regina/mt_posix.h

   1 /* This is the supporting header file for POSIX threads.
   2  * We need the following globals:
   3  *
   4  * 1) THREAD_PROTECT(varname)
   5  *    = a pseudo code NOT TERMINATED BY A SEMICOLON. After this point all
   6  *      code until a THREAD_UNPROTECT is executed by one thread at once.
   7  *      This may be done by a call to a semaphore action or something else.
   8  *      THREAD_PROTECT and THREAD_UNPROTECT define a C block logically.
   9  *      varname ist a variable created by PROTECTION_VAR()
  10  * 2) THREAD_UNPROTECT(varname)
  11  *    = see above
  12  * 3) PROTECTION_VAR(varname)
  13  *    = a pseudo code NOT TERMINATED BY A SEMICOLON. This define will
  14  *      create and initialize a local variable which may be used by
  15  *      THREAD_PROTECT and THREAD_UNPROTECT.
  16  *      Typical examples are the protection of static local variables.
  17  * 4) GLOBAL_PROTECTION_VAR(varname)
  18  *    = a pseudo code NOT TERMINATED BY A SEMICOLON. This define will
  19  *      create and initialize a global variable which may be used by
  20  *      THREAD_PROTECT and THREAD_UNPROTECT.
  21  *      Typical examples are the usage of the parser or global variables
  22  *      like macro_serialno.
  23  * 5) EXPORT_GLOBAL_PROTECTION_VAR(varname)
  24  *    = a pseudo code NOT TERMINATED BY A SEMICOLON. This define will
  25  *      export the varname in header files. There must exist one declaration
  26  *      of the variable done by GLOBAL_PROTECTION_VAR.
  27  * 6) GLOBAL_ENTRY_POINT()
  28  *    = initializes the process specific data and the thread specific data.
  29  *      This pseudo function is only called by those functions which are
  30  *      external (rexxsaa.h).
  31  *      It should return (tsd_t *) of the current thread.
  32  * 7) __regina_get_tsd()
  33  *    = pointer to a variable of type tsd_t.
  34  *      This may only exist after a GLOBAL_ENTRY_POINT()-call and must then
  35  *      exist.
  36  *
  37  */
  38
  39 #ifndef MT_H_INCLUDED
  40 #  error This file should included by mt.h, only.
  41 #endif
  42
  43 #include <pthread.h>
  44
  45 #define THREAD_PROTECT(varname) pthread_cleanup_push((void (*)(void *)) \
  46                                               pthread_mutex_unlock,&varname); \
  47                                 pthread_mutex_lock(&varname);
  48 #define THREAD_UNPROTECT(varname) pthread_cleanup_pop(1);
  49
  50 #define PROTECTION_VAR(varname) static pthread_mutex_t varname = \
  51                                                      PTHREAD_MUTEX_INITIALIZER;
  52
  53 #define EXPORT_GLOBAL_PROTECTION_VAR(varname) extern pthread_mutex_t varname;
  54 #define GLOBAL_PROTECTION_VAR(varname) pthread_mutex_t varname = \
  55                                                      PTHREAD_MUTEX_INITIALIZER;
  56
  57
  58 tsd_t *ReginaInitializeThread(void);
  59 #define GLOBAL_ENTRY_POINT() ReginaInitializeThread()
  60
  61 /* we need a pointer to tsd_t sometimes: */
  62 tsd_t *__regina_get_tsd(void);
  63
  64 /* NEVER USE __regina_get_tsd() IF YOU CAN GET THE VALUE FROM SOMEWHERE ELSE.
  65  * IT REDUCES THE EXECUTION SPEED SIGNIFICANTLY. TAKE THE VALUE FROM THE CALLER
  66  * WHERE IT IS POSSIBLE.
  67  */