Line data    Source code

       1             : /*
       2             :        Low cost access to a system time. This, in general, should not be included in user programs.
       3             : */
       4             : #pragma once
       5             : 
       6             : #include <petscsys.h>
       7             : 
       8             : /* SUBMANSEC = Sys */
       9             : 
      10             : PETSC_EXTERN PetscErrorCode PetscGetCPUTime(PetscLogDouble *);
      11             : 
      12             : /* Global counters */
      13             : PETSC_EXTERN PetscLogDouble petsc_BaseTime;
      14             : 
      15             : /*@
      16             :    PetscTime - Returns the current time from some base time in the past in seconds.
      17             : 
      18             :    Not Collective
      19             : 
      20             :    Output Parameter:
      21             : .  v - time counter
      22             : 
      23             :    Usage:
      24             : .vb
      25             :      PetscLogDouble v;
      26             :      PetscTime(&v);
      27             :      .... perform some calculation ...
      28             :      printf("Time for operation %g\n",v);
      29             : .ve
      30             : 
      31             :    Level: developer
      32             : 
      33             :    Note:
      34             :    Since the PETSc libraries incorporate timing of phases and operations, we do not recommend ever using `PetscTime()`.
      35             :    The options database command  `-log_view` activates PETSc library timing.
      36             :    See `PetscLogStageRegister()`, `PetscLogEventRegister()`, `PetscLogEventBegin()`, `PetscLogEventEnd()` for how to register
      37             :    stages and events in application codes.
      38             : 
      39             : .seealso: `PetscTimeSubtract()`, `PetscTimeAdd()`, `PetscLogStageRegister()`, `PetscLogEventRegister()`, `PetscLogEventBegin()`, `PetscLogEventEnd()`
      40             : @*/
      41         251 : static inline PetscErrorCode PetscTime(PetscLogDouble *v)
      42             : {
      43         251 :   *v = MPI_Wtime();
      44         251 :   return PETSC_SUCCESS;
      45             : }
      46             : 
      47             : /*@
      48             :    PetscTimeSubtract - Subtracts the current time (in seconds) from the value `v`.
      49             : 
      50             :    Not Collective
      51             : 
      52             :    Input Parameter:
      53             : .  v - time counter
      54             : 
      55             :    Output Parameter:
      56             : .  v - time counter (`v` = `v` - current time)
      57             : 
      58             :    Level: developer
      59             : 
      60             :    Note:
      61             :    Since the PETSc libraries incorporate timing of phases and operations, we do not always recommend using `PetscTimeSubtract()`.
      62             :    The options database command  `-log_view` activates PETSc library timing.
      63             :    See `PetscLogStageRegister()`, `PetscLogEventRegister()`, `PetscLogEventBegin()`, `PetscLogEventEnd()` for how to register
      64             :    stages and events in application codes.
      65             : 
      66             : .seealso: `PetscTime()`, `PetscTimeAdd()`, `PetscLogStageRegister()`, `PetscLogEventRegister()`, `PetscLogEventBegin()`, `PetscLogEventEnd()`
      67             : @*/
      68             : static inline PetscErrorCode PetscTimeSubtract(PetscLogDouble *v)
      69             : {
      70             :   *v -= MPI_Wtime();
      71             :   return PETSC_SUCCESS;
      72             : }
      73             : 
      74             : /*@
      75             :    PetscTimeAdd - Adds the current time (in seconds) to the value `v`.
      76             : 
      77             :    Not Collective
      78             : 
      79             :    Input Parameter:
      80             : .  v - time counter
      81             : 
      82             :    Output Parameter:
      83             : .  v - time counter (`v` = `v` + current time)
      84             : 
      85             :    Level: developer
      86             : 
      87             :    Note:
      88             :    Since the PETSc libraries incorporate timing of phases and operations,  we do not ever recommend using `PetscTimeAdd()`.
      89             :    The options database command `-log_view` activates PETSc library timing.
      90             : 
      91             : .seealso: `PetscTime()`, `PetscTimeSubtract()`, `PetscLogStageRegister()`, `PetscLogEventRegister()`, `PetscLogEventBegin()`, `PetscLogEventEnd()`
      92             : @*/
      93           2 : static inline PetscErrorCode PetscTimeAdd(PetscLogDouble *v)
      94             : {
      95           2 :   *v += MPI_Wtime();
      96           2 :   return PETSC_SUCCESS;
      97             : }