From f29d7f6b83f60ca8dd64ec89ea803f79324ac12f Mon Sep 17 00:00:00 2001 From: Christian Biesinger Date: Mon, 30 Sep 2019 16:47:37 -0500 Subject: [PATCH] Compute msymbol hash codes in parallel This is for the msymbol_hash and msymbol_demangled_hash hashtables in objfile_per_bfd_storage. This basically computes those hash codes together with the demangled symbol name in the background, before it inserts the symbols in the hash table. gdb/ChangeLog: 2019-11-27 Christian Biesinger * minsyms.c (add_minsym_to_hash_table): Use a previously computed hash code if possible. (add_minsym_to_demangled_hash_table): Likewise. (minimal_symbol_reader::install): Compute the hash codes for msymbol on the background thread. * symtab.h (struct minimal_symbol) : Add these fields. Change-Id: Ifaa3346e9998f05743bff9e2eaad3f83b954d071 --- gdb/ChangeLog | 10 ++++++++++ gdb/minsyms.c | 46 +++++++++++++++++++++++++++++++--------------- 2 files changed, 41 insertions(+), 15 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index c278a7746c6..64c8ab52cf1 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +2019-11-27 Christian Biesinger + + * minsyms.c (add_minsym_to_hash_table): Use a previously computed + hash code if possible. + (add_minsym_to_demangled_hash_table): Likewise. + (minimal_symbol_reader::install): Compute the hash codes for msymbol + on the background thread. + * symtab.h (struct minimal_symbol) : + Add these fields. + 2019-11-27 Christian Biesinger * minsyms.c (minimal_symbol_reader::install): Also compute the hash diff --git a/gdb/minsyms.c b/gdb/minsyms.c index 141c3d21935..94240c9955e 100644 --- a/gdb/minsyms.c +++ b/gdb/minsyms.c @@ -141,12 +141,12 @@ msymbol_hash (const char *string) /* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */ static void add_minsym_to_hash_table (struct minimal_symbol *sym, - struct minimal_symbol **table) + struct minimal_symbol **table, + unsigned int hash_value) { if (sym->hash_next == NULL) { - unsigned int hash - = msymbol_hash (sym->linkage_name ()) % MINIMAL_SYMBOL_HASH_SIZE; + unsigned int hash = hash_value % MINIMAL_SYMBOL_HASH_SIZE; sym->hash_next = table[hash]; table[hash] = sym; @@ -157,18 +157,16 @@ add_minsym_to_hash_table (struct minimal_symbol *sym, TABLE. */ static void add_minsym_to_demangled_hash_table (struct minimal_symbol *sym, - struct objfile *objfile) + struct objfile *objfile, + unsigned int hash_value) { if (sym->demangled_hash_next == NULL) { - unsigned int hash = search_name_hash (MSYMBOL_LANGUAGE (sym), - sym->search_name ()); - objfile->per_bfd->demangled_hash_languages.set (MSYMBOL_LANGUAGE (sym)); struct minimal_symbol **table = objfile->per_bfd->msymbol_demangled_hash; - unsigned int hash_index = hash % MINIMAL_SYMBOL_HASH_SIZE; + unsigned int hash_index = hash_value % MINIMAL_SYMBOL_HASH_SIZE; sym->demangled_hash_next = table[hash_index]; table[hash_index] = sym; } @@ -1266,6 +1264,10 @@ struct computed_hash_values size_t name_length; /* Hash code (using fast_hash) of the linkage_name. */ hashval_t mangled_name_hash; + /* The msymbol_hash of the linkage_name. */ + unsigned int minsym_hash; + /* The msymbol_hash of the search_name. */ + unsigned int minsym_demangled_hash; }; /* Build (or rebuild) the minimal symbol hash tables. This is necessary @@ -1273,23 +1275,28 @@ struct computed_hash_values thus causing the internal minimal_symbol pointers to become jumbled. */ static void -build_minimal_symbol_hash_tables (struct objfile *objfile) +build_minimal_symbol_hash_tables + (struct objfile *objfile, + const std::vector& hash_values) { int i; struct minimal_symbol *msym; /* (Re)insert the actual entries. */ - for ((i = objfile->per_bfd->minimal_symbol_count, + int mcount = objfile->per_bfd->minimal_symbol_count; + for ((i = 0, msym = objfile->per_bfd->msymbols.get ()); - i > 0; - i--, msym++) + i < mcount; + i++, msym++) { msym->hash_next = 0; - add_minsym_to_hash_table (msym, objfile->per_bfd->msymbol_hash); + add_minsym_to_hash_table (msym, objfile->per_bfd->msymbol_hash, + hash_values[i].minsym_hash); msym->demangled_hash_next = 0; if (msym->search_name () != msym->linkage_name ()) - add_minsym_to_demangled_hash_table (msym, objfile); + add_minsym_to_demangled_hash_table + (msym, objfile, hash_values[i].minsym_demangled_hash); } } @@ -1404,6 +1411,15 @@ minimal_symbol_reader::install () hash_values[idx].mangled_name_hash = fast_hash (msym->name, hash_values[idx].name_length); } + hash_values[idx].minsym_hash + = msymbol_hash (msym->linkage_name ()); + /* We only use this hash code if the search name differs + from the linkage name. See the code in + build_minimal_symbol_hash_tables. */ + if (msym->search_name () != msym->linkage_name ()) + hash_values[idx].minsym_demangled_hash + = search_name_hash (MSYMBOL_LANGUAGE (msym), + msym->search_name ()); } { /* To limit how long we hold the lock, we only acquire it here @@ -1425,7 +1441,7 @@ minimal_symbol_reader::install () } }); - build_minimal_symbol_hash_tables (m_objfile); + build_minimal_symbol_hash_tables (m_objfile, hash_values); } } -- 2.30.2