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[MDEV-28162] Replace PFS_atomic with std::atomic<T>

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PFS_atomic class contains wrappers around my_atomic_* operations, which
are macros to GNU atomic operations (__atomic_*). Due to different
implementations of compilers, clang may encounter errors when compiling
on x86_32 architecture.

The following functions are replaced with C++ std::atomic type in
performance schema code base:
  - PFS_atomic::store_*()
      -> my_atomic_store*
        -> __atomic_store_n()
    => std::atomic<T>::store()

  - PFS_atomic::load_*()
      -> my_atomic_load*
        -> __atomic_load_n()
    => std::atomic<T>::load()

  - PFS_atomic::add_*()
      -> my_atomic_add*
        -> __atomic_fetch_add()
    => std::atomic<T>::fetch_add()

  - PFS_atomic::cas_*()
    -> my_atomic_cas*
      -> __atomic_compare_exchange_n()
    => std::atomic<T>::compare_exchange_strong()

and PFS_atomic class could be dropped completely.

Note that in the wrapper memory order passed to original GNU atomic
extensions are hard-coded as `__ATOMIC_SEQ_CST`, which is equivalent to
`std::memory_order_seq_cst` in C++, and is the default parameter for
std::atomic_* functions.

All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer Amazon Web
Services.
This commit is contained in:
Meng-Hsiu Chiang
2023-12-06 19:48:53 +00:00
committed by Marko Mäkelä
parent d5bad49011
commit 55db59f16d
18 changed files with 109 additions and 248 deletions
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15
storage/perfschema/pfs_buffer_container.h
View File

@@ -87,7 +87,7 @@ public:
if (m_full)
return NULL;
monotonic= PFS_atomic::add_u32(& m_monotonic.m_u32, 1);
monotonic= m_monotonic.m_u32.fetch_add(1);
monotonic_max= monotonic + static_cast<uint>(m_max);
while (monotonic < monotonic_max)
@@ -99,7 +99,8 @@ public:
{
return pfs;
}
monotonic= PFS_atomic::add_u32(& m_monotonic.m_u32, 1);
monotonic= m_monotonic.m_u32.fetch_add(1);
}
m_full= true;
@@ -517,7 +518,7 @@ public:
ulong get_row_count()
{
ulong page_count= PFS_atomic::load_u32(& m_max_page_index.m_u32);
ulong page_count= m_max_page_index.m_u32.load();
return page_count * PFS_PAGE_SIZE;
}
@@ -554,11 +555,11 @@ public:
/*
1: Try to find an available record within the existing pages
*/
current_page_count= PFS_atomic::load_u32(& m_max_page_index.m_u32);
current_page_count= m_max_page_index.m_u32.load();
if (current_page_count != 0)
{
monotonic= PFS_atomic::load_u32(& m_monotonic.m_u32);
monotonic= m_monotonic.m_u32.load();
monotonic_max= monotonic + current_page_count;
while (monotonic < monotonic_max)
@@ -602,7 +603,7 @@ public:
counter faster and then move on to the detection of new pages,
in part 2: below.
*/
monotonic= PFS_atomic::add_u32(& m_monotonic.m_u32, 1);
monotonic= m_monotonic.m_u32.fetch_add(1);
};
}
@@ -683,7 +684,7 @@ public:
my_atomic_storeptr(typed_addr, ptr);
/* Advertise the new page */
PFS_atomic::add_u32(& m_max_page_index.m_u32, 1);
m_max_page_index.m_u32.fetch_add(1);
}
pthread_mutex_unlock(& m_critical_section);