1 /*
2  * kmp_global.cpp -- KPTS global variables for runtime support library
3  */
4 
5 
6 //===----------------------------------------------------------------------===//
7 //
8 //                     The LLVM Compiler Infrastructure
9 //
10 // This file is dual licensed under the MIT and the University of Illinois Open
11 // Source Licenses. See LICENSE.txt for details.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 
16 #include "kmp.h"
17 #include "kmp_affinity.h"
18 
19 kmp_key_t __kmp_gtid_threadprivate_key;
20 
21 #if KMP_ARCH_X86 || KMP_ARCH_X86_64
22 kmp_cpuinfo_t __kmp_cpuinfo = {0}; // Not initialized
23 #endif
24 
25 #if KMP_STATS_ENABLED
26 #include "kmp_stats.h"
27 // lock for modifying the global __kmp_stats_list
28 kmp_tas_lock_t __kmp_stats_lock;
29 
30 // global list of per thread stats, the head is a sentinel node which
31 // accumulates all stats produced before __kmp_create_worker is called.
32 kmp_stats_list *__kmp_stats_list;
33 
34 // thread local pointer to stats node within list
35 __thread kmp_stats_list *__kmp_stats_thread_ptr = NULL;
36 
37 // gives reference tick for all events (considered the 0 tick)
38 tsc_tick_count __kmp_stats_start_time;
39 #endif
40 
41 /* ----------------------------------------------------- */
42 /* INITIALIZATION VARIABLES */
43 /* they are syncronized to write during init, but read anytime */
44 volatile int __kmp_init_serial = FALSE;
45 volatile int __kmp_init_gtid = FALSE;
46 volatile int __kmp_init_common = FALSE;
47 volatile int __kmp_init_middle = FALSE;
48 volatile int __kmp_init_parallel = FALSE;
49 #if KMP_USE_MONITOR
50 volatile int __kmp_init_monitor =
51     0; /* 1 - launched, 2 - actually started (Windows* OS only) */
52 #endif
53 volatile int __kmp_init_user_locks = FALSE;
54 
55 /* list of address of allocated caches for commons */
56 kmp_cached_addr_t *__kmp_threadpriv_cache_list = NULL;
57 
58 int __kmp_init_counter = 0;
59 int __kmp_root_counter = 0;
60 int __kmp_version = 0;
61 
62 volatile kmp_uint32 __kmp_team_counter = 0;
63 volatile kmp_uint32 __kmp_task_counter = 0;
64 
65 unsigned int __kmp_init_wait =
66     KMP_DEFAULT_INIT_WAIT; /* initial number of spin-tests   */
67 unsigned int __kmp_next_wait =
68     KMP_DEFAULT_NEXT_WAIT; /* susequent number of spin-tests */
69 
70 size_t __kmp_stksize = KMP_DEFAULT_STKSIZE;
71 #if KMP_USE_MONITOR
72 size_t __kmp_monitor_stksize = 0; // auto adjust
73 #endif
74 size_t __kmp_stkoffset = KMP_DEFAULT_STKOFFSET;
75 int __kmp_stkpadding = KMP_MIN_STKPADDING;
76 
77 size_t __kmp_malloc_pool_incr = KMP_DEFAULT_MALLOC_POOL_INCR;
78 
79 // Barrier method defaults, settings, and strings.
80 // branch factor = 2^branch_bits (only relevant for tree & hyper barrier types)
81 #if KMP_ARCH_X86_64
82 kmp_uint32 __kmp_barrier_gather_bb_dflt = 2;
83 /* branch_factor = 4 */ /* hyper2: C78980 */
84 kmp_uint32 __kmp_barrier_release_bb_dflt = 2;
85 /* branch_factor = 4 */ /* hyper2: C78980 */
86 #else
87 kmp_uint32 __kmp_barrier_gather_bb_dflt = 2;
88 /* branch_factor = 4 */ /* communication in core for MIC */
89 kmp_uint32 __kmp_barrier_release_bb_dflt = 2;
90 /* branch_factor = 4 */ /* communication in core for MIC */
91 #endif // KMP_ARCH_X86_64
92 #if KMP_ARCH_X86_64
93 kmp_bar_pat_e __kmp_barrier_gather_pat_dflt = bp_hyper_bar; /* hyper2: C78980 */
94 kmp_bar_pat_e __kmp_barrier_release_pat_dflt =
95     bp_hyper_bar; /* hyper2: C78980 */
96 #else
97 kmp_bar_pat_e __kmp_barrier_gather_pat_dflt = bp_linear_bar;
98 kmp_bar_pat_e __kmp_barrier_release_pat_dflt = bp_linear_bar;
99 #endif
100 kmp_uint32 __kmp_barrier_gather_branch_bits[bs_last_barrier] = {0};
101 kmp_uint32 __kmp_barrier_release_branch_bits[bs_last_barrier] = {0};
102 kmp_bar_pat_e __kmp_barrier_gather_pattern[bs_last_barrier] = {bp_linear_bar};
103 kmp_bar_pat_e __kmp_barrier_release_pattern[bs_last_barrier] = {bp_linear_bar};
104 char const *__kmp_barrier_branch_bit_env_name[bs_last_barrier] = {
105     "KMP_PLAIN_BARRIER", "KMP_FORKJOIN_BARRIER"
106 #if KMP_FAST_REDUCTION_BARRIER
107     ,
108     "KMP_REDUCTION_BARRIER"
109 #endif // KMP_FAST_REDUCTION_BARRIER
110 };
111 char const *__kmp_barrier_pattern_env_name[bs_last_barrier] = {
112     "KMP_PLAIN_BARRIER_PATTERN", "KMP_FORKJOIN_BARRIER_PATTERN"
113 #if KMP_FAST_REDUCTION_BARRIER
114     ,
115     "KMP_REDUCTION_BARRIER_PATTERN"
116 #endif // KMP_FAST_REDUCTION_BARRIER
117 };
118 char const *__kmp_barrier_type_name[bs_last_barrier] = {"plain", "forkjoin"
119 #if KMP_FAST_REDUCTION_BARRIER
120                                                         ,
121                                                         "reduction"
122 #endif // KMP_FAST_REDUCTION_BARRIER
123 };
124 char const *__kmp_barrier_pattern_name[bp_last_bar] = {"linear", "tree",
125                                                        "hyper", "hierarchical"};
126 
127 int __kmp_allThreadsSpecified = 0;
128 size_t __kmp_align_alloc = CACHE_LINE;
129 
130 
131 int __kmp_generate_warnings = kmp_warnings_low;
132 int __kmp_reserve_warn = 0;
133 int __kmp_xproc = 0;
134 int __kmp_avail_proc = 0;
135 size_t __kmp_sys_min_stksize = KMP_MIN_STKSIZE;
136 int __kmp_sys_max_nth = KMP_MAX_NTH;
137 int __kmp_max_nth = 0;
138 int __kmp_threads_capacity = 0;
139 int __kmp_dflt_team_nth = 0;
140 int __kmp_dflt_team_nth_ub = 0;
141 int __kmp_tp_capacity = 0;
142 int __kmp_tp_cached = 0;
143 int __kmp_dflt_nested = FALSE;
144 int __kmp_dispatch_num_buffers = KMP_DFLT_DISP_NUM_BUFF;
145 int __kmp_dflt_max_active_levels =
146     KMP_MAX_ACTIVE_LEVELS_LIMIT; /* max_active_levels limit */
147 #if KMP_NESTED_HOT_TEAMS
148 int __kmp_hot_teams_mode = 0; /* 0 - free extra threads when reduced */
149 /* 1 - keep extra threads when reduced */
150 int __kmp_hot_teams_max_level = 1; /* nesting level of hot teams */
151 #endif
152 enum library_type __kmp_library = library_none;
153 enum sched_type __kmp_sched =
154     kmp_sch_default; /* scheduling method for runtime scheduling */
155 enum sched_type __kmp_static =
156     kmp_sch_static_greedy; /* default static scheduling method */
157 enum sched_type __kmp_guided =
158     kmp_sch_guided_iterative_chunked; /* default guided scheduling method */
159 enum sched_type __kmp_auto =
160     kmp_sch_guided_analytical_chunked; /* default auto scheduling method */
161 int __kmp_dflt_blocktime = KMP_DEFAULT_BLOCKTIME;
162 #if KMP_USE_MONITOR
163 int __kmp_monitor_wakeups = KMP_MIN_MONITOR_WAKEUPS;
164 int __kmp_bt_intervals = KMP_INTERVALS_FROM_BLOCKTIME(KMP_DEFAULT_BLOCKTIME,
165                                                       KMP_MIN_MONITOR_WAKEUPS);
166 #endif
167 #ifdef KMP_ADJUST_BLOCKTIME
168 int __kmp_zero_bt = FALSE;
169 #endif /* KMP_ADJUST_BLOCKTIME */
170 #ifdef KMP_DFLT_NTH_CORES
171 int __kmp_ncores = 0;
172 #endif
173 int __kmp_chunk = 0;
174 int __kmp_abort_delay = 0;
175 #if KMP_OS_LINUX && defined(KMP_TDATA_GTID)
176 int __kmp_gtid_mode = 3; /* use __declspec(thread) TLS to store gtid */
177 int __kmp_adjust_gtid_mode = FALSE;
178 #elif KMP_OS_WINDOWS
179 int __kmp_gtid_mode = 2; /* use TLS functions to store gtid */
180 int __kmp_adjust_gtid_mode = FALSE;
181 #else
182 int __kmp_gtid_mode = 0; /* select method to get gtid based on #threads */
183 int __kmp_adjust_gtid_mode = TRUE;
184 #endif /* KMP_OS_LINUX && defined(KMP_TDATA_GTID) */
185 #ifdef KMP_TDATA_GTID
186 #if KMP_OS_WINDOWS
187 __declspec(thread) int __kmp_gtid = KMP_GTID_DNE;
188 #else
189 __thread int __kmp_gtid = KMP_GTID_DNE;
190 #endif /* KMP_OS_WINDOWS - workaround because Intel(R) Many Integrated Core    \
191           compiler 20110316 doesn't accept __declspec */
192 #endif /* KMP_TDATA_GTID */
193 int __kmp_tls_gtid_min = INT_MAX;
194 int __kmp_foreign_tp = TRUE;
195 #if KMP_ARCH_X86 || KMP_ARCH_X86_64
196 int __kmp_inherit_fp_control = TRUE;
197 kmp_int16 __kmp_init_x87_fpu_control_word = 0;
198 kmp_uint32 __kmp_init_mxcsr = 0;
199 #endif /* KMP_ARCH_X86 || KMP_ARCH_X86_64 */
200 
201 #ifdef USE_LOAD_BALANCE
202 double __kmp_load_balance_interval = 1.0;
203 #endif /* USE_LOAD_BALANCE */
204 
205 kmp_nested_nthreads_t __kmp_nested_nth = {NULL, 0, 0};
206 
207 #if KMP_USE_ADAPTIVE_LOCKS
208 
209 kmp_adaptive_backoff_params_t __kmp_adaptive_backoff_params = {
210     1, 1024}; // TODO: tune it!
211 
212 #if KMP_DEBUG_ADAPTIVE_LOCKS
213 char *__kmp_speculative_statsfile = "-";
214 #endif
215 
216 #endif // KMP_USE_ADAPTIVE_LOCKS
217 
218 #if OMP_40_ENABLED
219 int __kmp_display_env = FALSE;
220 int __kmp_display_env_verbose = FALSE;
221 int __kmp_omp_cancellation = FALSE;
222 #endif
223 
224 /* map OMP 3.0 schedule types with our internal schedule types */
225 enum sched_type __kmp_sch_map[kmp_sched_upper - kmp_sched_lower_ext +
226                               kmp_sched_upper_std - kmp_sched_lower - 2] = {
227     kmp_sch_static_chunked, // ==> kmp_sched_static            = 1
228     kmp_sch_dynamic_chunked, // ==> kmp_sched_dynamic           = 2
229     kmp_sch_guided_chunked, // ==> kmp_sched_guided            = 3
230     kmp_sch_auto, // ==> kmp_sched_auto              = 4
231     kmp_sch_trapezoidal // ==> kmp_sched_trapezoidal       = 101
232     // will likely not be used, introduced here just to debug the code
233     // of public intel extension schedules
234 };
235 
236 #if KMP_OS_LINUX
237 enum clock_function_type __kmp_clock_function;
238 int __kmp_clock_function_param;
239 #endif /* KMP_OS_LINUX */
240 
241 #if KMP_MIC_SUPPORTED
242 enum mic_type __kmp_mic_type = non_mic;
243 #endif
244 
245 #if KMP_AFFINITY_SUPPORTED
246 
247 KMPAffinity *__kmp_affinity_dispatch = NULL;
248 
249 #if KMP_USE_HWLOC
250 int __kmp_hwloc_error = FALSE;
251 hwloc_topology_t __kmp_hwloc_topology = NULL;
252 #endif
253 
254 #if KMP_OS_WINDOWS
255 #if KMP_GROUP_AFFINITY
256 int __kmp_num_proc_groups = 1;
257 #endif /* KMP_GROUP_AFFINITY */
258 kmp_GetActiveProcessorCount_t __kmp_GetActiveProcessorCount = NULL;
259 kmp_GetActiveProcessorGroupCount_t __kmp_GetActiveProcessorGroupCount = NULL;
260 kmp_GetThreadGroupAffinity_t __kmp_GetThreadGroupAffinity = NULL;
261 kmp_SetThreadGroupAffinity_t __kmp_SetThreadGroupAffinity = NULL;
262 #endif /* KMP_OS_WINDOWS */
263 
264 size_t __kmp_affin_mask_size = 0;
265 enum affinity_type __kmp_affinity_type = affinity_default;
266 enum affinity_gran __kmp_affinity_gran = affinity_gran_default;
267 int __kmp_affinity_gran_levels = -1;
268 int __kmp_affinity_dups = TRUE;
269 enum affinity_top_method __kmp_affinity_top_method =
270     affinity_top_method_default;
271 int __kmp_affinity_compact = 0;
272 int __kmp_affinity_offset = 0;
273 int __kmp_affinity_verbose = FALSE;
274 int __kmp_affinity_warnings = TRUE;
275 int __kmp_affinity_respect_mask = affinity_respect_mask_default;
276 char *__kmp_affinity_proclist = NULL;
277 kmp_affin_mask_t *__kmp_affinity_masks = NULL;
278 unsigned __kmp_affinity_num_masks = 0;
279 
280 char const *__kmp_cpuinfo_file = NULL;
281 
282 #endif /* KMP_AFFINITY_SUPPORTED */
283 
284 #if OMP_40_ENABLED
285 kmp_nested_proc_bind_t __kmp_nested_proc_bind = {NULL, 0, 0};
286 int __kmp_affinity_num_places = 0;
287 #endif
288 
289 kmp_hws_item_t __kmp_hws_socket = {0, 0};
290 kmp_hws_item_t __kmp_hws_node = {0, 0};
291 kmp_hws_item_t __kmp_hws_tile = {0, 0};
292 kmp_hws_item_t __kmp_hws_core = {0, 0};
293 kmp_hws_item_t __kmp_hws_proc = {0, 0};
294 int __kmp_hws_requested = 0;
295 int __kmp_hws_abs_flag = 0; // absolute or per-item number requested
296 
297 #if OMP_40_ENABLED
298 kmp_int32 __kmp_default_device = 0;
299 #endif
300 
301 kmp_tasking_mode_t __kmp_tasking_mode = tskm_task_teams;
302 #if OMP_45_ENABLED
303 kmp_int32 __kmp_max_task_priority = 0;
304 #endif
305 
306 /* This check ensures that the compiler is passing the correct data type for the
307    flags formal parameter of the function kmpc_omp_task_alloc(). If the type is
308    not a 4-byte type, then give an error message about a non-positive length
309    array pointing here.  If that happens, the kmp_tasking_flags_t structure must
310    be redefined to have exactly 32 bits. */
311 KMP_BUILD_ASSERT(sizeof(kmp_tasking_flags_t) == 4);
312 
313 kmp_int32 __kmp_task_stealing_constraint =
314     1; /* Constrain task stealing by default */
315 
316 #ifdef DEBUG_SUSPEND
317 int __kmp_suspend_count = 0;
318 #endif
319 
320 int __kmp_settings = FALSE;
321 int __kmp_duplicate_library_ok = 0;
322 #if USE_ITT_BUILD
323 int __kmp_forkjoin_frames = 1;
324 int __kmp_forkjoin_frames_mode = 3;
325 #endif
326 PACKED_REDUCTION_METHOD_T __kmp_force_reduction_method =
327     reduction_method_not_defined;
328 int __kmp_determ_red = FALSE;
329 
330 #ifdef KMP_DEBUG
331 int kmp_a_debug = 0;
332 int kmp_b_debug = 0;
333 int kmp_c_debug = 0;
334 int kmp_d_debug = 0;
335 int kmp_e_debug = 0;
336 int kmp_f_debug = 0;
337 int kmp_diag = 0;
338 #endif
339 
340 /* For debug information logging using rotating buffer */
341 int __kmp_debug_buf =
342     FALSE; /* TRUE means use buffer, FALSE means print to stderr */
343 int __kmp_debug_buf_lines =
344     KMP_DEBUG_BUF_LINES_INIT; /* Lines of debug stored in buffer */
345 int __kmp_debug_buf_chars =
346     KMP_DEBUG_BUF_CHARS_INIT; /* Characters allowed per line in buffer */
347 int __kmp_debug_buf_atomic =
348     FALSE; /* TRUE means use atomic update of buffer entry pointer */
349 
350 char *__kmp_debug_buffer = NULL; /* Debug buffer itself */
351 int __kmp_debug_count =
352     0; /* Counter for number of lines printed in buffer so far */
353 int __kmp_debug_buf_warn_chars =
354     0; /* Keep track of char increase recommended in warnings */
355 /* end rotating debug buffer */
356 
357 #ifdef KMP_DEBUG
358 int __kmp_par_range; /* +1 => only go par for constructs in range */
359 /* -1 => only go par for constructs outside range */
360 char __kmp_par_range_routine[KMP_PAR_RANGE_ROUTINE_LEN] = {'\0'};
361 char __kmp_par_range_filename[KMP_PAR_RANGE_FILENAME_LEN] = {'\0'};
362 int __kmp_par_range_lb = 0;
363 int __kmp_par_range_ub = INT_MAX;
364 #endif /* KMP_DEBUG */
365 
366 /* For printing out dynamic storage map for threads and teams */
367 int __kmp_storage_map =
368     FALSE; /* True means print storage map for threads and teams */
369 int __kmp_storage_map_verbose =
370     FALSE; /* True means storage map includes placement info */
371 int __kmp_storage_map_verbose_specified = FALSE;
372 /* Initialize the library data structures when we fork a child process, defaults
373  * to TRUE */
374 int __kmp_need_register_atfork =
375     TRUE; /* At initialization, call pthread_atfork to install fork handler */
376 int __kmp_need_register_atfork_specified = TRUE;
377 
378 int __kmp_env_chunk = FALSE; /* KMP_CHUNK specified?     */
379 int __kmp_env_stksize = FALSE; /* KMP_STACKSIZE specified? */
380 int __kmp_env_omp_stksize = FALSE; /* OMP_STACKSIZE specified? */
381 int __kmp_env_all_threads =
382     FALSE; /* KMP_ALL_THREADS or KMP_MAX_THREADS specified? */
383 int __kmp_env_omp_all_threads = FALSE; /* OMP_THREAD_LIMIT specified? */
384 int __kmp_env_blocktime = FALSE; /* KMP_BLOCKTIME specified? */
385 int __kmp_env_checks = FALSE; /* KMP_CHECKS specified?    */
386 int __kmp_env_consistency_check = FALSE; /* KMP_CONSISTENCY_CHECK specified? */
387 
388 kmp_uint32 __kmp_yield_init = KMP_INIT_WAIT;
389 kmp_uint32 __kmp_yield_next = KMP_NEXT_WAIT;
390 
391 #if KMP_USE_MONITOR
392 kmp_uint32 __kmp_yielding_on = 1;
393 #endif
394 #if KMP_OS_CNK
395 kmp_uint32 __kmp_yield_cycle = 0;
396 #else
397 kmp_uint32 __kmp_yield_cycle = 1; /* Yield-cycle is on by default */
398 #endif
399 kmp_int32 __kmp_yield_on_count =
400     10; /* By default, yielding is on for 10 monitor periods. */
401 kmp_int32 __kmp_yield_off_count =
402     1; /* By default, yielding is off for 1 monitor periods. */
403 
404 /* ------------------------------------------------------ */
405 /* STATE mostly syncronized with global lock */
406 /* data written to rarely by masters, read often by workers */
407 /* TODO: None of this global padding stuff works consistently because the order
408    of declaration is not necessarily correlated to storage order. To fix this,
409    all the important globals must be put in a big structure instead. */
410 KMP_ALIGN_CACHE
411 kmp_info_t **__kmp_threads = NULL;
412 kmp_root_t **__kmp_root = NULL;
413 
414 /* data read/written to often by masters */
415 KMP_ALIGN_CACHE
416 volatile int __kmp_nth = 0;
417 volatile int __kmp_all_nth = 0;
418 int __kmp_thread_pool_nth = 0;
419 volatile kmp_info_t *__kmp_thread_pool = NULL;
420 volatile kmp_team_t *__kmp_team_pool = NULL;
421 
422 KMP_ALIGN_CACHE
423 volatile int __kmp_thread_pool_active_nth = 0;
424 
425 /* -------------------------------------------------
426  * GLOBAL/ROOT STATE */
427 KMP_ALIGN_CACHE
428 kmp_global_t __kmp_global = {{0}};
429 
430 /* ----------------------------------------------- */
431 /* GLOBAL SYNCHRONIZATION LOCKS */
432 /* TODO verify the need for these locks and if they need to be global */
433 
434 #if KMP_USE_INTERNODE_ALIGNMENT
435 /* Multinode systems have larger cache line granularity which can cause
436  * false sharing if the alignment is not large enough for these locks */
437 KMP_ALIGN_CACHE_INTERNODE
438 
439 kmp_bootstrap_lock_t __kmp_initz_lock = KMP_BOOTSTRAP_LOCK_INITIALIZER(
440     __kmp_initz_lock); /* Control initializations */
441 KMP_ALIGN_CACHE_INTERNODE
442 kmp_bootstrap_lock_t __kmp_forkjoin_lock; /* control fork/join access */
443 KMP_ALIGN_CACHE_INTERNODE
444 kmp_bootstrap_lock_t __kmp_exit_lock; /* exit() is not always thread-safe */
445 #if KMP_USE_MONITOR
446 KMP_ALIGN_CACHE_INTERNODE
447 kmp_bootstrap_lock_t __kmp_monitor_lock; /* control monitor thread creation */
448 #endif
449 /* used for the hack to allow threadprivate cache and __kmp_threads expansion
450    to co-exist */
451 KMP_ALIGN_CACHE_INTERNODE
452 kmp_bootstrap_lock_t __kmp_tp_cached_lock;
453 
454 KMP_ALIGN_CACHE_INTERNODE
455 kmp_lock_t __kmp_global_lock; /* Control OS/global access */
456 KMP_ALIGN_CACHE_INTERNODE
457 kmp_queuing_lock_t __kmp_dispatch_lock; /* Control dispatch access  */
458 KMP_ALIGN_CACHE_INTERNODE
459 kmp_lock_t __kmp_debug_lock; /* Control I/O access for KMP_DEBUG */
460 #else
461 KMP_ALIGN_CACHE
462 
463 kmp_bootstrap_lock_t __kmp_initz_lock = KMP_BOOTSTRAP_LOCK_INITIALIZER(
464     __kmp_initz_lock); /* Control initializations */
465 kmp_bootstrap_lock_t __kmp_forkjoin_lock; /* control fork/join access */
466 kmp_bootstrap_lock_t __kmp_exit_lock; /* exit() is not always thread-safe */
467 #if KMP_USE_MONITOR
468 kmp_bootstrap_lock_t __kmp_monitor_lock; /* control monitor thread creation */
469 #endif
470 /* used for the hack to allow threadprivate cache and __kmp_threads expansion
471    to co-exist */
472 kmp_bootstrap_lock_t __kmp_tp_cached_lock;
473 
474 KMP_ALIGN(128)
475 kmp_lock_t __kmp_global_lock; /* Control OS/global access */
476 KMP_ALIGN(128)
477 kmp_queuing_lock_t __kmp_dispatch_lock; /* Control dispatch access  */
478 KMP_ALIGN(128)
479 kmp_lock_t __kmp_debug_lock; /* Control I/O access for KMP_DEBUG */
480 #endif
481 
482 /* ----------------------------------------------- */
483 
484 #if KMP_HANDLE_SIGNALS
485 /* Signal handling is disabled by default, because it confuses users: In case of
486    sigsegv (or other trouble) in user code signal handler catches the signal,
487    which then "appears" in the monitor thread (when the monitor executes raise()
488    function). Users see signal in the monitor thread and blame OpenMP RTL.
489 
490    Grant said signal handling required on some older OSes (Irix?) supported by
491    KAI, because bad applications hung but not aborted. Currently it is not a
492    problem for Linux* OS, OS X* and Windows* OS.
493 
494    Grant: Found new hangs for EL4, EL5, and a Fedora Core machine.  So I'm
495    putting the default back for now to see if that fixes hangs on those
496    machines.
497 
498    2010-04013 Lev: It was a bug in Fortran RTL. Fortran RTL prints a kind of
499    stack backtrace when program is aborting, but the code is not signal-safe.
500    When multiple signals raised at the same time (which occurs in dynamic
501    negative tests because all the worker threads detects the same error),
502    Fortran RTL may hang. The bug finally fixed in Fortran RTL library provided
503    by Steve R., and will be available soon. */
504 int __kmp_handle_signals = FALSE;
505 #endif
506 
507 /* ----------------------------------------------- */
508 #ifdef BUILD_TV
509 kmp_key_t __kmp_tv_key = 0;
510 #endif
511 
512 /* ------------------------------------------------------------------------ */
513 
514 #ifdef DEBUG_SUSPEND
515 int get_suspend_count_(void) {
516   int count = __kmp_suspend_count;
517   __kmp_suspend_count = 0;
518   return count;
519 }
520 void set_suspend_count_(int *value) { __kmp_suspend_count = *value; }
521 #endif
522 
523 // Symbols for MS mutual detection.
524 int _You_must_link_with_exactly_one_OpenMP_library = 1;
525 int _You_must_link_with_Intel_OpenMP_library = 1;
526 #if KMP_OS_WINDOWS && (KMP_VERSION_MAJOR > 4)
527 int _You_must_link_with_Microsoft_OpenMP_library = 1;
528 #endif
529 
530 // end of file //
531