Commit 7f3f9027 authored by unknown's avatar unknown

Added comments to specify why no much mutex is needed.

parent 79f575a8
...@@ -142,7 +142,13 @@ int ha_heap::write_row(byte * buf) ...@@ -142,7 +142,13 @@ int ha_heap::write_row(byte * buf)
res= heap_write(file,buf); res= heap_write(file,buf);
if (!res && ++records_changed*HEAP_STATS_UPDATE_THRESHOLD > if (!res && ++records_changed*HEAP_STATS_UPDATE_THRESHOLD >
file->s->records) file->s->records)
{
/*
We can perform this safely since only one writer at the time is
allowed on the table.
*/
file->s->key_stat_version++; file->s->key_stat_version++;
}
return res; return res;
} }
...@@ -155,7 +161,13 @@ int ha_heap::update_row(const byte * old_data, byte * new_data) ...@@ -155,7 +161,13 @@ int ha_heap::update_row(const byte * old_data, byte * new_data)
res= heap_update(file,old_data,new_data); res= heap_update(file,old_data,new_data);
if (!res && ++records_changed*HEAP_STATS_UPDATE_THRESHOLD > if (!res && ++records_changed*HEAP_STATS_UPDATE_THRESHOLD >
file->s->records) file->s->records)
{
/*
We can perform this safely since only one writer at the time is
allowed on the table.
*/
file->s->key_stat_version++; file->s->key_stat_version++;
}
return res; return res;
} }
...@@ -166,7 +178,13 @@ int ha_heap::delete_row(const byte * buf) ...@@ -166,7 +178,13 @@ int ha_heap::delete_row(const byte * buf)
res= heap_delete(file,buf); res= heap_delete(file,buf);
if (!res && table->tmp_table == NO_TMP_TABLE && if (!res && table->tmp_table == NO_TMP_TABLE &&
++records_changed*HEAP_STATS_UPDATE_THRESHOLD > file->s->records) ++records_changed*HEAP_STATS_UPDATE_THRESHOLD > file->s->records)
{
/*
We can perform this safely since only one writer at the time is
allowed on the table.
*/
file->s->key_stat_version++; file->s->key_stat_version++;
}
return res; return res;
} }
...@@ -297,7 +315,13 @@ int ha_heap::delete_all_rows() ...@@ -297,7 +315,13 @@ int ha_heap::delete_all_rows()
{ {
heap_clear(file); heap_clear(file);
if (table->tmp_table == NO_TMP_TABLE) if (table->tmp_table == NO_TMP_TABLE)
{
/*
We can perform this safely since only one writer at the time is
allowed on the table.
*/
file->s->key_stat_version++; file->s->key_stat_version++;
}
return 0; return 0;
} }
......
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