1 /***************************************************************************** 2 3 Copyright (c) 1995, 2016, Oracle and/or its affiliates. All Rights Reserved. 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License, version 2.0, 7 as published by the Free Software Foundation. 8 9 This program is also distributed with certain software (including 10 but not limited to OpenSSL) that is licensed under separate terms, 11 as designated in a particular file or component or in included license 12 documentation. The authors of MySQL hereby grant you an additional 13 permission to link the program and your derivative works with the 14 separately licensed software that they have included with MySQL. 15 16 This program is distributed in the hope that it will be useful, 17 but WITHOUT ANY WARRANTY; without even the implied warranty of 18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 GNU General Public License, version 2.0, for more details. 20 21 You should have received a copy of the GNU General Public License along with 22 this program; if not, write to the Free Software Foundation, Inc., 23 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA 24 25 *****************************************************************************/ 26 27 /**************************************************//** 28 @file include/os0thread.h 29 The interface to the operating system 30 process and thread control primitives 31 32 Created 9/8/1995 Heikki Tuuri 33 *******************************************************/ 34 35 #ifndef os0thread_h 36 #define os0thread_h 37 38 #include "univ.i" 39 40 #ifdef UNIV_LINUX 41 #include <sys/types.h> 42 #endif 43 44 /* Maximum number of threads which can be created in the program; 45 this is also the size of the wait slot array for MySQL threads which 46 can wait inside InnoDB */ 47 48 #define OS_THREAD_MAX_N srv_max_n_threads 49 50 /* Possible fixed priorities for threads */ 51 #define OS_THREAD_PRIORITY_NONE 100 52 #define OS_THREAD_PRIORITY_BACKGROUND 1 53 #define OS_THREAD_PRIORITY_NORMAL 2 54 #define OS_THREAD_PRIORITY_ABOVE_NORMAL 3 55 56 #ifdef __WIN__ 57 typedef void* os_thread_t; 58 typedef DWORD os_thread_id_t; /*!< In Windows the thread id 59 is an unsigned long int */ 60 typedef os_thread_id_t os_tid_t; 61 extern "C" { 62 typedef LPTHREAD_START_ROUTINE os_thread_func_t; 63 } 64 65 /** Macro for specifying a Windows thread start function. */ 66 #define DECLARE_THREAD(func) WINAPI func 67 68 /** Required to get around a build error on Windows. Even though our functions 69 are defined/declared as WINAPI f(LPVOID a); the compiler complains that they 70 are defined as: os_thread_ret_t (__cdecl*)(void*). Because our functions 71 don't access the arguments and don't return any value, we should be safe. */ 72 #define os_thread_create(f,a,i) \ 73 os_thread_create_func(reinterpret_cast<os_thread_func_t>(f), a, i) 74 75 #else 76 77 typedef pthread_t os_thread_t; 78 typedef os_thread_t os_thread_id_t; /*!< In Unix we use the thread 79 handle itself as the id of 80 the thread */ 81 #ifdef UNIV_LINUX 82 typedef pid_t os_tid_t; /*!< An alias for pid_t on 83 Linux, where setpriority() 84 accepts thread id of this type 85 and not pthread_t */ 86 #else 87 typedef os_thread_id_t os_tid_t; 88 #endif 89 90 extern "C" { typedef void* (*os_thread_func_t)(void*); } 91 92 /** Macro for specifying a POSIX thread start function. */ 93 #define DECLARE_THREAD(func) func 94 #define os_thread_create(f,a,i) os_thread_create_func(f, a, i) 95 96 #endif /* __WIN__ */ 97 98 /* Define a function pointer type to use in a typecast */ 99 typedef void* (*os_posix_f_t) (void*); 100 101 #ifdef HAVE_PSI_INTERFACE 102 /* Define for performance schema registration key */ 103 typedef unsigned int mysql_pfs_key_t; 104 #endif 105 106 /***************************************************************//** 107 Compares two thread ids for equality. 108 @return TRUE if equal */ 109 UNIV_INTERN 110 ibool 111 os_thread_eq( 112 /*=========*/ 113 os_thread_id_t a, /*!< in: OS thread or thread id */ 114 os_thread_id_t b); /*!< in: OS thread or thread id */ 115 /****************************************************************//** 116 Converts an OS thread id to a ulint. It is NOT guaranteed that the ulint is 117 unique for the thread though! 118 @return thread identifier as a number */ 119 UNIV_INTERN 120 ulint 121 os_thread_pf( 122 /*=========*/ 123 os_thread_id_t a); /*!< in: OS thread identifier */ 124 /****************************************************************//** 125 Creates a new thread of execution. The execution starts from 126 the function given. The start function takes a void* parameter 127 and returns a ulint. 128 NOTE: We count the number of threads in os_thread_exit(). A created 129 thread should always use that to exit and not use return() to exit. 130 @return handle to the thread */ 131 UNIV_INTERN 132 os_thread_t 133 os_thread_create_func( 134 /*==================*/ 135 os_thread_func_t func, /*!< in: pointer to function 136 from which to start */ 137 void* arg, /*!< in: argument to start 138 function */ 139 os_thread_id_t* thread_id); /*!< out: id of the created 140 thread, or NULL */ 141 142 /** Waits until the specified thread completes and joins it. 143 Its return value is ignored. 144 @param[in,out] thread thread to join */ 145 UNIV_INTERN 146 void 147 os_thread_join( 148 os_thread_t thread); 149 150 /*****************************************************************//** 151 Exits the current thread. */ 152 UNIV_INTERN 153 void 154 os_thread_exit( 155 /*===========*/ 156 void* exit_value, /*!< in: exit value; in Windows this void* 157 is cast as a DWORD */ 158 bool detach = true) /*!< in: if true, the thread will be detached 159 right before exiting. If false, another thread 160 is responsible for joining this thread. */ 161 UNIV_COLD MY_ATTRIBUTE((noreturn)); 162 /*****************************************************************//** 163 Returns the thread identifier of current thread. 164 @return current thread identifier */ 165 UNIV_INTERN 166 os_thread_id_t 167 os_thread_get_curr_id(void); 168 /*========================*/ 169 /*****************************************************************//** 170 Returns the system-specific thread identifier of current thread. On Linux, 171 returns tid. On other systems currently returns os_thread_get_curr_id(). 172 173 @return current thread identifier */ 174 UNIV_INTERN 175 os_tid_t 176 os_thread_get_tid(void); 177 /*=====================*/ 178 /*****************************************************************//** 179 Advises the os to give up remainder of the thread's time slice. */ 180 UNIV_INTERN 181 void 182 os_thread_yield(void); 183 /*=================*/ 184 /*****************************************************************//** 185 The thread sleeps at least the time given in microseconds. */ 186 UNIV_INTERN 187 void 188 os_thread_sleep( 189 /*============*/ 190 ulint tm); /*!< in: time in microseconds */ 191 /*****************************************************************//** 192 Set relative scheduling priority for a given thread on Linux. Currently a 193 no-op on other systems. 194 195 @return An actual thread priority after the update */ 196 UNIV_INTERN 197 ulint 198 os_thread_set_priority( 199 /*===================*/ 200 os_tid_t thread_id, /*!< in: thread id */ 201 ulint relative_priority); /*!< in: system-specific 202 priority value */ 203 204 #ifndef UNIV_NONINL 205 #include "os0thread.ic" 206 #endif 207 208 #endif 209