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_cg_max_nth = 0;
139 int __kmp_teams_max_nth = 0;
140 int __kmp_threads_capacity = 0;
141 int __kmp_dflt_team_nth = 0;
142 int __kmp_dflt_team_nth_ub = 0;
143 int __kmp_tp_capacity = 0;
144 int __kmp_tp_cached = 0;
145 int __kmp_dflt_nested = FALSE;
146 int __kmp_dispatch_num_buffers = KMP_DFLT_DISP_NUM_BUFF;
147 int __kmp_dflt_max_active_levels =
148     KMP_MAX_ACTIVE_LEVELS_LIMIT; /* max_active_levels limit */
149 #if KMP_NESTED_HOT_TEAMS
150 int __kmp_hot_teams_mode = 0; /* 0 - free extra threads when reduced */
151 /* 1 - keep extra threads when reduced */
152 int __kmp_hot_teams_max_level = 1; /* nesting level of hot teams */
153 #endif
154 enum library_type __kmp_library = library_none;
155 enum sched_type __kmp_sched =
156     kmp_sch_default; /* scheduling method for runtime scheduling */
157 enum sched_type __kmp_static =
158     kmp_sch_static_greedy; /* default static scheduling method */
159 enum sched_type __kmp_guided =
160     kmp_sch_guided_iterative_chunked; /* default guided scheduling method */
161 enum sched_type __kmp_auto =
162     kmp_sch_guided_analytical_chunked; /* default auto scheduling method */
163 int __kmp_dflt_blocktime = KMP_DEFAULT_BLOCKTIME;
164 #if KMP_USE_MONITOR
165 int __kmp_monitor_wakeups = KMP_MIN_MONITOR_WAKEUPS;
166 int __kmp_bt_intervals = KMP_INTERVALS_FROM_BLOCKTIME(KMP_DEFAULT_BLOCKTIME,
167                                                       KMP_MIN_MONITOR_WAKEUPS);
168 #endif
169 #ifdef KMP_ADJUST_BLOCKTIME
170 int __kmp_zero_bt = FALSE;
171 #endif /* KMP_ADJUST_BLOCKTIME */
172 #ifdef KMP_DFLT_NTH_CORES
173 int __kmp_ncores = 0;
174 #endif
175 int __kmp_chunk = 0;
176 int __kmp_abort_delay = 0;
177 #if KMP_OS_LINUX && defined(KMP_TDATA_GTID)
178 int __kmp_gtid_mode = 3; /* use __declspec(thread) TLS to store gtid */
179 int __kmp_adjust_gtid_mode = FALSE;
180 #elif KMP_OS_WINDOWS
181 int __kmp_gtid_mode = 2; /* use TLS functions to store gtid */
182 int __kmp_adjust_gtid_mode = FALSE;
183 #else
184 int __kmp_gtid_mode = 0; /* select method to get gtid based on #threads */
185 int __kmp_adjust_gtid_mode = TRUE;
186 #endif /* KMP_OS_LINUX && defined(KMP_TDATA_GTID) */
187 #ifdef KMP_TDATA_GTID
188 #if KMP_OS_WINDOWS
189 __declspec(thread) int __kmp_gtid = KMP_GTID_DNE;
190 #else
191 __thread int __kmp_gtid = KMP_GTID_DNE;
192 #endif /* KMP_OS_WINDOWS - workaround because Intel(R) Many Integrated Core    \
193           compiler 20110316 doesn't accept __declspec */
194 #endif /* KMP_TDATA_GTID */
195 int __kmp_tls_gtid_min = INT_MAX;
196 int __kmp_foreign_tp = TRUE;
197 #if KMP_ARCH_X86 || KMP_ARCH_X86_64
198 int __kmp_inherit_fp_control = TRUE;
199 kmp_int16 __kmp_init_x87_fpu_control_word = 0;
200 kmp_uint32 __kmp_init_mxcsr = 0;
201 #endif /* KMP_ARCH_X86 || KMP_ARCH_X86_64 */
202 
203 #ifdef USE_LOAD_BALANCE
204 double __kmp_load_balance_interval = 1.0;
205 #endif /* USE_LOAD_BALANCE */
206 
207 kmp_nested_nthreads_t __kmp_nested_nth = {NULL, 0, 0};
208 
209 #if KMP_USE_ADAPTIVE_LOCKS
210 
211 kmp_adaptive_backoff_params_t __kmp_adaptive_backoff_params = {
212     1, 1024}; // TODO: tune it!
213 
214 #if KMP_DEBUG_ADAPTIVE_LOCKS
215 char *__kmp_speculative_statsfile = "-";
216 #endif
217 
218 #endif // KMP_USE_ADAPTIVE_LOCKS
219 
220 #if OMP_40_ENABLED
221 int __kmp_display_env = FALSE;
222 int __kmp_display_env_verbose = FALSE;
223 int __kmp_omp_cancellation = FALSE;
224 #endif
225 
226 /* map OMP 3.0 schedule types with our internal schedule types */
227 enum sched_type __kmp_sch_map[kmp_sched_upper - kmp_sched_lower_ext +
228                               kmp_sched_upper_std - kmp_sched_lower - 2] = {
229     kmp_sch_static_chunked, // ==> kmp_sched_static            = 1
230     kmp_sch_dynamic_chunked, // ==> kmp_sched_dynamic           = 2
231     kmp_sch_guided_chunked, // ==> kmp_sched_guided            = 3
232     kmp_sch_auto, // ==> kmp_sched_auto              = 4
233     kmp_sch_trapezoidal // ==> kmp_sched_trapezoidal       = 101
234     // will likely not be used, introduced here just to debug the code
235     // of public intel extension schedules
236 };
237 
238 #if KMP_OS_LINUX
239 enum clock_function_type __kmp_clock_function;
240 int __kmp_clock_function_param;
241 #endif /* KMP_OS_LINUX */
242 
243 #if KMP_MIC_SUPPORTED
244 enum mic_type __kmp_mic_type = non_mic;
245 #endif
246 
247 #if KMP_AFFINITY_SUPPORTED
248 
249 KMPAffinity *__kmp_affinity_dispatch = NULL;
250 
251 #if KMP_USE_HWLOC
252 int __kmp_hwloc_error = FALSE;
253 hwloc_topology_t __kmp_hwloc_topology = NULL;
254 #endif
255 
256 #if KMP_OS_WINDOWS
257 #if KMP_GROUP_AFFINITY
258 int __kmp_num_proc_groups = 1;
259 #endif /* KMP_GROUP_AFFINITY */
260 kmp_GetActiveProcessorCount_t __kmp_GetActiveProcessorCount = NULL;
261 kmp_GetActiveProcessorGroupCount_t __kmp_GetActiveProcessorGroupCount = NULL;
262 kmp_GetThreadGroupAffinity_t __kmp_GetThreadGroupAffinity = NULL;
263 kmp_SetThreadGroupAffinity_t __kmp_SetThreadGroupAffinity = NULL;
264 #endif /* KMP_OS_WINDOWS */
265 
266 size_t __kmp_affin_mask_size = 0;
267 enum affinity_type __kmp_affinity_type = affinity_default;
268 enum affinity_gran __kmp_affinity_gran = affinity_gran_default;
269 int __kmp_affinity_gran_levels = -1;
270 int __kmp_affinity_dups = TRUE;
271 enum affinity_top_method __kmp_affinity_top_method =
272     affinity_top_method_default;
273 int __kmp_affinity_compact = 0;
274 int __kmp_affinity_offset = 0;
275 int __kmp_affinity_verbose = FALSE;
276 int __kmp_affinity_warnings = TRUE;
277 int __kmp_affinity_respect_mask = affinity_respect_mask_default;
278 char *__kmp_affinity_proclist = NULL;
279 kmp_affin_mask_t *__kmp_affinity_masks = NULL;
280 unsigned __kmp_affinity_num_masks = 0;
281 
282 char const *__kmp_cpuinfo_file = NULL;
283 
284 #endif /* KMP_AFFINITY_SUPPORTED */
285 
286 #if OMP_40_ENABLED
287 kmp_nested_proc_bind_t __kmp_nested_proc_bind = {NULL, 0, 0};
288 int __kmp_affinity_num_places = 0;
289 #endif
290 
291 kmp_hws_item_t __kmp_hws_socket = {0, 0};
292 kmp_hws_item_t __kmp_hws_node = {0, 0};
293 kmp_hws_item_t __kmp_hws_tile = {0, 0};
294 kmp_hws_item_t __kmp_hws_core = {0, 0};
295 kmp_hws_item_t __kmp_hws_proc = {0, 0};
296 int __kmp_hws_requested = 0;
297 int __kmp_hws_abs_flag = 0; // absolute or per-item number requested
298 
299 #if OMP_40_ENABLED
300 kmp_int32 __kmp_default_device = 0;
301 #endif
302 
303 kmp_tasking_mode_t __kmp_tasking_mode = tskm_task_teams;
304 #if OMP_45_ENABLED
305 kmp_int32 __kmp_max_task_priority = 0;
306 kmp_uint64 __kmp_taskloop_min_tasks = 0;
307 #endif
308 
309 /* This check ensures that the compiler is passing the correct data type for the
310    flags formal parameter of the function kmpc_omp_task_alloc(). If the type is
311    not a 4-byte type, then give an error message about a non-positive length
312    array pointing here.  If that happens, the kmp_tasking_flags_t structure must
313    be redefined to have exactly 32 bits. */
314 KMP_BUILD_ASSERT(sizeof(kmp_tasking_flags_t) == 4);
315 
316 kmp_int32 __kmp_task_stealing_constraint =
317     1; /* Constrain task stealing by default */
318 
319 #ifdef DEBUG_SUSPEND
320 int __kmp_suspend_count = 0;
321 #endif
322 
323 int __kmp_settings = FALSE;
324 int __kmp_duplicate_library_ok = 0;
325 #if USE_ITT_BUILD
326 int __kmp_forkjoin_frames = 1;
327 int __kmp_forkjoin_frames_mode = 3;
328 #endif
329 PACKED_REDUCTION_METHOD_T __kmp_force_reduction_method =
330     reduction_method_not_defined;
331 int __kmp_determ_red = FALSE;
332 
333 #ifdef KMP_DEBUG
334 int kmp_a_debug = 0;
335 int kmp_b_debug = 0;
336 int kmp_c_debug = 0;
337 int kmp_d_debug = 0;
338 int kmp_e_debug = 0;
339 int kmp_f_debug = 0;
340 int kmp_diag = 0;
341 #endif
342 
343 /* For debug information logging using rotating buffer */
344 int __kmp_debug_buf =
345     FALSE; /* TRUE means use buffer, FALSE means print to stderr */
346 int __kmp_debug_buf_lines =
347     KMP_DEBUG_BUF_LINES_INIT; /* Lines of debug stored in buffer */
348 int __kmp_debug_buf_chars =
349     KMP_DEBUG_BUF_CHARS_INIT; /* Characters allowed per line in buffer */
350 int __kmp_debug_buf_atomic =
351     FALSE; /* TRUE means use atomic update of buffer entry pointer */
352 
353 char *__kmp_debug_buffer = NULL; /* Debug buffer itself */
354 int __kmp_debug_count =
355     0; /* Counter for number of lines printed in buffer so far */
356 int __kmp_debug_buf_warn_chars =
357     0; /* Keep track of char increase recommended in warnings */
358 /* end rotating debug buffer */
359 
360 #ifdef KMP_DEBUG
361 int __kmp_par_range; /* +1 => only go par for constructs in range */
362 /* -1 => only go par for constructs outside range */
363 char __kmp_par_range_routine[KMP_PAR_RANGE_ROUTINE_LEN] = {'\0'};
364 char __kmp_par_range_filename[KMP_PAR_RANGE_FILENAME_LEN] = {'\0'};
365 int __kmp_par_range_lb = 0;
366 int __kmp_par_range_ub = INT_MAX;
367 #endif /* KMP_DEBUG */
368 
369 /* For printing out dynamic storage map for threads and teams */
370 int __kmp_storage_map =
371     FALSE; /* True means print storage map for threads and teams */
372 int __kmp_storage_map_verbose =
373     FALSE; /* True means storage map includes placement info */
374 int __kmp_storage_map_verbose_specified = FALSE;
375 /* Initialize the library data structures when we fork a child process, defaults
376  * to TRUE */
377 int __kmp_need_register_atfork =
378     TRUE; /* At initialization, call pthread_atfork to install fork handler */
379 int __kmp_need_register_atfork_specified = TRUE;
380 
381 int __kmp_env_stksize = FALSE; /* KMP_STACKSIZE specified? */
382 int __kmp_env_blocktime = FALSE; /* KMP_BLOCKTIME specified? */
383 int __kmp_env_checks = FALSE; /* KMP_CHECKS specified?    */
384 int __kmp_env_consistency_check = FALSE; /* KMP_CONSISTENCY_CHECK specified? */
385 
386 kmp_uint32 __kmp_yield_init = KMP_INIT_WAIT;
387 kmp_uint32 __kmp_yield_next = KMP_NEXT_WAIT;
388 
389 #if KMP_USE_MONITOR
390 kmp_uint32 __kmp_yielding_on = 1;
391 #endif
392 #if KMP_OS_CNK
393 kmp_uint32 __kmp_yield_cycle = 0;
394 #else
395 kmp_uint32 __kmp_yield_cycle = 1; /* Yield-cycle is on by default */
396 #endif
397 kmp_int32 __kmp_yield_on_count =
398     10; /* By default, yielding is on for 10 monitor periods. */
399 kmp_int32 __kmp_yield_off_count =
400     1; /* By default, yielding is off for 1 monitor periods. */
401 
402 /* ------------------------------------------------------ */
403 /* STATE mostly syncronized with global lock */
404 /* data written to rarely by masters, read often by workers */
405 /* TODO: None of this global padding stuff works consistently because the order
406    of declaration is not necessarily correlated to storage order. To fix this,
407    all the important globals must be put in a big structure instead. */
408 KMP_ALIGN_CACHE
409 kmp_info_t **__kmp_threads = NULL;
410 kmp_root_t **__kmp_root = NULL;
411 
412 /* data read/written to often by masters */
413 KMP_ALIGN_CACHE
414 volatile int __kmp_nth = 0;
415 volatile int __kmp_all_nth = 0;
416 int __kmp_thread_pool_nth = 0;
417 volatile kmp_info_t *__kmp_thread_pool = NULL;
418 volatile kmp_team_t *__kmp_team_pool = NULL;
419 
420 KMP_ALIGN_CACHE
421 volatile int __kmp_thread_pool_active_nth = 0;
422 
423 /* -------------------------------------------------
424  * GLOBAL/ROOT STATE */
425 KMP_ALIGN_CACHE
426 kmp_global_t __kmp_global = {{0}};
427 
428 /* ----------------------------------------------- */
429 /* GLOBAL SYNCHRONIZATION LOCKS */
430 /* TODO verify the need for these locks and if they need to be global */
431 
432 #if KMP_USE_INTERNODE_ALIGNMENT
433 /* Multinode systems have larger cache line granularity which can cause
434  * false sharing if the alignment is not large enough for these locks */
435 KMP_ALIGN_CACHE_INTERNODE
436 
437 kmp_bootstrap_lock_t __kmp_initz_lock = KMP_BOOTSTRAP_LOCK_INITIALIZER(
438     __kmp_initz_lock); /* Control initializations */
439 KMP_ALIGN_CACHE_INTERNODE
440 kmp_bootstrap_lock_t __kmp_forkjoin_lock; /* control fork/join access */
441 KMP_ALIGN_CACHE_INTERNODE
442 kmp_bootstrap_lock_t __kmp_exit_lock; /* exit() is not always thread-safe */
443 #if KMP_USE_MONITOR
444 KMP_ALIGN_CACHE_INTERNODE
445 kmp_bootstrap_lock_t __kmp_monitor_lock; /* control monitor thread creation */
446 #endif
447 /* used for the hack to allow threadprivate cache and __kmp_threads expansion
448    to co-exist */
449 KMP_ALIGN_CACHE_INTERNODE
450 kmp_bootstrap_lock_t __kmp_tp_cached_lock;
451 
452 KMP_ALIGN_CACHE_INTERNODE
453 kmp_lock_t __kmp_global_lock; /* Control OS/global access */
454 KMP_ALIGN_CACHE_INTERNODE
455 kmp_queuing_lock_t __kmp_dispatch_lock; /* Control dispatch access  */
456 KMP_ALIGN_CACHE_INTERNODE
457 kmp_lock_t __kmp_debug_lock; /* Control I/O access for KMP_DEBUG */
458 #else
459 KMP_ALIGN_CACHE
460 
461 kmp_bootstrap_lock_t __kmp_initz_lock = KMP_BOOTSTRAP_LOCK_INITIALIZER(
462     __kmp_initz_lock); /* Control initializations */
463 kmp_bootstrap_lock_t __kmp_forkjoin_lock; /* control fork/join access */
464 kmp_bootstrap_lock_t __kmp_exit_lock; /* exit() is not always thread-safe */
465 #if KMP_USE_MONITOR
466 kmp_bootstrap_lock_t __kmp_monitor_lock; /* control monitor thread creation */
467 #endif
468 /* used for the hack to allow threadprivate cache and __kmp_threads expansion
469    to co-exist */
470 kmp_bootstrap_lock_t __kmp_tp_cached_lock;
471 
472 KMP_ALIGN(128)
473 kmp_lock_t __kmp_global_lock; /* Control OS/global access */
474 KMP_ALIGN(128)
475 kmp_queuing_lock_t __kmp_dispatch_lock; /* Control dispatch access  */
476 KMP_ALIGN(128)
477 kmp_lock_t __kmp_debug_lock; /* Control I/O access for KMP_DEBUG */
478 #endif
479 
480 /* ----------------------------------------------- */
481 
482 #if KMP_HANDLE_SIGNALS
483 /* Signal handling is disabled by default, because it confuses users: In case of
484    sigsegv (or other trouble) in user code signal handler catches the signal,
485    which then "appears" in the monitor thread (when the monitor executes raise()
486    function). Users see signal in the monitor thread and blame OpenMP RTL.
487 
488    Grant said signal handling required on some older OSes (Irix?) supported by
489    KAI, because bad applications hung but not aborted. Currently it is not a
490    problem for Linux* OS, OS X* and Windows* OS.
491 
492    Grant: Found new hangs for EL4, EL5, and a Fedora Core machine.  So I'm
493    putting the default back for now to see if that fixes hangs on those
494    machines.
495 
496    2010-04013 Lev: It was a bug in Fortran RTL. Fortran RTL prints a kind of
497    stack backtrace when program is aborting, but the code is not signal-safe.
498    When multiple signals raised at the same time (which occurs in dynamic
499    negative tests because all the worker threads detects the same error),
500    Fortran RTL may hang. The bug finally fixed in Fortran RTL library provided
501    by Steve R., and will be available soon. */
502 int __kmp_handle_signals = FALSE;
503 #endif
504 
505 #ifdef DEBUG_SUSPEND
506 int get_suspend_count_(void) {
507   int count = __kmp_suspend_count;
508   __kmp_suspend_count = 0;
509   return count;
510 }
511 void set_suspend_count_(int *value) { __kmp_suspend_count = *value; }
512 #endif
513 
514 // Symbols for MS mutual detection.
515 int _You_must_link_with_exactly_one_OpenMP_library = 1;
516 int _You_must_link_with_Intel_OpenMP_library = 1;
517 #if KMP_OS_WINDOWS && (KMP_VERSION_MAJOR > 4)
518 int _You_must_link_with_Microsoft_OpenMP_library = 1;
519 #endif
520 
521 // end of file //
522