock) (*(lock) = 0)
-
-#define S_INIT_LOCK(lock) S_UNLOCK(lock)
-
-#endif /* NEED_I386_TAS_ASM */
-
-
-#if defined(__alpha__) && defined(linux)
-
-#define S_LOCK(lock) do \
- { \
- slock_t res; \
- do \
- { \
- __asm__(" ldq $0, %0 \n\
- bne $0, already_set \n\
- ldq_l $0, %0 \n\
- bne $0, already_set \n\
- or $31, 1, $0 \n\
- stq_c $0, %0 \n\
- beq $0, stqc_fail \n\
- success: bis $31, $31, %1 \n\
- mb \n\
- jmp $31, end \n\
- stqc_fail: or $31, 1, $0 \n\
- already_set: bis $0, $0, %1 \n\
- end: nop ": "=m"(*lock), "=r"(res): :"0"); \
- } while (res != 0); \
- } while (0)
-
-
-#define S_UNLOCK(lock) (__asm__("mb"), *(lock) = 0)
-
-#define S_INIT_LOCK(lock) S_UNLOCK(lock)
-
-#endif /* defined(__alpha__) && defined(linux) */
-
-#if defined(linux) && defined(sparc)
-
-#define S_LOCK(lock) do \
- { \
- slock_t res; \
- do \
- { \
- __asm__("ldstub [%1], %0" \
- : "=&r"(res) \
- : "r"(lock)); \
- } while (!res != 0); \
- } while (0)
-
-#define S_UNLOCK(lock) (*(lock) = 0)
-
-#define S_INIT_LOCK(lock) S_UNLOCK(lock)
-
-#endif /* defined(linux) && defined(sparc) */
-
-#if defined(linux) && defined(PPC)
-
-#ifdef NOT_USED
-static int
-tas_dummy()
-{
- __asm__(" \n\
-tas: \n\
- lwarx 5,0,3 \n\
- cmpwi 5,0 \n\
- bne fail \n\
- addi 5,5,1 \n\
- stwcx. 5,0,3 \n\
- beq success \n\
-fail: li 3,1 \n\
- blr \n\
-success: \n\
- li 3,0 \n\
- blr \n\
- ");
-}
-#endif
-
-#define S_LOCK(lock) do \
- { \
- while (tas(lock)) \
- ; \
- } while (0)
-
-#define S_UNLOCK(lock) (*(lock) = 0)
-
-#define S_INIT_LOCK(lock) S_UNLOCK(lock)
-
-#endif /* defined(linux) && defined(PPC) */
-
-#endif /* HAS_TEST_AND_SET */
-
-#endif /* S_LOCK_H */
-/*-------------------------------------------------------------------------
- *
- * s_lock.h--
- * This file contains the implementation (if any) for spinlocks.
- *
- * Copyright (c) 1994, Regents of the University of California
- *
- *
- * IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/include/storage/s_lock.h,v 1.1 1997/09/18 14:20:59 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/include/storage/s_lock.h,v 1.2 1997/09/22 04:21:51 vadim Exp $
*
*-------------------------------------------------------------------------
*/
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