LLVM OpenMP* Runtime Library
kmp_lock.h
1/*
2 * kmp_lock.h -- lock header file
3 */
4
5//===----------------------------------------------------------------------===//
6//
7// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
8// See https://llvm.org/LICENSE.txt for license information.
9// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef KMP_LOCK_H
14#define KMP_LOCK_H
15
16#include <limits.h> // CHAR_BIT
17#include <stddef.h> // offsetof
18
19#include "kmp_debug.h"
20#include "kmp_os.h"
21
22#ifdef __cplusplus
23#include <atomic>
24
25extern "C" {
26#endif // __cplusplus
27
28// ----------------------------------------------------------------------------
29// Have to copy these definitions from kmp.h because kmp.h cannot be included
30// due to circular dependencies. Will undef these at end of file.
31
32#define KMP_PAD(type, sz) \
33 (sizeof(type) + (sz - ((sizeof(type) - 1) % (sz)) - 1))
34#define KMP_GTID_DNE (-2)
35
36// Forward declaration of ident and ident_t
37
38struct ident;
39typedef struct ident ident_t;
40
41// End of copied code.
42// ----------------------------------------------------------------------------
43
44// We need to know the size of the area we can assume that the compiler(s)
45// allocated for objects of type omp_lock_t and omp_nest_lock_t. The Intel
46// compiler always allocates a pointer-sized area, as does visual studio.
47//
48// gcc however, only allocates 4 bytes for regular locks, even on 64-bit
49// intel archs. It allocates at least 8 bytes for nested lock (more on
50// recent versions), but we are bounded by the pointer-sized chunks that
51// the Intel compiler allocates.
52
53#if KMP_OS_LINUX && defined(KMP_GOMP_COMPAT)
54#define OMP_LOCK_T_SIZE sizeof(int)
55#define OMP_NEST_LOCK_T_SIZE sizeof(void *)
56#else
57#define OMP_LOCK_T_SIZE sizeof(void *)
58#define OMP_NEST_LOCK_T_SIZE sizeof(void *)
59#endif
60
61// The Intel compiler allocates a 32-byte chunk for a critical section.
62// Both gcc and visual studio only allocate enough space for a pointer.
63// Sometimes we know that the space was allocated by the Intel compiler.
64#define OMP_CRITICAL_SIZE sizeof(void *)
65#define INTEL_CRITICAL_SIZE 32
66
67// lock flags
68typedef kmp_uint32 kmp_lock_flags_t;
69
70#define kmp_lf_critical_section 1
71
72// When a lock table is used, the indices are of kmp_lock_index_t
73typedef kmp_uint32 kmp_lock_index_t;
74
75// When memory allocated for locks are on the lock pool (free list),
76// it is treated as structs of this type.
77struct kmp_lock_pool {
78 union kmp_user_lock *next;
79 kmp_lock_index_t index;
80};
81
82typedef struct kmp_lock_pool kmp_lock_pool_t;
83
84extern void __kmp_validate_locks(void);
85
86// ----------------------------------------------------------------------------
87// There are 5 lock implementations:
88// 1. Test and set locks.
89// 2. futex locks (Linux* OS on x86 and
90// Intel(R) Many Integrated Core Architecture)
91// 3. Ticket (Lamport bakery) locks.
92// 4. Queuing locks (with separate spin fields).
93// 5. DRPA (Dynamically Reconfigurable Distributed Polling Area) locks
94//
95// and 3 lock purposes:
96// 1. Bootstrap locks -- Used for a few locks available at library
97// startup-shutdown time.
98// These do not require non-negative global thread ID's.
99// 2. Internal RTL locks -- Used everywhere else in the RTL
100// 3. User locks (includes critical sections)
101// ----------------------------------------------------------------------------
102
103// ============================================================================
104// Lock implementations.
105//
106// Test and set locks.
107//
108// Non-nested test and set locks differ from the other lock kinds (except
109// futex) in that we use the memory allocated by the compiler for the lock,
110// rather than a pointer to it.
111//
112// On lin32, lin_32e, and win_32, the space allocated may be as small as 4
113// bytes, so we have to use a lock table for nested locks, and avoid accessing
114// the depth_locked field for non-nested locks.
115//
116// Information normally available to the tools, such as lock location, lock
117// usage (normal lock vs. critical section), etc. is not available with test and
118// set locks.
119// ----------------------------------------------------------------------------
120
121struct kmp_base_tas_lock {
122 // KMP_LOCK_FREE(tas) => unlocked; locked: (gtid+1) of owning thread
123 std::atomic<kmp_int32> poll;
124 kmp_int32 depth_locked; // depth locked, for nested locks only
125};
126
127typedef struct kmp_base_tas_lock kmp_base_tas_lock_t;
128
129union kmp_tas_lock {
130 kmp_base_tas_lock_t lk;
131 kmp_lock_pool_t pool; // make certain struct is large enough
132 double lk_align; // use worst case alignment; no cache line padding
133};
134
135typedef union kmp_tas_lock kmp_tas_lock_t;
136
137// Static initializer for test and set lock variables. Usage:
138// kmp_tas_lock_t xlock = KMP_TAS_LOCK_INITIALIZER( xlock );
139#define KMP_TAS_LOCK_INITIALIZER(lock) \
140 { \
141 { KMP_LOCK_FREE(tas), 0 } \
142 }
143
144extern int __kmp_acquire_tas_lock(kmp_tas_lock_t *lck, kmp_int32 gtid);
145extern int __kmp_test_tas_lock(kmp_tas_lock_t *lck, kmp_int32 gtid);
146extern int __kmp_release_tas_lock(kmp_tas_lock_t *lck, kmp_int32 gtid);
147extern void __kmp_init_tas_lock(kmp_tas_lock_t *lck);
148extern void __kmp_destroy_tas_lock(kmp_tas_lock_t *lck);
149
150extern int __kmp_acquire_nested_tas_lock(kmp_tas_lock_t *lck, kmp_int32 gtid);
151extern int __kmp_test_nested_tas_lock(kmp_tas_lock_t *lck, kmp_int32 gtid);
152extern int __kmp_release_nested_tas_lock(kmp_tas_lock_t *lck, kmp_int32 gtid);
153extern void __kmp_init_nested_tas_lock(kmp_tas_lock_t *lck);
154extern void __kmp_destroy_nested_tas_lock(kmp_tas_lock_t *lck);
155
156#define KMP_LOCK_RELEASED 1
157#define KMP_LOCK_STILL_HELD 0
158#define KMP_LOCK_ACQUIRED_FIRST 1
159#define KMP_LOCK_ACQUIRED_NEXT 0
160#ifndef KMP_USE_FUTEX
161#define KMP_USE_FUTEX \
162 (KMP_OS_LINUX && \
163 (KMP_ARCH_X86 || KMP_ARCH_X86_64 || KMP_ARCH_ARM || KMP_ARCH_AARCH64))
164#endif
165#if KMP_USE_FUTEX
166
167// ----------------------------------------------------------------------------
168// futex locks. futex locks are only available on Linux* OS.
169//
170// Like non-nested test and set lock, non-nested futex locks use the memory
171// allocated by the compiler for the lock, rather than a pointer to it.
172//
173// Information normally available to the tools, such as lock location, lock
174// usage (normal lock vs. critical section), etc. is not available with test and
175// set locks. With non-nested futex locks, the lock owner is not even available.
176// ----------------------------------------------------------------------------
177
178struct kmp_base_futex_lock {
179 volatile kmp_int32 poll; // KMP_LOCK_FREE(futex) => unlocked
180 // 2*(gtid+1) of owning thread, 0 if unlocked
181 // locked: (gtid+1) of owning thread
182 kmp_int32 depth_locked; // depth locked, for nested locks only
183};
184
185typedef struct kmp_base_futex_lock kmp_base_futex_lock_t;
186
187union kmp_futex_lock {
188 kmp_base_futex_lock_t lk;
189 kmp_lock_pool_t pool; // make certain struct is large enough
190 double lk_align; // use worst case alignment
191 // no cache line padding
192};
193
194typedef union kmp_futex_lock kmp_futex_lock_t;
195
196// Static initializer for futex lock variables. Usage:
197// kmp_futex_lock_t xlock = KMP_FUTEX_LOCK_INITIALIZER( xlock );
198#define KMP_FUTEX_LOCK_INITIALIZER(lock) \
199 { \
200 { KMP_LOCK_FREE(futex), 0 } \
201 }
202
203extern int __kmp_acquire_futex_lock(kmp_futex_lock_t *lck, kmp_int32 gtid);
204extern int __kmp_test_futex_lock(kmp_futex_lock_t *lck, kmp_int32 gtid);
205extern int __kmp_release_futex_lock(kmp_futex_lock_t *lck, kmp_int32 gtid);
206extern void __kmp_init_futex_lock(kmp_futex_lock_t *lck);
207extern void __kmp_destroy_futex_lock(kmp_futex_lock_t *lck);
208
209extern int __kmp_acquire_nested_futex_lock(kmp_futex_lock_t *lck,
210 kmp_int32 gtid);
211extern int __kmp_test_nested_futex_lock(kmp_futex_lock_t *lck, kmp_int32 gtid);
212extern int __kmp_release_nested_futex_lock(kmp_futex_lock_t *lck,
213 kmp_int32 gtid);
214extern void __kmp_init_nested_futex_lock(kmp_futex_lock_t *lck);
215extern void __kmp_destroy_nested_futex_lock(kmp_futex_lock_t *lck);
216
217#endif // KMP_USE_FUTEX
218
219// ----------------------------------------------------------------------------
220// Ticket locks.
221
222#ifdef __cplusplus
223
224#ifdef _MSC_VER
225// MSVC won't allow use of std::atomic<> in a union since it has non-trivial
226// copy constructor.
227
228struct kmp_base_ticket_lock {
229 // `initialized' must be the first entry in the lock data structure!
230 std::atomic_bool initialized;
231 volatile union kmp_ticket_lock *self; // points to the lock union
232 ident_t const *location; // Source code location of omp_init_lock().
233 std::atomic_uint
234 next_ticket; // ticket number to give to next thread which acquires
235 std::atomic_uint now_serving; // ticket number for thread which holds the lock
236 std::atomic_int owner_id; // (gtid+1) of owning thread, 0 if unlocked
237 std::atomic_int depth_locked; // depth locked, for nested locks only
238 kmp_lock_flags_t flags; // lock specifics, e.g. critical section lock
239};
240#else
241struct kmp_base_ticket_lock {
242 // `initialized' must be the first entry in the lock data structure!
243 std::atomic<bool> initialized;
244 volatile union kmp_ticket_lock *self; // points to the lock union
245 ident_t const *location; // Source code location of omp_init_lock().
246 std::atomic<unsigned>
247 next_ticket; // ticket number to give to next thread which acquires
248 std::atomic<unsigned>
249 now_serving; // ticket number for thread which holds the lock
250 std::atomic<int> owner_id; // (gtid+1) of owning thread, 0 if unlocked
251 std::atomic<int> depth_locked; // depth locked, for nested locks only
252 kmp_lock_flags_t flags; // lock specifics, e.g. critical section lock
253};
254#endif
255
256#else // __cplusplus
257
258struct kmp_base_ticket_lock;
259
260#endif // !__cplusplus
261
262typedef struct kmp_base_ticket_lock kmp_base_ticket_lock_t;
263
264union KMP_ALIGN_CACHE kmp_ticket_lock {
265 kmp_base_ticket_lock_t
266 lk; // This field must be first to allow static initializing.
267 kmp_lock_pool_t pool;
268 double lk_align; // use worst case alignment
269 char lk_pad[KMP_PAD(kmp_base_ticket_lock_t, CACHE_LINE)];
270};
271
272typedef union kmp_ticket_lock kmp_ticket_lock_t;
273
274// Static initializer for simple ticket lock variables. Usage:
275// kmp_ticket_lock_t xlock = KMP_TICKET_LOCK_INITIALIZER( xlock );
276// Note the macro argument. It is important to make var properly initialized.
277#define KMP_TICKET_LOCK_INITIALIZER(lock) \
278 { \
279 { true, &(lock), NULL, 0U, 0U, 0, -1 } \
280 }
281
282extern int __kmp_acquire_ticket_lock(kmp_ticket_lock_t *lck, kmp_int32 gtid);
283extern int __kmp_test_ticket_lock(kmp_ticket_lock_t *lck, kmp_int32 gtid);
284extern int __kmp_test_ticket_lock_with_cheks(kmp_ticket_lock_t *lck,
285 kmp_int32 gtid);
286extern int __kmp_release_ticket_lock(kmp_ticket_lock_t *lck, kmp_int32 gtid);
287extern void __kmp_init_ticket_lock(kmp_ticket_lock_t *lck);
288extern void __kmp_destroy_ticket_lock(kmp_ticket_lock_t *lck);
289
290extern int __kmp_acquire_nested_ticket_lock(kmp_ticket_lock_t *lck,
291 kmp_int32 gtid);
292extern int __kmp_test_nested_ticket_lock(kmp_ticket_lock_t *lck,
293 kmp_int32 gtid);
294extern int __kmp_release_nested_ticket_lock(kmp_ticket_lock_t *lck,
295 kmp_int32 gtid);
296extern void __kmp_init_nested_ticket_lock(kmp_ticket_lock_t *lck);
297extern void __kmp_destroy_nested_ticket_lock(kmp_ticket_lock_t *lck);
298
299// ----------------------------------------------------------------------------
300// Queuing locks.
301
302#if KMP_USE_ADAPTIVE_LOCKS
303
304struct kmp_adaptive_lock_info;
305
306typedef struct kmp_adaptive_lock_info kmp_adaptive_lock_info_t;
307
308#if KMP_DEBUG_ADAPTIVE_LOCKS
309
310struct kmp_adaptive_lock_statistics {
311 /* So we can get stats from locks that haven't been destroyed. */
312 kmp_adaptive_lock_info_t *next;
313 kmp_adaptive_lock_info_t *prev;
314
315 /* Other statistics */
316 kmp_uint32 successfulSpeculations;
317 kmp_uint32 hardFailedSpeculations;
318 kmp_uint32 softFailedSpeculations;
319 kmp_uint32 nonSpeculativeAcquires;
320 kmp_uint32 nonSpeculativeAcquireAttempts;
321 kmp_uint32 lemmingYields;
322};
323
324typedef struct kmp_adaptive_lock_statistics kmp_adaptive_lock_statistics_t;
325
326extern void __kmp_print_speculative_stats();
327extern void __kmp_init_speculative_stats();
328
329#endif // KMP_DEBUG_ADAPTIVE_LOCKS
330
331struct kmp_adaptive_lock_info {
332 /* Values used for adaptivity.
333 Although these are accessed from multiple threads we don't access them
334 atomically, because if we miss updates it probably doesn't matter much. (It
335 just affects our decision about whether to try speculation on the lock). */
336 kmp_uint32 volatile badness;
337 kmp_uint32 volatile acquire_attempts;
338 /* Parameters of the lock. */
339 kmp_uint32 max_badness;
340 kmp_uint32 max_soft_retries;
341
342#if KMP_DEBUG_ADAPTIVE_LOCKS
343 kmp_adaptive_lock_statistics_t volatile stats;
344#endif
345};
346
347#endif // KMP_USE_ADAPTIVE_LOCKS
348
349struct kmp_base_queuing_lock {
350
351 // `initialized' must be the first entry in the lock data structure!
352 volatile union kmp_queuing_lock
353 *initialized; // Points to the lock union if in initialized state.
354
355 ident_t const *location; // Source code location of omp_init_lock().
356
357 KMP_ALIGN(8) // tail_id must be 8-byte aligned!
358
359 volatile kmp_int32
360 tail_id; // (gtid+1) of thread at tail of wait queue, 0 if empty
361 // Must be no padding here since head/tail used in 8-byte CAS
362 volatile kmp_int32
363 head_id; // (gtid+1) of thread at head of wait queue, 0 if empty
364 // Decl order assumes little endian
365 // bakery-style lock
366 volatile kmp_uint32
367 next_ticket; // ticket number to give to next thread which acquires
368 volatile kmp_uint32
369 now_serving; // ticket number for thread which holds the lock
370 volatile kmp_int32 owner_id; // (gtid+1) of owning thread, 0 if unlocked
371 kmp_int32 depth_locked; // depth locked, for nested locks only
372
373 kmp_lock_flags_t flags; // lock specifics, e.g. critical section lock
374};
375
376typedef struct kmp_base_queuing_lock kmp_base_queuing_lock_t;
377
378KMP_BUILD_ASSERT(offsetof(kmp_base_queuing_lock_t, tail_id) % 8 == 0);
379
380union KMP_ALIGN_CACHE kmp_queuing_lock {
381 kmp_base_queuing_lock_t
382 lk; // This field must be first to allow static initializing.
383 kmp_lock_pool_t pool;
384 double lk_align; // use worst case alignment
385 char lk_pad[KMP_PAD(kmp_base_queuing_lock_t, CACHE_LINE)];
386};
387
388typedef union kmp_queuing_lock kmp_queuing_lock_t;
389
390extern int __kmp_acquire_queuing_lock(kmp_queuing_lock_t *lck, kmp_int32 gtid);
391extern int __kmp_test_queuing_lock(kmp_queuing_lock_t *lck, kmp_int32 gtid);
392extern int __kmp_release_queuing_lock(kmp_queuing_lock_t *lck, kmp_int32 gtid);
393extern void __kmp_init_queuing_lock(kmp_queuing_lock_t *lck);
394extern void __kmp_destroy_queuing_lock(kmp_queuing_lock_t *lck);
395
396extern int __kmp_acquire_nested_queuing_lock(kmp_queuing_lock_t *lck,
397 kmp_int32 gtid);
398extern int __kmp_test_nested_queuing_lock(kmp_queuing_lock_t *lck,
399 kmp_int32 gtid);
400extern int __kmp_release_nested_queuing_lock(kmp_queuing_lock_t *lck,
401 kmp_int32 gtid);
402extern void __kmp_init_nested_queuing_lock(kmp_queuing_lock_t *lck);
403extern void __kmp_destroy_nested_queuing_lock(kmp_queuing_lock_t *lck);
404
405#if KMP_USE_ADAPTIVE_LOCKS
406
407// ----------------------------------------------------------------------------
408// Adaptive locks.
409struct kmp_base_adaptive_lock {
410 kmp_base_queuing_lock qlk;
411 KMP_ALIGN(CACHE_LINE)
412 kmp_adaptive_lock_info_t
413 adaptive; // Information for the speculative adaptive lock
414};
415
416typedef struct kmp_base_adaptive_lock kmp_base_adaptive_lock_t;
417
418union KMP_ALIGN_CACHE kmp_adaptive_lock {
419 kmp_base_adaptive_lock_t lk;
420 kmp_lock_pool_t pool;
421 double lk_align;
422 char lk_pad[KMP_PAD(kmp_base_adaptive_lock_t, CACHE_LINE)];
423};
424typedef union kmp_adaptive_lock kmp_adaptive_lock_t;
425
426#define GET_QLK_PTR(l) ((kmp_queuing_lock_t *)&(l)->lk.qlk)
427
428#endif // KMP_USE_ADAPTIVE_LOCKS
429
430// ----------------------------------------------------------------------------
431// DRDPA ticket locks.
432struct kmp_base_drdpa_lock {
433 // All of the fields on the first cache line are only written when
434 // initializing or reconfiguring the lock. These are relatively rare
435 // operations, so data from the first cache line will usually stay resident in
436 // the cache of each thread trying to acquire the lock.
437 //
438 // initialized must be the first entry in the lock data structure!
439 KMP_ALIGN_CACHE
440
441 volatile union kmp_drdpa_lock
442 *initialized; // points to the lock union if in initialized state
443 ident_t const *location; // Source code location of omp_init_lock().
444 std::atomic<std::atomic<kmp_uint64> *> polls;
445 std::atomic<kmp_uint64> mask; // is 2**num_polls-1 for mod op
446 kmp_uint64 cleanup_ticket; // thread with cleanup ticket
447 std::atomic<kmp_uint64> *old_polls; // will deallocate old_polls
448 kmp_uint32 num_polls; // must be power of 2
449
450 // next_ticket it needs to exist in a separate cache line, as it is
451 // invalidated every time a thread takes a new ticket.
452 KMP_ALIGN_CACHE
453
454 std::atomic<kmp_uint64> next_ticket;
455
456 // now_serving is used to store our ticket value while we hold the lock. It
457 // has a slightly different meaning in the DRDPA ticket locks (where it is
458 // written by the acquiring thread) than it does in the simple ticket locks
459 // (where it is written by the releasing thread).
460 //
461 // Since now_serving is only read and written in the critical section,
462 // it is non-volatile, but it needs to exist on a separate cache line,
463 // as it is invalidated at every lock acquire.
464 //
465 // Likewise, the vars used for nested locks (owner_id and depth_locked) are
466 // only written by the thread owning the lock, so they are put in this cache
467 // line. owner_id is read by other threads, so it must be declared volatile.
468 KMP_ALIGN_CACHE
469 kmp_uint64 now_serving; // doesn't have to be volatile
470 volatile kmp_uint32 owner_id; // (gtid+1) of owning thread, 0 if unlocked
471 kmp_int32 depth_locked; // depth locked
472 kmp_lock_flags_t flags; // lock specifics, e.g. critical section lock
473};
474
475typedef struct kmp_base_drdpa_lock kmp_base_drdpa_lock_t;
476
477union KMP_ALIGN_CACHE kmp_drdpa_lock {
478 kmp_base_drdpa_lock_t
479 lk; // This field must be first to allow static initializing. */
480 kmp_lock_pool_t pool;
481 double lk_align; // use worst case alignment
482 char lk_pad[KMP_PAD(kmp_base_drdpa_lock_t, CACHE_LINE)];
483};
484
485typedef union kmp_drdpa_lock kmp_drdpa_lock_t;
486
487extern int __kmp_acquire_drdpa_lock(kmp_drdpa_lock_t *lck, kmp_int32 gtid);
488extern int __kmp_test_drdpa_lock(kmp_drdpa_lock_t *lck, kmp_int32 gtid);
489extern int __kmp_release_drdpa_lock(kmp_drdpa_lock_t *lck, kmp_int32 gtid);
490extern void __kmp_init_drdpa_lock(kmp_drdpa_lock_t *lck);
491extern void __kmp_destroy_drdpa_lock(kmp_drdpa_lock_t *lck);
492
493extern int __kmp_acquire_nested_drdpa_lock(kmp_drdpa_lock_t *lck,
494 kmp_int32 gtid);
495extern int __kmp_test_nested_drdpa_lock(kmp_drdpa_lock_t *lck, kmp_int32 gtid);
496extern int __kmp_release_nested_drdpa_lock(kmp_drdpa_lock_t *lck,
497 kmp_int32 gtid);
498extern void __kmp_init_nested_drdpa_lock(kmp_drdpa_lock_t *lck);
499extern void __kmp_destroy_nested_drdpa_lock(kmp_drdpa_lock_t *lck);
500
501// ============================================================================
502// Lock purposes.
503// ============================================================================
504
505// Bootstrap locks.
506//
507// Bootstrap locks -- very few locks used at library initialization time.
508// Bootstrap locks are currently implemented as ticket locks.
509// They could also be implemented as test and set lock, but cannot be
510// implemented with other lock kinds as they require gtids which are not
511// available at initialization time.
512
513typedef kmp_ticket_lock_t kmp_bootstrap_lock_t;
514
515#define KMP_BOOTSTRAP_LOCK_INITIALIZER(lock) KMP_TICKET_LOCK_INITIALIZER((lock))
516#define KMP_BOOTSTRAP_LOCK_INIT(lock) \
517 kmp_bootstrap_lock_t lock = KMP_TICKET_LOCK_INITIALIZER(lock)
518
519static inline int __kmp_acquire_bootstrap_lock(kmp_bootstrap_lock_t *lck) {
520 return __kmp_acquire_ticket_lock(lck, KMP_GTID_DNE);
521}
522
523static inline int __kmp_test_bootstrap_lock(kmp_bootstrap_lock_t *lck) {
524 return __kmp_test_ticket_lock(lck, KMP_GTID_DNE);
525}
526
527static inline void __kmp_release_bootstrap_lock(kmp_bootstrap_lock_t *lck) {
528 __kmp_release_ticket_lock(lck, KMP_GTID_DNE);
529}
530
531static inline void __kmp_init_bootstrap_lock(kmp_bootstrap_lock_t *lck) {
532 __kmp_init_ticket_lock(lck);
533}
534
535static inline void __kmp_destroy_bootstrap_lock(kmp_bootstrap_lock_t *lck) {
536 __kmp_destroy_ticket_lock(lck);
537}
538
539// Internal RTL locks.
540//
541// Internal RTL locks are also implemented as ticket locks, for now.
542//
543// FIXME - We should go through and figure out which lock kind works best for
544// each internal lock, and use the type declaration and function calls for
545// that explicit lock kind (and get rid of this section).
546
547typedef kmp_ticket_lock_t kmp_lock_t;
548
549#define KMP_LOCK_INIT(lock) kmp_lock_t lock = KMP_TICKET_LOCK_INITIALIZER(lock)
550
551static inline int __kmp_acquire_lock(kmp_lock_t *lck, kmp_int32 gtid) {
552 return __kmp_acquire_ticket_lock(lck, gtid);
553}
554
555static inline int __kmp_test_lock(kmp_lock_t *lck, kmp_int32 gtid) {
556 return __kmp_test_ticket_lock(lck, gtid);
557}
558
559static inline void __kmp_release_lock(kmp_lock_t *lck, kmp_int32 gtid) {
560 __kmp_release_ticket_lock(lck, gtid);
561}
562
563static inline void __kmp_init_lock(kmp_lock_t *lck) {
564 __kmp_init_ticket_lock(lck);
565}
566
567static inline void __kmp_destroy_lock(kmp_lock_t *lck) {
568 __kmp_destroy_ticket_lock(lck);
569}
570
571// User locks.
572//
573// Do not allocate objects of type union kmp_user_lock!!! This will waste space
574// unless __kmp_user_lock_kind == lk_drdpa. Instead, check the value of
575// __kmp_user_lock_kind and allocate objects of the type of the appropriate
576// union member, and cast their addresses to kmp_user_lock_p.
577
578enum kmp_lock_kind {
579 lk_default = 0,
580 lk_tas,
581#if KMP_USE_FUTEX
582 lk_futex,
583#endif
584#if KMP_USE_DYNAMIC_LOCK && KMP_USE_TSX
585 lk_hle,
586 lk_rtm_queuing,
587 lk_rtm_spin,
588#endif
589 lk_ticket,
590 lk_queuing,
591 lk_drdpa,
592#if KMP_USE_ADAPTIVE_LOCKS
593 lk_adaptive
594#endif // KMP_USE_ADAPTIVE_LOCKS
595};
596
597typedef enum kmp_lock_kind kmp_lock_kind_t;
598
599extern kmp_lock_kind_t __kmp_user_lock_kind;
600
601union kmp_user_lock {
602 kmp_tas_lock_t tas;
603#if KMP_USE_FUTEX
604 kmp_futex_lock_t futex;
605#endif
606 kmp_ticket_lock_t ticket;
607 kmp_queuing_lock_t queuing;
608 kmp_drdpa_lock_t drdpa;
609#if KMP_USE_ADAPTIVE_LOCKS
610 kmp_adaptive_lock_t adaptive;
611#endif // KMP_USE_ADAPTIVE_LOCKS
612 kmp_lock_pool_t pool;
613};
614
615typedef union kmp_user_lock *kmp_user_lock_p;
616
617#if !KMP_USE_DYNAMIC_LOCK
618
619extern size_t __kmp_base_user_lock_size;
620extern size_t __kmp_user_lock_size;
621
622extern kmp_int32 (*__kmp_get_user_lock_owner_)(kmp_user_lock_p lck);
623
624static inline kmp_int32 __kmp_get_user_lock_owner(kmp_user_lock_p lck) {
625 KMP_DEBUG_ASSERT(__kmp_get_user_lock_owner_ != NULL);
626 return (*__kmp_get_user_lock_owner_)(lck);
627}
628
629extern int (*__kmp_acquire_user_lock_with_checks_)(kmp_user_lock_p lck,
630 kmp_int32 gtid);
631
632#if KMP_OS_LINUX && \
633 (KMP_ARCH_X86 || KMP_ARCH_X86_64 || KMP_ARCH_ARM || KMP_ARCH_AARCH64)
634
635#define __kmp_acquire_user_lock_with_checks(lck, gtid) \
636 if (__kmp_user_lock_kind == lk_tas) { \
637 if (__kmp_env_consistency_check) { \
638 char const *const func = "omp_set_lock"; \
639 if ((sizeof(kmp_tas_lock_t) <= OMP_LOCK_T_SIZE) && \
640 lck->tas.lk.depth_locked != -1) { \
641 KMP_FATAL(LockNestableUsedAsSimple, func); \
642 } \
643 if ((gtid >= 0) && (lck->tas.lk.poll - 1 == gtid)) { \
644 KMP_FATAL(LockIsAlreadyOwned, func); \
645 } \
646 } \
647 if (lck->tas.lk.poll != 0 || \
648 !__kmp_atomic_compare_store_acq(&lck->tas.lk.poll, 0, gtid + 1)) { \
649 kmp_uint32 spins; \
650 kmp_uint64 time; \
651 KMP_FSYNC_PREPARE(lck); \
652 KMP_INIT_YIELD(spins); \
653 KMP_INIT_BACKOFF(time); \
654 do { \
655 KMP_YIELD_OVERSUB_ELSE_SPIN(spins, time); \
656 } while ( \
657 lck->tas.lk.poll != 0 || \
658 !__kmp_atomic_compare_store_acq(&lck->tas.lk.poll, 0, gtid + 1)); \
659 } \
660 KMP_FSYNC_ACQUIRED(lck); \
661 } else { \
662 KMP_DEBUG_ASSERT(__kmp_acquire_user_lock_with_checks_ != NULL); \
663 (*__kmp_acquire_user_lock_with_checks_)(lck, gtid); \
664 }
665
666#else
667static inline int __kmp_acquire_user_lock_with_checks(kmp_user_lock_p lck,
668 kmp_int32 gtid) {
669 KMP_DEBUG_ASSERT(__kmp_acquire_user_lock_with_checks_ != NULL);
670 return (*__kmp_acquire_user_lock_with_checks_)(lck, gtid);
671}
672#endif
673
674extern int (*__kmp_test_user_lock_with_checks_)(kmp_user_lock_p lck,
675 kmp_int32 gtid);
676
677#if KMP_OS_LINUX && \
678 (KMP_ARCH_X86 || KMP_ARCH_X86_64 || KMP_ARCH_ARM || KMP_ARCH_AARCH64)
679
680#include "kmp_i18n.h" /* AC: KMP_FATAL definition */
681extern int __kmp_env_consistency_check; /* AC: copy from kmp.h here */
682static inline int __kmp_test_user_lock_with_checks(kmp_user_lock_p lck,
683 kmp_int32 gtid) {
684 if (__kmp_user_lock_kind == lk_tas) {
685 if (__kmp_env_consistency_check) {
686 char const *const func = "omp_test_lock";
687 if ((sizeof(kmp_tas_lock_t) <= OMP_LOCK_T_SIZE) &&
688 lck->tas.lk.depth_locked != -1) {
689 KMP_FATAL(LockNestableUsedAsSimple, func);
690 }
691 }
692 return ((lck->tas.lk.poll == 0) &&
693 __kmp_atomic_compare_store_acq(&lck->tas.lk.poll, 0, gtid + 1));
694 } else {
695 KMP_DEBUG_ASSERT(__kmp_test_user_lock_with_checks_ != NULL);
696 return (*__kmp_test_user_lock_with_checks_)(lck, gtid);
697 }
698}
699#else
700static inline int __kmp_test_user_lock_with_checks(kmp_user_lock_p lck,
701 kmp_int32 gtid) {
702 KMP_DEBUG_ASSERT(__kmp_test_user_lock_with_checks_ != NULL);
703 return (*__kmp_test_user_lock_with_checks_)(lck, gtid);
704}
705#endif
706
707extern int (*__kmp_release_user_lock_with_checks_)(kmp_user_lock_p lck,
708 kmp_int32 gtid);
709
710static inline void __kmp_release_user_lock_with_checks(kmp_user_lock_p lck,
711 kmp_int32 gtid) {
712 KMP_DEBUG_ASSERT(__kmp_release_user_lock_with_checks_ != NULL);
713 (*__kmp_release_user_lock_with_checks_)(lck, gtid);
714}
715
716extern void (*__kmp_init_user_lock_with_checks_)(kmp_user_lock_p lck);
717
718static inline void __kmp_init_user_lock_with_checks(kmp_user_lock_p lck) {
719 KMP_DEBUG_ASSERT(__kmp_init_user_lock_with_checks_ != NULL);
720 (*__kmp_init_user_lock_with_checks_)(lck);
721}
722
723// We need a non-checking version of destroy lock for when the RTL is
724// doing the cleanup as it can't always tell if the lock is nested or not.
725extern void (*__kmp_destroy_user_lock_)(kmp_user_lock_p lck);
726
727static inline void __kmp_destroy_user_lock(kmp_user_lock_p lck) {
728 KMP_DEBUG_ASSERT(__kmp_destroy_user_lock_ != NULL);
729 (*__kmp_destroy_user_lock_)(lck);
730}
731
732extern void (*__kmp_destroy_user_lock_with_checks_)(kmp_user_lock_p lck);
733
734static inline void __kmp_destroy_user_lock_with_checks(kmp_user_lock_p lck) {
735 KMP_DEBUG_ASSERT(__kmp_destroy_user_lock_with_checks_ != NULL);
736 (*__kmp_destroy_user_lock_with_checks_)(lck);
737}
738
739extern int (*__kmp_acquire_nested_user_lock_with_checks_)(kmp_user_lock_p lck,
740 kmp_int32 gtid);
741
742#if KMP_OS_LINUX && (KMP_ARCH_X86 || KMP_ARCH_X86_64)
743
744#define __kmp_acquire_nested_user_lock_with_checks(lck, gtid, depth) \
745 if (__kmp_user_lock_kind == lk_tas) { \
746 if (__kmp_env_consistency_check) { \
747 char const *const func = "omp_set_nest_lock"; \
748 if ((sizeof(kmp_tas_lock_t) <= OMP_NEST_LOCK_T_SIZE) && \
749 lck->tas.lk.depth_locked == -1) { \
750 KMP_FATAL(LockSimpleUsedAsNestable, func); \
751 } \
752 } \
753 if (lck->tas.lk.poll - 1 == gtid) { \
754 lck->tas.lk.depth_locked += 1; \
755 *depth = KMP_LOCK_ACQUIRED_NEXT; \
756 } else { \
757 if ((lck->tas.lk.poll != 0) || \
758 !__kmp_atomic_compare_store_acq(&lck->tas.lk.poll, 0, gtid + 1)) { \
759 kmp_uint32 spins; \
760 kmp_uint64 time; \
761 KMP_FSYNC_PREPARE(lck); \
762 KMP_INIT_YIELD(spins); \
763 KMP_INIT_BACKOFF(time); \
764 do { \
765 KMP_YIELD_OVERSUB_ELSE_SPIN(spins, time); \
766 } while ( \
767 (lck->tas.lk.poll != 0) || \
768 !__kmp_atomic_compare_store_acq(&lck->tas.lk.poll, 0, gtid + 1)); \
769 } \
770 lck->tas.lk.depth_locked = 1; \
771 *depth = KMP_LOCK_ACQUIRED_FIRST; \
772 } \
773 KMP_FSYNC_ACQUIRED(lck); \
774 } else { \
775 KMP_DEBUG_ASSERT(__kmp_acquire_nested_user_lock_with_checks_ != NULL); \
776 *depth = (*__kmp_acquire_nested_user_lock_with_checks_)(lck, gtid); \
777 }
778
779#else
780static inline void
781__kmp_acquire_nested_user_lock_with_checks(kmp_user_lock_p lck, kmp_int32 gtid,
782 int *depth) {
783 KMP_DEBUG_ASSERT(__kmp_acquire_nested_user_lock_with_checks_ != NULL);
784 *depth = (*__kmp_acquire_nested_user_lock_with_checks_)(lck, gtid);
785}
786#endif
787
788extern int (*__kmp_test_nested_user_lock_with_checks_)(kmp_user_lock_p lck,
789 kmp_int32 gtid);
790
791#if KMP_OS_LINUX && (KMP_ARCH_X86 || KMP_ARCH_X86_64)
792static inline int __kmp_test_nested_user_lock_with_checks(kmp_user_lock_p lck,
793 kmp_int32 gtid) {
794 if (__kmp_user_lock_kind == lk_tas) {
795 int retval;
796 if (__kmp_env_consistency_check) {
797 char const *const func = "omp_test_nest_lock";
798 if ((sizeof(kmp_tas_lock_t) <= OMP_NEST_LOCK_T_SIZE) &&
799 lck->tas.lk.depth_locked == -1) {
800 KMP_FATAL(LockSimpleUsedAsNestable, func);
801 }
802 }
803 KMP_DEBUG_ASSERT(gtid >= 0);
804 if (lck->tas.lk.poll - 1 ==
805 gtid) { /* __kmp_get_tas_lock_owner( lck ) == gtid */
806 return ++lck->tas.lk.depth_locked; /* same owner, depth increased */
807 }
808 retval = ((lck->tas.lk.poll == 0) &&
809 __kmp_atomic_compare_store_acq(&lck->tas.lk.poll, 0, gtid + 1));
810 if (retval) {
811 KMP_MB();
812 lck->tas.lk.depth_locked = 1;
813 }
814 return retval;
815 } else {
816 KMP_DEBUG_ASSERT(__kmp_test_nested_user_lock_with_checks_ != NULL);
817 return (*__kmp_test_nested_user_lock_with_checks_)(lck, gtid);
818 }
819}
820#else
821static inline int __kmp_test_nested_user_lock_with_checks(kmp_user_lock_p lck,
822 kmp_int32 gtid) {
823 KMP_DEBUG_ASSERT(__kmp_test_nested_user_lock_with_checks_ != NULL);
824 return (*__kmp_test_nested_user_lock_with_checks_)(lck, gtid);
825}
826#endif
827
828extern int (*__kmp_release_nested_user_lock_with_checks_)(kmp_user_lock_p lck,
829 kmp_int32 gtid);
830
831static inline int
832__kmp_release_nested_user_lock_with_checks(kmp_user_lock_p lck,
833 kmp_int32 gtid) {
834 KMP_DEBUG_ASSERT(__kmp_release_nested_user_lock_with_checks_ != NULL);
835 return (*__kmp_release_nested_user_lock_with_checks_)(lck, gtid);
836}
837
838extern void (*__kmp_init_nested_user_lock_with_checks_)(kmp_user_lock_p lck);
839
840static inline void
841__kmp_init_nested_user_lock_with_checks(kmp_user_lock_p lck) {
842 KMP_DEBUG_ASSERT(__kmp_init_nested_user_lock_with_checks_ != NULL);
843 (*__kmp_init_nested_user_lock_with_checks_)(lck);
844}
845
846extern void (*__kmp_destroy_nested_user_lock_with_checks_)(kmp_user_lock_p lck);
847
848static inline void
849__kmp_destroy_nested_user_lock_with_checks(kmp_user_lock_p lck) {
850 KMP_DEBUG_ASSERT(__kmp_destroy_nested_user_lock_with_checks_ != NULL);
851 (*__kmp_destroy_nested_user_lock_with_checks_)(lck);
852}
853
854// user lock functions which do not necessarily exist for all lock kinds.
855//
856// The "set" functions usually have wrapper routines that check for a NULL set
857// function pointer and call it if non-NULL.
858//
859// In some cases, it makes sense to have a "get" wrapper function check for a
860// NULL get function pointer and return NULL / invalid value / error code if
861// the function pointer is NULL.
862//
863// In other cases, the calling code really should differentiate between an
864// unimplemented function and one that is implemented but returning NULL /
865// invalid value. If this is the case, no get function wrapper exists.
866
867extern int (*__kmp_is_user_lock_initialized_)(kmp_user_lock_p lck);
868
869// no set function; fields set during local allocation
870
871extern const ident_t *(*__kmp_get_user_lock_location_)(kmp_user_lock_p lck);
872
873static inline const ident_t *__kmp_get_user_lock_location(kmp_user_lock_p lck) {
874 if (__kmp_get_user_lock_location_ != NULL) {
875 return (*__kmp_get_user_lock_location_)(lck);
876 } else {
877 return NULL;
878 }
879}
880
881extern void (*__kmp_set_user_lock_location_)(kmp_user_lock_p lck,
882 const ident_t *loc);
883
884static inline void __kmp_set_user_lock_location(kmp_user_lock_p lck,
885 const ident_t *loc) {
886 if (__kmp_set_user_lock_location_ != NULL) {
887 (*__kmp_set_user_lock_location_)(lck, loc);
888 }
889}
890
891extern kmp_lock_flags_t (*__kmp_get_user_lock_flags_)(kmp_user_lock_p lck);
892
893extern void (*__kmp_set_user_lock_flags_)(kmp_user_lock_p lck,
894 kmp_lock_flags_t flags);
895
896static inline void __kmp_set_user_lock_flags(kmp_user_lock_p lck,
897 kmp_lock_flags_t flags) {
898 if (__kmp_set_user_lock_flags_ != NULL) {
899 (*__kmp_set_user_lock_flags_)(lck, flags);
900 }
901}
902
903// The function which sets up all of the vtbl pointers for kmp_user_lock_t.
904extern void __kmp_set_user_lock_vptrs(kmp_lock_kind_t user_lock_kind);
905
906// Macros for binding user lock functions.
907#define KMP_BIND_USER_LOCK_TEMPLATE(nest, kind, suffix) \
908 { \
909 __kmp_acquire##nest##user_lock_with_checks_ = (int (*)( \
910 kmp_user_lock_p, kmp_int32))__kmp_acquire##nest##kind##_##suffix; \
911 __kmp_release##nest##user_lock_with_checks_ = (int (*)( \
912 kmp_user_lock_p, kmp_int32))__kmp_release##nest##kind##_##suffix; \
913 __kmp_test##nest##user_lock_with_checks_ = (int (*)( \
914 kmp_user_lock_p, kmp_int32))__kmp_test##nest##kind##_##suffix; \
915 __kmp_init##nest##user_lock_with_checks_ = \
916 (void (*)(kmp_user_lock_p))__kmp_init##nest##kind##_##suffix; \
917 __kmp_destroy##nest##user_lock_with_checks_ = \
918 (void (*)(kmp_user_lock_p))__kmp_destroy##nest##kind##_##suffix; \
919 }
920
921#define KMP_BIND_USER_LOCK(kind) KMP_BIND_USER_LOCK_TEMPLATE(_, kind, lock)
922#define KMP_BIND_USER_LOCK_WITH_CHECKS(kind) \
923 KMP_BIND_USER_LOCK_TEMPLATE(_, kind, lock_with_checks)
924#define KMP_BIND_NESTED_USER_LOCK(kind) \
925 KMP_BIND_USER_LOCK_TEMPLATE(_nested_, kind, lock)
926#define KMP_BIND_NESTED_USER_LOCK_WITH_CHECKS(kind) \
927 KMP_BIND_USER_LOCK_TEMPLATE(_nested_, kind, lock_with_checks)
928
929// User lock table & lock allocation
930/* On 64-bit Linux* OS (and OS X*) GNU compiler allocates only 4 bytems memory
931 for lock variable, which is not enough to store a pointer, so we have to use
932 lock indexes instead of pointers and maintain lock table to map indexes to
933 pointers.
934
935
936 Note: The first element of the table is not a pointer to lock! It is a
937 pointer to previously allocated table (or NULL if it is the first table).
938
939 Usage:
940
941 if ( OMP_LOCK_T_SIZE < sizeof( <lock> ) ) { // or OMP_NEST_LOCK_T_SIZE
942 Lock table is fully utilized. User locks are indexes, so table is used on
943 user lock operation.
944 Note: it may be the case (lin_32) that we don't need to use a lock
945 table for regular locks, but do need the table for nested locks.
946 }
947 else {
948 Lock table initialized but not actually used.
949 }
950*/
951
952struct kmp_lock_table {
953 kmp_lock_index_t used; // Number of used elements
954 kmp_lock_index_t allocated; // Number of allocated elements
955 kmp_user_lock_p *table; // Lock table.
956};
957
958typedef struct kmp_lock_table kmp_lock_table_t;
959
960extern kmp_lock_table_t __kmp_user_lock_table;
961extern kmp_user_lock_p __kmp_lock_pool;
962
963struct kmp_block_of_locks {
964 struct kmp_block_of_locks *next_block;
965 void *locks;
966};
967
968typedef struct kmp_block_of_locks kmp_block_of_locks_t;
969
970extern kmp_block_of_locks_t *__kmp_lock_blocks;
971extern int __kmp_num_locks_in_block;
972
973extern kmp_user_lock_p __kmp_user_lock_allocate(void **user_lock,
974 kmp_int32 gtid,
975 kmp_lock_flags_t flags);
976extern void __kmp_user_lock_free(void **user_lock, kmp_int32 gtid,
977 kmp_user_lock_p lck);
978extern kmp_user_lock_p __kmp_lookup_user_lock(void **user_lock,
979 char const *func);
980extern void __kmp_cleanup_user_locks();
981
982#define KMP_CHECK_USER_LOCK_INIT() \
983 { \
984 if (!TCR_4(__kmp_init_user_locks)) { \
985 __kmp_acquire_bootstrap_lock(&__kmp_initz_lock); \
986 if (!TCR_4(__kmp_init_user_locks)) { \
987 TCW_4(__kmp_init_user_locks, TRUE); \
988 } \
989 __kmp_release_bootstrap_lock(&__kmp_initz_lock); \
990 } \
991 }
992
993#endif // KMP_USE_DYNAMIC_LOCK
994
995#undef KMP_PAD
996#undef KMP_GTID_DNE
997
998#if KMP_USE_DYNAMIC_LOCK
999// KMP_USE_DYNAMIC_LOCK enables dynamic dispatch of lock functions without
1000// breaking the current compatibility. Essential functionality of this new code
1001// is dynamic dispatch, but it also implements (or enables implementation of)
1002// hinted user lock and critical section which will be part of OMP 4.5 soon.
1003//
1004// Lock type can be decided at creation time (i.e., lock initialization), and
1005// subsequent lock function call on the created lock object requires type
1006// extraction and call through jump table using the extracted type. This type
1007// information is stored in two different ways depending on the size of the lock
1008// object, and we differentiate lock types by this size requirement - direct and
1009// indirect locks.
1010//
1011// Direct locks:
1012// A direct lock object fits into the space created by the compiler for an
1013// omp_lock_t object, and TAS/Futex lock falls into this category. We use low
1014// one byte of the lock object as the storage for the lock type, and appropriate
1015// bit operation is required to access the data meaningful to the lock
1016// algorithms. Also, to differentiate direct lock from indirect lock, 1 is
1017// written to LSB of the lock object. The newly introduced "hle" lock is also a
1018// direct lock.
1019//
1020// Indirect locks:
1021// An indirect lock object requires more space than the compiler-generated
1022// space, and it should be allocated from heap. Depending on the size of the
1023// compiler-generated space for the lock (i.e., size of omp_lock_t), this
1024// omp_lock_t object stores either the address of the heap-allocated indirect
1025// lock (void * fits in the object) or an index to the indirect lock table entry
1026// that holds the address. Ticket/Queuing/DRDPA/Adaptive lock falls into this
1027// category, and the newly introduced "rtm" lock is also an indirect lock which
1028// was implemented on top of the Queuing lock. When the omp_lock_t object holds
1029// an index (not lock address), 0 is written to LSB to differentiate the lock
1030// from a direct lock, and the remaining part is the actual index to the
1031// indirect lock table.
1032
1033#include <stdint.h> // for uintptr_t
1034
1035// Shortcuts
1036#define KMP_USE_INLINED_TAS \
1037 (KMP_OS_LINUX && (KMP_ARCH_X86 || KMP_ARCH_X86_64 || KMP_ARCH_ARM)) && 1
1038#define KMP_USE_INLINED_FUTEX KMP_USE_FUTEX && 0
1039
1040// List of lock definitions; all nested locks are indirect locks.
1041// hle lock is xchg lock prefixed with XACQUIRE/XRELEASE.
1042// All nested locks are indirect lock types.
1043#if KMP_USE_TSX
1044#if KMP_USE_FUTEX
1045#define KMP_FOREACH_D_LOCK(m, a) m(tas, a) m(futex, a) m(hle, a) m(rtm_spin, a)
1046#define KMP_FOREACH_I_LOCK(m, a) \
1047 m(ticket, a) m(queuing, a) m(adaptive, a) m(drdpa, a) m(rtm_queuing, a) \
1048 m(nested_tas, a) m(nested_futex, a) m(nested_ticket, a) \
1049 m(nested_queuing, a) m(nested_drdpa, a)
1050#else
1051#define KMP_FOREACH_D_LOCK(m, a) m(tas, a) m(hle, a) m(rtm_spin, a)
1052#define KMP_FOREACH_I_LOCK(m, a) \
1053 m(ticket, a) m(queuing, a) m(adaptive, a) m(drdpa, a) m(rtm_queuing, a) \
1054 m(nested_tas, a) m(nested_ticket, a) m(nested_queuing, a) \
1055 m(nested_drdpa, a)
1056#endif // KMP_USE_FUTEX
1057#define KMP_LAST_D_LOCK lockseq_rtm_spin
1058#else
1059#if KMP_USE_FUTEX
1060#define KMP_FOREACH_D_LOCK(m, a) m(tas, a) m(futex, a)
1061#define KMP_FOREACH_I_LOCK(m, a) \
1062 m(ticket, a) m(queuing, a) m(drdpa, a) m(nested_tas, a) m(nested_futex, a) \
1063 m(nested_ticket, a) m(nested_queuing, a) m(nested_drdpa, a)
1064#define KMP_LAST_D_LOCK lockseq_futex
1065#else
1066#define KMP_FOREACH_D_LOCK(m, a) m(tas, a)
1067#define KMP_FOREACH_I_LOCK(m, a) \
1068 m(ticket, a) m(queuing, a) m(drdpa, a) m(nested_tas, a) m(nested_ticket, a) \
1069 m(nested_queuing, a) m(nested_drdpa, a)
1070#define KMP_LAST_D_LOCK lockseq_tas
1071#endif // KMP_USE_FUTEX
1072#endif // KMP_USE_TSX
1073
1074// Information used in dynamic dispatch
1075#define KMP_LOCK_SHIFT \
1076 8 // number of low bits to be used as tag for direct locks
1077#define KMP_FIRST_D_LOCK lockseq_tas
1078#define KMP_FIRST_I_LOCK lockseq_ticket
1079#define KMP_LAST_I_LOCK lockseq_nested_drdpa
1080#define KMP_NUM_I_LOCKS \
1081 (locktag_nested_drdpa + 1) // number of indirect lock types
1082
1083// Base type for dynamic locks.
1084typedef kmp_uint32 kmp_dyna_lock_t;
1085
1086// Lock sequence that enumerates all lock kinds. Always make this enumeration
1087// consistent with kmp_lockseq_t in the include directory.
1088typedef enum {
1089 lockseq_indirect = 0,
1090#define expand_seq(l, a) lockseq_##l,
1091 KMP_FOREACH_D_LOCK(expand_seq, 0) KMP_FOREACH_I_LOCK(expand_seq, 0)
1092#undef expand_seq
1093} kmp_dyna_lockseq_t;
1094
1095// Enumerates indirect lock tags.
1096typedef enum {
1097#define expand_tag(l, a) locktag_##l,
1098 KMP_FOREACH_I_LOCK(expand_tag, 0)
1099#undef expand_tag
1100} kmp_indirect_locktag_t;
1101
1102// Utility macros that extract information from lock sequences.
1103#define KMP_IS_D_LOCK(seq) \
1104 ((seq) >= KMP_FIRST_D_LOCK && (seq) <= KMP_LAST_D_LOCK)
1105#define KMP_IS_I_LOCK(seq) \
1106 ((seq) >= KMP_FIRST_I_LOCK && (seq) <= KMP_LAST_I_LOCK)
1107#define KMP_GET_I_TAG(seq) (kmp_indirect_locktag_t)((seq)-KMP_FIRST_I_LOCK)
1108#define KMP_GET_D_TAG(seq) ((seq) << 1 | 1)
1109
1110// Enumerates direct lock tags starting from indirect tag.
1111typedef enum {
1112#define expand_tag(l, a) locktag_##l = KMP_GET_D_TAG(lockseq_##l),
1113 KMP_FOREACH_D_LOCK(expand_tag, 0)
1114#undef expand_tag
1115} kmp_direct_locktag_t;
1116
1117// Indirect lock type
1118typedef struct {
1119 kmp_user_lock_p lock;
1120 kmp_indirect_locktag_t type;
1121} kmp_indirect_lock_t;
1122
1123// Function tables for direct locks. Set/unset/test differentiate functions
1124// with/without consistency checking.
1125extern void (*__kmp_direct_init[])(kmp_dyna_lock_t *, kmp_dyna_lockseq_t);
1126extern void (**__kmp_direct_destroy)(kmp_dyna_lock_t *);
1127extern int (**__kmp_direct_set)(kmp_dyna_lock_t *, kmp_int32);
1128extern int (**__kmp_direct_unset)(kmp_dyna_lock_t *, kmp_int32);
1129extern int (**__kmp_direct_test)(kmp_dyna_lock_t *, kmp_int32);
1130
1131// Function tables for indirect locks. Set/unset/test differentiate functions
1132// with/without consistency checking.
1133extern void (*__kmp_indirect_init[])(kmp_user_lock_p);
1134extern void (**__kmp_indirect_destroy)(kmp_user_lock_p);
1135extern int (**__kmp_indirect_set)(kmp_user_lock_p, kmp_int32);
1136extern int (**__kmp_indirect_unset)(kmp_user_lock_p, kmp_int32);
1137extern int (**__kmp_indirect_test)(kmp_user_lock_p, kmp_int32);
1138
1139// Extracts direct lock tag from a user lock pointer
1140#define KMP_EXTRACT_D_TAG(l) \
1141 (*((kmp_dyna_lock_t *)(l)) & ((1 << KMP_LOCK_SHIFT) - 1) & \
1142 -(*((kmp_dyna_lock_t *)(l)) & 1))
1143
1144// Extracts indirect lock index from a user lock pointer
1145#define KMP_EXTRACT_I_INDEX(l) (*(kmp_lock_index_t *)(l) >> 1)
1146
1147// Returns function pointer to the direct lock function with l (kmp_dyna_lock_t
1148// *) and op (operation type).
1149#define KMP_D_LOCK_FUNC(l, op) __kmp_direct_##op[KMP_EXTRACT_D_TAG(l)]
1150
1151// Returns function pointer to the indirect lock function with l
1152// (kmp_indirect_lock_t *) and op (operation type).
1153#define KMP_I_LOCK_FUNC(l, op) \
1154 __kmp_indirect_##op[((kmp_indirect_lock_t *)(l))->type]
1155
1156// Initializes a direct lock with the given lock pointer and lock sequence.
1157#define KMP_INIT_D_LOCK(l, seq) \
1158 __kmp_direct_init[KMP_GET_D_TAG(seq)]((kmp_dyna_lock_t *)l, seq)
1159
1160// Initializes an indirect lock with the given lock pointer and lock sequence.
1161#define KMP_INIT_I_LOCK(l, seq) \
1162 __kmp_direct_init[0]((kmp_dyna_lock_t *)(l), seq)
1163
1164// Returns "free" lock value for the given lock type.
1165#define KMP_LOCK_FREE(type) (locktag_##type)
1166
1167// Returns "busy" lock value for the given lock teyp.
1168#define KMP_LOCK_BUSY(v, type) ((v) << KMP_LOCK_SHIFT | locktag_##type)
1169
1170// Returns lock value after removing (shifting) lock tag.
1171#define KMP_LOCK_STRIP(v) ((v) >> KMP_LOCK_SHIFT)
1172
1173// Initializes global states and data structures for managing dynamic user
1174// locks.
1175extern void __kmp_init_dynamic_user_locks();
1176
1177// Allocates and returns an indirect lock with the given indirect lock tag.
1178extern kmp_indirect_lock_t *
1179__kmp_allocate_indirect_lock(void **, kmp_int32, kmp_indirect_locktag_t);
1180
1181// Cleans up global states and data structures for managing dynamic user locks.
1182extern void __kmp_cleanup_indirect_user_locks();
1183
1184// Default user lock sequence when not using hinted locks.
1185extern kmp_dyna_lockseq_t __kmp_user_lock_seq;
1186
1187// Jump table for "set lock location", available only for indirect locks.
1188extern void (*__kmp_indirect_set_location[KMP_NUM_I_LOCKS])(kmp_user_lock_p,
1189 const ident_t *);
1190#define KMP_SET_I_LOCK_LOCATION(lck, loc) \
1191 { \
1192 if (__kmp_indirect_set_location[(lck)->type] != NULL) \
1193 __kmp_indirect_set_location[(lck)->type]((lck)->lock, loc); \
1194 }
1195
1196// Jump table for "set lock flags", available only for indirect locks.
1197extern void (*__kmp_indirect_set_flags[KMP_NUM_I_LOCKS])(kmp_user_lock_p,
1198 kmp_lock_flags_t);
1199#define KMP_SET_I_LOCK_FLAGS(lck, flag) \
1200 { \
1201 if (__kmp_indirect_set_flags[(lck)->type] != NULL) \
1202 __kmp_indirect_set_flags[(lck)->type]((lck)->lock, flag); \
1203 }
1204
1205// Jump table for "get lock location", available only for indirect locks.
1206extern const ident_t *(*__kmp_indirect_get_location[KMP_NUM_I_LOCKS])(
1207 kmp_user_lock_p);
1208#define KMP_GET_I_LOCK_LOCATION(lck) \
1209 (__kmp_indirect_get_location[(lck)->type] != NULL \
1210 ? __kmp_indirect_get_location[(lck)->type]((lck)->lock) \
1211 : NULL)
1212
1213// Jump table for "get lock flags", available only for indirect locks.
1214extern kmp_lock_flags_t (*__kmp_indirect_get_flags[KMP_NUM_I_LOCKS])(
1215 kmp_user_lock_p);
1216#define KMP_GET_I_LOCK_FLAGS(lck) \
1217 (__kmp_indirect_get_flags[(lck)->type] != NULL \
1218 ? __kmp_indirect_get_flags[(lck)->type]((lck)->lock) \
1219 : NULL)
1220
1221// number of kmp_indirect_lock_t objects to be allocated together
1222#define KMP_I_LOCK_CHUNK 1024
1223// Keep at a power of 2 since it is used in multiplication & division
1224KMP_BUILD_ASSERT(KMP_I_LOCK_CHUNK % 2 == 0);
1225// number of row entries in the initial lock table
1226#define KMP_I_LOCK_TABLE_INIT_NROW_PTRS 8
1227
1228// Lock table for indirect locks.
1229typedef struct kmp_indirect_lock_table {
1230 kmp_indirect_lock_t **table; // blocks of indirect locks allocated
1231 kmp_uint32 nrow_ptrs; // number *table pointer entries in table
1232 kmp_lock_index_t next; // index to the next lock to be allocated
1233 struct kmp_indirect_lock_table *next_table;
1234} kmp_indirect_lock_table_t;
1235
1236extern kmp_indirect_lock_table_t __kmp_i_lock_table;
1237
1238// Returns the indirect lock associated with the given index.
1239// Returns nullptr if no lock at given index
1240static inline kmp_indirect_lock_t *__kmp_get_i_lock(kmp_lock_index_t idx) {
1241 kmp_indirect_lock_table_t *lock_table = &__kmp_i_lock_table;
1242 while (lock_table) {
1243 kmp_lock_index_t max_locks = lock_table->nrow_ptrs * KMP_I_LOCK_CHUNK;
1244 if (idx < max_locks) {
1245 kmp_lock_index_t row = idx / KMP_I_LOCK_CHUNK;
1246 kmp_lock_index_t col = idx % KMP_I_LOCK_CHUNK;
1247 if (!lock_table->table[row] || idx >= lock_table->next)
1248 break;
1249 return &lock_table->table[row][col];
1250 }
1251 idx -= max_locks;
1252 lock_table = lock_table->next_table;
1253 }
1254 return nullptr;
1255}
1256
1257// Number of locks in a lock block, which is fixed to "1" now.
1258// TODO: No lock block implementation now. If we do support, we need to manage
1259// lock block data structure for each indirect lock type.
1260extern int __kmp_num_locks_in_block;
1261
1262// Fast lock table lookup without consistency checking
1263#define KMP_LOOKUP_I_LOCK(l) \
1264 ((OMP_LOCK_T_SIZE < sizeof(void *)) \
1265 ? __kmp_get_i_lock(KMP_EXTRACT_I_INDEX(l)) \
1266 : *((kmp_indirect_lock_t **)(l)))
1267
1268// Used once in kmp_error.cpp
1269extern kmp_int32 __kmp_get_user_lock_owner(kmp_user_lock_p, kmp_uint32);
1270
1271#else // KMP_USE_DYNAMIC_LOCK
1272
1273#define KMP_LOCK_BUSY(v, type) (v)
1274#define KMP_LOCK_FREE(type) 0
1275#define KMP_LOCK_STRIP(v) (v)
1276
1277#endif // KMP_USE_DYNAMIC_LOCK
1278
1279// data structure for using backoff within spin locks.
1280typedef struct {
1281 kmp_uint32 step; // current step
1282 kmp_uint32 max_backoff; // upper bound of outer delay loop
1283 kmp_uint32 min_tick; // size of inner delay loop in ticks (machine-dependent)
1284} kmp_backoff_t;
1285
1286// Runtime's default backoff parameters
1287extern kmp_backoff_t __kmp_spin_backoff_params;
1288
1289// Backoff function
1290extern void __kmp_spin_backoff(kmp_backoff_t *);
1291
1292#ifdef __cplusplus
1293} // extern "C"
1294#endif // __cplusplus
1295
1296#endif /* KMP_LOCK_H */
Definition: kmp.h:234