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2020-09-23qemu/atomic.h: rename atomic_ to qatomic_Stefan Hajnoczi
clang's C11 atomic_fetch_*() functions only take a C11 atomic type pointer argument. QEMU uses direct types (int, etc) and this causes a compiler error when a QEMU code calls these functions in a source file that also included <stdatomic.h> via a system header file: $ CC=clang CXX=clang++ ./configure ... && make ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid) Avoid using atomic_*() names in QEMU's atomic.h since that namespace is used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h and <stdatomic.h> can co-exist. I checked /usr/include on my machine and searched GitHub for existing "qatomic_" users but there seem to be none. This patch was generated using: $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \ sort -u >/tmp/changed_identifiers $ for identifier in $(</tmp/changed_identifiers); do sed -i "s%\<$identifier\>%q$identifier%g" \ $(git grep -I -l "\<$identifier\>") done I manually fixed line-wrap issues and misaligned rST tables. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
2020-04-13atomics: update documentationPaolo Bonzini
Some of the constraints on operand sizes have been relaxed, so adjust the documentation. Deprecate atomic_mb_read and atomic_mb_set; it is not really possible to use them correctly because they do not interoperate with sequentially-consistent RMW operations. Finally, extend the memory barrier pairing section to cover acquire and release semantics in general, roughly based on the KVM Forum 2016 talk, "<atomic.h> weapons". Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-11atomics: convert to reStructuredTextPaolo Bonzini
No attempts to fix or update the text; these are left for the next patch in the series. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>