--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/memory/filemap.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,522 @@
+/*
+ * Copyright 2003-2006 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_filemap.cpp.incl"
+# include <sys/stat.h>
+# include <errno.h>
+
+#ifndef O_BINARY       // if defined (Win32) use binary files.
+#define O_BINARY 0     // otherwise do nothing.
+#endif
+
+
+extern address JVM_FunctionAtStart();
+extern address JVM_FunctionAtEnd();
+
+// Complain and stop. All error conditions occuring during the writing of
+// an archive file should stop the process.  Unrecoverable errors during
+// the reading of the archive file should stop the process.
+
+static void fail(const char *msg, va_list ap) {
+  // This occurs very early during initialization: tty is not initialized.
+  jio_fprintf(defaultStream::error_stream(),
+              "An error has occured while processing the"
+              " shared archive file.\n");
+  jio_vfprintf(defaultStream::error_stream(), msg, ap);
+  jio_fprintf(defaultStream::error_stream(), "\n");
+  vm_exit_during_initialization("Unable to use shared archive.", NULL);
+}
+
+
+void FileMapInfo::fail_stop(const char *msg, ...) {
+        va_list ap;
+  va_start(ap, msg);
+  fail(msg, ap);        // Never returns.
+  va_end(ap);           // for completeness.
+}
+
+
+// Complain and continue.  Recoverable errors during the reading of the
+// archive file may continue (with sharing disabled).
+//
+// If we continue, then disable shared spaces and close the file.
+
+void FileMapInfo::fail_continue(const char *msg, ...) {
+  va_list ap;
+  va_start(ap, msg);
+  if (RequireSharedSpaces) {
+    fail(msg, ap);
+  }
+  va_end(ap);
+  UseSharedSpaces = false;
+  close();
+}
+
+
+// Fill in the fileMapInfo structure with data about this VM instance.
+
+void FileMapInfo::populate_header(size_t alignment) {
+  _header._magic = 0xf00baba2;
+  _header._version = _current_version;
+  _header._alignment = alignment;
+
+  // The following fields are for sanity checks for whether this archive
+  // will function correctly with this JVM and the bootclasspath it's
+  // invoked with.
+
+  // JVM version string ... changes on each build.
+  const char *vm_version = VM_Version::internal_vm_info_string();
+  if (strlen(vm_version) < (JVM_IDENT_MAX-1)) {
+    strcpy(_header._jvm_ident, vm_version);
+  } else {
+    fail_stop("JVM Ident field for shared archive is too long"
+              " - truncated to <%s>", _header._jvm_ident);
+  }
+
+  // Build checks on classpath and jar files
+  _header._num_jars = 0;
+  ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
+  for ( ; cpe != NULL; cpe = cpe->next()) {
+
+    if (cpe->is_jar_file()) {
+      if (_header._num_jars >= JVM_SHARED_JARS_MAX) {
+        fail_stop("Too many jar files to share.", NULL);
+      }
+
+      // Jar file - record timestamp and file size.
+      struct stat st;
+      const char *path = cpe->name();
+      if (os::stat(path, &st) != 0) {
+        // If we can't access a jar file in the boot path, then we can't
+        // make assumptions about where classes get loaded from.
+        fail_stop("Unable to open jar file %s.", path);
+      }
+      _header._jar[_header._num_jars]._timestamp = st.st_mtime;
+      _header._jar[_header._num_jars]._filesize = st.st_size;
+      _header._num_jars++;
+    } else {
+
+      // If directories appear in boot classpath, they must be empty to
+      // avoid having to verify each individual class file.
+      const char* name = ((ClassPathDirEntry*)cpe)->name();
+      if (!os::dir_is_empty(name)) {
+        fail_stop("Boot classpath directory %s is not empty.", name);
+      }
+    }
+  }
+}
+
+
+// Read the FileMapInfo information from the file.
+
+bool FileMapInfo::init_from_file(int fd) {
+
+  size_t n = read(fd, &_header, sizeof(struct FileMapHeader));
+  if (n != sizeof(struct FileMapHeader)) {
+    fail_continue("Unable to read the file header.");
+    return false;
+  }
+  if (_header._version != current_version()) {
+    fail_continue("The shared archive file has the wrong version.");
+    return false;
+  }
+  _file_offset = (long)n;
+  return true;
+}
+
+
+// Read the FileMapInfo information from the file.
+bool FileMapInfo::open_for_read() {
+  _full_path = Arguments::GetSharedArchivePath();
+  int fd = open(_full_path, O_RDONLY | O_BINARY, 0);
+  if (fd < 0) {
+    if (errno == ENOENT) {
+      // Not locating the shared archive is ok.
+      fail_continue("Specified shared archive not found.");
+    } else {
+      fail_continue("Failed to open shared archive file (%s).",
+                    strerror(errno));
+    }
+    return false;
+  }
+
+  _fd = fd;
+  _file_open = true;
+  return true;
+}
+
+
+// Write the FileMapInfo information to the file.
+
+void FileMapInfo::open_for_write() {
+ _full_path = Arguments::GetSharedArchivePath();
+  if (PrintSharedSpaces) {
+    tty->print_cr("Dumping shared data to file: ");
+    tty->print_cr("   %s", _full_path);
+  }
+
+  // Remove the existing file in case another process has it open.
+  remove(_full_path);
+  int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
+  if (fd < 0) {
+    fail_stop("Unable to create shared archive file %s.", _full_path);
+  }
+  _fd = fd;
+  _file_offset = 0;
+  _file_open = true;
+}
+
+
+// Write the header to the file, seek to the next allocation boundary.
+
+void FileMapInfo::write_header() {
+  write_bytes_aligned(&_header, sizeof(FileMapHeader));
+}
+
+
+// Dump shared spaces to file.
+
+void FileMapInfo::write_space(int i, CompactibleSpace* space, bool read_only) {
+  align_file_position();
+  struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
+  write_region(i, (char*)space->bottom(), space->used(),
+               space->capacity(), read_only, false);
+}
+
+
+// Dump region to file.
+
+void FileMapInfo::write_region(int region, char* base, size_t size,
+                               size_t capacity, bool read_only,
+                               bool allow_exec) {
+  struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[region];
+
+  if (_file_open) {
+    guarantee(si->_file_offset == _file_offset, "file offset mismatch.");
+    if (PrintSharedSpaces) {
+      tty->print_cr("Shared file region %d: 0x%x bytes, addr 0x%x,"
+                    " file offset 0x%x", region, size, base, _file_offset);
+    }
+  } else {
+    si->_file_offset = _file_offset;
+  }
+  si->_base = base;
+  si->_used = size;
+  si->_capacity = capacity;
+  si->_read_only = read_only;
+  si->_allow_exec = allow_exec;
+  write_bytes_aligned(base, (int)size);
+}
+
+
+// Dump bytes to file -- at the current file position.
+
+void FileMapInfo::write_bytes(const void* buffer, int nbytes) {
+  if (_file_open) {
+    int n = ::write(_fd, buffer, nbytes);
+    if (n != nbytes) {
+      // It is dangerous to leave the corrupted shared archive file around,
+      // close and remove the file. See bug 6372906.
+      close();
+      remove(_full_path);
+      fail_stop("Unable to write to shared archive file.", NULL);
+    }
+  }
+  _file_offset += nbytes;
+}
+
+
+// Align file position to an allocation unit boundary.
+
+void FileMapInfo::align_file_position() {
+  long new_file_offset = align_size_up(_file_offset, os::vm_allocation_granularity());
+  if (new_file_offset != _file_offset) {
+    _file_offset = new_file_offset;
+    if (_file_open) {
+      // Seek one byte back from the target and write a byte to insure
+      // that the written file is the correct length.
+      _file_offset -= 1;
+      if (lseek(_fd, _file_offset, SEEK_SET) < 0) {
+        fail_stop("Unable to seek.", NULL);
+      }
+      char zero = 0;
+      write_bytes(&zero, 1);
+    }
+  }
+}
+
+
+// Dump bytes to file -- at the current file position.
+
+void FileMapInfo::write_bytes_aligned(const void* buffer, int nbytes) {
+  align_file_position();
+  write_bytes(buffer, nbytes);
+  align_file_position();
+}
+
+
+// Close the shared archive file.  This does NOT unmap mapped regions.
+
+void FileMapInfo::close() {
+  if (_file_open) {
+    if (::close(_fd) < 0) {
+      fail_stop("Unable to close the shared archive file.");
+    }
+    _file_open = false;
+    _fd = -1;
+  }
+}
+
+
+// Memory map a shared space from the archive file.
+
+bool FileMapInfo::map_space(int i, ReservedSpace rs, ContiguousSpace* space) {
+  struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
+  if (space != NULL) {
+    if (si->_base != (char*)space->bottom() ||
+        si->_capacity != space->capacity()) {
+      fail_continue("Shared space base address does not match.");
+      return false;
+    }
+  }
+  bool result = (map_region(i, rs) != NULL);
+  if (space != NULL && result) {
+    space->set_top((HeapWord*)(si->_base + si->_used));
+    space->set_saved_mark();
+  }
+  return result;
+}
+
+
+// JVM/TI RedefineClasses() support:
+// Remap the shared readonly space to shared readwrite, private.
+bool FileMapInfo::remap_shared_readonly_as_readwrite() {
+  struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[0];
+  if (!si->_read_only) {
+    // the space is already readwrite so we are done
+    return true;
+  }
+  size_t used = si->_used;
+  size_t size = align_size_up(used, os::vm_allocation_granularity());
+  if (!open_for_read()) {
+    return false;
+  }
+  char *base = os::remap_memory(_fd, _full_path, si->_file_offset,
+                                si->_base, size, false /* !read_only */,
+                                si->_allow_exec);
+  close();
+  if (base == NULL) {
+    fail_continue("Unable to remap shared readonly space (errno=%d).", errno);
+    return false;
+  }
+  if (base != si->_base) {
+    fail_continue("Unable to remap shared readonly space at required address.");
+    return false;
+  }
+  si->_read_only = false;
+  return true;
+}
+
+
+// Memory map a region in the address space.
+
+char* FileMapInfo::map_region(int i, ReservedSpace rs) {
+  struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
+  size_t used = si->_used;
+  size_t size = align_size_up(used, os::vm_allocation_granularity());
+
+  ReservedSpace mapped_rs = rs.first_part(size, true, true);
+  ReservedSpace unmapped_rs = rs.last_part(size);
+  mapped_rs.release();
+
+  return map_region(i, true);
+}
+
+
+// Memory map a region in the address space.
+
+char* FileMapInfo::map_region(int i, bool address_must_match) {
+  struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
+  size_t used = si->_used;
+  size_t size = align_size_up(used, os::vm_allocation_granularity());
+  char *requested_addr = 0;
+  if (address_must_match) {
+    requested_addr = si->_base;
+  }
+  char *base = os::map_memory(_fd, _full_path, si->_file_offset,
+                              requested_addr, size, si->_read_only,
+                              si->_allow_exec);
+  if (base == NULL) {
+    fail_continue("Unable to map shared space.");
+    return NULL;
+  }
+  if (address_must_match) {
+    if (base != si->_base) {
+      fail_continue("Unable to map shared space at required address.");
+      return NULL;
+    }
+  } else {
+    si->_base = base;          // save mapped address for unmapping.
+  }
+  return base;
+}
+
+
+// Unmap a memory region in the address space.
+
+void FileMapInfo::unmap_region(int i) {
+  struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
+  size_t used = si->_used;
+  size_t size = align_size_up(used, os::vm_allocation_granularity());
+  if (!os::unmap_memory(si->_base, size)) {
+    fail_stop("Unable to unmap shared space.");
+  }
+}
+
+
+void FileMapInfo::assert_mark(bool check) {
+  if (!check) {
+    fail_stop("Mark mismatch while restoring from shared file.", NULL);
+  }
+}
+
+
+FileMapInfo* FileMapInfo::_current_info = NULL;
+
+
+// Open the shared archive file, read and validate the header
+// information (version, boot classpath, etc.).  If initialization
+// fails, shared spaces are disabled and the file is closed. [See
+// fail_continue.]
+
+
+bool FileMapInfo::initialize() {
+  assert(UseSharedSpaces, "UseSharedSpaces expected.");
+
+  if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) {
+    fail_continue("Tool agent requires sharing to be disabled.");
+    return false;
+  }
+
+  if (!open_for_read()) {
+    return false;
+  }
+
+  init_from_file(_fd);
+  if (!validate()) {
+    return false;
+  }
+
+  SharedReadOnlySize =  _header._space[0]._capacity;
+  SharedReadWriteSize = _header._space[1]._capacity;
+  SharedMiscDataSize =  _header._space[2]._capacity;
+  SharedMiscCodeSize =  _header._space[3]._capacity;
+  return true;
+}
+
+
+bool FileMapInfo::validate() {
+  if (_header._version != current_version()) {
+    fail_continue("The shared archive file is the wrong version.");
+    return false;
+  }
+  if (_header._magic != (int)0xf00baba2) {
+    fail_continue("The shared archive file has a bad magic number.");
+    return false;
+  }
+  if (strncmp(_header._jvm_ident, VM_Version::internal_vm_info_string(),
+              JVM_IDENT_MAX-1) != 0) {
+    fail_continue("The shared archive file was created by a different"
+                  " version or build of HotSpot.");
+    return false;
+  }
+
+  // Cannot verify interpreter yet, as it can only be created after the GC
+  // heap has been initialized.
+
+  if (_header._num_jars >= JVM_SHARED_JARS_MAX) {
+    fail_continue("Too many jar files to share.");
+    return false;
+  }
+
+  // Build checks on classpath and jar files
+  int num_jars_now = 0;
+  ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
+  for ( ; cpe != NULL; cpe = cpe->next()) {
+
+    if (cpe->is_jar_file()) {
+      if (num_jars_now < _header._num_jars) {
+
+        // Jar file - verify timestamp and file size.
+        struct stat st;
+        const char *path = cpe->name();
+        if (os::stat(path, &st) != 0) {
+          fail_continue("Unable to open jar file %s.", path);
+          return false;
+        }
+        if (_header._jar[num_jars_now]._timestamp != st.st_mtime ||
+            _header._jar[num_jars_now]._filesize != st.st_size) {
+          fail_continue("A jar file is not the one used while building"
+                        " the shared archive file.");
+          return false;
+        }
+      }
+      ++num_jars_now;
+    } else {
+
+      // If directories appear in boot classpath, they must be empty to
+      // avoid having to verify each individual class file.
+      const char* name = ((ClassPathDirEntry*)cpe)->name();
+      if (!os::dir_is_empty(name)) {
+        fail_continue("Boot classpath directory %s is not empty.", name);
+        return false;
+      }
+    }
+  }
+  if (num_jars_now < _header._num_jars) {
+    fail_continue("The number of jar files in the boot classpath is"
+                  " less than the number the shared archive was created with.");
+    return false;
+  }
+
+  return true;
+}
+
+// The following method is provided to see whether a given pointer
+// falls in the mapped shared space.
+// Param:
+// p, The given pointer
+// Return:
+// True if the p is within the mapped shared space, otherwise, false.
+bool FileMapInfo::is_in_shared_space(const void* p) {
+  for (int i = 0; i < CompactingPermGenGen::n_regions; i++) {
+    if (p >= _header._space[i]._base &&
+        p < _header._space[i]._base + _header._space[i]._used) {
+      return true;
+    }
+  }
+
+  return false;
+}