Mercurial > hg > graal-compiler
diff src/os/windows/vm/perfMemory_windows.cpp @ 0:a61af66fc99e jdk7-b24
Initial load
author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | 98cb887364d3 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/os/windows/vm/perfMemory_windows.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,1776 @@ +/* + * 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; +}