1 /*
2  * kmp_global.cpp -- KPTS global variables for runtime support library
3  */
4 
5 //===----------------------------------------------------------------------===//
6 //
7 //                     The LLVM Compiler Infrastructure
8 //
9 // This file is dual licensed under the MIT and the University of Illinois Open
10 // Source Licenses. See LICENSE.txt for details.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "kmp.h"
15 #include "kmp_affinity.h"
16 
17 kmp_key_t __kmp_gtid_threadprivate_key;
18 
19 #if KMP_ARCH_X86 || KMP_ARCH_X86_64
20 kmp_cpuinfo_t __kmp_cpuinfo = {0}; // Not initialized
21 #endif
22 
23 #if KMP_STATS_ENABLED
24 #include "kmp_stats.h"
25 // lock for modifying the global __kmp_stats_list
26 kmp_tas_lock_t __kmp_stats_lock;
27 
28 // global list of per thread stats, the head is a sentinel node which
29 // accumulates all stats produced before __kmp_create_worker is called.
30 kmp_stats_list *__kmp_stats_list;
31 
32 // thread local pointer to stats node within list
33 __thread kmp_stats_list *__kmp_stats_thread_ptr = NULL;
34 
35 // gives reference tick for all events (considered the 0 tick)
36 tsc_tick_count __kmp_stats_start_time;
37 #endif
38 
39 /* ----------------------------------------------------- */
40 /* INITIALIZATION VARIABLES */
41 /* they are syncronized to write during init, but read anytime */
42 volatile int __kmp_init_serial = FALSE;
43 volatile int __kmp_init_gtid = FALSE;
44 volatile int __kmp_init_common = FALSE;
45 volatile int __kmp_init_middle = FALSE;
46 volatile int __kmp_init_parallel = FALSE;
47 #if KMP_USE_MONITOR
48 volatile int __kmp_init_monitor =
49     0; /* 1 - launched, 2 - actually started (Windows* OS only) */
50 #endif
51 volatile int __kmp_init_user_locks = FALSE;
52 
53 /* list of address of allocated caches for commons */
54 kmp_cached_addr_t *__kmp_threadpriv_cache_list = NULL;
55 
56 int __kmp_init_counter = 0;
57 int __kmp_root_counter = 0;
58 int __kmp_version = 0;
59 
60 volatile kmp_uint32 __kmp_team_counter = 0;
61 volatile kmp_uint32 __kmp_task_counter = 0;
62 
63 unsigned int __kmp_init_wait =
64     KMP_DEFAULT_INIT_WAIT; /* initial number of spin-tests   */
65 unsigned int __kmp_next_wait =
66     KMP_DEFAULT_NEXT_WAIT; /* susequent number of spin-tests */
67 
68 size_t __kmp_stksize = KMP_DEFAULT_STKSIZE;
69 #if KMP_USE_MONITOR
70 size_t __kmp_monitor_stksize = 0; // auto adjust
71 #endif
72 size_t __kmp_stkoffset = KMP_DEFAULT_STKOFFSET;
73 int __kmp_stkpadding = KMP_MIN_STKPADDING;
74 
75 size_t __kmp_malloc_pool_incr = KMP_DEFAULT_MALLOC_POOL_INCR;
76 
77 // Barrier method defaults, settings, and strings.
78 // branch factor = 2^branch_bits (only relevant for tree & hyper barrier types)
79 #if KMP_ARCH_X86_64
80 kmp_uint32 __kmp_barrier_gather_bb_dflt = 2;
81 /* branch_factor = 4 */ /* hyper2: C78980 */
82 kmp_uint32 __kmp_barrier_release_bb_dflt = 2;
83 /* branch_factor = 4 */ /* hyper2: C78980 */
84 #else
85 kmp_uint32 __kmp_barrier_gather_bb_dflt = 2;
86 /* branch_factor = 4 */ /* communication in core for MIC */
87 kmp_uint32 __kmp_barrier_release_bb_dflt = 2;
88 /* branch_factor = 4 */ /* communication in core for MIC */
89 #endif // KMP_ARCH_X86_64
90 #if KMP_ARCH_X86_64
91 kmp_bar_pat_e __kmp_barrier_gather_pat_dflt = bp_hyper_bar; /* hyper2: C78980 */
92 kmp_bar_pat_e __kmp_barrier_release_pat_dflt =
93     bp_hyper_bar; /* hyper2: C78980 */
94 #else
95 kmp_bar_pat_e __kmp_barrier_gather_pat_dflt = bp_linear_bar;
96 kmp_bar_pat_e __kmp_barrier_release_pat_dflt = bp_linear_bar;
97 #endif
98 kmp_uint32 __kmp_barrier_gather_branch_bits[bs_last_barrier] = {0};
99 kmp_uint32 __kmp_barrier_release_branch_bits[bs_last_barrier] = {0};
100 kmp_bar_pat_e __kmp_barrier_gather_pattern[bs_last_barrier] = {bp_linear_bar};
101 kmp_bar_pat_e __kmp_barrier_release_pattern[bs_last_barrier] = {bp_linear_bar};
102 char const *__kmp_barrier_branch_bit_env_name[bs_last_barrier] = {
103     "KMP_PLAIN_BARRIER", "KMP_FORKJOIN_BARRIER"
104 #if KMP_FAST_REDUCTION_BARRIER
105     ,
106     "KMP_REDUCTION_BARRIER"
107 #endif // KMP_FAST_REDUCTION_BARRIER
108 };
109 char const *__kmp_barrier_pattern_env_name[bs_last_barrier] = {
110     "KMP_PLAIN_BARRIER_PATTERN", "KMP_FORKJOIN_BARRIER_PATTERN"
111 #if KMP_FAST_REDUCTION_BARRIER
112     ,
113     "KMP_REDUCTION_BARRIER_PATTERN"
114 #endif // KMP_FAST_REDUCTION_BARRIER
115 };
116 char const *__kmp_barrier_type_name[bs_last_barrier] = {"plain", "forkjoin"
117 #if KMP_FAST_REDUCTION_BARRIER
118                                                         ,
119                                                         "reduction"
120 #endif // KMP_FAST_REDUCTION_BARRIER
121 };
122 char const *__kmp_barrier_pattern_name[bp_last_bar] = {"linear", "tree",
123                                                        "hyper", "hierarchical"};
124 
125 int __kmp_allThreadsSpecified = 0;
126 size_t __kmp_align_alloc = CACHE_LINE;
127 
128 int __kmp_generate_warnings = kmp_warnings_low;
129 int __kmp_reserve_warn = 0;
130 int __kmp_xproc = 0;
131 int __kmp_avail_proc = 0;
132 size_t __kmp_sys_min_stksize = KMP_MIN_STKSIZE;
133 int __kmp_sys_max_nth = KMP_MAX_NTH;
134 int __kmp_max_nth = 0;
135 int __kmp_cg_max_nth = 0;
136 int __kmp_teams_max_nth = 0;
137 int __kmp_threads_capacity = 0;
138 int __kmp_dflt_team_nth = 0;
139 int __kmp_dflt_team_nth_ub = 0;
140 int __kmp_tp_capacity = 0;
141 int __kmp_tp_cached = 0;
142 int __kmp_dflt_nested = FALSE;
143 int __kmp_dispatch_num_buffers = KMP_DFLT_DISP_NUM_BUFF;
144 int __kmp_dflt_max_active_levels =
145     KMP_MAX_ACTIVE_LEVELS_LIMIT; /* max_active_levels limit */
146 #if KMP_NESTED_HOT_TEAMS
147 int __kmp_hot_teams_mode = 0; /* 0 - free extra threads when reduced */
148 /* 1 - keep extra threads when reduced */
149 int __kmp_hot_teams_max_level = 1; /* nesting level of hot teams */
150 #endif
151 enum library_type __kmp_library = library_none;
152 enum sched_type __kmp_sched =
153     kmp_sch_default; /* scheduling method for runtime scheduling */
154 enum sched_type __kmp_static =
155     kmp_sch_static_greedy; /* default static scheduling method */
156 enum sched_type __kmp_guided =
157     kmp_sch_guided_iterative_chunked; /* default guided scheduling method */
158 enum sched_type __kmp_auto =
159     kmp_sch_guided_analytical_chunked; /* default auto scheduling method */
160 int __kmp_dflt_blocktime = KMP_DEFAULT_BLOCKTIME;
161 #if KMP_USE_MONITOR
162 int __kmp_monitor_wakeups = KMP_MIN_MONITOR_WAKEUPS;
163 int __kmp_bt_intervals = KMP_INTERVALS_FROM_BLOCKTIME(KMP_DEFAULT_BLOCKTIME,
164                                                       KMP_MIN_MONITOR_WAKEUPS);
165 #endif
166 #ifdef KMP_ADJUST_BLOCKTIME
167 int __kmp_zero_bt = FALSE;
168 #endif /* KMP_ADJUST_BLOCKTIME */
169 #ifdef KMP_DFLT_NTH_CORES
170 int __kmp_ncores = 0;
171 #endif
172 int __kmp_chunk = 0;
173 int __kmp_abort_delay = 0;
174 #if KMP_OS_LINUX && defined(KMP_TDATA_GTID)
175 int __kmp_gtid_mode = 3; /* use __declspec(thread) TLS to store gtid */
176 int __kmp_adjust_gtid_mode = FALSE;
177 #elif KMP_OS_WINDOWS
178 int __kmp_gtid_mode = 2; /* use TLS functions to store gtid */
179 int __kmp_adjust_gtid_mode = FALSE;
180 #else
181 int __kmp_gtid_mode = 0; /* select method to get gtid based on #threads */
182 int __kmp_adjust_gtid_mode = TRUE;
183 #endif /* KMP_OS_LINUX && defined(KMP_TDATA_GTID) */
184 #ifdef KMP_TDATA_GTID
185 #if KMP_OS_WINDOWS
186 __declspec(thread) int __kmp_gtid = KMP_GTID_DNE;
187 #else
188 __thread int __kmp_gtid = KMP_GTID_DNE;
189 #endif /* KMP_OS_WINDOWS - workaround because Intel(R) Many Integrated Core    \
190           compiler 20110316 doesn't accept __declspec */
191 #endif /* KMP_TDATA_GTID */
192 int __kmp_tls_gtid_min = INT_MAX;
193 int __kmp_foreign_tp = TRUE;
194 #if KMP_ARCH_X86 || KMP_ARCH_X86_64
195 int __kmp_inherit_fp_control = TRUE;
196 kmp_int16 __kmp_init_x87_fpu_control_word = 0;
197 kmp_uint32 __kmp_init_mxcsr = 0;
198 #endif /* KMP_ARCH_X86 || KMP_ARCH_X86_64 */
199 
200 #ifdef USE_LOAD_BALANCE
201 double __kmp_load_balance_interval = 1.0;
202 #endif /* USE_LOAD_BALANCE */
203 
204 kmp_nested_nthreads_t __kmp_nested_nth = {NULL, 0, 0};
205 
206 #if KMP_USE_ADAPTIVE_LOCKS
207 
208 kmp_adaptive_backoff_params_t __kmp_adaptive_backoff_params = {
209     1, 1024}; // TODO: tune it!
210 
211 #if KMP_DEBUG_ADAPTIVE_LOCKS
212 char *__kmp_speculative_statsfile = "-";
213 #endif
214 
215 #endif // KMP_USE_ADAPTIVE_LOCKS
216 
217 #if OMP_40_ENABLED
218 int __kmp_display_env = FALSE;
219 int __kmp_display_env_verbose = FALSE;
220 int __kmp_omp_cancellation = FALSE;
221 #endif
222 
223 /* map OMP 3.0 schedule types with our internal schedule types */
224 enum sched_type __kmp_sch_map[kmp_sched_upper - kmp_sched_lower_ext +
225                               kmp_sched_upper_std - kmp_sched_lower - 2] = {
226     kmp_sch_static_chunked, // ==> kmp_sched_static            = 1
227     kmp_sch_dynamic_chunked, // ==> kmp_sched_dynamic           = 2
228     kmp_sch_guided_chunked, // ==> kmp_sched_guided            = 3
229     kmp_sch_auto, // ==> kmp_sched_auto              = 4
230     kmp_sch_trapezoidal // ==> kmp_sched_trapezoidal       = 101
231     // will likely not be used, introduced here just to debug the code
232     // of public intel extension schedules
233 };
234 
235 #if KMP_OS_LINUX
236 enum clock_function_type __kmp_clock_function;
237 int __kmp_clock_function_param;
238 #endif /* KMP_OS_LINUX */
239 
240 #if KMP_MIC_SUPPORTED
241 enum mic_type __kmp_mic_type = non_mic;
242 #endif
243 
244 #if KMP_AFFINITY_SUPPORTED
245 
246 KMPAffinity *__kmp_affinity_dispatch = NULL;
247 
248 #if KMP_USE_HWLOC
249 int __kmp_hwloc_error = FALSE;
250 hwloc_topology_t __kmp_hwloc_topology = NULL;
251 #endif
252 
253 #if KMP_OS_WINDOWS
254 #if KMP_GROUP_AFFINITY
255 int __kmp_num_proc_groups = 1;
256 #endif /* KMP_GROUP_AFFINITY */
257 kmp_GetActiveProcessorCount_t __kmp_GetActiveProcessorCount = NULL;
258 kmp_GetActiveProcessorGroupCount_t __kmp_GetActiveProcessorGroupCount = NULL;
259 kmp_GetThreadGroupAffinity_t __kmp_GetThreadGroupAffinity = NULL;
260 kmp_SetThreadGroupAffinity_t __kmp_SetThreadGroupAffinity = NULL;
261 #endif /* KMP_OS_WINDOWS */
262 
263 size_t __kmp_affin_mask_size = 0;
264 enum affinity_type __kmp_affinity_type = affinity_default;
265 enum affinity_gran __kmp_affinity_gran = affinity_gran_default;
266 int __kmp_affinity_gran_levels = -1;
267 int __kmp_affinity_dups = TRUE;
268 enum affinity_top_method __kmp_affinity_top_method =
269     affinity_top_method_default;
270 int __kmp_affinity_compact = 0;
271 int __kmp_affinity_offset = 0;
272 int __kmp_affinity_verbose = FALSE;
273 int __kmp_affinity_warnings = TRUE;
274 int __kmp_affinity_respect_mask = affinity_respect_mask_default;
275 char *__kmp_affinity_proclist = NULL;
276 kmp_affin_mask_t *__kmp_affinity_masks = NULL;
277 unsigned __kmp_affinity_num_masks = 0;
278 
279 char const *__kmp_cpuinfo_file = NULL;
280 
281 #endif /* KMP_AFFINITY_SUPPORTED */
282 
283 #if OMP_40_ENABLED
284 kmp_nested_proc_bind_t __kmp_nested_proc_bind = {NULL, 0, 0};
285 int __kmp_affinity_num_places = 0;
286 #endif
287 
288 kmp_hws_item_t __kmp_hws_socket = {0, 0};
289 kmp_hws_item_t __kmp_hws_node = {0, 0};
290 kmp_hws_item_t __kmp_hws_tile = {0, 0};
291 kmp_hws_item_t __kmp_hws_core = {0, 0};
292 kmp_hws_item_t __kmp_hws_proc = {0, 0};
293 int __kmp_hws_requested = 0;
294 int __kmp_hws_abs_flag = 0; // absolute or per-item number requested
295 
296 #if OMP_40_ENABLED
297 kmp_int32 __kmp_default_device = 0;
298 #endif
299 
300 kmp_tasking_mode_t __kmp_tasking_mode = tskm_task_teams;
301 #if OMP_45_ENABLED
302 kmp_int32 __kmp_max_task_priority = 0;
303 kmp_uint64 __kmp_taskloop_min_tasks = 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_stksize = FALSE; /* KMP_STACKSIZE specified? */
379 int __kmp_env_blocktime = FALSE; /* KMP_BLOCKTIME specified? */
380 int __kmp_env_checks = FALSE; /* KMP_CHECKS specified?    */
381 int __kmp_env_consistency_check = FALSE; /* KMP_CONSISTENCY_CHECK specified? */
382 
383 kmp_uint32 __kmp_yield_init = KMP_INIT_WAIT;
384 kmp_uint32 __kmp_yield_next = KMP_NEXT_WAIT;
385 
386 #if KMP_USE_MONITOR
387 kmp_uint32 __kmp_yielding_on = 1;
388 #endif
389 #if KMP_OS_CNK
390 kmp_uint32 __kmp_yield_cycle = 0;
391 #else
392 kmp_uint32 __kmp_yield_cycle = 1; /* Yield-cycle is on by default */
393 #endif
394 kmp_int32 __kmp_yield_on_count =
395     10; /* By default, yielding is on for 10 monitor periods. */
396 kmp_int32 __kmp_yield_off_count =
397     1; /* By default, yielding is off for 1 monitor periods. */
398 
399 /* ------------------------------------------------------ */
400 /* STATE mostly syncronized with global lock */
401 /* data written to rarely by masters, read often by workers */
402 /* TODO: None of this global padding stuff works consistently because the order
403    of declaration is not necessarily correlated to storage order. To fix this,
404    all the important globals must be put in a big structure instead. */
405 KMP_ALIGN_CACHE
406 kmp_info_t **__kmp_threads = NULL;
407 kmp_root_t **__kmp_root = NULL;
408 
409 /* data read/written to often by masters */
410 KMP_ALIGN_CACHE
411 volatile int __kmp_nth = 0;
412 volatile int __kmp_all_nth = 0;
413 int __kmp_thread_pool_nth = 0;
414 volatile kmp_info_t *__kmp_thread_pool = NULL;
415 volatile kmp_team_t *__kmp_team_pool = NULL;
416 
417 KMP_ALIGN_CACHE
418 volatile int __kmp_thread_pool_active_nth = 0;
419 
420 /* -------------------------------------------------
421  * GLOBAL/ROOT STATE */
422 KMP_ALIGN_CACHE
423 kmp_global_t __kmp_global = {{0}};
424 
425 /* ----------------------------------------------- */
426 /* GLOBAL SYNCHRONIZATION LOCKS */
427 /* TODO verify the need for these locks and if they need to be global */
428 
429 #if KMP_USE_INTERNODE_ALIGNMENT
430 /* Multinode systems have larger cache line granularity which can cause
431  * false sharing if the alignment is not large enough for these locks */
432 KMP_ALIGN_CACHE_INTERNODE
433 
434 kmp_bootstrap_lock_t __kmp_initz_lock = KMP_BOOTSTRAP_LOCK_INITIALIZER(
435     __kmp_initz_lock); /* Control initializations */
436 KMP_ALIGN_CACHE_INTERNODE
437 kmp_bootstrap_lock_t __kmp_forkjoin_lock; /* control fork/join access */
438 KMP_ALIGN_CACHE_INTERNODE
439 kmp_bootstrap_lock_t __kmp_exit_lock; /* exit() is not always thread-safe */
440 #if KMP_USE_MONITOR
441 KMP_ALIGN_CACHE_INTERNODE
442 kmp_bootstrap_lock_t __kmp_monitor_lock; /* control monitor thread creation */
443 #endif
444 /* used for the hack to allow threadprivate cache and __kmp_threads expansion
445    to co-exist */
446 KMP_ALIGN_CACHE_INTERNODE
447 kmp_bootstrap_lock_t __kmp_tp_cached_lock;
448 
449 KMP_ALIGN_CACHE_INTERNODE
450 kmp_lock_t __kmp_global_lock; /* Control OS/global access */
451 KMP_ALIGN_CACHE_INTERNODE
452 kmp_queuing_lock_t __kmp_dispatch_lock; /* Control dispatch access  */
453 KMP_ALIGN_CACHE_INTERNODE
454 kmp_lock_t __kmp_debug_lock; /* Control I/O access for KMP_DEBUG */
455 #else
456 KMP_ALIGN_CACHE
457 
458 kmp_bootstrap_lock_t __kmp_initz_lock = KMP_BOOTSTRAP_LOCK_INITIALIZER(
459     __kmp_initz_lock); /* Control initializations */
460 kmp_bootstrap_lock_t __kmp_forkjoin_lock; /* control fork/join access */
461 kmp_bootstrap_lock_t __kmp_exit_lock; /* exit() is not always thread-safe */
462 #if KMP_USE_MONITOR
463 kmp_bootstrap_lock_t __kmp_monitor_lock; /* control monitor thread creation */
464 #endif
465 /* used for the hack to allow threadprivate cache and __kmp_threads expansion
466    to co-exist */
467 kmp_bootstrap_lock_t __kmp_tp_cached_lock;
468 
469 KMP_ALIGN(128)
470 kmp_lock_t __kmp_global_lock; /* Control OS/global access */
471 KMP_ALIGN(128)
472 kmp_queuing_lock_t __kmp_dispatch_lock; /* Control dispatch access  */
473 KMP_ALIGN(128)
474 kmp_lock_t __kmp_debug_lock; /* Control I/O access for KMP_DEBUG */
475 #endif
476 
477 /* ----------------------------------------------- */
478 
479 #if KMP_HANDLE_SIGNALS
480 /* Signal handling is disabled by default, because it confuses users: In case of
481    sigsegv (or other trouble) in user code signal handler catches the signal,
482    which then "appears" in the monitor thread (when the monitor executes raise()
483    function). Users see signal in the monitor thread and blame OpenMP RTL.
484 
485    Grant said signal handling required on some older OSes (Irix?) supported by
486    KAI, because bad applications hung but not aborted. Currently it is not a
487    problem for Linux* OS, OS X* and Windows* OS.
488 
489    Grant: Found new hangs for EL4, EL5, and a Fedora Core machine.  So I'm
490    putting the default back for now to see if that fixes hangs on those
491    machines.
492 
493    2010-04013 Lev: It was a bug in Fortran RTL. Fortran RTL prints a kind of
494    stack backtrace when program is aborting, but the code is not signal-safe.
495    When multiple signals raised at the same time (which occurs in dynamic
496    negative tests because all the worker threads detects the same error),
497    Fortran RTL may hang. The bug finally fixed in Fortran RTL library provided
498    by Steve R., and will be available soon. */
499 int __kmp_handle_signals = FALSE;
500 #endif
501 
502 #ifdef DEBUG_SUSPEND
503 int get_suspend_count_(void) {
504   int count = __kmp_suspend_count;
505   __kmp_suspend_count = 0;
506   return count;
507 }
508 void set_suspend_count_(int *value) { __kmp_suspend_count = *value; }
509 #endif
510 
511 // Symbols for MS mutual detection.
512 int _You_must_link_with_exactly_one_OpenMP_library = 1;
513 int _You_must_link_with_Intel_OpenMP_library = 1;
514 #if KMP_OS_WINDOWS && (KMP_VERSION_MAJOR > 4)
515 int _You_must_link_with_Microsoft_OpenMP_library = 1;
516 #endif
517 
518 // end of file //
519