Mercurial > hg > truffle
diff src/share/vm/classfile/sharedPathsMiscInfo.hpp @ 20375:6e0cb14ce59b
8046070: Class Data Sharing clean up and refactoring
Summary: Cleaned up CDS to be more configurable, maintainable and extensible
Reviewed-by: dholmes, coleenp, acorn, mchung
author | iklam |
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date | Thu, 21 Aug 2014 13:57:51 -0700 |
parents | |
children | bb239308be67 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/classfile/sharedPathsMiscInfo.hpp Thu Aug 21 13:57:51 2014 -0700 @@ -0,0 +1,187 @@ +/* + * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#ifndef SHARE_VM_CLASSFILE_SHAREDPATHSMISCINFO_HPP +#define SHARE_VM_CLASSFILE_SHAREDPATHSMISCINFO_HPP + +#include "runtime/os.hpp" + +// During dumping time, when processing class paths, we build up the dump-time +// classpath. The JAR files that exist are stored in the list ClassLoader::_first_entry. +// However, we need to store other "misc" information for run-time checking, such as +// +// + The values of Arguments::get_sysclasspath() used during dumping. +// +// + The meta-index file(s) used during dumping (incl modification time and size) +// +// + The class path elements specified during dumping but did not exist -- +// these elements must also be specified at run time, and they also must not +// exist at run time. +// +// These misc items are stored in a linear buffer in SharedPathsMiscInfo. +// The storage format is stream oriented to minimize its size. +// +// When writing the information to the archive file, SharedPathsMiscInfo is stored in +// the archive file header. At run-time, this information is used only during initialization +// (accessed using read() instead of mmap()), and is deallocated afterwards to save space. +// +// The SharedPathsMiscInfo class is used for both creating the the information (during +// dumping time) and validation (at run time). Different constructors are used in the +// two situations. See below. + +class SharedPathsMiscInfo : public CHeapObj<mtClass> { +protected: + char* _buf_start; + char* _cur_ptr; + char* _end_ptr; + int _buf_size; + bool _allocated; // was _buf_start allocated by me? + void ensure_size(size_t needed_bytes); + void add_path(const char* path, int type); + + void write(const void* ptr, size_t size); + bool read(void* ptr, size_t size); + + static void trace_class_path(const char* msg, const char* name = NULL) { + ClassLoader::trace_class_path(msg, name); + } +protected: + static bool fail(const char* msg, const char* name = NULL); + virtual bool check(jint type, const char* path); + +public: + enum { + INITIAL_BUF_SIZE = 128 + }; + // This constructor is used when creating the misc information (during dump) + SharedPathsMiscInfo() { + _buf_size = INITIAL_BUF_SIZE; + _cur_ptr = _buf_start = NEW_C_HEAP_ARRAY(char, _buf_size, mtClass); + _allocated = true; + } + // This constructor is used when validating the misc info (during run time) + SharedPathsMiscInfo(char *buff, int size) { + _cur_ptr = _buf_start = buff; + _end_ptr = _buf_start + size; + _buf_size = size; + _allocated = false; + } + ~SharedPathsMiscInfo() { + if (_allocated) { + FREE_C_HEAP_ARRAY(char, _buf_start, mtClass); + } + } + int get_used_bytes() { + return _cur_ptr - _buf_start; + } + void* buffer() { + return _buf_start; + } + + // writing -- + + // The path must not exist at run-time + void add_nonexist_path(const char* path) { + add_path(path, NON_EXIST); + } + + // The path must exist and have required size and modification time + void add_required_file(const char* path) { + add_path(path, REQUIRED); + + struct stat st; + if (os::stat(path, &st) != 0) { + assert(0, "sanity"); + ClassLoader::exit_with_path_failure("failed to os::stat(%s)", path); // should not happen + } + write_time(st.st_mtime); + write_long(st.st_size); + } + + // The path must exist, and must contain exactly <num_entries> files/dirs + void add_boot_classpath(const char* path) { + add_path(path, BOOT); + } + int write_jint(jint num) { + write(&num, sizeof(num)); + return 0; + } + void write_time(time_t t) { + write(&t, sizeof(t)); + } + void write_long(long l) { + write(&l, sizeof(l)); + } + + bool dump_to_file(int fd) { + int n = get_used_bytes(); + return (os::write(fd, _buf_start, n) == (size_t)n); + } + + // reading -- + + enum { + BOOT = 1, + NON_EXIST = 2, + REQUIRED = 3 + }; + + virtual const char* type_name(int type) { + switch (type) { + case BOOT: return "BOOT"; + case NON_EXIST: return "NON_EXIST"; + case REQUIRED: return "REQUIRED"; + default: ShouldNotReachHere(); return "?"; + } + } + + virtual void print_path(outputStream* out, int type, const char* path) { + switch (type) { + case BOOT: + out->print("Expecting -Dsun.boot.class.path=%s", path); + break; + case NON_EXIST: + out->print("Expecting that %s does not exist", path); + break; + case REQUIRED: + out->print("Expecting that file %s must exist and not altered", path); + break; + default: + ShouldNotReachHere(); + } + } + + bool check(); + bool read_jint(jint *ptr) { + return read(ptr, sizeof(jint)); + } + bool read_long(long *ptr) { + return read(ptr, sizeof(long)); + } + bool read_time(time_t *ptr) { + return read(ptr, sizeof(time_t)); + } +}; + +#endif // SHARE_VM_CLASSFILE_SHAREDPATHSMISCINFO_HPP