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 /* Maximum number of threads which can be created in the program; 41 this is also the size of the wait slot array for MySQL threads which 42 can wait inside InnoDB */ 43 44 #define OS_THREAD_MAX_N srv_max_n_threads 45 46 /* Possible fixed priorities for threads */ 47 #define OS_THREAD_PRIORITY_NONE 100 48 #define OS_THREAD_PRIORITY_BACKGROUND 1 49 #define OS_THREAD_PRIORITY_NORMAL 2 50 #define OS_THREAD_PRIORITY_ABOVE_NORMAL 3 51 52 #ifdef __WIN__ 53 typedef void* os_thread_t; 54 typedef DWORD os_thread_id_t; /*!< In Windows the thread id 55 is an unsigned long int */ 56 extern "C" { 57 typedef LPTHREAD_START_ROUTINE os_thread_func_t; 58 } 59 60 /** Macro for specifying a Windows thread start function. */ 61 #define DECLARE_THREAD(func) WINAPI func 62 63 /** Required to get around a build error on Windows. Even though our functions 64 are defined/declared as WINAPI f(LPVOID a); the compiler complains that they 65 are defined as: os_thread_ret_t (__cdecl*)(void*). Because our functions 66 don't access the arguments and don't return any value, we should be safe. */ 67 #define os_thread_create(f,a,i) \ 68 os_thread_create_func(reinterpret_cast<os_thread_func_t>(f), a, i) 69 70 #else 71 72 typedef pthread_t os_thread_t; 73 typedef os_thread_t os_thread_id_t; /*!< In Unix we use the thread 74 handle itself as the id of 75 the thread */ 76 extern "C" { typedef void* (*os_thread_func_t)(void*); } 77 78 /** Macro for specifying a POSIX thread start function. */ 79 #define DECLARE_THREAD(func) func 80 #define os_thread_create(f,a,i) os_thread_create_func(f, a, i) 81 82 #endif /* __WIN__ */ 83 84 /* Define a function pointer type to use in a typecast */ 85 typedef void* (*os_posix_f_t) (void*); 86 87 #ifdef HAVE_PSI_INTERFACE 88 /* Define for performance schema registration key */ 89 typedef unsigned int mysql_pfs_key_t; 90 #endif 91 92 /***************************************************************//** 93 Compares two thread ids for equality. 94 @return TRUE if equal */ 95 UNIV_INTERN 96 ibool 97 os_thread_eq( 98 /*=========*/ 99 os_thread_id_t a, /*!< in: OS thread or thread id */ 100 os_thread_id_t b); /*!< in: OS thread or thread id */ 101 /****************************************************************//** 102 Converts an OS thread id to a ulint. It is NOT guaranteed that the ulint is 103 unique for the thread though! 104 @return thread identifier as a number */ 105 UNIV_INTERN 106 ulint 107 os_thread_pf( 108 /*=========*/ 109 os_thread_id_t a); /*!< in: OS thread identifier */ 110 /****************************************************************//** 111 Creates a new thread of execution. The execution starts from 112 the function given. The start function takes a void* parameter 113 and returns a ulint. 114 NOTE: We count the number of threads in os_thread_exit(). A created 115 thread should always use that to exit and not use return() to exit. 116 @return handle to the thread */ 117 UNIV_INTERN 118 os_thread_t 119 os_thread_create_func( 120 /*==================*/ 121 os_thread_func_t func, /*!< in: pointer to function 122 from which to start */ 123 void* arg, /*!< in: argument to start 124 function */ 125 os_thread_id_t* thread_id); /*!< out: id of the created 126 thread, or NULL */ 127 128 /** Waits until the specified thread completes and joins it. 129 Its return value is ignored. 130 @param[in,out] thread thread to join */ 131 UNIV_INTERN 132 void 133 os_thread_join( 134 os_thread_t thread); 135 136 /*****************************************************************//** 137 Exits the current thread. */ 138 UNIV_INTERN 139 void 140 os_thread_exit( 141 /*===========*/ 142 void* exit_value, /*!< in: exit value; in Windows this void* 143 is cast as a DWORD */ 144 bool detach = true) /*!< in: if true, the thread will be detached 145 right before exiting. If false, another thread 146 is responsible for joining this thread. */ 147 UNIV_COLD MY_ATTRIBUTE((noreturn)); 148 /*****************************************************************//** 149 Returns the thread identifier of current thread. 150 @return current thread identifier */ 151 UNIV_INTERN 152 os_thread_id_t 153 os_thread_get_curr_id(void); 154 /*========================*/ 155 /*****************************************************************//** 156 Advises the os to give up remainder of the thread's time slice. */ 157 UNIV_INTERN 158 void 159 os_thread_yield(void); 160 /*=================*/ 161 /*****************************************************************//** 162 The thread sleeps at least the time given in microseconds. */ 163 UNIV_INTERN 164 void 165 os_thread_sleep( 166 /*============*/ 167 ulint tm); /*!< in: time in microseconds */ 168 169 #ifndef UNIV_NONINL 170 #include "os0thread.ic" 171 #endif 172 173 #endif 174