a0445d806c
* Take a stab at using constructors to initialize instead of
function-entry macros. This is a work in progress. It's good enough to
run `many_dsets`.
* Committing clang-format changes
* Add the `many_dsets` benchmark and some scripts I used on jelly for
setting up the build/test environment and for recording/flame-graphing
profiles.
* Committing clang-format changes
* Change my Makefile and environment script to work both on jelly
and on mayll (and probably on Summit).
* Disable clang-format "fix."
* Replace the `if (!H5_TERM_GLOBAL)` test in each FUNC_ENTER_ macro with
`if (true)`.
* Fix bad grammar in a comment.
* Instead of labeling the H5*__init_package routines constructors, fold
each into an initialization routine, H5*_init(), and call each of
the H5*_init() routines. Call most of the H5*_init() routines from
H5_init_library() in an explicit order that I found out earlier by
instrumenting each __init_package routine and running the library
tests. Roll H5FD*__init_package routines into H5FD*_init() routines.
This change ends just-in-time initialization of package dependencies by
package initializers.
Don't track in per-package variables (H5_PKG_INIT_VAR) whether each
package has been initialized. Instead, track in a single library
variable whether the whole library is initialized or not.
Drive the initialization of packages by H5_init_library() with a table
of initializer routines. Also drive the termination of packages by
H5_term_library() with a table.
Perform initialization as needed from FUNC_ENTER_API_INIT(err). This
basically restores the old behavior of that macro.
Delete a bunch of #definitions in H5private.h that have fallen out of
use with these changes.
* Committing clang-format changes
* Undo the bad auto-formatting that appears to have occurred in spite
of my disabling it. Bracket some code in /* clang-format off */ /*
clang-format on */ to prevent a recurrence.
* Remove a diagnostic abort().
* Fix a logic error: print a comma between every package terminator run,
and don't print an initial comma.
* Complete the changes I started in H5_term_library() that undo the bad
auto-formatting.
Stop tracking whether package "tops" were initialized in per-package
variables H5*_top_package_initialize_s. H5_term_library() takes care of
that for them.
Remove H5R_top_term_package() and H5R_term_package(), they don't do
anything.
* Committing clang-format changes
* NFCI. Simplify macro text: replace `if (true) {` with `{`.
* Fix formatting and suppress clang-format on a longer range.
* Quiet some unused label, unused variable complaints that cropped up
after I simplified the FUNC_ENTER_ macros for the sake of performance.
* Committing clang-format changes
* Delete some programs and scripts that don't belong in the pull request.
* Use the right function-entry macro.
* Use a sensible format and disable auto-formatting.
* Stop calling do-nothing initializer H5FS_init(). Delete it.
* Document what changes to make if the default VFD changes.
* While I am here, change an `await_prior` flag on the terminator table
to `true` to match the previous, non-table-driven code that was here.
Found the oversight making the following changes:
NFCI: insert an empty line and copy over slightly-edited comments from
the previous version, where those comments still correctly explained how
library termination operated.
* NFCI: lower a staircase.
* Replace every occurrence of FUNC_ENTER_NOAPI_INIT(...) with H5_PUSH_FUNC
since that is all that that macro does any more.
Quiet a bunch of new warnings by changing FUNC_ENTER_NOAPI(...) to
FUNC_ENTER_NOAPI_NOERR and removing disused `done:` labels.
* NFCI: add curly braces around a multiline statement.
* Quiet a signed/unsigned comparison warning.
* Add some documentation about library initialization and shutdown.
* Make sure that the library is initialized, or else that initialization
is already underway, before performing any VFD's initialization.
* Committing clang-format changes
* Committing clang-format changes
* Reduce differences from `develop` branch.
* Always initialize `tot_init`.
* Committing clang-format changes
* Fix typo: H5SL_init initializes skip lists, not VOL.
* Remove H5_TERM_GLOBAL test in H5T_init. H5T_init was unusual in that
it tested H5_TERM_GLOBAL and exited early if it was set. No other
module initializers did that, and I cannot find any reason that should
be necessary. Tests still pass when I remove it, so away it goes.
* Use HD prefix.
* Add function header comments.
* Drop the intermediate variable, it's only used once.
* Extract subroutine `H5FDperform_init(hid_t (*init)(void))` that
initializes the library, if necessary, before calling its VFD-initializer
argument. Use H5FDperform_init in the definition of the symbols
H5FD_<vfd> (e.g., H5FD_SEC2), which may be evaluated before the library
is initialized, like so:
```
```
I implement H5FDperform_init in its own source file, H5FDperform.c,
and exclude that file from trace processing because the `bin/trace`
cannot deal with the function-pointer type.
* Straggler from last: add new source file src/H5FDperform.c.
* Committing clang-format changes
* Add a missing file to the MANIFEST.
* Switch to FUNC_ENTER_API_NOINIT in H5FDperform_init() and hbool_t in
H5_term_library().
Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>
2.6 KiB
HDF5 Library initialization and shutdown
Application perspective
Implicit initialization and shutdown
When a developer exports a new symbol as part of the HDF5 library, they should make sure that an application cannot enter the library in an uninitialized state through a new API function, or read an uninitialized value from a non-function HDF5 symbol.
The HDF5 library initializes itself when an application either enters
the library through an API function call such as H5Fopen, or when
an application evaluates an HDF5 symbol that represents either a
property-list identifier such as H5F_ACC_RDONLY or H5F_ACC_RDWR,
a property-list class identifier such as H5P_FILE_ACCESS, a VFD
identifier such as H5FD_FAMILY or H5FD_SEC2, or a type identifier
such as H5T_NATIVE_INT64.
The library sets a flag when initialization occurs and as long as the flag is set, skips initialization.
The library provides a couple of macros that initialize the library
as necessary. The library is initialized as a side-effect of the
FUNC_ENTER_API* macros used at the top of most API functions. HDF5
library symbols other than functions are provided through #defines
that use H5OPEN to introduce a library-initialization call (H5open)
at each site where a non-function symbol is used.
Ordinarily the library registers an atexit(3) handler to shut itself
down when the application exits.
Explicit initialization and shutdown
An application may use an API call, H5open, to explicitly initialize
the library. H5close explicitly shuts down the library.
Library internals perspective
No matter how library initializion begins, eventually the internal
function H5_init_library will be called. H5_init_library is
responsible for calling the initializers for every internal HDF5
library module (aka "package") in the correct order so that no module is
initialized before its prerequisite modules. A table in H5_init_library
establishes the order of initialization. If a developer adds a
module to the library that it is appropriate to initialize with the rest
of the library, then they should insert its initializer into the right
place in the table.
H5_term_library drives library shutdown. Library shutdown is
table-driven, too. If a developer adds a module that needs to release
resources during library shutdown, then they should add a call at the
right place to the shutdown table. Note that some entries in the shutdown
table are marked as "barriers," and if a new module should only be
shutdown strictly after the preceding modules, then it should be marked
as a barrier. See the comments in H5_term_library for more information.