1 /* 2 Copyright (c) 2005-2020 Intel Corporation 3 4 Licensed under the Apache License, Version 2.0 (the "License"); 5 you may not use this file except in compliance with the License. 6 You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10 Unless required by applicable law or agreed to in writing, software 11 distributed under the License is distributed on an "AS IS" BASIS, 12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 See the License for the specific language governing permissions and 14 limitations under the License. 15 */ 16 17 #ifndef _TBB_governor_H 18 #define _TBB_governor_H 19 20 #include "tbb/task_scheduler_init.h" 21 #include "../rml/include/rml_tbb.h" 22 23 #include "tbb_misc.h" // for AvailableHwConcurrency 24 #include "tls.h" 25 26 #if __TBB_SURVIVE_THREAD_SWITCH 27 #include "cilk-tbb-interop.h" 28 #endif /* __TBB_SURVIVE_THREAD_SWITCH */ 29 30 namespace tbb { 31 namespace internal { 32 33 class market; 34 class generic_scheduler; 35 class __TBB_InitOnce; 36 37 namespace rml { 38 class tbb_client; 39 } 40 41 //------------------------------------------------------------------------ 42 // Class governor 43 //------------------------------------------------------------------------ 44 45 //! The class handles access to the single instance of market, and to TLS to keep scheduler instances. 46 /** It also supports automatic on-demand initialization of the TBB scheduler. 47 The class contains only static data members and methods.*/ 48 class governor { 49 private: 50 friend class __TBB_InitOnce; 51 friend class market; 52 53 //! TLS for scheduler instances associated with individual threads 54 static basic_tls<uintptr_t> theTLS; 55 56 //! Caches the maximal level of parallelism supported by the hardware 57 static unsigned DefaultNumberOfThreads; 58 59 //! Caches the size of OS regular memory page 60 static size_t DefaultPageSize; 61 62 static rml::tbb_factory theRMLServerFactory; 63 64 static bool UsePrivateRML; 65 66 // Flags for runtime-specific conditions 67 static bool is_speculation_enabled; 68 static bool is_rethrow_broken; 69 70 //! Create key for thread-local storage and initialize RML. 71 static void acquire_resources (); 72 73 //! Destroy the thread-local storage key and deinitialize RML. 74 static void release_resources (); 75 76 static rml::tbb_server* create_rml_server ( rml::tbb_client& ); 77 78 //! The internal routine to undo automatic initialization. 79 /** The signature is written with void* so that the routine 80 can be the destructor argument to pthread_key_create. */ 81 static void auto_terminate(void* scheduler); 82 83 public: default_num_threads()84 static unsigned default_num_threads () { 85 // No memory fence required, because at worst each invoking thread calls AvailableHwConcurrency once. 86 return DefaultNumberOfThreads ? DefaultNumberOfThreads : 87 DefaultNumberOfThreads = AvailableHwConcurrency(); 88 } default_page_size()89 static size_t default_page_size () { 90 return DefaultPageSize ? DefaultPageSize : 91 DefaultPageSize = DefaultSystemPageSize(); 92 } 93 static void one_time_init(); 94 //! Processes scheduler initialization request (possibly nested) in a master thread 95 /** If necessary creates new instance of arena and/or local scheduler. 96 The auto_init argument specifies if the call is due to automatic initialization. **/ 97 static generic_scheduler* init_scheduler( int num_threads, stack_size_type stack_size, bool auto_init ); 98 99 //! Automatic initialization of scheduler in a master thread with default settings without arena 100 static generic_scheduler* init_scheduler_weak(); 101 102 //! Processes scheduler termination request (possibly nested) in a master thread 103 static bool terminate_scheduler( generic_scheduler* s, bool blocking ); 104 105 //! Register TBB scheduler instance in thread-local storage. 106 static void sign_on( generic_scheduler* s ); 107 108 //! Unregister TBB scheduler instance from thread-local storage. 109 static void sign_off( generic_scheduler* s ); 110 111 //! Used to check validity of the local scheduler TLS contents. 112 static bool is_set( generic_scheduler* s ); 113 114 //! Temporarily set TLS slot to the given scheduler 115 static void assume_scheduler( generic_scheduler* s ); 116 117 //! Computes the value of the TLS 118 static uintptr_t tls_value_of( generic_scheduler* s ); 119 120 // TODO IDEA: refactor bit manipulations over pointer types to a class? 121 //! Converts TLS value to the scheduler pointer tls_scheduler_of(uintptr_t v)122 static generic_scheduler* tls_scheduler_of( uintptr_t v ) { 123 return (generic_scheduler*)(v & ~uintptr_t(1)); 124 } 125 126 //! Obtain the thread-local instance of the TBB scheduler. 127 /** If the scheduler has not been initialized yet, initialization is done automatically. 128 Note that auto-initialized scheduler instance is destroyed only when its thread terminates. **/ local_scheduler()129 static generic_scheduler* local_scheduler () { 130 uintptr_t v = theTLS.get(); 131 return (v&1) ? tls_scheduler_of(v) : init_scheduler( task_scheduler_init::automatic, 0, /*auto_init=*/true ); 132 } 133 local_scheduler_weak()134 static generic_scheduler* local_scheduler_weak () { 135 uintptr_t v = theTLS.get(); 136 return v ? tls_scheduler_of(v) : init_scheduler_weak(); 137 } 138 local_scheduler_if_initialized()139 static generic_scheduler* local_scheduler_if_initialized () { 140 return tls_scheduler_of( theTLS.get() ); 141 } 142 143 //! Undo automatic initialization if necessary; call when a thread exits. terminate_auto_initialized_scheduler()144 static void terminate_auto_initialized_scheduler() { 145 auto_terminate( local_scheduler_if_initialized() ); 146 } 147 148 static void print_version_info (); 149 150 static void initialize_rml_factory (); 151 152 static bool does_client_join_workers (const tbb::internal::rml::tbb_client &client); 153 154 #if __TBB_SURVIVE_THREAD_SWITCH 155 static __cilk_tbb_retcode stack_op_handler( __cilk_tbb_stack_op op, void* ); 156 #endif /* __TBB_SURVIVE_THREAD_SWITCH */ 157 speculation_enabled()158 static bool speculation_enabled() { return is_speculation_enabled; } rethrow_exception_broken()159 static bool rethrow_exception_broken() { return is_rethrow_broken; } 160 161 }; // class governor 162 163 } // namespace internal 164 } // namespace tbb 165 166 #endif /* _TBB_governor_H */ 167