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reduce contention around the symbol table #2842

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-01-06 16:47:06 -08:00
parent 88fc4c82aa
commit 670e8f8d67
1 changed files with 44 additions and 11 deletions
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55
src/util/symbol.cpp
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@ -23,7 +23,7 @@ Revision History:
#include "util/string_buffer.h"
#include <cstring>
static DECLARE_MUTEX(g_symbol_lock);
symbol symbol::m_dummy(TAG(void*, nullptr, 2));
const symbol symbol::null;
@ -34,11 +34,21 @@ const symbol symbol::null;
class internal_symbol_table {
region m_region; //!< Region used to store symbol strings.
str_hashtable m_table; //!< Table of created symbol strings.
DECLARE_MUTEX(lock);
public:
internal_symbol_table() {
ALLOC_MUTEX(lock);
}
~internal_symbol_table() {
DEALLOC_MUTEX(lock);
}
char const * get_str(char const * d) {
const char * result;
lock_guard lock(*g_symbol_lock);
lock_guard _lock(*lock);
str_hashtable::entry * e;
if (m_table.insert_if_not_there_core(d, e)) {
// new entry
@ -60,30 +70,53 @@ public:
}
};
static internal_symbol_table* g_symbol_table = nullptr;
struct internal_symbol_tables {
unsigned sz;
internal_symbol_table** tables;
internal_symbol_tables(unsigned sz): sz(sz), tables(alloc_vect<internal_symbol_table*>(sz)) {
for (unsigned i = 0; i < sz; ++i) {
tables[i] = alloc(internal_symbol_table);
}
}
~internal_symbol_tables() {
for (unsigned i = 0; i < sz; ++i) {
dealloc(tables[i]);
}
dealloc_vect<internal_symbol_table*>(tables, sz);
}
char const * get_str(char const * d) {
auto* table = tables[string_hash(d, static_cast<unsigned>(strlen(d)), 251) % sz];
return table->get_str(d);
}
};
static internal_symbol_tables* g_symbol_tables = nullptr;
void initialize_symbols() {
if (!g_symbol_table) {
ALLOC_MUTEX(g_symbol_lock);
g_symbol_table = alloc(internal_symbol_table);
if (!g_symbol_tables) {
unsigned num_tables = 2 * std::min((unsigned) std::thread::hardware_concurrency(), 64u);
g_symbol_tables = alloc(internal_symbol_tables, num_tables);
}
}
void finalize_symbols() {
DEALLOC_MUTEX(g_symbol_lock);
dealloc(g_symbol_table);
g_symbol_table = nullptr;
dealloc(g_symbol_tables);
g_symbol_tables = nullptr;
}
symbol::symbol(char const * d) {
if (d == nullptr)
m_data = nullptr;
else
m_data = g_symbol_table->get_str(d);
m_data = g_symbol_tables->get_str(d);
}
symbol & symbol::operator=(char const * d) {
m_data = g_symbol_table->get_str(d);
m_data = g_symbol_tables->get_str(d);
return *this;
}