release/src/router/mysql/storage/innobase/include/os0thread.h

   1 /******************************************************
   2 The interface to the operating system
   3 process and thread control primitives
   4
   5 (c) 1995 Innobase Oy
   6
   7 Created 9/8/1995 Heikki Tuuri
   8 *******************************************************/
   9
  10 #ifndef os0thread_h
  11 #define os0thread_h
  12
  13 #include "univ.i"
  14
  15 /* Maximum number of threads which can be created in the program;
  16 this is also the size of the wait slot array for MySQL threads which
  17 can wait inside InnoDB */
  18
  19 #define OS_THREAD_MAX_N         srv_max_n_threads
  20
  21
  22 /* Possible fixed priorities for threads */
  23 #define OS_THREAD_PRIORITY_NONE         100
  24 #define OS_THREAD_PRIORITY_BACKGROUND   1
  25 #define OS_THREAD_PRIORITY_NORMAL       2
  26 #define OS_THREAD_PRIORITY_ABOVE_NORMAL 3
  27
  28 #ifdef __WIN__
  29 typedef void*                   os_thread_t;
  30 typedef ulint                   os_thread_id_t; /* In Windows the thread id
  31                                                 is an unsigned long int */
  32 #else
  33 typedef pthread_t               os_thread_t;
  34 typedef os_thread_t             os_thread_id_t; /* In Unix we use the thread
  35                                                 handle itself as the id of
  36                                                 the thread */
  37 #endif
  38
  39 /* Define a function pointer type to use in a typecast */
  40 typedef void* (*os_posix_f_t) (void*);
  41
  42 /*******************************************************************
  43 Compares two thread ids for equality. */
  44
  45 ibool
  46 os_thread_eq(
  47 /*=========*/
  48                                 /* out: TRUE if equal */
  49         os_thread_id_t  a,      /* in: OS thread or thread id */
  50         os_thread_id_t  b);     /* in: OS thread or thread id */
  51 /********************************************************************
  52 Converts an OS thread id to a ulint. It is NOT guaranteed that the ulint is
  53 unique for the thread though! */
  54
  55 ulint
  56 os_thread_pf(
  57 /*=========*/
  58                                 /* out: unsigned long int */
  59         os_thread_id_t  a);     /* in: thread or thread id */
  60 /********************************************************************
  61 Creates a new thread of execution. The execution starts from
  62 the function given. The start function takes a void* parameter
  63 and returns a ulint.
  64 NOTE: We count the number of threads in os_thread_exit(). A created
  65 thread should always use that to exit and not use return() to exit. */
  66
  67 os_thread_t
  68 os_thread_create(
  69 /*=============*/
  70                                                 /* out: handle to the thread */
  71 #ifndef __WIN__
  72                  os_posix_f_t            start_f,
  73 #else
  74         ulint (*start_f)(void*),                /* in: pointer to function
  75                                                 from which to start */
  76 #endif
  77         void*                   arg,            /* in: argument to start
  78                                                 function */
  79         os_thread_id_t*         thread_id);     /* out: id of the created
  80                                                 thread, or NULL */
  81 int
  82 os_thread_join(
  83 /*===========*/
  84   os_thread_id_t  thread_id);   /* in: id of the thread to join */
  85 /*********************************************************************
  86 Exits the current thread. */
  87
  88 void
  89 os_thread_exit(
  90 /*===========*/
  91         void*   exit_value);    /* in: exit value; in Windows this void*
  92                                 is cast as a DWORD */
  93 /*********************************************************************
  94 Returns the thread identifier of current thread. */
  95
  96 os_thread_id_t
  97 os_thread_get_curr_id(void);
  98 /*========================*/
  99 /*********************************************************************
 100 Returns handle to the current thread. */
 101
 102 os_thread_t
 103 os_thread_get_curr(void);
 104 /*====================*/
 105 /*********************************************************************
 106 Advises the os to give up remainder of the thread's time slice. */
 107
 108 void
 109 os_thread_yield(void);
 110 /*=================*/
 111 /*********************************************************************
 112 The thread sleeps at least the time given in microseconds. */
 113
 114 void
 115 os_thread_sleep(
 116 /*============*/
 117         ulint   tm);    /* in: time in microseconds */
 118 /**********************************************************************
 119 Gets a thread priority. */
 120
 121 ulint
 122 os_thread_get_priority(
 123 /*===================*/
 124                                 /* out: priority */
 125         os_thread_t     handle);/* in: OS handle to the thread */
 126 /**********************************************************************
 127 Sets a thread priority. */
 128
 129 void
 130 os_thread_set_priority(
 131 /*===================*/
 132         os_thread_t     handle, /* in: OS handle to the thread */
 133         ulint           pri);   /* in: priority: one of OS_PRIORITY_... */
 134 /**********************************************************************
 135 Gets the last operating system error code for the calling thread. */
 136
 137 ulint
 138 os_thread_get_last_error(void);
 139 /*==========================*/
 140
 141 #ifndef UNIV_NONINL
 142 #include "os0thread.ic"
 143 #endif
 144
 145 #endif