gcc/libitm/dispatch.h
2021-01-04 10:26:59 +01:00

356 lines
16 KiB
C++

/* Copyright (C) 2011-2021 Free Software Foundation, Inc.
Contributed by Torvald Riegel <triegel@redhat.com>.
This file is part of the GNU Transactional Memory Library (libitm).
Libitm 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; either version 3 of the License, or
(at your option) any later version.
Libitm 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.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#ifndef DISPATCH_H
#define DISPATCH_H 1
#include "libitm.h"
#include "common.h"
// Creates ABI load/store methods (can be made virtual or static using M,
// use M2 to create separate methods names for virtual and static)
// The _PV variants are for the pure-virtual methods in the base class.
#define ITM_READ_M(T, LSMOD, M, M2) \
M _ITM_TYPE_##T ITM_REGPARM ITM_##LSMOD##T##M2 (const _ITM_TYPE_##T *ptr) \
{ \
return load(ptr, abi_dispatch::LSMOD); \
}
#define ITM_READ_M_PV(T, LSMOD, M, M2) \
M _ITM_TYPE_##T ITM_REGPARM ITM_##LSMOD##T##M2 (const _ITM_TYPE_##T *ptr) \
= 0;
#define ITM_WRITE_M(T, LSMOD, M, M2) \
M void ITM_REGPARM ITM_##LSMOD##T##M2 (_ITM_TYPE_##T *ptr, \
_ITM_TYPE_##T val) \
{ \
store(ptr, val, abi_dispatch::LSMOD); \
}
#define ITM_WRITE_M_PV(T, LSMOD, M, M2) \
M void ITM_REGPARM ITM_##LSMOD##T##M2 (_ITM_TYPE_##T *ptr, \
_ITM_TYPE_##T val) \
= 0;
// Creates ABI load/store methods for all load/store modifiers for a particular
// type.
#define CREATE_DISPATCH_METHODS_T(T, M, M2) \
ITM_READ_M(T, R, M, M2) \
ITM_READ_M(T, RaR, M, M2) \
ITM_READ_M(T, RaW, M, M2) \
ITM_READ_M(T, RfW, M, M2) \
ITM_WRITE_M(T, W, M, M2) \
ITM_WRITE_M(T, WaR, M, M2) \
ITM_WRITE_M(T, WaW, M, M2)
#define CREATE_DISPATCH_METHODS_T_PV(T, M, M2) \
ITM_READ_M_PV(T, R, M, M2) \
ITM_READ_M_PV(T, RaR, M, M2) \
ITM_READ_M_PV(T, RaW, M, M2) \
ITM_READ_M_PV(T, RfW, M, M2) \
ITM_WRITE_M_PV(T, W, M, M2) \
ITM_WRITE_M_PV(T, WaR, M, M2) \
ITM_WRITE_M_PV(T, WaW, M, M2)
// Creates ABI load/store methods for all types.
// See CREATE_DISPATCH_FUNCTIONS for comments.
#define CREATE_DISPATCH_METHODS(M, M2) \
CREATE_DISPATCH_METHODS_T (U1, M, M2) \
CREATE_DISPATCH_METHODS_T (U2, M, M2) \
CREATE_DISPATCH_METHODS_T (U4, M, M2) \
CREATE_DISPATCH_METHODS_T (U8, M, M2) \
CREATE_DISPATCH_METHODS_T (F, M, M2) \
CREATE_DISPATCH_METHODS_T (D, M, M2) \
CREATE_DISPATCH_METHODS_T (E, M, M2) \
CREATE_DISPATCH_METHODS_T (CF, M, M2) \
CREATE_DISPATCH_METHODS_T (CD, M, M2) \
CREATE_DISPATCH_METHODS_T (CE, M, M2)
#define CREATE_DISPATCH_METHODS_PV(M, M2) \
CREATE_DISPATCH_METHODS_T_PV (U1, M, M2) \
CREATE_DISPATCH_METHODS_T_PV (U2, M, M2) \
CREATE_DISPATCH_METHODS_T_PV (U4, M, M2) \
CREATE_DISPATCH_METHODS_T_PV (U8, M, M2) \
CREATE_DISPATCH_METHODS_T_PV (F, M, M2) \
CREATE_DISPATCH_METHODS_T_PV (D, M, M2) \
CREATE_DISPATCH_METHODS_T_PV (E, M, M2) \
CREATE_DISPATCH_METHODS_T_PV (CF, M, M2) \
CREATE_DISPATCH_METHODS_T_PV (CD, M, M2) \
CREATE_DISPATCH_METHODS_T_PV (CE, M, M2)
// Creates memcpy/memmove/memset methods.
#define CREATE_DISPATCH_METHODS_MEM() \
virtual void memtransfer(void *dst, const void* src, size_t size, \
bool may_overlap, ls_modifier dst_mod, ls_modifier src_mod) \
{ \
if (size > 0) \
memtransfer_static(dst, src, size, may_overlap, dst_mod, src_mod); \
} \
virtual void memset(void *dst, int c, size_t size, ls_modifier mod) \
{ \
if (size > 0) \
memset_static(dst, c, size, mod); \
}
#define CREATE_DISPATCH_METHODS_MEM_PV() \
virtual void memtransfer(void *dst, const void* src, size_t size, \
bool may_overlap, ls_modifier dst_mod, ls_modifier src_mod) = 0; \
virtual void memset(void *dst, int c, size_t size, ls_modifier mod) = 0;
// Creates ABI load/store functions that can target either a class or an
// object.
#define ITM_READ(T, LSMOD, TARGET, M2) \
_ITM_TYPE_##T ITM_REGPARM _ITM_##LSMOD##T (const _ITM_TYPE_##T *ptr) \
{ \
return TARGET ITM_##LSMOD##T##M2(ptr); \
}
#define ITM_WRITE(T, LSMOD, TARGET, M2) \
void ITM_REGPARM _ITM_##LSMOD##T (_ITM_TYPE_##T *ptr, _ITM_TYPE_##T val) \
{ \
TARGET ITM_##LSMOD##T##M2(ptr, val); \
}
// Creates ABI load/store functions for all load/store modifiers for a
// particular type.
#define CREATE_DISPATCH_FUNCTIONS_T(T, TARGET, M2) \
ITM_READ(T, R, TARGET, M2) \
ITM_READ(T, RaR, TARGET, M2) \
ITM_READ(T, RaW, TARGET, M2) \
ITM_READ(T, RfW, TARGET, M2) \
ITM_WRITE(T, W, TARGET, M2) \
ITM_WRITE(T, WaR, TARGET, M2) \
ITM_WRITE(T, WaW, TARGET, M2)
// Creates ABI memcpy/memmove/memset functions.
#define ITM_MEMTRANSFER_DEF(TARGET, M2, NAME, READ, WRITE) \
void ITM_REGPARM _ITM_memcpy##NAME(void *dst, const void *src, size_t size) \
{ \
TARGET memtransfer##M2 (dst, src, size, \
false, GTM::abi_dispatch::WRITE, GTM::abi_dispatch::READ); \
} \
void ITM_REGPARM _ITM_memmove##NAME(void *dst, const void *src, size_t size) \
{ \
TARGET memtransfer##M2 (dst, src, size, \
GTM::abi_dispatch::memmove_overlap_check(dst, src, size, \
GTM::abi_dispatch::WRITE, GTM::abi_dispatch::READ), \
GTM::abi_dispatch::WRITE, GTM::abi_dispatch::READ); \
}
#define ITM_MEMSET_DEF(TARGET, M2, WRITE) \
void ITM_REGPARM _ITM_memset##WRITE(void *dst, int c, size_t size) \
{ \
TARGET memset##M2 (dst, c, size, GTM::abi_dispatch::WRITE); \
} \
// ??? The number of virtual methods is large (7*4 for integers, 7*6 for FP,
// 7*3 for vectors). Is the cache footprint so costly that we should go for
// a small table instead (i.e., only have two virtual load/store methods for
// each supported type)? Note that this doesn't affect custom code paths at
// all because these use only direct calls.
// A large cache footprint could especially decrease HTM performance (due
// to HTM capacity). We could add the modifier (RaR etc.) as parameter, which
// would give us just 4*2+6*2+3*2 functions (so we'd just need one line for
// the integer loads/stores), but then the modifier can be checked only at
// runtime.
// For memcpy/memmove/memset, we just have two virtual methods (memtransfer
// and memset).
#define CREATE_DISPATCH_FUNCTIONS(TARGET, M2) \
CREATE_DISPATCH_FUNCTIONS_T (U1, TARGET, M2) \
CREATE_DISPATCH_FUNCTIONS_T (U2, TARGET, M2) \
CREATE_DISPATCH_FUNCTIONS_T (U4, TARGET, M2) \
CREATE_DISPATCH_FUNCTIONS_T (U8, TARGET, M2) \
CREATE_DISPATCH_FUNCTIONS_T (F, TARGET, M2) \
CREATE_DISPATCH_FUNCTIONS_T (D, TARGET, M2) \
CREATE_DISPATCH_FUNCTIONS_T (E, TARGET, M2) \
CREATE_DISPATCH_FUNCTIONS_T (CF, TARGET, M2) \
CREATE_DISPATCH_FUNCTIONS_T (CD, TARGET, M2) \
CREATE_DISPATCH_FUNCTIONS_T (CE, TARGET, M2) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RnWt, NONTXNAL, W) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RnWtaR, NONTXNAL, WaR) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RnWtaW, NONTXNAL, WaW) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RtWn, R, NONTXNAL) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RtWt, R, W) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RtWtaR, R, WaR) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RtWtaW, R, WaW) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RtaRWn, RaR, NONTXNAL) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RtaRWt, RaR, W) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RtaRWtaR, RaR, WaR) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RtaRWtaW, RaR, WaW) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RtaWWn, RaW, NONTXNAL) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RtaWWt, RaW, W) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RtaWWtaR, RaW, WaR) \
ITM_MEMTRANSFER_DEF(TARGET, M2, RtaWWtaW, RaW, WaW) \
ITM_MEMSET_DEF(TARGET, M2, W) \
ITM_MEMSET_DEF(TARGET, M2, WaR) \
ITM_MEMSET_DEF(TARGET, M2, WaW)
// Creates ABI load/store functions that delegate to a transactional memcpy.
#define ITM_READ_MEMCPY(T, LSMOD, TARGET, M2) \
_ITM_TYPE_##T ITM_REGPARM _ITM_##LSMOD##T (const _ITM_TYPE_##T *ptr)\
{ \
_ITM_TYPE_##T v; \
TARGET memtransfer##M2(&v, ptr, sizeof(_ITM_TYPE_##T), false, \
GTM::abi_dispatch::NONTXNAL, GTM::abi_dispatch::LSMOD); \
return v; \
}
#define ITM_WRITE_MEMCPY(T, LSMOD, TARGET, M2) \
void ITM_REGPARM _ITM_##LSMOD##T (_ITM_TYPE_##T *ptr, _ITM_TYPE_##T val)\
{ \
TARGET memtransfer##M2(ptr, &val, sizeof(_ITM_TYPE_##T), false, \
GTM::abi_dispatch::LSMOD, GTM::abi_dispatch::NONTXNAL); \
}
#define CREATE_DISPATCH_FUNCTIONS_T_MEMCPY(T, TARGET, M2) \
ITM_READ_MEMCPY(T, R, TARGET, M2) \
ITM_READ_MEMCPY(T, RaR, TARGET, M2) \
ITM_READ_MEMCPY(T, RaW, TARGET, M2) \
ITM_READ_MEMCPY(T, RfW, TARGET, M2) \
ITM_WRITE_MEMCPY(T, W, TARGET, M2) \
ITM_WRITE_MEMCPY(T, WaR, TARGET, M2) \
ITM_WRITE_MEMCPY(T, WaW, TARGET, M2)
namespace GTM HIDDEN {
struct gtm_transaction_cp;
struct method_group
{
// Start using a TM method from this group. This constructs required meta
// data on demand when this method group is actually used. Will be called
// either on first use or after a previous call to fini().
virtual void init() = 0;
// Stop using any method from this group for now. This can be used to
// destruct meta data as soon as this method group is not used anymore.
virtual void fini() = 0;
// This can be overriden to implement more light-weight re-initialization.
virtual void reinit()
{
fini();
init();
}
};
// This is the base interface that all TM methods have to implement.
struct abi_dispatch
{
public:
enum ls_modifier { NONTXNAL, R, RaR, RaW, RfW, W, WaR, WaW };
private:
// Disallow copies
abi_dispatch(const abi_dispatch &) = delete;
abi_dispatch& operator=(const abi_dispatch &) = delete;
public:
// Starts or restarts a transaction. Is called right before executing the
// transactional application code (by either returning from
// gtm_thread::begin_transaction or doing the longjmp when restarting).
// Returns NO_RESTART if the transaction started successfully. Returns
// a real restart reason if it couldn't start and does need to abort. This
// allows TM methods to just give up and delegate ensuring progress to the
// restart mechanism. If it returns a restart reason, this call must be
// idempotent because it will trigger the restart mechanism, which could
// switch to a different TM method.
virtual gtm_restart_reason begin_or_restart() = 0;
// Tries to commit the transaction. Iff this returns true, the transaction
// got committed and all per-transaction data will have been reset.
// Currently, this is called only for the commit of the outermost
// transaction, or when switching to serial mode (which can happen in a
// nested transaction).
// If privatization safety must be ensured in a quiescence-based way, set
// priv_time to a value different to 0. Nontransactional code will not be
// executed after this commit until all registered threads' shared_state is
// larger than or equal to this value.
virtual bool trycommit(gtm_word& priv_time) = 0;
// Rolls back a transaction. Called on abort or after trycommit() returned
// false.
virtual void rollback(gtm_transaction_cp *cp = 0) = 0;
// Returns true iff the snapshot is most recent, which will be the case if
// this transaction cannot be the reason why other transactions cannot
// ensure privatization safety.
virtual bool snapshot_most_recent() = 0;
// Return an alternative method that is compatible with the current
// method but supports closed nesting. Return zero if there is none.
// Note that too be compatible, it must be possible to switch to this other
// method on begin of a nested transaction without committing or restarting
// the parent method.
virtual abi_dispatch* closed_nesting_alternative() { return 0; }
// Returns true iff this method group supports the current situation.
// NUMBER_OF_THREADS is the current number of threads that might execute
// transactions.
virtual bool supports(unsigned number_of_threads) { return true; }
bool read_only () const { return m_read_only; }
bool write_through() const { return m_write_through; }
bool can_run_uninstrumented_code() const
{
return m_can_run_uninstrumented_code;
}
// Returns true iff this TM method supports closed nesting.
bool closed_nesting() const { return m_closed_nesting; }
// Returns STATE_SERIAL or STATE_SERIAL | STATE_IRREVOCABLE iff the TM
// method only works for serial-mode transactions.
uint32_t requires_serial() const { return m_requires_serial; }
method_group* get_method_group() const { return m_method_group; }
static void *operator new(size_t s) { return xmalloc (s); }
static void operator delete(void *p) { free (p); }
public:
static bool memmove_overlap_check(void *dst, const void *src, size_t size,
ls_modifier dst_mod, ls_modifier src_mod);
// Creates the ABI dispatch methods for loads and stores.
// ??? Should the dispatch table instead be embedded in the dispatch object
// to avoid the indirect lookup in the vtable?
CREATE_DISPATCH_METHODS_PV(virtual, )
// Creates the ABI dispatch methods for memcpy/memmove/memset.
CREATE_DISPATCH_METHODS_MEM_PV()
protected:
const bool m_read_only;
const bool m_write_through;
const bool m_can_run_uninstrumented_code;
const bool m_closed_nesting;
const uint32_t m_requires_serial;
method_group* const m_method_group;
abi_dispatch(bool ro, bool wt, bool uninstrumented, bool closed_nesting,
uint32_t requires_serial, method_group* mg) :
m_read_only(ro), m_write_through(wt),
m_can_run_uninstrumented_code(uninstrumented),
m_closed_nesting(closed_nesting), m_requires_serial(requires_serial),
m_method_group(mg)
{ }
};
}
#endif // DISPATCH_H