Tianocore/edk2.git/MdeModulePkg/Include/Guid/DelayedDispatch.h, branch master

MdeModulePkg: Replace include guards with #pragma once

2026-02-23T21:01:28+00:00

Replace traditional `#ifndef`/`#define`/`#endif` include guards with `#pragma` once. `#pragma once` is a widely supported preprocessor directive that prevents header files from being included multiple times. It is supported by all toolchains used to build edk2: GCC, Clang/LLVM, and MSVC. Compared to macro-based include guards, `#pragma once`: - Eliminates the risk of macro name collisions or copy/paste errors where two headers inadvertently use the same guard macro. - Eliminate inconsistency in the way include guard macros are named (e.g., some files use `__FILE_H__`, others use `FILE_H_`, etc.). - Reduces boilerplate (three lines replaced by one). - Avoids polluting the macro namespace with guard symbols. - Can improve build times as the preprocessor can skip re-opening the file entirely, rather than re-reading it to find the matching `#endif` ("multiple-include optimization"). - Note that some compilers may already optimize traditional include guards, by recognzining the idiomatic pattern. This change is made acknowledging that overall portability of the code will technically be reduced, as `#pragma once` is not part of the C/C++ standards. However, this is considered acceptable given: 1. edk2 already defines a subset of supported compilers in BaseTools/Conf/tools_def.template, all of which have supported `#pragma once` for over two decades. 2. There have been concerns raised to the project about inconsistent include guard naming and potential macro collisions. Approximate compiler support dates: - MSVC: Supported since Visual C++ 4.2 (1996) - GCC: Supported since 3.4 (2004) (http://gnu.ist.utl.pt/software/gcc/gcc-3.4/changes.html) - Clang (LLVM based): Since initial release in 2007 Signed-off-by: Michael Kubacki

MdeModulePkg: Add PcdDelayedDispatchMaxEntries

2025-09-23T01:02:04+00:00

The current fixed value of 8 for `DELAYED_DISPATCH_MAX_ENTRIES` is not large enough to accommodate platform usage. This change replaces the macro with a PCD that can be configured by platforms. In the case the default PCD value is too small, an error message explaining that the PCD should be updated will be printed followed by an assert. Signed-off-by: Michael Kubacki

MdeModulePkg: PeiMain: Introduce implementation of delayed dispatch

2024-10-17T08:51:15+00:00

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4496 This change adds the implementation that fits the needs and description of PI spec defined Delayed Dispatch PPI in Pei Core. The PPI would allow minimal delay for registered callbacks. As well as allowing other functions to wait for GUIDed delayed dispatch callbacks. Cc: Jian J Wang Cc: Dandan Bi Cc: Liming Gao Cc: Debkumar De Cc: Catharine West Co-authored-by: Mike Turner Co-authored-by: Sachin Ganesh Signed-off-by: Kun Qin