1 /* Copyright (C) 2011-2013 Free Software Foundation, Inc.
2    Contributed by Torvald Riegel <triegel@redhat.com>.
3 
4    This file is part of the GNU Transactional Memory Library (libitm).
5 
6    Libitm is free software; you can redistribute it and/or modify it
7    under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 3 of the License, or
9    (at your option) any later version.
10 
11    Libitm is distributed in the hope that it will be useful, but WITHOUT ANY
12    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13    FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14    more details.
15 
16    Under Section 7 of GPL version 3, you are granted additional
17    permissions described in the GCC Runtime Library Exception, version
18    3.1, as published by the Free Software Foundation.
19 
20    You should have received a copy of the GNU General Public License and
21    a copy of the GCC Runtime Library Exception along with this program;
22    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23    <http://www.gnu.org/licenses/>.  */
24 
25 #ifndef DISPATCH_H
26 #define DISPATCH_H 1
27 
28 #include "libitm.h"
29 #include "common.h"
30 
31 // Creates ABI load/store methods (can be made virtual or static using M,
32 // use M2 to create separate methods names for virtual and static)
33 // The _PV variants are for the pure-virtual methods in the base class.
34 #define ITM_READ_M(T, LSMOD, M, M2)                                         \
35   M _ITM_TYPE_##T ITM_REGPARM ITM_##LSMOD##T##M2 (const _ITM_TYPE_##T *ptr) \
36   {                                                                         \
37     return load(ptr, abi_dispatch::LSMOD);                                  \
38   }
39 
40 #define ITM_READ_M_PV(T, LSMOD, M, M2)                                      \
41   M _ITM_TYPE_##T ITM_REGPARM ITM_##LSMOD##T##M2 (const _ITM_TYPE_##T *ptr) \
42   = 0;
43 
44 #define ITM_WRITE_M(T, LSMOD, M, M2)                         \
45   M void ITM_REGPARM ITM_##LSMOD##T##M2 (_ITM_TYPE_##T *ptr, \
46 					 _ITM_TYPE_##T val)  \
47   {                                                          \
48     store(ptr, val, abi_dispatch::LSMOD);                    \
49   }
50 
51 #define ITM_WRITE_M_PV(T, LSMOD, M, M2)                      \
52   M void ITM_REGPARM ITM_##LSMOD##T##M2 (_ITM_TYPE_##T *ptr, \
53 					 _ITM_TYPE_##T val)  \
54   = 0;
55 
56 // Creates ABI load/store methods for all load/store modifiers for a particular
57 // type.
58 #define CREATE_DISPATCH_METHODS_T(T, M, M2) \
59   ITM_READ_M(T, R, M, M2)                \
60   ITM_READ_M(T, RaR, M, M2)              \
61   ITM_READ_M(T, RaW, M, M2)              \
62   ITM_READ_M(T, RfW, M, M2)              \
63   ITM_WRITE_M(T, W, M, M2)               \
64   ITM_WRITE_M(T, WaR, M, M2)             \
65   ITM_WRITE_M(T, WaW, M, M2)
66 #define CREATE_DISPATCH_METHODS_T_PV(T, M, M2) \
67   ITM_READ_M_PV(T, R, M, M2)                \
68   ITM_READ_M_PV(T, RaR, M, M2)              \
69   ITM_READ_M_PV(T, RaW, M, M2)              \
70   ITM_READ_M_PV(T, RfW, M, M2)              \
71   ITM_WRITE_M_PV(T, W, M, M2)               \
72   ITM_WRITE_M_PV(T, WaR, M, M2)             \
73   ITM_WRITE_M_PV(T, WaW, M, M2)
74 
75 // Creates ABI load/store methods for all types.
76 // See CREATE_DISPATCH_FUNCTIONS for comments.
77 #define CREATE_DISPATCH_METHODS(M, M2)  \
78   CREATE_DISPATCH_METHODS_T (U1, M, M2) \
79   CREATE_DISPATCH_METHODS_T (U2, M, M2) \
80   CREATE_DISPATCH_METHODS_T (U4, M, M2) \
81   CREATE_DISPATCH_METHODS_T (U8, M, M2) \
82   CREATE_DISPATCH_METHODS_T (F, M, M2)  \
83   CREATE_DISPATCH_METHODS_T (D, M, M2)  \
84   CREATE_DISPATCH_METHODS_T (E, M, M2)  \
85   CREATE_DISPATCH_METHODS_T (CF, M, M2) \
86   CREATE_DISPATCH_METHODS_T (CD, M, M2) \
87   CREATE_DISPATCH_METHODS_T (CE, M, M2)
88 #define CREATE_DISPATCH_METHODS_PV(M, M2)  \
89   CREATE_DISPATCH_METHODS_T_PV (U1, M, M2) \
90   CREATE_DISPATCH_METHODS_T_PV (U2, M, M2) \
91   CREATE_DISPATCH_METHODS_T_PV (U4, M, M2) \
92   CREATE_DISPATCH_METHODS_T_PV (U8, M, M2) \
93   CREATE_DISPATCH_METHODS_T_PV (F, M, M2)  \
94   CREATE_DISPATCH_METHODS_T_PV (D, M, M2)  \
95   CREATE_DISPATCH_METHODS_T_PV (E, M, M2)  \
96   CREATE_DISPATCH_METHODS_T_PV (CF, M, M2) \
97   CREATE_DISPATCH_METHODS_T_PV (CD, M, M2) \
98   CREATE_DISPATCH_METHODS_T_PV (CE, M, M2)
99 
100 // Creates memcpy/memmove/memset methods.
101 #define CREATE_DISPATCH_METHODS_MEM()  \
102 virtual void memtransfer(void *dst, const void* src, size_t size,    \
103     bool may_overlap, ls_modifier dst_mod, ls_modifier src_mod)       \
104 {                                                                     \
105   if (size > 0)                                                       \
106     memtransfer_static(dst, src, size, may_overlap, dst_mod, src_mod); \
107 }                                                                     \
108 virtual void memset(void *dst, int c, size_t size, ls_modifier mod)  \
109 {                                                                     \
110   if (size > 0)                                                       \
111     memset_static(dst, c, size, mod);                                 \
112 }
113 
114 #define CREATE_DISPATCH_METHODS_MEM_PV()  \
115 virtual void memtransfer(void *dst, const void* src, size_t size,       \
116     bool may_overlap, ls_modifier dst_mod, ls_modifier src_mod) = 0;     \
117 virtual void memset(void *dst, int c, size_t size, ls_modifier mod) = 0;
118 
119 
120 // Creates ABI load/store functions that can target either a class or an
121 // object.
122 #define ITM_READ(T, LSMOD, TARGET, M2)                                 \
123   _ITM_TYPE_##T ITM_REGPARM _ITM_##LSMOD##T (const _ITM_TYPE_##T *ptr) \
124   {                                                                    \
125     return TARGET ITM_##LSMOD##T##M2(ptr);                            \
126   }
127 
128 #define ITM_WRITE(T, LSMOD, TARGET, M2)                                    \
129   void ITM_REGPARM _ITM_##LSMOD##T (_ITM_TYPE_##T *ptr, _ITM_TYPE_##T val) \
130   {                                                                        \
131     TARGET ITM_##LSMOD##T##M2(ptr, val);                                  \
132   }
133 
134 // Creates ABI load/store functions for all load/store modifiers for a
135 // particular type.
136 #define CREATE_DISPATCH_FUNCTIONS_T(T, TARGET, M2) \
137   ITM_READ(T, R, TARGET, M2)                \
138   ITM_READ(T, RaR, TARGET, M2)              \
139   ITM_READ(T, RaW, TARGET, M2)              \
140   ITM_READ(T, RfW, TARGET, M2)              \
141   ITM_WRITE(T, W, TARGET, M2)               \
142   ITM_WRITE(T, WaR, TARGET, M2)             \
143   ITM_WRITE(T, WaW, TARGET, M2)
144 
145 // Creates ABI memcpy/memmove/memset functions.
146 #define ITM_MEMTRANSFER_DEF(TARGET, M2, NAME, READ, WRITE) \
147 void ITM_REGPARM _ITM_memcpy##NAME(void *dst, const void *src, size_t size)  \
148 {                                                                            \
149   TARGET memtransfer##M2 (dst, src, size,                                   \
150 	     false, GTM::abi_dispatch::WRITE, GTM::abi_dispatch::READ);      \
151 }                                                                            \
152 void ITM_REGPARM _ITM_memmove##NAME(void *dst, const void *src, size_t size) \
153 {                                                                            \
154   TARGET memtransfer##M2 (dst, src, size,                                   \
155       GTM::abi_dispatch::memmove_overlap_check(dst, src, size,               \
156 	  GTM::abi_dispatch::WRITE, GTM::abi_dispatch::READ),                \
157       GTM::abi_dispatch::WRITE, GTM::abi_dispatch::READ);                    \
158 }
159 
160 #define ITM_MEMSET_DEF(TARGET, M2, WRITE) \
161 void ITM_REGPARM _ITM_memset##WRITE(void *dst, int c, size_t size) \
162 {                                                                  \
163   TARGET memset##M2 (dst, c, size, GTM::abi_dispatch::WRITE);     \
164 }                                                                  \
165 
166 
167 // ??? The number of virtual methods is large (7*4 for integers, 7*6 for FP,
168 // 7*3 for vectors). Is the cache footprint so costly that we should go for
169 // a small table instead (i.e., only have two virtual load/store methods for
170 // each supported type)? Note that this doesn't affect custom code paths at
171 // all because these use only direct calls.
172 // A large cache footprint could especially decrease HTM performance (due
173 // to HTM capacity). We could add the modifier (RaR etc.) as parameter, which
174 // would give us just 4*2+6*2+3*2 functions (so we'd just need one line for
175 // the integer loads/stores), but then the modifier can be checked only at
176 // runtime.
177 // For memcpy/memmove/memset, we just have two virtual methods (memtransfer
178 // and memset).
179 #define CREATE_DISPATCH_FUNCTIONS(TARGET, M2)  \
180   CREATE_DISPATCH_FUNCTIONS_T (U1, TARGET, M2) \
181   CREATE_DISPATCH_FUNCTIONS_T (U2, TARGET, M2) \
182   CREATE_DISPATCH_FUNCTIONS_T (U4, TARGET, M2) \
183   CREATE_DISPATCH_FUNCTIONS_T (U8, TARGET, M2) \
184   CREATE_DISPATCH_FUNCTIONS_T (F, TARGET, M2)  \
185   CREATE_DISPATCH_FUNCTIONS_T (D, TARGET, M2)  \
186   CREATE_DISPATCH_FUNCTIONS_T (E, TARGET, M2)  \
187   CREATE_DISPATCH_FUNCTIONS_T (CF, TARGET, M2) \
188   CREATE_DISPATCH_FUNCTIONS_T (CD, TARGET, M2) \
189   CREATE_DISPATCH_FUNCTIONS_T (CE, TARGET, M2) \
190   ITM_MEMTRANSFER_DEF(TARGET, M2, RnWt,     NONTXNAL, W)      \
191   ITM_MEMTRANSFER_DEF(TARGET, M2, RnWtaR,   NONTXNAL, WaR)    \
192   ITM_MEMTRANSFER_DEF(TARGET, M2, RnWtaW,   NONTXNAL, WaW)    \
193   ITM_MEMTRANSFER_DEF(TARGET, M2, RtWn,     R,      NONTXNAL) \
194   ITM_MEMTRANSFER_DEF(TARGET, M2, RtWt,     R,      W)        \
195   ITM_MEMTRANSFER_DEF(TARGET, M2, RtWtaR,   R,      WaR)      \
196   ITM_MEMTRANSFER_DEF(TARGET, M2, RtWtaW,   R,      WaW)      \
197   ITM_MEMTRANSFER_DEF(TARGET, M2, RtaRWn,   RaR,    NONTXNAL) \
198   ITM_MEMTRANSFER_DEF(TARGET, M2, RtaRWt,   RaR,    W)        \
199   ITM_MEMTRANSFER_DEF(TARGET, M2, RtaRWtaR, RaR,    WaR)      \
200   ITM_MEMTRANSFER_DEF(TARGET, M2, RtaRWtaW, RaR,    WaW)      \
201   ITM_MEMTRANSFER_DEF(TARGET, M2, RtaWWn,   RaW,    NONTXNAL) \
202   ITM_MEMTRANSFER_DEF(TARGET, M2, RtaWWt,   RaW,    W)        \
203   ITM_MEMTRANSFER_DEF(TARGET, M2, RtaWWtaR, RaW,    WaR)      \
204   ITM_MEMTRANSFER_DEF(TARGET, M2, RtaWWtaW, RaW,    WaW)      \
205   ITM_MEMSET_DEF(TARGET, M2, W)   \
206   ITM_MEMSET_DEF(TARGET, M2, WaR) \
207   ITM_MEMSET_DEF(TARGET, M2, WaW)
208 
209 
210 // Creates ABI load/store functions that delegate to a transactional memcpy.
211 #define ITM_READ_MEMCPY(T, LSMOD, TARGET, M2)                         \
212   _ITM_TYPE_##T ITM_REGPARM _ITM_##LSMOD##T (const _ITM_TYPE_##T *ptr)\
213   {                                                                   \
214     _ITM_TYPE_##T v;                                                  \
215     TARGET memtransfer##M2(&v, ptr, sizeof(_ITM_TYPE_##T), false,    \
216 	GTM::abi_dispatch::NONTXNAL, GTM::abi_dispatch::LSMOD);       \
217     return v;                                                         \
218   }
219 
220 #define ITM_WRITE_MEMCPY(T, LSMOD, TARGET, M2)                            \
221   void ITM_REGPARM _ITM_##LSMOD##T (_ITM_TYPE_##T *ptr, _ITM_TYPE_##T val)\
222   {                                                                       \
223     TARGET memtransfer##M2(ptr, &val, sizeof(_ITM_TYPE_##T), false,      \
224 	GTM::abi_dispatch::LSMOD, GTM::abi_dispatch::NONTXNAL);           \
225   }
226 
227 #define CREATE_DISPATCH_FUNCTIONS_T_MEMCPY(T, TARGET, M2) \
228   ITM_READ_MEMCPY(T, R, TARGET, M2)                \
229   ITM_READ_MEMCPY(T, RaR, TARGET, M2)              \
230   ITM_READ_MEMCPY(T, RaW, TARGET, M2)              \
231   ITM_READ_MEMCPY(T, RfW, TARGET, M2)              \
232   ITM_WRITE_MEMCPY(T, W, TARGET, M2)               \
233   ITM_WRITE_MEMCPY(T, WaR, TARGET, M2)             \
234   ITM_WRITE_MEMCPY(T, WaW, TARGET, M2)
235 
236 
237 namespace GTM HIDDEN {
238 
239 struct gtm_transaction_cp;
240 
241 struct method_group
242 {
243   // Start using a TM method from this group. This constructs required meta
244   // data on demand when this method group is actually used. Will be called
245   // either on first use or after a previous call to fini().
246   virtual void init() = 0;
247   // Stop using any method from this group for now. This can be used to
248   // destruct meta data as soon as this method group is not used anymore.
249   virtual void fini() = 0;
250   // This can be overriden to implement more light-weight re-initialization.
reinitmethod_group251   virtual void reinit()
252   {
253     fini();
254     init();
255   }
256 };
257 
258 
259 // This is the base interface that all TM methods have to implement.
260 struct abi_dispatch
261 {
262 public:
263   enum ls_modifier { NONTXNAL, R, RaR, RaW, RfW, W, WaR, WaW };
264 
265 private:
266   // Disallow copies
267   abi_dispatch(const abi_dispatch &) = delete;
268   abi_dispatch& operator=(const abi_dispatch &) = delete;
269 
270 public:
271   // Starts or restarts a transaction. Is called right before executing the
272   // transactional application code (by either returning from
273   // gtm_thread::begin_transaction or doing the longjmp when restarting).
274   // Returns NO_RESTART if the transaction started successfully. Returns
275   // a real restart reason if it couldn't start and does need to abort. This
276   // allows TM methods to just give up and delegate ensuring progress to the
277   // restart mechanism. If it returns a restart reason, this call must be
278   // idempotent because it will trigger the restart mechanism, which could
279   // switch to a different TM method.
280   virtual gtm_restart_reason begin_or_restart() = 0;
281   // Tries to commit the transaction. Iff this returns true, the transaction
282   // got committed and all per-transaction data will have been reset.
283   // Currently, this is called only for the commit of the outermost
284   // transaction, or when switching to serial mode (which can happen in a
285   // nested transaction).
286   // If privatization safety must be ensured in a quiescence-based way, set
287   // priv_time to a value different to 0. Nontransactional code will not be
288   // executed after this commit until all registered threads' shared_state is
289   // larger than or equal to this value.
290   virtual bool trycommit(gtm_word& priv_time) = 0;
291   // Rolls back a transaction. Called on abort or after trycommit() returned
292   // false.
293   virtual void rollback(gtm_transaction_cp *cp = 0) = 0;
294 
295   // Return an alternative method that is compatible with the current
296   // method but supports closed nesting. Return zero if there is none.
297   // Note that too be compatible, it must be possible to switch to this other
298   // method on begin of a nested transaction without committing or restarting
299   // the parent method.
closed_nesting_alternativeabi_dispatch300   virtual abi_dispatch* closed_nesting_alternative() { return 0; }
301   // Returns true iff this method group supports the current situation.
302   // NUMBER_OF_THREADS is the current number of threads that might execute
303   // transactions.
supportsabi_dispatch304   virtual bool supports(unsigned number_of_threads) { return true; }
305 
read_onlyabi_dispatch306   bool read_only () const { return m_read_only; }
write_throughabi_dispatch307   bool write_through() const { return m_write_through; }
can_run_uninstrumented_codeabi_dispatch308   bool can_run_uninstrumented_code() const
309   {
310     return m_can_run_uninstrumented_code;
311   }
312   // Returns true iff this TM method supports closed nesting.
closed_nestingabi_dispatch313   bool closed_nesting() const { return m_closed_nesting; }
314   // Returns STATE_SERIAL or STATE_SERIAL | STATE_IRREVOCABLE iff the TM
315   // method only works for serial-mode transactions.
requires_serialabi_dispatch316   uint32_t requires_serial() const { return m_requires_serial; }
get_method_groupabi_dispatch317   method_group* get_method_group() const { return m_method_group; }
318 
newabi_dispatch319   static void *operator new(size_t s) { return xmalloc (s); }
deleteabi_dispatch320   static void operator delete(void *p) { free (p); }
321 
322 public:
323   static bool memmove_overlap_check(void *dst, const void *src, size_t size,
324       ls_modifier dst_mod, ls_modifier src_mod);
325 
326   // Creates the ABI dispatch methods for loads and stores.
327   // ??? Should the dispatch table instead be embedded in the dispatch object
328   // to avoid the indirect lookup in the vtable?
329   CREATE_DISPATCH_METHODS_PV(virtual, )
330   // Creates the ABI dispatch methods for memcpy/memmove/memset.
331   CREATE_DISPATCH_METHODS_MEM_PV()
332 
333 protected:
334   const bool m_read_only;
335   const bool m_write_through;
336   const bool m_can_run_uninstrumented_code;
337   const bool m_closed_nesting;
338   const uint32_t m_requires_serial;
339   method_group* const m_method_group;
abi_dispatchabi_dispatch340   abi_dispatch(bool ro, bool wt, bool uninstrumented, bool closed_nesting,
341       uint32_t requires_serial, method_group* mg) :
342     m_read_only(ro), m_write_through(wt),
343     m_can_run_uninstrumented_code(uninstrumented),
344     m_closed_nesting(closed_nesting), m_requires_serial(requires_serial),
345     m_method_group(mg)
346   { }
347 };
348 
349 }
350 
351 #endif // DISPATCH_H
352