solver_session Module


Uses


Variables

Type Visibility Attributes Name Initial
integer, public, parameter :: solver_status_ok = 0

Operation completed successfully.
integer, public, parameter :: solver_status_invalid_argument = 1

Caller supplied an invalid handle, key, buffer, or scalar argument.
integer, public, parameter :: solver_status_invalid_state = 2

Operation requires an initialised runtime, but the session is not ready.
integer, public, parameter :: solver_status_config_error = 3

Config loading or validation failed.
integer, public, parameter :: solver_status_io_error = 4

File I/O or other runtime setup/output work failed.
integer, public, parameter :: solver_status_busy = 5

Reserved for adapters that need to report temporary v1 exclusivity/busy state.

Derived Types

type, public ::  solver_progress_t

Polling-friendly runtime summary exposed to adapters.

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Components

Type Visibility Attributes Name Initial
integer, public :: iteration = 0
integer, public :: n_point = 0
logical, public :: is_initialized = .false.
logical, public :: is_finished = .false.
real(kind=wp), public :: sim_time = 0.0_wp
real(kind=wp), public :: time_stop = 0.0_wp
real(kind=wp), public :: dt = 0.0_wp
real(kind=wp), public :: residual = 0.0_wp

type, public ::  solver_session_t

Mutable solver session that owns one configuration and, optionally, one runtime.

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Components

Type Visibility Attributes Name Initial
type(config_t), public :: cfg
type(solver_run_context_t), public :: ctx
integer, public :: dim = 1

Problem dimension: 1 or 2. Set ONLY by solver_session_load_namelist via config_dim.read_dim on the namelist PATH; LOAD_CONFIG_INLINE / SET-built configs carry no namelist buffer and stay dim=1 (spec 2026-07-03 §2.7).
type(config_2d_t), public :: cfg_2d
type(solver_run_context_2d_t), public :: ctx_2d
character(len=512), public :: nml_path = ''
character(len=512), public :: case_dir = ''

Case directory anchoring relative file paths for a LOAD_CONFIG_INLINE config (which has no namelist path to derive it from); '' -> resolve against the process cwd (unchanged legacy behaviour).
logical, public :: has_runtime = .false.
character(len=512), public :: last_error = ''

Subroutines

public subroutine solver_session_create(session)

Reset a session to its default empty state.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(out) :: session

public subroutine solver_session_destroy(session)

Tear down any live runtime allocations and clear the last error.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session

public subroutine solver_session_load_namelist(session, filename, status, message, case_dir)

Load configuration from a namelist file into the session.

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Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
character(len=*), intent(in) :: filename
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message
character(len=*), intent(in), optional :: case_dir

Optional case directory (LOAD_NAMELIST's case_dir) to anchor relative file paths; when absent/empty the namelist's own directory is used.

public subroutine solver_session_prepare_inline(session, dim, case_dir)

Prepare a session to receive a LOAD_CONFIG_INLINE config: discard any live runtime, fix the problem dimension, and record the case directory that anchors relative file paths (inline configs carry no namelist path to derive it from). Must be called BEFORE applying the config entries so the dim-aware SET_* setters target the correct 1D/2D config. Collective-safe: every rank passes the same decoded dim/case_dir.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
integer, intent(in) :: dim
character(len=*), intent(in), optional :: case_dir

public subroutine solver_session_resolve_case_paths(session)

Resolve relative file-valued parameters (grid_file) in the active config against the session's case directory. The inline path bypasses read_config/read_config_2d, where this resolution otherwise lives, so it is applied here after the inline entries land. Absolute paths and an empty case_dir are left unchanged.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session

public subroutine solver_session_initialize(session, status, message)

Validate the current configuration and allocate the runtime context.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_advance(session, max_steps, steps_taken, finished, status, message)

Advance the runtime by at most max_steps iterations.

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Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
integer, intent(in) :: max_steps
integer, intent(out) :: steps_taken
logical, intent(out) :: finished
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_run_to_end(session, status, message, on_progress, every_steps, every_seconds)

Run the current session until time_stop is reached.

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Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message
procedure(progress_callback_i), optional :: on_progress
integer, intent(in), optional :: every_steps
real(kind=wp), intent(in), optional :: every_seconds

public subroutine solver_session_get_progress(session, progress, status, message)

Copy out a lightweight progress snapshot for polling clients.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(in) :: session
type(solver_progress_t), intent(out) :: progress
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_get_point_count(session, n_point, status, message)

Return the current grid-point count expected by solution copy-out buffers.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(in) :: session
integer, intent(out) :: n_point
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_get_global_point_count(session, n_point_global, status, message)

Return the global grid-point count (= n_cell + 1, identical on every rank). Distinct from solver_session_get_point_count, which returns this rank's local interior point count after domain decomposition. Callers that need to size a whole-domain buffer (e.g. the GUI's plot frame, post-run result reader) want this value.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(in) :: session
integer, intent(out) :: n_point_global
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_get_global_grid_shape(session, nx, ny, status, message)

Global structured-grid shape. dim=2: (nx_global, ny_global); dim=1: (n_pt_global, 1). Feeds the nx/ny fields of the 2D INITIALIZE and COPY_SOLUTION replies (spec §4.2).

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(in) :: session
integer, intent(out) :: nx
integer, intent(out) :: ny
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_copy_solution(session, x, rho, u, p, status, message)

Copy the current primitive-variable solution into caller-owned arrays.

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Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(in) :: session
real(kind=wp), intent(out) :: x(:)
real(kind=wp), intent(out) :: rho(:)
real(kind=wp), intent(out) :: u(:)
real(kind=wp), intent(out) :: p(:)
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_copy_global_solution(session, x_global, rho_global, u_global, p_global, status, message)

Gather the current solution from every rank onto rank 0 and fill the caller-owned global arrays. Collective: must be invoked on every rank with the same call sequence as the MPI worker pool. On non-root ranks the output arrays may be size 0 and are not written.

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Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
real(kind=wp), intent(out) :: x_global(:)
real(kind=wp), intent(out) :: rho_global(:)
real(kind=wp), intent(out) :: u_global(:)
real(kind=wp), intent(out) :: p_global(:)
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_copy_global_solution_2d(session, primitives, buf, offsets, nx, ny, status, message)

Gather the 2D solution to rank 0 and pack the requested primitive fields into ONE flat buffer, one nxny block per primitive in request order, each block i-fastest (x-contiguous) — the pack order of solution_gather_2d.write_global_field, so these fields match result_2d.dat columns exactly. offsets are 0-based BYTE offsets ((k-1)nxny8), computed identically on every rank. Supported names: x, y, rho, u, v, p; unknown names copy x with a warning (1D wire-compat leniency). Collective: every rank must call; buffer-size agreement is reduced with par_lor so no rank can return early past the gather.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
character(len=*), intent(in) :: primitives(:)
real(kind=wp), intent(out) :: buf(:)
integer(kind=int64), intent(out) :: offsets(:)
integer, intent(out) :: nx
integer, intent(out) :: ny
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_write_result(session, filename, status, message)

Write the current solution in the standard result.dat-style text format.

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Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
character(len=*), intent(in), optional :: filename
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_write_checkpoint(session, base, status, message, written_path)

Force an immediate checkpoint write using the configured or overridden base name.

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Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
character(len=*), intent(in), optional :: base
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message
character(len=*), intent(out), optional :: written_path

Optional. On success, the real on-disk path the

public subroutine solver_session_last_error(session, message)

Copy the last stored writable-operation error message.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(in) :: session
character(len=*), intent(out) :: message

public subroutine solver_session_get_integer(session, key, value, status, message)

Read an integer configuration field by canonical schema key.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(in) :: session
character(len=*), intent(in) :: key
integer, intent(out) :: value
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_get_real(session, key, value, status, message)

Read a scalar real configuration field by canonical schema key.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(in) :: session
character(len=*), intent(in) :: key
real(kind=wp), intent(out) :: value
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_get_logical(session, key, value, status, message)

Read a logical configuration field by canonical schema key.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(in) :: session
character(len=*), intent(in) :: key
logical, intent(out) :: value
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_get_string(session, key, value, status, message)

Read a string or choice-token configuration field by canonical schema key.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(in) :: session
character(len=*), intent(in) :: key
character(len=*), intent(out) :: value
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_get_real3(session, key, value, status, message)

Read a real-3 configuration field by canonical schema key.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(in) :: session
character(len=*), intent(in) :: key
real(kind=wp), intent(out) :: value(3)
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_set_integer(session, key, value, status, message)

Set an integer configuration field and invalidate any live runtime.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
character(len=*), intent(in) :: key
integer, intent(in) :: value
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_set_real(session, key, value, status, message)

Set a scalar real configuration field and invalidate any live runtime.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
character(len=*), intent(in) :: key
real(kind=wp), intent(in) :: value
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_set_logical(session, key, value, status, message)

Set a logical configuration field and invalidate any live runtime.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
character(len=*), intent(in) :: key
logical, intent(in) :: value
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_set_string(session, key, value, status, message)

Set a string or choice-token configuration field and invalidate any runtime.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
character(len=*), intent(in) :: key
character(len=*), intent(in) :: value
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

public subroutine solver_session_set_real3(session, key, value, status, message)

Set a real-3 configuration field and invalidate any live runtime.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
character(len=*), intent(in) :: key
real(kind=wp), intent(in) :: value(3)
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

private subroutine reset_runtime(session)

Tear down the live runtime context while keeping editable config state.

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Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session

private subroutine finish(session, status_code, err, status, message)

Store the last writable-operation error and mirror it to optional outputs.

Arguments

Type IntentOptional Attributes Name
type(solver_session_t), intent(inout) :: session
integer, intent(in) :: status_code
character(len=*), intent(in) :: err
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message

private subroutine finish_readonly(status_code, err, status, message)

Mirror readonly-operation status without mutating the session state.

Arguments

Type IntentOptional Attributes Name
integer, intent(in) :: status_code
character(len=*), intent(in) :: err
integer, intent(out), optional :: status
character(len=*), intent(out), optional :: message