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8241427: Coarsen locking in Modules::add_module_exports

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Reviewed-by: lfoltan, hseigel
This commit is contained in:
Claes Redestad 2020-03-26 00:02:08 +01:00
parent 60fae77974
commit 0d22ad6400
6 changed files with 57 additions and 84 deletions
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109
src/hotspot/share/classfile/modules.cpp
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@ -108,13 +108,16 @@ static ModuleEntry* get_module_entry(jobject module, TRAPS) {
return java_lang_Module::module_entry(m);
}
static PackageEntry* get_package_entry(ModuleEntry* module_entry, const char* package_name, TRAPS) {
ResourceMark rm(THREAD);
if (package_name == NULL) return NULL;
static PackageEntry* get_locked_package_entry(ModuleEntry* module_entry, const char* package_name, TRAPS) {
assert(Module_lock->owned_by_self(), "should have the Module_lock");
assert(package_name != NULL, "Precondition");
TempNewSymbol pkg_symbol = SymbolTable::new_symbol(package_name);
PackageEntryTable* package_entry_table = module_entry->loader_data()->packages();
assert(package_entry_table != NULL, "Unexpected null package entry table");
return package_entry_table->lookup_only(pkg_symbol);
PackageEntry* package_entry = package_entry_table->locked_lookup_only(pkg_symbol);
assert(package_entry == NULL || package_entry->module() == module_entry, "Unexpectedly found a package linked to another module");
return package_entry;
}
static PackageEntry* get_package_entry_by_name(Symbol* package,
@ -525,32 +528,35 @@ void Modules::add_module_exports(jobject from_module, const char* package_name,
}
}
PackageEntry *package_entry = get_package_entry(from_module_entry, package_name, CHECK);
ResourceMark rm(THREAD);
PackageEntry* package_entry = NULL;
{
MutexLocker ml(THREAD, Module_lock);
package_entry = get_locked_package_entry(from_module_entry, package_name, CHECK);
// Do nothing if modules are the same
// If the package is not found we'll throw an exception later
if (from_module_entry != to_module_entry &&
package_entry != NULL) {
package_entry->set_exported(to_module_entry);
}
}
// Handle errors and logging outside locked section
if (package_entry == NULL) {
ResourceMark rm(THREAD);
THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
err_msg("Package %s not found in from_module %s",
package_name != NULL ? package_name : "",
from_module_entry->name()->as_C_string()));
}
if (package_entry->module() != from_module_entry) {
THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
err_msg("Package: %s found in module %s, not in from_module: %s",
if (log_is_enabled(Debug, module)) {
ResourceMark rm(THREAD);
log_debug(module)("add_module_exports(): package %s in module %s is exported to module %s",
package_entry->name()->as_C_string(),
package_entry->module()->name()->as_C_string(),
from_module_entry->name()->as_C_string()));
}
log_debug(module)("add_module_exports(): package %s in module %s is exported to module %s",
package_entry->name()->as_C_string(),
from_module_entry->name()->as_C_string(),
to_module_entry == NULL ? "NULL" :
from_module_entry->name()->as_C_string(),
to_module_entry == NULL ? "NULL" :
to_module_entry->is_named() ?
to_module_entry->name()->as_C_string() : UNNAMED_MODULE);
// Do nothing if modules are the same.
if (from_module_entry != to_module_entry) {
package_entry->set_exported(to_module_entry);
to_module_entry->name()->as_C_string() : UNNAMED_MODULE);
}
}
@ -668,21 +674,6 @@ jobject Modules::get_named_module(Handle h_loader, const char* package_name, TRA
return NULL;
}
// This method is called by JFR and by the above method.
jobject Modules::get_module(Symbol* package_name, Handle h_loader, TRAPS) {
const PackageEntry* const pkg_entry =
get_package_entry_by_name(package_name, h_loader, THREAD);
const ModuleEntry* const module_entry = (pkg_entry != NULL ? pkg_entry->module() : NULL);
if (module_entry != NULL &&
module_entry->module() != NULL) {
return JNIHandles::make_local(THREAD, module_entry->module());
}
return NULL;
}
// Export package in module to all unnamed modules.
void Modules::add_module_exports_to_all_unnamed(jobject module, const char* package_name, TRAPS) {
if (module == NULL) {
@ -699,29 +690,35 @@ void Modules::add_module_exports_to_all_unnamed(jobject module, const char* pack
"module is invalid");
}
if (module_entry->is_named()) { // No-op for unnamed module.
PackageEntry *package_entry = get_package_entry(module_entry, package_name, CHECK);
ResourceMark rm(THREAD);
if (package_entry == NULL) {
THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
err_msg("Package %s not found in module %s",
package_name != NULL ? package_name : "",
module_entry->name()->as_C_string()));
}
if (package_entry->module() != module_entry) {
THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
err_msg("Package: %s found in module %s, not in module: %s",
package_entry->name()->as_C_string(),
package_entry->module()->name()->as_C_string(),
module_entry->name()->as_C_string()));
}
// No-op for unnamed module and open modules
if (!module_entry->is_named() || module_entry->is_open())
return;
PackageEntry* package_entry = NULL;
{
MutexLocker m1(THREAD, Module_lock);
package_entry = get_locked_package_entry(module_entry, package_name, CHECK);
// Mark package as exported to all unnamed modules.
if (package_entry != NULL) {
package_entry->set_is_exported_allUnnamed();
}
}
// Handle errors and logging outside locked section
if (package_entry == NULL) {
ResourceMark rm(THREAD);
THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
err_msg("Package %s not found in module %s",
package_name != NULL ? package_name : "",
module_entry->name()->as_C_string()));
}
if (log_is_enabled(Debug, module)) {
ResourceMark rm(THREAD);
log_debug(module)("add_module_exports_to_all_unnamed(): package %s in module"
" %s is exported to all unnamed modules",
package_entry->name()->as_C_string(),
module_entry->name()->as_C_string());
// Mark package as exported to all unnamed modules.
package_entry->set_is_exported_allUnnamed();
}
}