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 kmp_uint64 __kmp_taskloop_min_tasks = 0;
305 #endif
306 
307 /* This check ensures that the compiler is passing the correct data type for the
308    flags formal parameter of the function kmpc_omp_task_alloc(). If the type is
309    not a 4-byte type, then give an error message about a non-positive length
310    array pointing here.  If that happens, the kmp_tasking_flags_t structure must
311    be redefined to have exactly 32 bits. */
312 KMP_BUILD_ASSERT(sizeof(kmp_tasking_flags_t) == 4);
313 
314 kmp_int32 __kmp_task_stealing_constraint =
315     1; /* Constrain task stealing by default */
316 
317 #ifdef DEBUG_SUSPEND
318 int __kmp_suspend_count = 0;
319 #endif
320 
321 int __kmp_settings = FALSE;
322 int __kmp_duplicate_library_ok = 0;
323 #if USE_ITT_BUILD
324 int __kmp_forkjoin_frames = 1;
325 int __kmp_forkjoin_frames_mode = 3;
326 #endif
327 PACKED_REDUCTION_METHOD_T __kmp_force_reduction_method =
328     reduction_method_not_defined;
329 int __kmp_determ_red = FALSE;
330 
331 #ifdef KMP_DEBUG
332 int kmp_a_debug = 0;
333 int kmp_b_debug = 0;
334 int kmp_c_debug = 0;
335 int kmp_d_debug = 0;
336 int kmp_e_debug = 0;
337 int kmp_f_debug = 0;
338 int kmp_diag = 0;
339 #endif
340 
341 /* For debug information logging using rotating buffer */
342 int __kmp_debug_buf =
343     FALSE; /* TRUE means use buffer, FALSE means print to stderr */
344 int __kmp_debug_buf_lines =
345     KMP_DEBUG_BUF_LINES_INIT; /* Lines of debug stored in buffer */
346 int __kmp_debug_buf_chars =
347     KMP_DEBUG_BUF_CHARS_INIT; /* Characters allowed per line in buffer */
348 int __kmp_debug_buf_atomic =
349     FALSE; /* TRUE means use atomic update of buffer entry pointer */
350 
351 char *__kmp_debug_buffer = NULL; /* Debug buffer itself */
352 int __kmp_debug_count =
353     0; /* Counter for number of lines printed in buffer so far */
354 int __kmp_debug_buf_warn_chars =
355     0; /* Keep track of char increase recommended in warnings */
356 /* end rotating debug buffer */
357 
358 #ifdef KMP_DEBUG
359 int __kmp_par_range; /* +1 => only go par for constructs in range */
360 /* -1 => only go par for constructs outside range */
361 char __kmp_par_range_routine[KMP_PAR_RANGE_ROUTINE_LEN] = {'\0'};
362 char __kmp_par_range_filename[KMP_PAR_RANGE_FILENAME_LEN] = {'\0'};
363 int __kmp_par_range_lb = 0;
364 int __kmp_par_range_ub = INT_MAX;
365 #endif /* KMP_DEBUG */
366 
367 /* For printing out dynamic storage map for threads and teams */
368 int __kmp_storage_map =
369     FALSE; /* True means print storage map for threads and teams */
370 int __kmp_storage_map_verbose =
371     FALSE; /* True means storage map includes placement info */
372 int __kmp_storage_map_verbose_specified = FALSE;
373 /* Initialize the library data structures when we fork a child process, defaults
374  * to TRUE */
375 int __kmp_need_register_atfork =
376     TRUE; /* At initialization, call pthread_atfork to install fork handler */
377 int __kmp_need_register_atfork_specified = TRUE;
378 
379 int __kmp_env_stksize = FALSE; /* KMP_STACKSIZE specified? */
380 int __kmp_env_blocktime = FALSE; /* KMP_BLOCKTIME specified? */
381 int __kmp_env_checks = FALSE; /* KMP_CHECKS specified?    */
382 int __kmp_env_consistency_check = FALSE; /* KMP_CONSISTENCY_CHECK specified? */
383 
384 kmp_uint32 __kmp_yield_init = KMP_INIT_WAIT;
385 kmp_uint32 __kmp_yield_next = KMP_NEXT_WAIT;
386 
387 #if KMP_USE_MONITOR
388 kmp_uint32 __kmp_yielding_on = 1;
389 #endif
390 #if KMP_OS_CNK
391 kmp_uint32 __kmp_yield_cycle = 0;
392 #else
393 kmp_uint32 __kmp_yield_cycle = 1; /* Yield-cycle is on by default */
394 #endif
395 kmp_int32 __kmp_yield_on_count =
396     10; /* By default, yielding is on for 10 monitor periods. */
397 kmp_int32 __kmp_yield_off_count =
398     1; /* By default, yielding is off for 1 monitor periods. */
399 
400 /* ------------------------------------------------------ */
401 /* STATE mostly syncronized with global lock */
402 /* data written to rarely by masters, read often by workers */
403 /* TODO: None of this global padding stuff works consistently because the order
404    of declaration is not necessarily correlated to storage order. To fix this,
405    all the important globals must be put in a big structure instead. */
406 KMP_ALIGN_CACHE
407 kmp_info_t **__kmp_threads = NULL;
408 kmp_root_t **__kmp_root = NULL;
409 
410 /* data read/written to often by masters */
411 KMP_ALIGN_CACHE
412 volatile int __kmp_nth = 0;
413 volatile int __kmp_all_nth = 0;
414 int __kmp_thread_pool_nth = 0;
415 volatile kmp_info_t *__kmp_thread_pool = NULL;
416 volatile kmp_team_t *__kmp_team_pool = NULL;
417 
418 KMP_ALIGN_CACHE
419 volatile int __kmp_thread_pool_active_nth = 0;
420 
421 /* -------------------------------------------------
422  * GLOBAL/ROOT STATE */
423 KMP_ALIGN_CACHE
424 kmp_global_t __kmp_global = {{0}};
425 
426 /* ----------------------------------------------- */
427 /* GLOBAL SYNCHRONIZATION LOCKS */
428 /* TODO verify the need for these locks and if they need to be global */
429 
430 #if KMP_USE_INTERNODE_ALIGNMENT
431 /* Multinode systems have larger cache line granularity which can cause
432  * false sharing if the alignment is not large enough for these locks */
433 KMP_ALIGN_CACHE_INTERNODE
434 
435 kmp_bootstrap_lock_t __kmp_initz_lock = KMP_BOOTSTRAP_LOCK_INITIALIZER(
436     __kmp_initz_lock); /* Control initializations */
437 KMP_ALIGN_CACHE_INTERNODE
438 kmp_bootstrap_lock_t __kmp_forkjoin_lock; /* control fork/join access */
439 KMP_ALIGN_CACHE_INTERNODE
440 kmp_bootstrap_lock_t __kmp_exit_lock; /* exit() is not always thread-safe */
441 #if KMP_USE_MONITOR
442 KMP_ALIGN_CACHE_INTERNODE
443 kmp_bootstrap_lock_t __kmp_monitor_lock; /* control monitor thread creation */
444 #endif
445 /* used for the hack to allow threadprivate cache and __kmp_threads expansion
446    to co-exist */
447 KMP_ALIGN_CACHE_INTERNODE
448 kmp_bootstrap_lock_t __kmp_tp_cached_lock;
449 
450 KMP_ALIGN_CACHE_INTERNODE
451 kmp_lock_t __kmp_global_lock; /* Control OS/global access */
452 KMP_ALIGN_CACHE_INTERNODE
453 kmp_queuing_lock_t __kmp_dispatch_lock; /* Control dispatch access  */
454 KMP_ALIGN_CACHE_INTERNODE
455 kmp_lock_t __kmp_debug_lock; /* Control I/O access for KMP_DEBUG */
456 #else
457 KMP_ALIGN_CACHE
458 
459 kmp_bootstrap_lock_t __kmp_initz_lock = KMP_BOOTSTRAP_LOCK_INITIALIZER(
460     __kmp_initz_lock); /* Control initializations */
461 kmp_bootstrap_lock_t __kmp_forkjoin_lock; /* control fork/join access */
462 kmp_bootstrap_lock_t __kmp_exit_lock; /* exit() is not always thread-safe */
463 #if KMP_USE_MONITOR
464 kmp_bootstrap_lock_t __kmp_monitor_lock; /* control monitor thread creation */
465 #endif
466 /* used for the hack to allow threadprivate cache and __kmp_threads expansion
467    to co-exist */
468 kmp_bootstrap_lock_t __kmp_tp_cached_lock;
469 
470 KMP_ALIGN(128)
471 kmp_lock_t __kmp_global_lock; /* Control OS/global access */
472 KMP_ALIGN(128)
473 kmp_queuing_lock_t __kmp_dispatch_lock; /* Control dispatch access  */
474 KMP_ALIGN(128)
475 kmp_lock_t __kmp_debug_lock; /* Control I/O access for KMP_DEBUG */
476 #endif
477 
478 /* ----------------------------------------------- */
479 
480 #if KMP_HANDLE_SIGNALS
481 /* Signal handling is disabled by default, because it confuses users: In case of
482    sigsegv (or other trouble) in user code signal handler catches the signal,
483    which then "appears" in the monitor thread (when the monitor executes raise()
484    function). Users see signal in the monitor thread and blame OpenMP RTL.
485 
486    Grant said signal handling required on some older OSes (Irix?) supported by
487    KAI, because bad applications hung but not aborted. Currently it is not a
488    problem for Linux* OS, OS X* and Windows* OS.
489 
490    Grant: Found new hangs for EL4, EL5, and a Fedora Core machine.  So I'm
491    putting the default back for now to see if that fixes hangs on those
492    machines.
493 
494    2010-04013 Lev: It was a bug in Fortran RTL. Fortran RTL prints a kind of
495    stack backtrace when program is aborting, but the code is not signal-safe.
496    When multiple signals raised at the same time (which occurs in dynamic
497    negative tests because all the worker threads detects the same error),
498    Fortran RTL may hang. The bug finally fixed in Fortran RTL library provided
499    by Steve R., and will be available soon. */
500 int __kmp_handle_signals = FALSE;
501 #endif
502 
503 /* ----------------------------------------------- */
504 #ifdef BUILD_TV
505 kmp_key_t __kmp_tv_key = 0;
506 #endif
507 
508 /* ------------------------------------------------------------------------ */
509 
510 #ifdef DEBUG_SUSPEND
511 int get_suspend_count_(void) {
512   int count = __kmp_suspend_count;
513   __kmp_suspend_count = 0;
514   return count;
515 }
516 void set_suspend_count_(int *value) { __kmp_suspend_count = *value; }
517 #endif
518 
519 // Symbols for MS mutual detection.
520 int _You_must_link_with_exactly_one_OpenMP_library = 1;
521 int _You_must_link_with_Intel_OpenMP_library = 1;
522 #if KMP_OS_WINDOWS && (KMP_VERSION_MAJOR > 4)
523 int _You_must_link_with_Microsoft_OpenMP_library = 1;
524 #endif
525 
526 // end of file //
527