workbench/libs/thread/createcondition.c

   1 /*
   2  * thread.library - threading and synchronisation primitives
   3  *
   4  * Copyright © 2007 Robert Norris
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the same terms as AROS itself.
   8  */
   9
  10 #include "thread_intern.h"
  11
  12 #include <exec/memory.h>
  13 #include <exec/lists.h>
  14 #include <proto/exec.h>
  15
  16 /*****************************************************************************
  17
  18     NAME */
  19         AROS_LH0(void *, CreateCondition,
  20
  21 /*  SYNOPSIS */
  22
  23 /*  LOCATION */
  24         struct ThreadBase *, ThreadBase, 15, Thread)
  25
  26 /*  FUNCTION
  27         Creates a condition variable.
  28
  29     INPUTS
  30         None.
  31
  32     RESULT
  33         The newly created condition, or NULL if one couldn't be created.
  34
  35     NOTES
  36         Condition cond = CreateCondition();
  37
  38     EXAMPLE
  39
  40     BUGS
  41
  42     SEE ALSO
  43         DestroyCondition(), WaitCondition(), SignalCondition(),
  44         BroadcastCondition()
  45
  46     INTERNALS
  47
  48 *****************************************************************************/
  49 {
  50     AROS_LIBFUNC_INIT
  51
  52     struct _Condition *c;
  53
  54     /* allocate */
  55     if ((c = AllocMem(sizeof(struct _Condition), MEMF_PUBLIC)) == NULL)
  56         return NULL;
  57
  58     /* initialise */
  59     InitSemaphore(&c->lock);
  60     NEWLIST(&c->waiters);
  61     c->count = 0;
  62
  63     return (void *) c;
  64
  65     AROS_LIBFUNC_EXIT
  66 } /* CreateCondition */