truffle: src/os/windows/vm/perfMemory

comparison src/os/windows/vm/perfMemory_windows.cpp @ 0:a61af66fc99e jdk7-b24

Initial load

author	duke
date	Sat, 01 Dec 2007 00:00:00 +0000
parents
children	98cb887364d3

comparison

equal deleted inserted replaced

--1:000000000000
+:a61af66fc99e
+/*
+* Copyright 2001-2007 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/_perfMemory_windows.cpp.incl"
+#include <windows.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <lmcons.h>
+typedef BOOL (WINAPI *SetSecurityDescriptorControlFnPtr)(
+IN PSECURITY_DESCRIPTOR pSecurityDescriptor,
+IN SECURITY_DESCRIPTOR_CONTROL ControlBitsOfInterest,
+IN SECURITY_DESCRIPTOR_CONTROL ControlBitsToSet);
+// Standard Memory Implementation Details
+// create the PerfData memory region in standard memory.
+//
+static char* create_standard_memory(size_t size) {
+// allocate an aligned chuck of memory
+char* mapAddress = os::reserve_memory(size);
+if (mapAddress == NULL) {
+return NULL;
+}
+// commit memory
+if (!os::commit_memory(mapAddress, size)) {
+if (PrintMiscellaneous && Verbose) {
+warning("Could not commit PerfData memory\n");
+}
+os::release_memory(mapAddress, size);
+return NULL;
+}
+return mapAddress;
+}
+// delete the PerfData memory region
+//
+static void delete_standard_memory(char* addr, size_t size) {
+// there are no persistent external resources to cleanup for standard
+// memory. since DestroyJavaVM does not support unloading of the JVM,
+// cleanup of the memory resource is not performed. The memory will be
+// reclaimed by the OS upon termination of the process.
+//
+return;
+}
+// save the specified memory region to the given file
+//
+static void save_memory_to_file(char* addr, size_t size) {
+const char* destfile = PerfMemory::get_perfdata_file_path();
+assert(destfile[0] != '\0', "invalid Perfdata file path");
+int fd = ::_open(destfile, _O_BINARY|_O_CREAT|_O_WRONLY|_O_TRUNC,
+_S_IREAD|_S_IWRITE);
+if (fd == OS_ERR) {
+if (PrintMiscellaneous && Verbose) {
+warning("Could not create Perfdata save file: %s: %s\n",
+destfile, strerror(errno));
+}
+} else {
+for (size_t remaining = size; remaining > 0;) {
+int nbytes = ::_write(fd, addr, (unsigned int)remaining);
+if (nbytes == OS_ERR) {
+if (PrintMiscellaneous && Verbose) {
+warning("Could not write Perfdata save file: %s: %s\n",
+destfile, strerror(errno));
+}
+break;
+}
+remaining -= (size_t)nbytes;
+addr += nbytes;
+}
+int result = ::_close(fd);
+if (PrintMiscellaneous && Verbose) {
+if (result == OS_ERR) {
+warning("Could not close %s: %s\n", destfile, strerror(errno));
+}
+}
+}
+FREE_C_HEAP_ARRAY(char, destfile);
+}
+// Shared Memory Implementation Details
+// Note: the win32 shared memory implementation uses two objects to represent
+// the shared memory: a windows kernel based file mapping object and a backing
+// store file. On windows, the name space for shared memory is a kernel
+// based name space that is disjoint from other win32 name spaces. Since Java
+// is unaware of this name space, a parallel file system based name space is
+// maintained, which provides a common file system based shared memory name
+// space across the supported platforms and one that Java apps can deal with
+// through simple file apis.
+//
+// For performance and resource cleanup reasons, it is recommended that the
+// user specific directory and the backing store file be stored in either a
+// RAM based file system or a local disk based file system. Network based
+// file systems are not recommended for performance reasons. In addition,
+// use of SMB network based file systems may result in unsuccesful cleanup
+// of the disk based resource on exit of the VM. The Windows TMP and TEMP
+// environement variables, as used by the GetTempPath() Win32 API (see
+// os::get_temp_directory() in os_win32.cpp), control the location of the
+// user specific directory and the shared memory backing store file.
+static HANDLE sharedmem_fileMapHandle = NULL;
+static HANDLE sharedmem_fileHandle = INVALID_HANDLE_VALUE;
+static char*  sharedmem_fileName = NULL;
+// return the user specific temporary directory name.
+//
+// the caller is expected to free the allocated memory.
+//
+static char* get_user_tmp_dir(const char* user) {
+const char* tmpdir = os::get_temp_directory();
+const char* perfdir = PERFDATA_NAME;
+size_t nbytes = strlen(tmpdir) + strlen(perfdir) + strlen(user) + 2;
+char* dirname = NEW_C_HEAP_ARRAY(char, nbytes);
+// construct the path name to user specific tmp directory
+_snprintf(dirname, nbytes, "%s%s_%s", tmpdir, perfdir, user);
+return dirname;
+}
+// convert the given file name into a process id. if the file
+// does not meet the file naming constraints, return 0.
+//
+static int filename_to_pid(const char* filename) {
+// a filename that doesn't begin with a digit is not a
+// candidate for conversion.
+//
+if (!isdigit(*filename)) {
+return 0;
+}
+// check if file name can be converted to an integer without
+// any leftover characters.
+//
+char* remainder = NULL;
+errno = 0;
+int pid = (int)strtol(filename, &remainder, 10);
+if (errno != 0) {
+return 0;
+}
+// check for left over characters. If any, then the filename is
+// not a candidate for conversion.
+//
+if (remainder != NULL && *remainder != '\0') {
+return 0;
+}
+// successful conversion, return the pid
+return pid;
+}
+// check if the given path is considered a secure directory for
+// the backing store files. Returns true if the directory exists
+// and is considered a secure location. Returns false if the path
+// is a symbolic link or if an error occured.
+//
+static bool is_directory_secure(const char* path) {
+DWORD fa;
+fa = GetFileAttributes(path);
+if (fa == 0xFFFFFFFF) {
+DWORD lasterror = GetLastError();
+if (lasterror == ERROR_FILE_NOT_FOUND) {
+return false;
+}
+else {
+// unexpected error, declare the path insecure
+if (PrintMiscellaneous && Verbose) {
+warning("could not get attributes for file %s: ",
+" lasterror = %d\n", path, lasterror);
+}
+return false;
+}
+}
+if (fa & FILE_ATTRIBUTE_REPARSE_POINT) {
+// we don't accept any redirection for the user specific directory
+// so declare the path insecure. This may be too conservative,
+// as some types of reparse points might be acceptable, but it
+// is probably more secure to avoid these conditions.
+//
+if (PrintMiscellaneous && Verbose) {
+warning("%s is a reparse point\n", path);
+}
+return false;
+}
+if (fa & FILE_ATTRIBUTE_DIRECTORY) {
+// this is the expected case. Since windows supports symbolic
+// links to directories only, not to files, there is no need
+// to check for open write permissions on the directory. If the
+// directory has open write permissions, any files deposited that
+// are not expected will be removed by the cleanup code.
+//
+return true;
+}
+else {
+// this is either a regular file or some other type of file,
+// any of which are unexpected and therefore insecure.
+//
+if (PrintMiscellaneous && Verbose) {
+warning("%s is not a directory, file attributes = "
+INTPTR_FORMAT "\n", path, fa);
+}
+return false;
+}
+}
+// return the user name for the owner of this process
+//
+// the caller is expected to free the allocated memory.
+//
+static char* get_user_name() {
+/* get the user name. This code is adapted from code found in
+* the jdk in src/windows/native/java/lang/java_props_md.c
+* java_props_md.c  1.29 02/02/06. According to the original
+* source, the call to GetUserName is avoided because of a resulting
+* increase in footprint of 100K.
+*/
+char* user = getenv("USERNAME");
+char buf[UNLEN+1];
+DWORD buflen = sizeof(buf);
+if (user == NULL || strlen(user) == 0) {
+if (GetUserName(buf, &buflen)) {
+user = buf;
+}
+else {
+return NULL;
+}
+}
+char* user_name = NEW_C_HEAP_ARRAY(char, strlen(user)+1);
+strcpy(user_name, user);
+return user_name;
+}
+// return the name of the user that owns the process identified by vmid.
+//
+// This method uses a slow directory search algorithm to find the backing
+// store file for the specified vmid and returns the user name, as determined
+// by the user name suffix of the hsperfdata_<username> directory name.
+//
+// the caller is expected to free the allocated memory.
+//
+static char* get_user_name_slow(int vmid) {
+// directory search
+char* oldest_user = NULL;
+time_t oldest_ctime = 0;
+const char* tmpdirname = os::get_temp_directory();
+DIR* tmpdirp = os::opendir(tmpdirname);
+if (tmpdirp == NULL) {
+return NULL;
+}
+// for each entry in the directory that matches the pattern hsperfdata_*,
+// open the directory and check if the file for the given vmid exists.
+// The file with the expected name and the latest creation date is used
+// to determine the user name for the process id.
+//
+struct dirent* dentry;
+char* tdbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(tmpdirname));
+errno = 0;
+while ((dentry = os::readdir(tmpdirp, (struct dirent *)tdbuf)) != NULL) {
+// check if the directory entry is a hsperfdata file
+if (strncmp(dentry->d_name, PERFDATA_NAME, strlen(PERFDATA_NAME)) != 0) {
+continue;
+}
+char* usrdir_name = NEW_C_HEAP_ARRAY(char,
+strlen(tmpdirname) + strlen(dentry->d_name) + 1);
+strcpy(usrdir_name, tmpdirname);
+strcat(usrdir_name, dentry->d_name);
+DIR* subdirp = os::opendir(usrdir_name);
+if (subdirp == NULL) {
+FREE_C_HEAP_ARRAY(char, usrdir_name);
+continue;
+}
+// Since we don't create the backing store files in directories
+// pointed to by symbolic links, we also don't follow them when
+// looking for the files. We check for a symbolic link after the
+// call to opendir in order to eliminate a small window where the
+// symlink can be exploited.
+//
+if (!is_directory_secure(usrdir_name)) {
+FREE_C_HEAP_ARRAY(char, usrdir_name);
+os::closedir(subdirp);
+continue;
+}
+struct dirent* udentry;
+char* udbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(usrdir_name));
+errno = 0;
+while ((udentry = os::readdir(subdirp, (struct dirent *)udbuf)) != NULL) {
+if (filename_to_pid(udentry->d_name) == vmid) {
+struct stat statbuf;
+char* filename = NEW_C_HEAP_ARRAY(char,
+strlen(usrdir_name) + strlen(udentry->d_name) + 2);
+strcpy(filename, usrdir_name);
+strcat(filename, "\\");
+strcat(filename, udentry->d_name);
+if (::stat(filename, &statbuf) == OS_ERR) {
+FREE_C_HEAP_ARRAY(char, filename);
+continue;
+}
+// skip over files that are not regular files.
+if ((statbuf.st_mode & S_IFMT) != S_IFREG) {
+FREE_C_HEAP_ARRAY(char, filename);
+continue;
+}
+// compare and save filename with latest creation time
+if (statbuf.st_size > 0 && statbuf.st_ctime > oldest_ctime) {
+if (statbuf.st_ctime > oldest_ctime) {
+char* user = strchr(dentry->d_name, '_') + 1;
+if (oldest_user != NULL) FREE_C_HEAP_ARRAY(char, oldest_user);
+oldest_user = NEW_C_HEAP_ARRAY(char, strlen(user)+1);
+strcpy(oldest_user, user);
+oldest_ctime = statbuf.st_ctime;
+}
+}
+FREE_C_HEAP_ARRAY(char, filename);
+}
+}
+os::closedir(subdirp);
+FREE_C_HEAP_ARRAY(char, udbuf);
+FREE_C_HEAP_ARRAY(char, usrdir_name);
+}
+os::closedir(tmpdirp);
+FREE_C_HEAP_ARRAY(char, tdbuf);
+return(oldest_user);
+}
+// return the name of the user that owns the process identified by vmid.
+//
+// note: this method should only be used via the Perf native methods.
+// There are various costs to this method and limiting its use to the
+// Perf native methods limits the impact to monitoring applications only.
+//
+static char* get_user_name(int vmid) {
+// A fast implementation is not provided at this time. It's possible
+// to provide a fast process id to user name mapping function using
+// the win32 apis, but the default ACL for the process object only
+// allows processes with the same owner SID to acquire the process
+// handle (via OpenProcess(PROCESS_QUERY_INFORMATION)). It's possible
+// to have the JVM change the ACL for the process object to allow arbitrary
+// users to access the process handle and the process security token.
+// The security ramifications need to be studied before providing this
+// mechanism.
+//
+return get_user_name_slow(vmid);
+}
+// return the name of the shared memory file mapping object for the
+// named shared memory region for the given user name and vmid.
+//
+// The file mapping object's name is not the file name. It is a name
+// in a separate name space.
+//
+// the caller is expected to free the allocated memory.
+//
+static char *get_sharedmem_objectname(const char* user, int vmid) {
+// construct file mapping object's name, add 3 for two '_' and a
+// null terminator.
+int nbytes = (int)strlen(PERFDATA_NAME) + (int)strlen(user) + 3;
+// the id is converted to an unsigned value here because win32 allows
+// negative process ids. However, OpenFileMapping API complains
+// about a name containing a '-' characters.
+//
+nbytes += UINT_CHARS;
+char* name = NEW_C_HEAP_ARRAY(char, nbytes);
+_snprintf(name, nbytes, "%s_%s_%u", PERFDATA_NAME, user, vmid);
+return name;
+}
+// return the file name of the backing store file for the named
+// shared memory region for the given user name and vmid.
+//
+// the caller is expected to free the allocated memory.
+//
+static char* get_sharedmem_filename(const char* dirname, int vmid) {
+// add 2 for the file separator and a null terminator.
+size_t nbytes = strlen(dirname) + UINT_CHARS + 2;
+char* name = NEW_C_HEAP_ARRAY(char, nbytes);
+_snprintf(name, nbytes, "%s\\%d", dirname, vmid);
+return name;
+}
+// remove file
+//
+// this method removes the file with the given file name.
+//
+// Note: if the indicated file is on an SMB network file system, this
+// method may be unsuccessful in removing the file.
+//
+static void remove_file(const char* dirname, const char* filename) {
+size_t nbytes = strlen(dirname) + strlen(filename) + 2;
+char* path = NEW_C_HEAP_ARRAY(char, nbytes);
+strcpy(path, dirname);
+strcat(path, "\\");
+strcat(path, filename);
+if (::unlink(path) == OS_ERR) {
+if (PrintMiscellaneous && Verbose) {
+if (errno != ENOENT) {
+warning("Could not unlink shared memory backing"
+" store file %s : %s\n", path, strerror(errno));
+}
+}
+}
+FREE_C_HEAP_ARRAY(char, path);
+}
+// returns true if the process represented by pid is alive, otherwise
+// returns false. the validity of the result is only accurate if the
+// target process is owned by the same principal that owns this process.
+// this method should not be used if to test the status of an otherwise
+// arbitrary process unless it is know that this process has the appropriate
+// privileges to guarantee a result valid.
+//
+static bool is_alive(int pid) {
+HANDLE ph = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, pid);
+if (ph == NULL) {
+// the process does not exist.
+if (PrintMiscellaneous && Verbose) {
+DWORD lastError = GetLastError();
+if (lastError != ERROR_INVALID_PARAMETER) {
+warning("OpenProcess failed: %d\n", GetLastError());
+}
+}
+return false;
+}
+DWORD exit_status;
+if (!GetExitCodeProcess(ph, &exit_status)) {
+if (PrintMiscellaneous && Verbose) {
+warning("GetExitCodeProcess failed: %d\n", GetLastError());
+}
+CloseHandle(ph);
+return false;
+}
+CloseHandle(ph);
+return (exit_status == STILL_ACTIVE) ? true : false;
+}
+// check if the file system is considered secure for the backing store files
+//
+static bool is_filesystem_secure(const char* path) {
+char root_path[MAX_PATH];
+char fs_type[MAX_PATH];
+if (PerfBypassFileSystemCheck) {
+if (PrintMiscellaneous && Verbose) {
+warning("bypassing file system criteria checks for %s\n", path);
+}
+return true;
+}
+char* first_colon = strchr((char *)path, ':');
+if (first_colon == NULL) {
+if (PrintMiscellaneous && Verbose) {
+warning("expected device specifier in path: %s\n", path);
+}
+return false;
+}
+size_t len = (size_t)(first_colon - path);
+assert(len + 2 <= MAX_PATH, "unexpected device specifier length");
+strncpy(root_path, path, len + 1);
+root_path[len + 1] = '\\';
+root_path[len + 2] = '\0';
+// check that we have something like "C:\" or "AA:\"
+assert(strlen(root_path) >= 3, "device specifier too short");
+assert(strchr(root_path, ':') != NULL, "bad device specifier format");
+assert(strchr(root_path, '\\') != NULL, "bad device specifier format");
+DWORD maxpath;
+DWORD flags;
+if (!GetVolumeInformation(root_path, NULL, 0, NULL, &maxpath,
+&flags, fs_type, MAX_PATH)) {
+// we can't get information about the volume, so assume unsafe.
+if (PrintMiscellaneous && Verbose) {
+warning("could not get device information for %s: "
+" path = %s: lasterror = %d\n",
+root_path, path, GetLastError());
+}
+return false;
+}
+if ((flags & FS_PERSISTENT_ACLS) == 0) {
+// file system doesn't support ACLs, declare file system unsafe
+if (PrintMiscellaneous && Verbose) {
+warning("file system type %s on device %s does not support"
+" ACLs\n", fs_type, root_path);
+}
+return false;
+}
+if ((flags & FS_VOL_IS_COMPRESSED) != 0) {
+// file system is compressed, declare file system unsafe
+if (PrintMiscellaneous && Verbose) {
+warning("file system type %s on device %s is compressed\n",
+fs_type, root_path);
+}
+return false;
+}
+return true;
+}
+// cleanup stale shared memory resources
+//
+// This method attempts to remove all stale shared memory files in
+// the named user temporary directory. It scans the named directory
+// for files matching the pattern ^$[0-9]*$. For each file found, the
+// process id is extracted from the file name and a test is run to
+// determine if the process is alive. If the process is not alive,
+// any stale file resources are removed.
+//
+static void cleanup_sharedmem_resources(const char* dirname) {
+// open the user temp directory
+DIR* dirp = os::opendir(dirname);
+if (dirp == NULL) {
+// directory doesn't exist, so there is nothing to cleanup
+return;
+}
+if (!is_directory_secure(dirname)) {
+// the directory is not secure, don't attempt any cleanup
+return;
+}
+// for each entry in the directory that matches the expected file
+// name pattern, determine if the file resources are stale and if
+// so, remove the file resources. Note, instrumented HotSpot processes
+// for this user may start and/or terminate during this search and
+// remove or create new files in this directory. The behavior of this
+// loop under these conditions is dependent upon the implementation of
+// opendir/readdir.
+//
+struct dirent* entry;
+char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(dirname));
+errno = 0;
+while ((entry = os::readdir(dirp, (struct dirent *)dbuf)) != NULL) {
+int pid = filename_to_pid(entry->d_name);
+if (pid == 0) {
+if (strcmp(entry->d_name, ".") != 0 && strcmp(entry->d_name, "..") != 0) {
+// attempt to remove all unexpected files, except "." and ".."
+remove_file(dirname, entry->d_name);
+}
+errno = 0;
+continue;
+}
+// we now have a file name that converts to a valid integer
+// that could represent a process id . if this process id
+// matches the current process id or the process is not running,
+// then remove the stale file resources.
+//
+// process liveness is detected by checking the exit status
+// of the process. if the process id is valid and the exit status
+// indicates that it is still running, the file file resources
+// are not removed. If the process id is invalid, or if we don't
+// have permissions to check the process status, or if the process
+// id is valid and the process has terminated, the the file resources
+// are assumed to be stale and are removed.
+//
+if (pid == os::current_process_id() || !is_alive(pid)) {
+// we can only remove the file resources. Any mapped views
+// of the file can only be unmapped by the processes that
+// opened those views and the file mapping object will not
+// get removed until all views are unmapped.
+//
+remove_file(dirname, entry->d_name);
+}
+errno = 0;
+}
+os::closedir(dirp);
+FREE_C_HEAP_ARRAY(char, dbuf);
+}
+// create a file mapping object with the requested name, and size
+// from the file represented by the given Handle object
+//
+static HANDLE create_file_mapping(const char* name, HANDLE fh, LPSECURITY_ATTRIBUTES fsa, size_t size) {
+DWORD lowSize = (DWORD)size;
+DWORD highSize = 0;
+HANDLE fmh = NULL;
+// Create a file mapping object with the given name. This function
+// will grow the file to the specified size.
+//
+fmh = CreateFileMapping(
+fh,                 /* HANDLE file handle for backing store */
+fsa,                /* LPSECURITY_ATTRIBUTES Not inheritable */
+PAGE_READWRITE,     /* DWORD protections */
+highSize,           /* DWORD High word of max size */
+lowSize,            /* DWORD Low word of max size */
+name);              /* LPCTSTR name for object */
+if (fmh == NULL) {
+if (PrintMiscellaneous && Verbose) {
+warning("CreateFileMapping failed, lasterror = %d\n", GetLastError());
+}
+return NULL;
+}
+if (GetLastError() == ERROR_ALREADY_EXISTS) {
+// a stale file mapping object was encountered. This object may be
+// owned by this or some other user and cannot be removed until
+// the other processes either exit or close their mapping objects
+// and/or mapped views of this mapping object.
+//
+if (PrintMiscellaneous && Verbose) {
+warning("file mapping already exists, lasterror = %d\n", GetLastError());
+}
+CloseHandle(fmh);
+return NULL;
+}
+return fmh;
+}
+// method to free the given security descriptor and the contained
+// access control list.
+//
+static void free_security_desc(PSECURITY_DESCRIPTOR pSD) {
+BOOL success, exists, isdefault;
+PACL pACL;
+if (pSD != NULL) {
+// get the access control list from the security descriptor
+success = GetSecurityDescriptorDacl(pSD, &exists, &pACL, &isdefault);
+// if an ACL existed and it was not a default acl, then it must
+// be an ACL we enlisted. free the resources.
+//
+if (success && exists && pACL != NULL && !isdefault) {
+FREE_C_HEAP_ARRAY(char, pACL);
+}
+// free the security descriptor
+FREE_C_HEAP_ARRAY(char, pSD);
+}
+}
+// method to free up a security attributes structure and any
+// contained security descriptors and ACL
+//
+static void free_security_attr(LPSECURITY_ATTRIBUTES lpSA) {
+if (lpSA != NULL) {
+// free the contained security descriptor and the ACL
+free_security_desc(lpSA->lpSecurityDescriptor);
+lpSA->lpSecurityDescriptor = NULL;
+// free the security attributes structure
+FREE_C_HEAP_ARRAY(char, lpSA);
+}
+}
+// get the user SID for the process indicated by the process handle
+//
+static PSID get_user_sid(HANDLE hProcess) {
+HANDLE hAccessToken;
+PTOKEN_USER token_buf = NULL;
+DWORD rsize = 0;
+if (hProcess == NULL) {
+return NULL;
+}
+// get the process token
+if (!OpenProcessToken(hProcess, TOKEN_READ, &hAccessToken)) {
+if (PrintMiscellaneous && Verbose) {
+warning("OpenProcessToken failure: lasterror = %d \n", GetLastError());
+}
+return NULL;
+}
+// determine the size of the token structured needed to retrieve
+// the user token information from the access token.
+//
+if (!GetTokenInformation(hAccessToken, TokenUser, NULL, rsize, &rsize)) {
+DWORD lasterror = GetLastError();
+if (lasterror != ERROR_INSUFFICIENT_BUFFER) {
+if (PrintMiscellaneous && Verbose) {
+warning("GetTokenInformation failure: lasterror = %d,"
+" rsize = %d\n", lasterror, rsize);
+}
+CloseHandle(hAccessToken);
+return NULL;
+}
+}
+token_buf = (PTOKEN_USER) NEW_C_HEAP_ARRAY(char, rsize);
+// get the user token information
+if (!GetTokenInformation(hAccessToken, TokenUser, token_buf, rsize, &rsize)) {
+if (PrintMiscellaneous && Verbose) {
+warning("GetTokenInformation failure: lasterror = %d,"
+" rsize = %d\n", GetLastError(), rsize);
+}
+FREE_C_HEAP_ARRAY(char, token_buf);
+CloseHandle(hAccessToken);
+return NULL;
+}
+DWORD nbytes = GetLengthSid(token_buf->User.Sid);
+PSID pSID = NEW_C_HEAP_ARRAY(char, nbytes);
+if (!CopySid(nbytes, pSID, token_buf->User.Sid)) {
+if (PrintMiscellaneous && Verbose) {
+warning("GetTokenInformation failure: lasterror = %d,"
+" rsize = %d\n", GetLastError(), rsize);
+}
+FREE_C_HEAP_ARRAY(char, token_buf);
+FREE_C_HEAP_ARRAY(char, pSID);
+CloseHandle(hAccessToken);
+return NULL;
+}
+// close the access token.
+CloseHandle(hAccessToken);
+FREE_C_HEAP_ARRAY(char, token_buf);
+return pSID;
+}
+// structure used to consolidate access control entry information
+//
+typedef struct ace_data {
+PSID pSid;      // SID of the ACE
+DWORD mask;     // mask for the ACE
+} ace_data_t;
+// method to add an allow access control entry with the access rights
+// indicated in mask for the principal indicated in SID to the given
+// security descriptor. Much of the DACL handling was adapted from
+// the example provided here:
+//      http://support.microsoft.com/kb/102102/EN-US/
+//
+static bool add_allow_aces(PSECURITY_DESCRIPTOR pSD,
+ace_data_t aces[], int ace_count) {
+PACL newACL = NULL;
+PACL oldACL = NULL;
+if (pSD == NULL) {
+return false;
+}
+BOOL exists, isdefault;
+// retrieve any existing access control list.
+if (!GetSecurityDescriptorDacl(pSD, &exists, &oldACL, &isdefault)) {
+if (PrintMiscellaneous && Verbose) {
+warning("GetSecurityDescriptor failure: lasterror = %d \n",
+GetLastError());
+}
+return false;
+}
+// get the size of the DACL
+ACL_SIZE_INFORMATION aclinfo;
+// GetSecurityDescriptorDacl may return true value for exists (lpbDaclPresent)
+// while oldACL is NULL for some case.
+if (oldACL == NULL) {
+exists = FALSE;
+}
+if (exists) {
+if (!GetAclInformation(oldACL, &aclinfo,
+sizeof(ACL_SIZE_INFORMATION),
+AclSizeInformation)) {
+if (PrintMiscellaneous && Verbose) {
+warning("GetAclInformation failure: lasterror = %d \n", GetLastError());
+return false;
+}
+}
+} else {
+aclinfo.AceCount = 0; // assume NULL DACL
+aclinfo.AclBytesFree = 0;
+aclinfo.AclBytesInUse = sizeof(ACL);
+}
+// compute the size needed for the new ACL
+// initial size of ACL is sum of the following:
+//   * size of ACL structure.
+//   * size of each ACE structure that ACL is to contain minus the sid
+//     sidStart member (DWORD) of the ACE.
+//   * length of the SID that each ACE is to contain.
+DWORD newACLsize = aclinfo.AclBytesInUse +
+(sizeof(ACCESS_ALLOWED_ACE) - sizeof(DWORD)) * ace_count;
+for (int i = 0; i < ace_count; i++) {
+newACLsize += GetLengthSid(aces[i].pSid);
+}
+// create the new ACL
+newACL = (PACL) NEW_C_HEAP_ARRAY(char, newACLsize);
+if (!InitializeAcl(newACL, newACLsize, ACL_REVISION)) {
+if (PrintMiscellaneous && Verbose) {
+warning("InitializeAcl failure: lasterror = %d \n", GetLastError());
+}
+FREE_C_HEAP_ARRAY(char, newACL);
+return false;
+}
+unsigned int ace_index = 0;
+// copy any existing ACEs from the old ACL (if any) to the new ACL.
+if (aclinfo.AceCount != 0) {
+while (ace_index < aclinfo.AceCount) {
+LPVOID ace;
+if (!GetAce(oldACL, ace_index, &ace)) {
+if (PrintMiscellaneous && Verbose) {
+warning("InitializeAcl failure: lasterror = %d \n", GetLastError());
+}
+FREE_C_HEAP_ARRAY(char, newACL);
+return false;
+}
+if (((ACCESS_ALLOWED_ACE *)ace)->Header.AceFlags && INHERITED_ACE) {
+// this is an inherited, allowed ACE; break from loop so we can
+// add the new access allowed, non-inherited ACE in the correct
+// position, immediately following all non-inherited ACEs.
+break;
+}
+// determine if the SID of this ACE matches any of the SIDs
+// for which we plan to set ACEs.
+int matches = 0;
+for (int i = 0; i < ace_count; i++) {
+if (EqualSid(aces[i].pSid, &(((ACCESS_ALLOWED_ACE *)ace)->SidStart))) {
+matches++;
+break;
+}
+}
+// if there are no SID matches, then add this existing ACE to the new ACL
+if (matches == 0) {
+if (!AddAce(newACL, ACL_REVISION, MAXDWORD, ace,
+((PACE_HEADER)ace)->AceSize)) {
+if (PrintMiscellaneous && Verbose) {
+warning("AddAce failure: lasterror = %d \n", GetLastError());
+}
+FREE_C_HEAP_ARRAY(char, newACL);
+return false;
+}
+}
+ace_index++;
+}
+}
+// add the passed-in access control entries to the new ACL
+for (int i = 0; i < ace_count; i++) {
+if (!AddAccessAllowedAce(newACL, ACL_REVISION,
+aces[i].mask, aces[i].pSid)) {
+if (PrintMiscellaneous && Verbose) {
+warning("AddAccessAllowedAce failure: lasterror = %d \n",
+GetLastError());
+}
+FREE_C_HEAP_ARRAY(char, newACL);
+return false;
+}
+}
+// now copy the rest of the inherited ACEs from the old ACL
+if (aclinfo.AceCount != 0) {
+// picking up at ace_index, where we left off in the
+// previous ace_index loop
+while (ace_index < aclinfo.AceCount) {
+LPVOID ace;
+if (!GetAce(oldACL, ace_index, &ace)) {
+if (PrintMiscellaneous && Verbose) {
+warning("InitializeAcl failure: lasterror = %d \n", GetLastError());
+}
+FREE_C_HEAP_ARRAY(char, newACL);
+return false;
+}
+if (!AddAce(newACL, ACL_REVISION, MAXDWORD, ace,
+((PACE_HEADER)ace)->AceSize)) {
+if (PrintMiscellaneous && Verbose) {
+warning("AddAce failure: lasterror = %d \n", GetLastError());
+}
+FREE_C_HEAP_ARRAY(char, newACL);
+return false;
+}
+ace_index++;
+}
+}
+// add the new ACL to the security descriptor.
+if (!SetSecurityDescriptorDacl(pSD, TRUE, newACL, FALSE)) {
+if (PrintMiscellaneous && Verbose) {
+warning("SetSecurityDescriptorDacl failure:"
+" lasterror = %d \n", GetLastError());
+}
+FREE_C_HEAP_ARRAY(char, newACL);
+return false;
+}
+// if running on windows 2000 or later, set the automatic inheritence
+// control flags.
+SetSecurityDescriptorControlFnPtr _SetSecurityDescriptorControl;
+_SetSecurityDescriptorControl = (SetSecurityDescriptorControlFnPtr)
+GetProcAddress(GetModuleHandle(TEXT("advapi32.dll")),
+"SetSecurityDescriptorControl");
+if (_SetSecurityDescriptorControl != NULL) {
+// We do not want to further propogate inherited DACLs, so making them
+// protected prevents that.
+if (!_SetSecurityDescriptorControl(pSD, SE_DACL_PROTECTED,
+SE_DACL_PROTECTED)) {
+if (PrintMiscellaneous && Verbose) {
+warning("SetSecurityDescriptorControl failure:"
+" lasterror = %d \n", GetLastError());
+}
+FREE_C_HEAP_ARRAY(char, newACL);
+return false;
+}
+}
+// Note, the security descriptor maintains a reference to the newACL, not
+// a copy of it. Therefore, the newACL is not freed here. It is freed when
+// the security descriptor containing its reference is freed.
+//
+return true;
+}
+// method to create a security attributes structure, which contains a
+// security descriptor and an access control list comprised of 0 or more
+// access control entries. The method take an array of ace_data structures
+// that indicate the ACE to be added to the security descriptor.
+//
+// the caller must free the resources associated with the security
+// attributes structure created by this method by calling the
+// free_security_attr() method.
+//
+static LPSECURITY_ATTRIBUTES make_security_attr(ace_data_t aces[], int count) {
+// allocate space for a security descriptor
+PSECURITY_DESCRIPTOR pSD = (PSECURITY_DESCRIPTOR)
+NEW_C_HEAP_ARRAY(char, SECURITY_DESCRIPTOR_MIN_LENGTH);
+// initialize the security descriptor
+if (!InitializeSecurityDescriptor(pSD, SECURITY_DESCRIPTOR_REVISION)) {
+if (PrintMiscellaneous && Verbose) {
+warning("InitializeSecurityDescriptor failure: "
+"lasterror = %d \n", GetLastError());
+}
+free_security_desc(pSD);
+return NULL;
+}
+// add the access control entries
+if (!add_allow_aces(pSD, aces, count)) {
+free_security_desc(pSD);
+return NULL;
+}
+// allocate and initialize the security attributes structure and
+// return it to the caller.
+//
+LPSECURITY_ATTRIBUTES lpSA = (LPSECURITY_ATTRIBUTES)
+NEW_C_HEAP_ARRAY(char, sizeof(SECURITY_ATTRIBUTES));
+lpSA->nLength = sizeof(SECURITY_ATTRIBUTES);
+lpSA->lpSecurityDescriptor = pSD;
+lpSA->bInheritHandle = FALSE;
+return(lpSA);
+}
+// method to create a security attributes structure with a restrictive
+// access control list that creates a set access rights for the user/owner
+// of the securable object and a separate set access rights for everyone else.
+// also provides for full access rights for the administrator group.
+//
+// the caller must free the resources associated with the security
+// attributes structure created by this method by calling the
+// free_security_attr() method.
+//
+static LPSECURITY_ATTRIBUTES make_user_everybody_admin_security_attr(
+DWORD umask, DWORD emask, DWORD amask) {
+ace_data_t aces[3];
+// initialize the user ace data
+aces[0].pSid = get_user_sid(GetCurrentProcess());
+aces[0].mask = umask;
+// get the well known SID for BUILTIN\Administrators
+PSID administratorsSid = NULL;
+SID_IDENTIFIER_AUTHORITY SIDAuthAdministrators = SECURITY_NT_AUTHORITY;
+if (!AllocateAndInitializeSid( &SIDAuthAdministrators, 2,
+SECURITY_BUILTIN_DOMAIN_RID,
+DOMAIN_ALIAS_RID_ADMINS,
+0, 0, 0, 0, 0, 0, &administratorsSid)) {
+if (PrintMiscellaneous && Verbose) {
+warning("AllocateAndInitializeSid failure: "
+"lasterror = %d \n", GetLastError());
+}
+return NULL;
+}
+// initialize the ace data for administrator group
+aces[1].pSid = administratorsSid;
+aces[1].mask = amask;
+// get the well known SID for the universal Everybody
+PSID everybodySid = NULL;
+SID_IDENTIFIER_AUTHORITY SIDAuthEverybody = SECURITY_WORLD_SID_AUTHORITY;
+if (!AllocateAndInitializeSid( &SIDAuthEverybody, 1, SECURITY_WORLD_RID,
+0, 0, 0, 0, 0, 0, 0, &everybodySid)) {
+if (PrintMiscellaneous && Verbose) {
+warning("AllocateAndInitializeSid failure: "
+"lasterror = %d \n", GetLastError());
+}
+return NULL;
+}
+// initialize the ace data for everybody else.
+aces[2].pSid = everybodySid;
+aces[2].mask = emask;
+// create a security attributes structure with access control
+// entries as initialized above.
+LPSECURITY_ATTRIBUTES lpSA = make_security_attr(aces, 3);
+FREE_C_HEAP_ARRAY(char, aces[0].pSid);
+FreeSid(everybodySid);
+FreeSid(administratorsSid);
+return(lpSA);
+}
+// method to create the security attributes structure for restricting
+// access to the user temporary directory.
+//
+// the caller must free the resources associated with the security
+// attributes structure created by this method by calling the
+// free_security_attr() method.
+//
+static LPSECURITY_ATTRIBUTES make_tmpdir_security_attr() {
+// create full access rights for the user/owner of the directory
+// and read-only access rights for everybody else. This is
+// effectively equivalent to UNIX 755 permissions on a directory.
+//
+DWORD umask = STANDARD_RIGHTS_REQUIRED | FILE_ALL_ACCESS;
+DWORD emask = GENERIC_READ | FILE_LIST_DIRECTORY | FILE_TRAVERSE;
+DWORD amask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS;
+return make_user_everybody_admin_security_attr(umask, emask, amask);
+}
+// method to create the security attributes structure for restricting
+// access to the shared memory backing store file.
+//
+// the caller must free the resources associated with the security
+// attributes structure created by this method by calling the
+// free_security_attr() method.
+//
+static LPSECURITY_ATTRIBUTES make_file_security_attr() {
+// create extensive access rights for the user/owner of the file
+// and attribute read-only access rights for everybody else. This
+// is effectively equivalent to UNIX 600 permissions on a file.
+//
+DWORD umask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS;
+DWORD emask = STANDARD_RIGHTS_READ | FILE_READ_ATTRIBUTES |
+FILE_READ_EA | FILE_LIST_DIRECTORY | FILE_TRAVERSE;
+DWORD amask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS;
+return make_user_everybody_admin_security_attr(umask, emask, amask);
+}
+// method to create the security attributes structure for restricting
+// access to the name shared memory file mapping object.
+//
+// the caller must free the resources associated with the security
+// attributes structure created by this method by calling the
+// free_security_attr() method.
+//
+static LPSECURITY_ATTRIBUTES make_smo_security_attr() {
+// create extensive access rights for the user/owner of the shared
+// memory object and attribute read-only access rights for everybody
+// else. This is effectively equivalent to UNIX 600 permissions on
+// on the shared memory object.
+//
+DWORD umask = STANDARD_RIGHTS_REQUIRED | FILE_MAP_ALL_ACCESS;
+DWORD emask = STANDARD_RIGHTS_READ; // attributes only
+DWORD amask = STANDARD_RIGHTS_ALL | FILE_MAP_ALL_ACCESS;
+return make_user_everybody_admin_security_attr(umask, emask, amask);
+}
+// make the user specific temporary directory
+//
+static bool make_user_tmp_dir(const char* dirname) {
+LPSECURITY_ATTRIBUTES pDirSA = make_tmpdir_security_attr();
+if (pDirSA == NULL) {
+return false;
+}
+// create the directory with the given security attributes
+if (!CreateDirectory(dirname, pDirSA)) {
+DWORD lasterror = GetLastError();
+if (lasterror == ERROR_ALREADY_EXISTS) {
+// The directory already exists and was probably created by another
+// JVM instance. However, this could also be the result of a
+// deliberate symlink. Verify that the existing directory is safe.
+//
+if (!is_directory_secure(dirname)) {
+// directory is not secure
+if (PrintMiscellaneous && Verbose) {
+warning("%s directory is insecure\n", dirname);
+}
+return false;
+}
+// The administrator should be able to delete this directory.
+// But the directory created by previous version of JVM may not
+// have permission for administrators to delete this directory.
+// So add full permission to the administrator. Also setting new
+// DACLs might fix the corrupted the DACLs.
+SECURITY_INFORMATION secInfo = DACL_SECURITY_INFORMATION;
+if (!SetFileSecurity(dirname, secInfo, pDirSA->lpSecurityDescriptor)) {
+if (PrintMiscellaneous && Verbose) {
+lasterror = GetLastError();
+warning("SetFileSecurity failed for %s directory.  lasterror %d \n",
+dirname, lasterror);
+}
+}
+}
+else {
+if (PrintMiscellaneous && Verbose) {
+warning("CreateDirectory failed: %d\n", GetLastError());
+}
+return false;
+}
+}
+// free the security attributes structure
+free_security_attr(pDirSA);
+return true;
+}
+// create the shared memory resources
+//
+// This function creates the shared memory resources. This includes
+// the backing store file and the file mapping shared memory object.
+//
+static HANDLE create_sharedmem_resources(const char* dirname, const char* filename, const char* objectname, size_t size) {
+HANDLE fh = INVALID_HANDLE_VALUE;
+HANDLE fmh = NULL;
+// create the security attributes for the backing store file
+LPSECURITY_ATTRIBUTES lpFileSA = make_file_security_attr();
+if (lpFileSA == NULL) {
+return NULL;
+}
+// create the security attributes for the shared memory object
+LPSECURITY_ATTRIBUTES lpSmoSA = make_smo_security_attr();
+if (lpSmoSA == NULL) {
+free_security_attr(lpFileSA);
+return NULL;
+}
+// create the user temporary directory
+if (!make_user_tmp_dir(dirname)) {
+// could not make/find the directory or the found directory
+// was not secure
+return NULL;
+}
+// Create the file - the FILE_FLAG_DELETE_ON_CLOSE flag allows the
+// file to be deleted by the last process that closes its handle to
+// the file. This is important as the apis do not allow a terminating
+// JVM being monitored by another process to remove the file name.
+//
+// the FILE_SHARE_DELETE share mode is valid only in winnt
+//
+fh = CreateFile(
+filename,                   /* LPCTSTR file name */
+GENERIC_READ|GENERIC_WRITE, /* DWORD desired access */
+(os::win32::is_nt() ? FILE_SHARE_DELETE : 0)|
+FILE_SHARE_READ,            /* DWORD share mode, future READONLY
+* open operations allowed
+*/
+lpFileSA,                   /* LPSECURITY security attributes */
+CREATE_ALWAYS,              /* DWORD creation disposition
+* create file, if it already
+* exists, overwrite it.
+*/
+FILE_FLAG_DELETE_ON_CLOSE,  /* DWORD flags and attributes */
+NULL);                      /* HANDLE template file access */
+free_security_attr(lpFileSA);
+if (fh == INVALID_HANDLE_VALUE) {
+DWORD lasterror = GetLastError();
+if (PrintMiscellaneous && Verbose) {
+warning("could not create file %s: %d\n", filename, lasterror);
+}
+return NULL;
+}
+// try to create the file mapping
+fmh = create_file_mapping(objectname, fh, lpSmoSA, size);
+free_security_attr(lpSmoSA);
+if (fmh == NULL) {
+// closing the file handle here will decrement the reference count
+// on the file. When all processes accessing the file close their
+// handle to it, the reference count will decrement to 0 and the
+// OS will delete the file. These semantics are requested by the
+// FILE_FLAG_DELETE_ON_CLOSE flag in CreateFile call above.
+CloseHandle(fh);
+fh = NULL;
+return NULL;
+}
+// the file has been successfully created and the file mapping
+// object has been created.
+sharedmem_fileHandle = fh;
+sharedmem_fileName = strdup(filename);
+return fmh;
+}
+// open the shared memory object for the given vmid.
+//
+static HANDLE open_sharedmem_object(const char* objectname, DWORD ofm_access, TRAPS) {
+HANDLE fmh;
+// open the file mapping with the requested mode
+fmh = OpenFileMapping(
+ofm_access,       /* DWORD access mode */
+FALSE,            /* BOOL inherit flag - Do not allow inherit */
+objectname);      /* name for object */
+if (fmh == NULL) {
+if (PrintMiscellaneous && Verbose) {
+warning("OpenFileMapping failed for shared memory object %s:"
+" lasterror = %d\n", objectname, GetLastError());
+}
+THROW_MSG_(vmSymbols::java_lang_Exception(),
+"Could not open PerfMemory", INVALID_HANDLE_VALUE);
+}
+return fmh;;
+}
+// create a named shared memory region
+//
+// On Win32, a named shared memory object has a name space that
+// is independent of the file system name space. Shared memory object,
+// or more precisely, file mapping objects, provide no mechanism to
+// inquire the size of the memory region. There is also no api to
+// enumerate the memory regions for various processes.
+//
+// This implementation utilizes the shared memory name space in parallel
+// with the file system name space. This allows us to determine the
+// size of the shared memory region from the size of the file and it
+// allows us to provide a common, file system based name space for
+// shared memory across platforms.
+//
+static char* mapping_create_shared(size_t size) {
+void *mapAddress;
+int vmid = os::current_process_id();
+// get the name of the user associated with this process
+char* user = get_user_name();
+if (user == NULL) {
+return NULL;
+}
+// construct the name of the user specific temporary directory
+char* dirname = get_user_tmp_dir(user);
+// check that the file system is secure - i.e. it supports ACLs.
+if (!is_filesystem_secure(dirname)) {
+return NULL;
+}
+// create the names of the backing store files and for the
+// share memory object.
+//
+char* filename = get_sharedmem_filename(dirname, vmid);
+char* objectname = get_sharedmem_objectname(user, vmid);
+// cleanup any stale shared memory resources
+cleanup_sharedmem_resources(dirname);
+assert(((size != 0) && (size % os::vm_page_size() == 0)),
+"unexpected PerfMemry region size");
+FREE_C_HEAP_ARRAY(char, user);
+// create the shared memory resources
+sharedmem_fileMapHandle =
+create_sharedmem_resources(dirname, filename, objectname, size);
+FREE_C_HEAP_ARRAY(char, filename);
+FREE_C_HEAP_ARRAY(char, objectname);
+FREE_C_HEAP_ARRAY(char, dirname);
+if (sharedmem_fileMapHandle == NULL) {
+return NULL;
+}
+// map the file into the address space
+mapAddress = MapViewOfFile(
+sharedmem_fileMapHandle, /* HANDLE = file mapping object */
+FILE_MAP_ALL_ACCESS,     /* DWORD access flags */
+0,                       /* DWORD High word of offset */
+0,                       /* DWORD Low word of offset */
+(DWORD)size);            /* DWORD Number of bytes to map */
+if (mapAddress == NULL) {
+if (PrintMiscellaneous && Verbose) {
+warning("MapViewOfFile failed, lasterror = %d\n", GetLastError());
+}
+CloseHandle(sharedmem_fileMapHandle);
+sharedmem_fileMapHandle = NULL;
+return NULL;
+}
+// clear the shared memory region
+(void)memset(mapAddress, '\0', size);
+return (char*) mapAddress;
+}
+// this method deletes the file mapping object.
+//
+static void delete_file_mapping(char* addr, size_t size) {
+// cleanup the persistent shared memory resources. since DestroyJavaVM does
+// not support unloading of the JVM, unmapping of the memory resource is not
+// performed. The memory will be reclaimed by the OS upon termination of all
+// processes mapping the resource. The file mapping handle and the file
+// handle are closed here to expedite the remove of the file by the OS. The
+// file is not removed directly because it was created with
+// FILE_FLAG_DELETE_ON_CLOSE semantics and any attempt to remove it would
+// be unsuccessful.
+// close the fileMapHandle. the file mapping will still be retained
+// by the OS as long as any other JVM processes has an open file mapping
+// handle or a mapped view of the file.
+//
+if (sharedmem_fileMapHandle != NULL) {
+CloseHandle(sharedmem_fileMapHandle);
+sharedmem_fileMapHandle = NULL;
+}
+// close the file handle. This will decrement the reference count on the
+// backing store file. When the reference count decrements to 0, the OS
+// will delete the file. These semantics apply because the file was
+// created with the FILE_FLAG_DELETE_ON_CLOSE flag.
+//
+if (sharedmem_fileHandle != INVALID_HANDLE_VALUE) {
+CloseHandle(sharedmem_fileHandle);
+sharedmem_fileHandle = INVALID_HANDLE_VALUE;
+}
+}
+// this method determines the size of the shared memory file
+//
+static size_t sharedmem_filesize(const char* filename, TRAPS) {
+struct stat statbuf;
+// get the file size
+//
+// on win95/98/me, _stat returns a file size of 0 bytes, but on
+// winnt/2k the appropriate file size is returned. support for
+// the sharable aspects of performance counters was abandonded
+// on the non-nt win32 platforms due to this and other api
+// inconsistencies
+//
+if (::stat(filename, &statbuf) == OS_ERR) {
+if (PrintMiscellaneous && Verbose) {
+warning("stat %s failed: %s\n", filename, strerror(errno));
+}
+THROW_MSG_0(vmSymbols::java_io_IOException(),
+"Could not determine PerfMemory size");
+}
+if ((statbuf.st_size == 0) || (statbuf.st_size % os::vm_page_size() != 0)) {
+if (PrintMiscellaneous && Verbose) {
+warning("unexpected file size: size = " SIZE_FORMAT "\n",
+statbuf.st_size);
+}
+THROW_MSG_0(vmSymbols::java_lang_Exception(),
+"Invalid PerfMemory size");
+}
+return statbuf.st_size;
+}
+// this method opens a file mapping object and maps the object
+// into the address space of the process
+//
+static void open_file_mapping(const char* user, int vmid,
+PerfMemory::PerfMemoryMode mode,
+char** addrp, size_t* sizep, TRAPS) {
+ResourceMark rm;
+void *mapAddress = 0;
+size_t size;
+HANDLE fmh;
+DWORD ofm_access;
+DWORD mv_access;
+const char* luser = NULL;
+if (mode == PerfMemory::PERF_MODE_RO) {
+ofm_access = FILE_MAP_READ;
+mv_access = FILE_MAP_READ;
+}
+else if (mode == PerfMemory::PERF_MODE_RW) {
+#ifdef LATER
+ofm_access = FILE_MAP_READ | FILE_MAP_WRITE;
+mv_access = FILE_MAP_READ | FILE_MAP_WRITE;
+#else
+THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
+"Unsupported access mode");
+#endif
+}
+else {
+THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
+"Illegal access mode");
+}
+// if a user name wasn't specified, then find the user name for
+// the owner of the target vm.
+if (user == NULL || strlen(user) == 0) {
+luser = get_user_name(vmid);
+}
+else {
+luser = user;
+}
+if (luser == NULL) {
+THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
+"Could not map vmid to user name");
+}
+// get the names for the resources for the target vm
+char* dirname = get_user_tmp_dir(luser);
+// since we don't follow symbolic links when creating the backing
+// store file, we also don't following them when attaching
+//
+if (!is_directory_secure(dirname)) {
+FREE_C_HEAP_ARRAY(char, dirname);
+THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
+"Process not found");
+}
+char* filename = get_sharedmem_filename(dirname, vmid);
+char* objectname = get_sharedmem_objectname(luser, vmid);
+// copy heap memory to resource memory. the objectname and
+// filename are passed to methods that may throw exceptions.
+// using resource arrays for these names prevents the leaks
+// that would otherwise occur.
+//
+char* rfilename = NEW_RESOURCE_ARRAY(char, strlen(filename) + 1);
+char* robjectname = NEW_RESOURCE_ARRAY(char, strlen(objectname) + 1);
+strcpy(rfilename, filename);
+strcpy(robjectname, objectname);
+// free the c heap resources that are no longer needed
+if (luser != user) FREE_C_HEAP_ARRAY(char, luser);
+FREE_C_HEAP_ARRAY(char, dirname);
+FREE_C_HEAP_ARRAY(char, filename);
+FREE_C_HEAP_ARRAY(char, objectname);
+if (*sizep == 0) {
+size = sharedmem_filesize(rfilename, CHECK);
+assert(size != 0, "unexpected size");
+}
+// Open the file mapping object with the given name
+fmh = open_sharedmem_object(robjectname, ofm_access, CHECK);
+assert(fmh != INVALID_HANDLE_VALUE, "unexpected handle value");
+// map the entire file into the address space
+mapAddress = MapViewOfFile(
+fmh,             /* HANDLE Handle of file mapping object */
+mv_access,       /* DWORD access flags */
+0,               /* DWORD High word of offset */
+0,               /* DWORD Low word of offset */
+size);           /* DWORD Number of bytes to map */
+if (mapAddress == NULL) {
+if (PrintMiscellaneous && Verbose) {
+warning("MapViewOfFile failed, lasterror = %d\n", GetLastError());
+}
+CloseHandle(fmh);
+THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(),
+"Could not map PerfMemory");
+}
+*addrp = (char*)mapAddress;
+*sizep = size;
+// File mapping object can be closed at this time without
+// invalidating the mapped view of the file
+CloseHandle(fmh);
+if (PerfTraceMemOps) {
+tty->print("mapped " SIZE_FORMAT " bytes for vmid %d at "
+INTPTR_FORMAT "\n", size, vmid, mapAddress);
+}
+}
+// this method unmaps the the mapped view of the the
+// file mapping object.
+//
+static void remove_file_mapping(char* addr) {
+// the file mapping object was closed in open_file_mapping()
+// after the file map view was created. We only need to
+// unmap the file view here.
+UnmapViewOfFile(addr);
+}
+// create the PerfData memory region in shared memory.
+static char* create_shared_memory(size_t size) {
+return mapping_create_shared(size);
+}
+// release a named, shared memory region
+//
+void delete_shared_memory(char* addr, size_t size) {
+delete_file_mapping(addr, size);
+}
+// create the PerfData memory region
+//
+// This method creates the memory region used to store performance
+// data for the JVM. The memory may be created in standard or
+// shared memory.
+//
+void PerfMemory::create_memory_region(size_t size) {
+if (PerfDisableSharedMem || !os::win32::is_nt()) {
+// do not share the memory for the performance data.
+PerfDisableSharedMem = true;
+_start = create_standard_memory(size);
+}
+else {
+_start = create_shared_memory(size);
+if (_start == NULL) {
+// creation of the shared memory region failed, attempt
+// to create a contiguous, non-shared memory region instead.
+//
+if (PrintMiscellaneous && Verbose) {
+warning("Reverting to non-shared PerfMemory region.\n");
+}
+PerfDisableSharedMem = true;
+_start = create_standard_memory(size);
+}
+}
+if (_start != NULL) _capacity = size;
+}
+// delete the PerfData memory region
+//
+// This method deletes the memory region used to store performance
+// data for the JVM. The memory region indicated by the <address, size>
+// tuple will be inaccessible after a call to this method.
+//
+void PerfMemory::delete_memory_region() {
+assert((start() != NULL && capacity() > 0), "verify proper state");
+// If user specifies PerfDataSaveFile, it will save the performance data
+// to the specified file name no matter whether PerfDataSaveToFile is specified
+// or not. In other word, -XX:PerfDataSaveFile=.. overrides flag
+// -XX:+PerfDataSaveToFile.
+if (PerfDataSaveToFile || PerfDataSaveFile != NULL) {
+save_memory_to_file(start(), capacity());
+}
+if (PerfDisableSharedMem) {
+delete_standard_memory(start(), capacity());
+}
+else {
+delete_shared_memory(start(), capacity());
+}
+}
+// attach to the PerfData memory region for another JVM
+//
+// This method returns an <address, size> tuple that points to
+// a memory buffer that is kept reasonably synchronized with
+// the PerfData memory region for the indicated JVM. This
+// buffer may be kept in synchronization via shared memory
+// or some other mechanism that keeps the buffer updated.
+//
+// If the JVM chooses not to support the attachability feature,
+// this method should throw an UnsupportedOperation exception.
+//
+// This implementation utilizes named shared memory to map
+// the indicated process's PerfData memory region into this JVMs
+// address space.
+//
+void PerfMemory::attach(const char* user, int vmid, PerfMemoryMode mode,
+char** addrp, size_t* sizep, TRAPS) {
+if (vmid == 0 || vmid == os::current_process_id()) {
+*addrp = start();
+*sizep = capacity();
+return;
+}
+open_file_mapping(user, vmid, mode, addrp, sizep, CHECK);
+}
+// detach from the PerfData memory region of another JVM
+//
+// This method detaches the PerfData memory region of another
+// JVM, specified as an <address, size> tuple of a buffer
+// in this process's address space. This method may perform
+// arbitrary actions to accomplish the detachment. The memory
+// region specified by <address, size> will be inaccessible after
+// a call to this method.
+//
+// If the JVM chooses not to support the attachability feature,
+// this method should throw an UnsupportedOperation exception.
+//
+// This implementation utilizes named shared memory to detach
+// the indicated process's PerfData memory region from this
+// process's address space.
+//
+void PerfMemory::detach(char* addr, size_t bytes, TRAPS) {
+assert(addr != 0, "address sanity check");
+assert(bytes > 0, "capacity sanity check");
+if (PerfMemory::contains(addr) || PerfMemory::contains(addr + bytes - 1)) {
+// prevent accidental detachment of this process's PerfMemory region
+return;
+}
+remove_file_mapping(addr);
+}
+char* PerfMemory::backing_store_filename() {
+return sharedmem_fileName;
+}

Mercurial > hg > truffle

comparison src/os/windows/vm/perfMemory_windows.cpp @ 0:a61af66fc99e jdk7-b24