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 KMP_THREAD_LOCAL 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 KMP_THREAD_LOCAL int __kmp_gtid = KMP_GTID_DNE;
186 #endif /* KMP_TDATA_GTID */
187 int __kmp_tls_gtid_min = INT_MAX;
188 int __kmp_foreign_tp = TRUE;
189 #if KMP_ARCH_X86 || KMP_ARCH_X86_64
190 int __kmp_inherit_fp_control = TRUE;
191 kmp_int16 __kmp_init_x87_fpu_control_word = 0;
192 kmp_uint32 __kmp_init_mxcsr = 0;
193 #endif /* KMP_ARCH_X86 || KMP_ARCH_X86_64 */
194 
195 #ifdef USE_LOAD_BALANCE
196 double __kmp_load_balance_interval = 1.0;
197 #endif /* USE_LOAD_BALANCE */
198 
199 kmp_nested_nthreads_t __kmp_nested_nth = {NULL, 0, 0};
200 
201 #if KMP_USE_ADAPTIVE_LOCKS
202 
203 kmp_adaptive_backoff_params_t __kmp_adaptive_backoff_params = {
204     1, 1024}; // TODO: tune it!
205 
206 #if KMP_DEBUG_ADAPTIVE_LOCKS
207 char *__kmp_speculative_statsfile = "-";
208 #endif
209 
210 #endif // KMP_USE_ADAPTIVE_LOCKS
211 
212 #if OMP_40_ENABLED
213 int __kmp_display_env = FALSE;
214 int __kmp_display_env_verbose = FALSE;
215 int __kmp_omp_cancellation = FALSE;
216 #endif
217 
218 /* map OMP 3.0 schedule types with our internal schedule types */
219 enum sched_type __kmp_sch_map[kmp_sched_upper - kmp_sched_lower_ext +
220                               kmp_sched_upper_std - kmp_sched_lower - 2] = {
221     kmp_sch_static_chunked, // ==> kmp_sched_static            = 1
222     kmp_sch_dynamic_chunked, // ==> kmp_sched_dynamic           = 2
223     kmp_sch_guided_chunked, // ==> kmp_sched_guided            = 3
224     kmp_sch_auto, // ==> kmp_sched_auto              = 4
225     kmp_sch_trapezoidal // ==> kmp_sched_trapezoidal       = 101
226     // will likely not be used, introduced here just to debug the code
227     // of public intel extension schedules
228 };
229 
230 #if KMP_OS_LINUX
231 enum clock_function_type __kmp_clock_function;
232 int __kmp_clock_function_param;
233 #endif /* KMP_OS_LINUX */
234 
235 #if KMP_MIC_SUPPORTED
236 enum mic_type __kmp_mic_type = non_mic;
237 #endif
238 
239 #if KMP_AFFINITY_SUPPORTED
240 
241 KMPAffinity *__kmp_affinity_dispatch = NULL;
242 
243 #if KMP_USE_HWLOC
244 int __kmp_hwloc_error = FALSE;
245 hwloc_topology_t __kmp_hwloc_topology = NULL;
246 #endif
247 
248 #if KMP_OS_WINDOWS
249 #if KMP_GROUP_AFFINITY
250 int __kmp_num_proc_groups = 1;
251 #endif /* KMP_GROUP_AFFINITY */
252 kmp_GetActiveProcessorCount_t __kmp_GetActiveProcessorCount = NULL;
253 kmp_GetActiveProcessorGroupCount_t __kmp_GetActiveProcessorGroupCount = NULL;
254 kmp_GetThreadGroupAffinity_t __kmp_GetThreadGroupAffinity = NULL;
255 kmp_SetThreadGroupAffinity_t __kmp_SetThreadGroupAffinity = NULL;
256 #endif /* KMP_OS_WINDOWS */
257 
258 size_t __kmp_affin_mask_size = 0;
259 enum affinity_type __kmp_affinity_type = affinity_default;
260 enum affinity_gran __kmp_affinity_gran = affinity_gran_default;
261 int __kmp_affinity_gran_levels = -1;
262 int __kmp_affinity_dups = TRUE;
263 enum affinity_top_method __kmp_affinity_top_method =
264     affinity_top_method_default;
265 int __kmp_affinity_compact = 0;
266 int __kmp_affinity_offset = 0;
267 int __kmp_affinity_verbose = FALSE;
268 int __kmp_affinity_warnings = TRUE;
269 int __kmp_affinity_respect_mask = affinity_respect_mask_default;
270 char *__kmp_affinity_proclist = NULL;
271 kmp_affin_mask_t *__kmp_affinity_masks = NULL;
272 unsigned __kmp_affinity_num_masks = 0;
273 
274 char const *__kmp_cpuinfo_file = NULL;
275 
276 #endif /* KMP_AFFINITY_SUPPORTED */
277 
278 #if OMP_40_ENABLED
279 kmp_nested_proc_bind_t __kmp_nested_proc_bind = {NULL, 0, 0};
280 int __kmp_affinity_num_places = 0;
281 #endif
282 
283 kmp_hws_item_t __kmp_hws_socket = {0, 0};
284 kmp_hws_item_t __kmp_hws_node = {0, 0};
285 kmp_hws_item_t __kmp_hws_tile = {0, 0};
286 kmp_hws_item_t __kmp_hws_core = {0, 0};
287 kmp_hws_item_t __kmp_hws_proc = {0, 0};
288 int __kmp_hws_requested = 0;
289 int __kmp_hws_abs_flag = 0; // absolute or per-item number requested
290 
291 #if OMP_40_ENABLED
292 kmp_int32 __kmp_default_device = 0;
293 #endif
294 
295 kmp_tasking_mode_t __kmp_tasking_mode = tskm_task_teams;
296 #if OMP_45_ENABLED
297 kmp_int32 __kmp_max_task_priority = 0;
298 kmp_uint64 __kmp_taskloop_min_tasks = 0;
299 #endif
300 
301 #if OMP_50_ENABLED && OMPT_SUPPORT
302 char const *__kmp_tool_libraries = NULL;
303 #endif
304 
305 /* This check ensures that the compiler is passing the correct data type for the
306    flags formal parameter of the function kmpc_omp_task_alloc(). If the type is
307    not a 4-byte type, then give an error message about a non-positive length
308    array pointing here.  If that happens, the kmp_tasking_flags_t structure must
309    be redefined to have exactly 32 bits. */
310 KMP_BUILD_ASSERT(sizeof(kmp_tasking_flags_t) == 4);
311 
312 kmp_int32 __kmp_task_stealing_constraint =
313     1; /* Constrain task stealing by default */
314 
315 #ifdef DEBUG_SUSPEND
316 int __kmp_suspend_count = 0;
317 #endif
318 
319 int __kmp_settings = FALSE;
320 int __kmp_duplicate_library_ok = 0;
321 #if USE_ITT_BUILD
322 int __kmp_forkjoin_frames = 1;
323 int __kmp_forkjoin_frames_mode = 3;
324 #endif
325 PACKED_REDUCTION_METHOD_T __kmp_force_reduction_method =
326     reduction_method_not_defined;
327 int __kmp_determ_red = FALSE;
328 
329 #ifdef KMP_DEBUG
330 int kmp_a_debug = 0;
331 int kmp_b_debug = 0;
332 int kmp_c_debug = 0;
333 int kmp_d_debug = 0;
334 int kmp_e_debug = 0;
335 int kmp_f_debug = 0;
336 int kmp_diag = 0;
337 #endif
338 
339 /* For debug information logging using rotating buffer */
340 int __kmp_debug_buf =
341     FALSE; /* TRUE means use buffer, FALSE means print to stderr */
342 int __kmp_debug_buf_lines =
343     KMP_DEBUG_BUF_LINES_INIT; /* Lines of debug stored in buffer */
344 int __kmp_debug_buf_chars =
345     KMP_DEBUG_BUF_CHARS_INIT; /* Characters allowed per line in buffer */
346 int __kmp_debug_buf_atomic =
347     FALSE; /* TRUE means use atomic update of buffer entry pointer */
348 
349 char *__kmp_debug_buffer = NULL; /* Debug buffer itself */
350 int __kmp_debug_count =
351     0; /* Counter for number of lines printed in buffer so far */
352 int __kmp_debug_buf_warn_chars =
353     0; /* Keep track of char increase recommended in warnings */
354 /* end rotating debug buffer */
355 
356 #ifdef KMP_DEBUG
357 int __kmp_par_range; /* +1 => only go par for constructs in range */
358 /* -1 => only go par for constructs outside range */
359 char __kmp_par_range_routine[KMP_PAR_RANGE_ROUTINE_LEN] = {'\0'};
360 char __kmp_par_range_filename[KMP_PAR_RANGE_FILENAME_LEN] = {'\0'};
361 int __kmp_par_range_lb = 0;
362 int __kmp_par_range_ub = INT_MAX;
363 #endif /* KMP_DEBUG */
364 
365 /* For printing out dynamic storage map for threads and teams */
366 int __kmp_storage_map =
367     FALSE; /* True means print storage map for threads and teams */
368 int __kmp_storage_map_verbose =
369     FALSE; /* True means storage map includes placement info */
370 int __kmp_storage_map_verbose_specified = FALSE;
371 /* Initialize the library data structures when we fork a child process, defaults
372  * to TRUE */
373 int __kmp_need_register_atfork =
374     TRUE; /* At initialization, call pthread_atfork to install fork handler */
375 int __kmp_need_register_atfork_specified = TRUE;
376 
377 int __kmp_env_stksize = FALSE; /* KMP_STACKSIZE specified? */
378 int __kmp_env_blocktime = FALSE; /* KMP_BLOCKTIME specified? */
379 int __kmp_env_checks = FALSE; /* KMP_CHECKS specified?    */
380 int __kmp_env_consistency_check = FALSE; /* KMP_CONSISTENCY_CHECK specified? */
381 
382 kmp_uint32 __kmp_yield_init = KMP_INIT_WAIT;
383 kmp_uint32 __kmp_yield_next = KMP_NEXT_WAIT;
384 
385 #if KMP_USE_MONITOR
386 kmp_uint32 __kmp_yielding_on = 1;
387 #endif
388 #if KMP_OS_CNK
389 kmp_uint32 __kmp_yield_cycle = 0;
390 #else
391 kmp_uint32 __kmp_yield_cycle = 1; /* Yield-cycle is on by default */
392 #endif
393 kmp_int32 __kmp_yield_on_count =
394     10; /* By default, yielding is on for 10 monitor periods. */
395 kmp_int32 __kmp_yield_off_count =
396     1; /* By default, yielding is off for 1 monitor periods. */
397 
398 /* ------------------------------------------------------ */
399 /* STATE mostly syncronized with global lock */
400 /* data written to rarely by masters, read often by workers */
401 /* TODO: None of this global padding stuff works consistently because the order
402    of declaration is not necessarily correlated to storage order. To fix this,
403    all the important globals must be put in a big structure instead. */
404 KMP_ALIGN_CACHE
405 kmp_info_t **__kmp_threads = NULL;
406 kmp_root_t **__kmp_root = NULL;
407 
408 /* data read/written to often by masters */
409 KMP_ALIGN_CACHE
410 volatile int __kmp_nth = 0;
411 volatile int __kmp_all_nth = 0;
412 int __kmp_thread_pool_nth = 0;
413 volatile kmp_info_t *__kmp_thread_pool = NULL;
414 volatile kmp_team_t *__kmp_team_pool = NULL;
415 
416 KMP_ALIGN_CACHE
417 volatile int __kmp_thread_pool_active_nth = 0;
418 
419 /* -------------------------------------------------
420  * GLOBAL/ROOT STATE */
421 KMP_ALIGN_CACHE
422 kmp_global_t __kmp_global = {{0}};
423 
424 /* ----------------------------------------------- */
425 /* GLOBAL SYNCHRONIZATION LOCKS */
426 /* TODO verify the need for these locks and if they need to be global */
427 
428 #if KMP_USE_INTERNODE_ALIGNMENT
429 /* Multinode systems have larger cache line granularity which can cause
430  * false sharing if the alignment is not large enough for these locks */
431 KMP_ALIGN_CACHE_INTERNODE
432 
433 kmp_bootstrap_lock_t __kmp_initz_lock = KMP_BOOTSTRAP_LOCK_INITIALIZER(
434     __kmp_initz_lock); /* Control initializations */
435 KMP_ALIGN_CACHE_INTERNODE
436 kmp_bootstrap_lock_t __kmp_forkjoin_lock; /* control fork/join access */
437 KMP_ALIGN_CACHE_INTERNODE
438 kmp_bootstrap_lock_t __kmp_exit_lock; /* exit() is not always thread-safe */
439 #if KMP_USE_MONITOR
440 KMP_ALIGN_CACHE_INTERNODE
441 kmp_bootstrap_lock_t __kmp_monitor_lock; /* control monitor thread creation */
442 #endif
443 /* used for the hack to allow threadprivate cache and __kmp_threads expansion
444    to co-exist */
445 KMP_ALIGN_CACHE_INTERNODE
446 kmp_bootstrap_lock_t __kmp_tp_cached_lock;
447 
448 KMP_ALIGN_CACHE_INTERNODE
449 kmp_lock_t __kmp_global_lock; /* Control OS/global access */
450 KMP_ALIGN_CACHE_INTERNODE
451 kmp_queuing_lock_t __kmp_dispatch_lock; /* Control dispatch access  */
452 KMP_ALIGN_CACHE_INTERNODE
453 kmp_lock_t __kmp_debug_lock; /* Control I/O access for KMP_DEBUG */
454 #else
455 KMP_ALIGN_CACHE
456 
457 kmp_bootstrap_lock_t __kmp_initz_lock = KMP_BOOTSTRAP_LOCK_INITIALIZER(
458     __kmp_initz_lock); /* Control initializations */
459 kmp_bootstrap_lock_t __kmp_forkjoin_lock; /* control fork/join access */
460 kmp_bootstrap_lock_t __kmp_exit_lock; /* exit() is not always thread-safe */
461 #if KMP_USE_MONITOR
462 kmp_bootstrap_lock_t __kmp_monitor_lock; /* control monitor thread creation */
463 #endif
464 /* used for the hack to allow threadprivate cache and __kmp_threads expansion
465    to co-exist */
466 kmp_bootstrap_lock_t __kmp_tp_cached_lock;
467 
468 KMP_ALIGN(128)
469 kmp_lock_t __kmp_global_lock; /* Control OS/global access */
470 KMP_ALIGN(128)
471 kmp_queuing_lock_t __kmp_dispatch_lock; /* Control dispatch access  */
472 KMP_ALIGN(128)
473 kmp_lock_t __kmp_debug_lock; /* Control I/O access for KMP_DEBUG */
474 #endif
475 
476 /* ----------------------------------------------- */
477 
478 #if KMP_HANDLE_SIGNALS
479 /* Signal handling is disabled by default, because it confuses users: In case of
480    sigsegv (or other trouble) in user code signal handler catches the signal,
481    which then "appears" in the monitor thread (when the monitor executes raise()
482    function). Users see signal in the monitor thread and blame OpenMP RTL.
483 
484    Grant said signal handling required on some older OSes (Irix?) supported by
485    KAI, because bad applications hung but not aborted. Currently it is not a
486    problem for Linux* OS, OS X* and Windows* OS.
487 
488    Grant: Found new hangs for EL4, EL5, and a Fedora Core machine.  So I'm
489    putting the default back for now to see if that fixes hangs on those
490    machines.
491 
492    2010-04013 Lev: It was a bug in Fortran RTL. Fortran RTL prints a kind of
493    stack backtrace when program is aborting, but the code is not signal-safe.
494    When multiple signals raised at the same time (which occurs in dynamic
495    negative tests because all the worker threads detects the same error),
496    Fortran RTL may hang. The bug finally fixed in Fortran RTL library provided
497    by Steve R., and will be available soon. */
498 int __kmp_handle_signals = FALSE;
499 #endif
500 
501 #ifdef DEBUG_SUSPEND
502 int get_suspend_count_(void) {
503   int count = __kmp_suspend_count;
504   __kmp_suspend_count = 0;
505   return count;
506 }
507 void set_suspend_count_(int *value) { __kmp_suspend_count = *value; }
508 #endif
509 
510 // Symbols for MS mutual detection.
511 int _You_must_link_with_exactly_one_OpenMP_library = 1;
512 int _You_must_link_with_Intel_OpenMP_library = 1;
513 #if KMP_OS_WINDOWS && (KMP_VERSION_MAJOR > 4)
514 int _You_must_link_with_Microsoft_OpenMP_library = 1;
515 #endif
516 
517 // end of file //
518