rom/exec/findtaskbypid.c

   1 /*
   2     Copyright © 1995-2015, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <exec/execbase.h>
   7 #include <exec/tasks.h>
   8
   9 #include "exec_intern.h"
  10
  11 /*****************************************************************************
  12
  13     NAME */
  14 #include <proto/exec.h>
  15
  16         AROS_LH1(struct Task *, FindTaskByPID,
  17
  18 /*  SYNOPSIS */
  19         AROS_LHA(ULONG, id, D0),
  20
  21 /*  LOCATION */
  22         struct ExecBase *, SysBase, 166, Exec)
  23
  24 /*  FUNCTION
  25         Scan through the task lists searching for the task whose
  26         et_UniqueID field matches.
  27
  28     INPUTS
  29         id      -   The task ID to match.
  30
  31     RESULT
  32         Address of the Task control structure that matches, or
  33         NULL otherwise.
  34
  35     NOTES
  36         This function is source-compatible with MorphOS.
  37
  38     EXAMPLE
  39
  40     BUGS
  41
  42     SEE ALSO
  43
  44     INTERNALS
  45
  46 ******************************************************************************/
  47 {
  48     AROS_LIBFUNC_INIT
  49
  50 #if defined(__AROSEXEC_SMP__)
  51     spinlock_t *listLock;
  52 #endif
  53     struct Task *t;
  54     struct ETask *et;
  55
  56     /* First up, check running task(s) */
  57 #if defined(__AROSEXEC_SMP__)
  58     listLock = EXEC_SPINLOCK_LOCK(&PrivExecBase(SysBase)->TaskRunningSpinLock, SPINLOCK_MODE_READ);
  59     Forbid();
  60     ForeachNode(&PrivExecBase(SysBase)->TaskRunning, t)
  61     {
  62         et = GetETask(t);
  63         if (et != NULL && et->et_UniqueID == id)
  64         {
  65             EXEC_SPINLOCK_UNLOCK(listLock);
  66             Permit();
  67             return t;
  68         }
  69     }
  70     EXEC_SPINLOCK_UNLOCK(listLock);
  71     Permit();
  72     listLock = EXEC_SPINLOCK_LOCK(&PrivExecBase(SysBase)->TaskSpinningLock, SPINLOCK_MODE_READ);
  73     Forbid();
  74     ForeachNode(&PrivExecBase(SysBase)->TaskSpinning, t)
  75     {
  76         et = GetETask(t);
  77         if (et != NULL && et->et_UniqueID == id)
  78         {
  79             EXEC_SPINLOCK_UNLOCK(listLock);
  80             Permit();
  81             return t;
  82         }
  83     }
  84     EXEC_SPINLOCK_UNLOCK(listLock);
  85     Permit();
  86     listLock = EXEC_SPINLOCK_LOCK(&PrivExecBase(SysBase)->TaskReadySpinLock, SPINLOCK_MODE_READ);
  87     Forbid();
  88 #else
  89     Disable();
  90     if (GET_THIS_TASK != NULL)
  91     {
  92         et = GetETask(GET_THIS_TASK);
  93         if (et != NULL && et->et_UniqueID == id)
  94         {
  95             Enable();
  96             return GET_THIS_TASK;
  97         }
  98     }
  99 #endif
 100     /*  Next, go through the ready list */
 101     ForeachNode(&SysBase->TaskReady, t)
 102     {
 103         et = GetETask(t);
 104         if (et != NULL && et->et_UniqueID == id)
 105         {
 106 #if defined(__AROSEXEC_SMP__)
 107             EXEC_SPINLOCK_UNLOCK(listLock);
 108             Permit();
 109 #else
 110             Enable();
 111 #endif
 112             return t;
 113         }
 114     }
 115 #if defined(__AROSEXEC_SMP__)
 116     EXEC_SPINLOCK_UNLOCK(listLock);
 117     Permit();
 118     listLock = EXEC_SPINLOCK_LOCK(&PrivExecBase(SysBase)->TaskWaitSpinLock, SPINLOCK_MODE_READ);
 119     Forbid();
 120 #endif
 121     /* Finally, go through the wait list */
 122     ForeachNode(&SysBase->TaskWait, t)
 123     {
 124         et = GetETask(t);
 125         if (et != NULL && et->et_UniqueID == id)
 126         {
 127 #if defined(__AROSEXEC_SMP__)
 128             EXEC_SPINLOCK_UNLOCK(listLock);
 129             Permit();
 130 #else
 131             Enable();
 132 #endif
 133             return t;
 134         }
 135     }
 136
 137 #if defined(__AROSEXEC_SMP__)
 138     EXEC_SPINLOCK_UNLOCK(listLock);
 139     Permit();
 140 #else
 141     Enable();
 142 #endif
 143
 144     return NULL;
 145
 146     AROS_LIBFUNC_EXIT
 147 }