Java example source code file (os.hpp)
The os.hpp Java example source code
/*
* Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#ifndef SHARE_VM_RUNTIME_OS_HPP
#define SHARE_VM_RUNTIME_OS_HPP
#include "jvmtifiles/jvmti.h"
#include "runtime/atomic.hpp"
#include "runtime/extendedPC.hpp"
#include "runtime/handles.hpp"
#include "utilities/top.hpp"
#ifdef TARGET_OS_FAMILY_linux
# include "jvm_linux.h"
# include <setjmp.h>
#endif
#ifdef TARGET_OS_FAMILY_solaris
# include "jvm_solaris.h"
# include <setjmp.h>
#endif
#ifdef TARGET_OS_FAMILY_windows
# include "jvm_windows.h"
#endif
#ifdef TARGET_OS_FAMILY_bsd
# include "jvm_bsd.h"
# include <setjmp.h>
#endif
class AgentLibrary;
// os defines the interface to operating system; this includes traditional
// OS services (time, I/O) as well as other functionality with system-
// dependent code.
typedef void (*dll_func)(...);
class Thread;
class JavaThread;
class Event;
class DLL;
class FileHandle;
template<class E> class GrowableArray;
// %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
// Platform-independent error return values from OS functions
enum OSReturn {
OS_OK = 0, // Operation was successful
OS_ERR = -1, // Operation failed
OS_INTRPT = -2, // Operation was interrupted
OS_TIMEOUT = -3, // Operation timed out
OS_NOMEM = -5, // Operation failed for lack of memory
OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
};
enum ThreadPriority { // JLS 20.20.1-3
NoPriority = -1, // Initial non-priority value
MinPriority = 1, // Minimum priority
NormPriority = 5, // Normal (non-daemon) priority
NearMaxPriority = 9, // High priority, used for VMThread
MaxPriority = 10, // Highest priority, used for WatcherThread
// ensures that VMThread doesn't starve profiler
CriticalPriority = 11 // Critical thread priority
};
// Executable parameter flag for os::commit_memory() and
// os::commit_memory_or_exit().
const bool ExecMem = true;
// Typedef for structured exception handling support
typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
class os: AllStatic {
friend class VMStructs;
public:
enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
private:
static OSThread* _starting_thread;
static address _polling_page;
static volatile int32_t * _mem_serialize_page;
static uintptr_t _serialize_page_mask;
public:
static size_t _page_sizes[page_sizes_max];
private:
static void init_page_sizes(size_t default_page_size) {
_page_sizes[0] = default_page_size;
_page_sizes[1] = 0; // sentinel
}
static char* pd_reserve_memory(size_t bytes, char* addr = 0,
size_t alignment_hint = 0);
static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
static void pd_split_reserved_memory(char *base, size_t size,
size_t split, bool realloc);
static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
bool executable);
// Same as pd_commit_memory() that either succeeds or calls
// vm_exit_out_of_memory() with the specified mesg.
static void pd_commit_memory_or_exit(char* addr, size_t bytes,
bool executable, const char* mesg);
static void pd_commit_memory_or_exit(char* addr, size_t size,
size_t alignment_hint,
bool executable, const char* mesg);
static bool pd_uncommit_memory(char* addr, size_t bytes);
static bool pd_release_memory(char* addr, size_t bytes);
static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
char *addr, size_t bytes, bool read_only = false,
bool allow_exec = false);
static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
char *addr, size_t bytes, bool read_only,
bool allow_exec);
static bool pd_unmap_memory(char *addr, size_t bytes);
static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
public:
static void init(void); // Called before command line parsing
static void init_before_ergo(void); // Called after command line parsing
// before VM ergonomics processing.
static jint init_2(void); // Called after command line parsing
// and VM ergonomics processing
static void init_globals(void) { // Called from init_globals() in init.cpp
init_globals_ext();
}
static void init_3(void); // Called at the end of vm init
// File names are case-insensitive on windows only
// Override me as needed
static int file_name_strcmp(const char* s1, const char* s2);
static bool getenv(const char* name, char* buffer, int len);
static bool have_special_privileges();
static jlong javaTimeMillis();
static jlong javaTimeNanos();
static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
static void run_periodic_checks();
// Returns the elapsed time in seconds since the vm started.
static double elapsedTime();
// Returns real time in seconds since an arbitrary point
// in the past.
static bool getTimesSecs(double* process_real_time,
double* process_user_time,
double* process_system_time);
// Interface to the performance counter
static jlong elapsed_counter();
static jlong elapsed_frequency();
// The "virtual time" of a thread is the amount of time a thread has
// actually run. The first function indicates whether the OS supports
// this functionality for the current thread, and if so:
// * the second enables vtime tracking (if that is required).
// * the third tells whether vtime is enabled.
// * the fourth returns the elapsed virtual time for the current
// thread.
static bool supports_vtime();
static bool enable_vtime();
static bool vtime_enabled();
static double elapsedVTime();
// Return current local time in a string (YYYY-MM-DD HH:MM:SS).
// It is MT safe, but not async-safe, as reading time zone
// information may require a lock on some platforms.
static char* local_time_string(char *buf, size_t buflen);
static struct tm* localtime_pd (const time_t* clock, struct tm* res);
// Fill in buffer with current local time as an ISO-8601 string.
// E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
// Returns buffer, or NULL if it failed.
static char* iso8601_time(char* buffer, size_t buffer_length);
// Interface for detecting multiprocessor system
static inline bool is_MP() {
assert(_processor_count > 0, "invalid processor count");
return _processor_count > 1 || AssumeMP;
}
static julong available_memory();
static julong physical_memory();
static bool has_allocatable_memory_limit(julong* limit);
static bool is_server_class_machine();
// number of CPUs
static int processor_count() {
return _processor_count;
}
static void set_processor_count(int count) { _processor_count = count; }
// Returns the number of CPUs this process is currently allowed to run on.
// Note that on some OSes this can change dynamically.
static int active_processor_count();
// Bind processes to processors.
// This is a two step procedure:
// first you generate a distribution of processes to processors,
// then you bind processes according to that distribution.
// Compute a distribution for number of processes to processors.
// Stores the processor id's into the distribution array argument.
// Returns true if it worked, false if it didn't.
static bool distribute_processes(uint length, uint* distribution);
// Binds the current process to a processor.
// Returns true if it worked, false if it didn't.
static bool bind_to_processor(uint processor_id);
// Give a name to the current thread.
static void set_native_thread_name(const char *name);
// Interface for stack banging (predetect possible stack overflow for
// exception processing) There are guard pages, and above that shadow
// pages for stack overflow checking.
static bool uses_stack_guard_pages();
static bool allocate_stack_guard_pages();
static void bang_stack_shadow_pages();
static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
// OS interface to Virtual Memory
// Return the default page size.
static int vm_page_size();
// Return the page size to use for a region of memory. The min_pages argument
// is a hint intended to limit fragmentation; it says the returned page size
// should be <= region_max_size / min_pages. Because min_pages is a hint,
// this routine may return a size larger than region_max_size / min_pages.
//
// The current implementation ignores min_pages if a larger page size is an
// exact multiple of both region_min_size and region_max_size. This allows
// larger pages to be used when doing so would not cause fragmentation; in
// particular, a single page can be used when region_min_size ==
// region_max_size == a supported page size.
static size_t page_size_for_region(size_t region_min_size,
size_t region_max_size,
uint min_pages);
// Return the largest page size that can be used
static size_t max_page_size() {
// The _page_sizes array is sorted in descending order.
return _page_sizes[0];
}
// Methods for tracing page sizes returned by the above method; enabled by
// TracePageSizes. The region_{min,max}_size parameters should be the values
// passed to page_size_for_region() and page_size should be the result of that
// call. The (optional) base and size parameters should come from the
// ReservedSpace base() and size() methods.
static void trace_page_sizes(const char* str, const size_t* page_sizes,
int count) PRODUCT_RETURN;
static void trace_page_sizes(const char* str, const size_t region_min_size,
const size_t region_max_size,
const size_t page_size,
const char* base = NULL,
const size_t size = 0) PRODUCT_RETURN;
static int vm_allocation_granularity();
static char* reserve_memory(size_t bytes, char* addr = 0,
size_t alignment_hint = 0);
static char* reserve_memory(size_t bytes, char* addr,
size_t alignment_hint, MEMFLAGS flags);
static char* reserve_memory_aligned(size_t size, size_t alignment);
static char* attempt_reserve_memory_at(size_t bytes, char* addr);
static void split_reserved_memory(char *base, size_t size,
size_t split, bool realloc);
static bool commit_memory(char* addr, size_t bytes, bool executable);
static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
bool executable);
// Same as commit_memory() that either succeeds or calls
// vm_exit_out_of_memory() with the specified mesg.
static void commit_memory_or_exit(char* addr, size_t bytes,
bool executable, const char* mesg);
static void commit_memory_or_exit(char* addr, size_t size,
size_t alignment_hint,
bool executable, const char* mesg);
static bool uncommit_memory(char* addr, size_t bytes);
static bool release_memory(char* addr, size_t bytes);
enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
static bool protect_memory(char* addr, size_t bytes, ProtType prot,
bool is_committed = true);
static bool guard_memory(char* addr, size_t bytes);
static bool unguard_memory(char* addr, size_t bytes);
static bool create_stack_guard_pages(char* addr, size_t bytes);
static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
static bool remove_stack_guard_pages(char* addr, size_t bytes);
static char* map_memory(int fd, const char* file_name, size_t file_offset,
char *addr, size_t bytes, bool read_only = false,
bool allow_exec = false);
static char* remap_memory(int fd, const char* file_name, size_t file_offset,
char *addr, size_t bytes, bool read_only,
bool allow_exec);
static bool unmap_memory(char *addr, size_t bytes);
static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
// NUMA-specific interface
static bool numa_has_static_binding();
static bool numa_has_group_homing();
static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
static void numa_make_global(char *addr, size_t bytes);
static size_t numa_get_groups_num();
static size_t numa_get_leaf_groups(int *ids, size_t size);
static bool numa_topology_changed();
static int numa_get_group_id();
// Page manipulation
struct page_info {
size_t size;
int lgrp_id;
};
static bool get_page_info(char *start, page_info* info);
static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
static char* non_memory_address_word();
// reserve, commit and pin the entire memory region
static char* reserve_memory_special(size_t size, size_t alignment,
char* addr, bool executable);
static bool release_memory_special(char* addr, size_t bytes);
static void large_page_init();
static size_t large_page_size();
static bool can_commit_large_page_memory();
static bool can_execute_large_page_memory();
// OS interface to polling page
static address get_polling_page() { return _polling_page; }
static void set_polling_page(address page) { _polling_page = page; }
static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
static void make_polling_page_unreadable();
static void make_polling_page_readable();
// Routines used to serialize the thread state without using membars
static void serialize_thread_states();
// Since we write to the serialize page from every thread, we
// want stores to be on unique cache lines whenever possible
// in order to minimize CPU cross talk. We pre-compute the
// amount to shift the thread* to make this offset unique to
// each thread.
static int get_serialize_page_shift_count() {
return SerializePageShiftCount;
}
static void set_serialize_page_mask(uintptr_t mask) {
_serialize_page_mask = mask;
}
static unsigned int get_serialize_page_mask() {
return _serialize_page_mask;
}
static void set_memory_serialize_page(address page);
static address get_memory_serialize_page() {
return (address)_mem_serialize_page;
}
static inline void write_memory_serialize_page(JavaThread *thread) {
uintptr_t page_offset = ((uintptr_t)thread >>
get_serialize_page_shift_count()) &
get_serialize_page_mask();
*(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
}
static bool is_memory_serialize_page(JavaThread *thread, address addr) {
if (UseMembar) return false;
// Previously this function calculated the exact address of this
// thread's serialize page, and checked if the faulting address
// was equal. However, some platforms mask off faulting addresses
// to the page size, so now we just check that the address is
// within the page. This makes the thread argument unnecessary,
// but we retain the NULL check to preserve existing behaviour.
if (thread == NULL) return false;
address page = (address) _mem_serialize_page;
return addr >= page && addr < (page + os::vm_page_size());
}
static void block_on_serialize_page_trap();
// threads
enum ThreadType {
vm_thread,
cgc_thread, // Concurrent GC thread
pgc_thread, // Parallel GC thread
java_thread,
compiler_thread,
watcher_thread,
os_thread
};
static bool create_thread(Thread* thread,
ThreadType thr_type,
size_t stack_size = 0);
static bool create_main_thread(JavaThread* thread);
static bool create_attached_thread(JavaThread* thread);
static void pd_start_thread(Thread* thread);
static void start_thread(Thread* thread);
static void initialize_thread(Thread* thr);
static void free_thread(OSThread* osthread);
// thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
static intx current_thread_id();
static int current_process_id();
static int sleep(Thread* thread, jlong ms, bool interruptable);
static int naked_sleep();
static void infinite_sleep(); // never returns, use with CAUTION
static void yield(); // Yields to all threads with same priority
enum YieldResult {
YIELD_SWITCHED = 1, // caller descheduled, other ready threads exist & ran
YIELD_NONEREADY = 0, // No other runnable/ready threads.
// platform-specific yield return immediately
YIELD_UNKNOWN = -1 // Unknown: platform doesn't support _SWITCHED or _NONEREADY
// YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong"
// yield that can be used in lieu of blocking.
} ;
static YieldResult NakedYield () ;
static void yield_all(int attempts = 0); // Yields to all other threads including lower priority
static void loop_breaker(int attempts); // called from within tight loops to possibly influence time-sharing
static OSReturn set_priority(Thread* thread, ThreadPriority priority);
static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
static void interrupt(Thread* thread);
static bool is_interrupted(Thread* thread, bool clear_interrupted);
static int pd_self_suspend_thread(Thread* thread);
static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
static frame fetch_frame_from_context(void* ucVoid);
static ExtendedPC get_thread_pc(Thread *thread);
static void breakpoint();
static address current_stack_pointer();
static address current_stack_base();
static size_t current_stack_size();
static void verify_stack_alignment() PRODUCT_RETURN;
static int message_box(const char* title, const char* message);
static char* do_you_want_to_debug(const char* message);
// run cmd in a separate process and return its exit code; or -1 on failures
static int fork_and_exec(char *cmd);
// Set file to send error reports.
static void set_error_file(const char *logfile);
// os::exit() is merged with vm_exit()
// static void exit(int num);
// Terminate the VM, but don't exit the process
static void shutdown();
// Terminate with an error. Default is to generate a core file on platforms
// that support such things. This calls shutdown() and then aborts.
static void abort(bool dump_core = true);
// Die immediately, no exit hook, no abort hook, no cleanup.
static void die();
// File i/o operations
static const int default_file_open_flags();
static int open(const char *path, int oflag, int mode);
static FILE* open(int fd, const char* mode);
static int close(int fd);
static jlong lseek(int fd, jlong offset, int whence);
static char* native_path(char *path);
static int ftruncate(int fd, jlong length);
static int fsync(int fd);
static int available(int fd, jlong *bytes);
//File i/o operations
static size_t read(int fd, void *buf, unsigned int nBytes);
static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
static size_t write(int fd, const void *buf, unsigned int nBytes);
// Reading directories.
static DIR* opendir(const char* dirname);
static int readdir_buf_size(const char *path);
static struct dirent* readdir(DIR* dirp, dirent* dbuf);
static int closedir(DIR* dirp);
// Dynamic library extension
static const char* dll_file_extension();
static const char* get_temp_directory();
static const char* get_current_directory(char *buf, size_t buflen);
// Builds a platform-specific full library path given a ld path and lib name
// Returns true if buffer contains full path to existing file, false otherwise
static bool dll_build_name(char* buffer, size_t size,
const char* pathname, const char* fname);
// Symbol lookup, find nearest function name; basically it implements
// dladdr() for all platforms. Name of the nearest function is copied
// to buf. Distance from its base address is optionally returned as offset.
// If function name is not found, buf[0] is set to '\0' and offset is
// set to -1 (if offset is non-NULL).
static bool dll_address_to_function_name(address addr, char* buf,
int buflen, int* offset);
// Locate DLL/DSO. On success, full path of the library is copied to
// buf, and offset is optionally set to be the distance between addr
// and the library's base address. On failure, buf[0] is set to '\0'
// and offset is set to -1 (if offset is non-NULL).
static bool dll_address_to_library_name(address addr, char* buf,
int buflen, int* offset);
// Find out whether the pc is in the static code for jvm.dll/libjvm.so.
static bool address_is_in_vm(address addr);
// Loads .dll/.so and
// in case of error it checks if .dll/.so was built for the
// same architecture as Hotspot is running on
static void* dll_load(const char *name, char *ebuf, int ebuflen);
// lookup symbol in a shared library
static void* dll_lookup(void* handle, const char* name);
// Unload library
static void dll_unload(void *lib);
// Return the handle of this process
static void* get_default_process_handle();
// Check for static linked agent library
static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
size_t syms_len);
// Find agent entry point
static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
const char *syms[], size_t syms_len);
// Print out system information; they are called by fatal error handler.
// Output format may be different on different platforms.
static void print_os_info(outputStream* st);
static void print_os_info_brief(outputStream* st);
static void print_cpu_info(outputStream* st);
static void pd_print_cpu_info(outputStream* st);
static void print_memory_info(outputStream* st);
static void print_dll_info(outputStream* st);
static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
static void print_context(outputStream* st, void* context);
static void print_register_info(outputStream* st, void* context);
static void print_siginfo(outputStream* st, void* siginfo);
static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
static void print_date_and_time(outputStream* st);
static void print_location(outputStream* st, intptr_t x, bool verbose = false);
static size_t lasterror(char *buf, size_t len);
static int get_last_error();
// Determines whether the calling process is being debugged by a user-mode debugger.
static bool is_debugger_attached();
// wait for a key press if PauseAtExit is set
static void wait_for_keypress_at_exit(void);
// The following two functions are used by fatal error handler to trace
// native (C) frames. They are not part of frame.hpp/frame.cpp because
// frame.hpp/cpp assume thread is JavaThread, and also because different
// OS/compiler may have different convention or provide different API to
// walk C frames.
//
// We don't attempt to become a debugger, so we only follow frames if that
// does not require a lookup in the unwind table, which is part of the binary
// file but may be unsafe to read after a fatal error. So on x86, we can
// only walk stack if %ebp is used as frame pointer; on ia64, it's not
// possible to walk C stack without having the unwind table.
static bool is_first_C_frame(frame *fr);
static frame get_sender_for_C_frame(frame *fr);
// return current frame. pc() and sp() are set to NULL on failure.
static frame current_frame();
static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
// returns a string to describe the exception/signal;
// returns NULL if exception_code is not an OS exception/signal.
static const char* exception_name(int exception_code, char* buf, size_t buflen);
// Returns native Java library, loads if necessary
static void* native_java_library();
// Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
static void jvm_path(char *buf, jint buflen);
// Returns true if we are running in a headless jre.
static bool is_headless_jre();
// JNI names
static void print_jni_name_prefix_on(outputStream* st, int args_size);
static void print_jni_name_suffix_on(outputStream* st, int args_size);
// File conventions
static const char* file_separator();
static const char* line_separator();
static const char* path_separator();
// Init os specific system properties values
static void init_system_properties_values();
// IO operations, non-JVM_ version.
static int stat(const char* path, struct stat* sbuf);
static bool dir_is_empty(const char* path);
// IO operations on binary files
static int create_binary_file(const char* path, bool rewrite_existing);
static jlong current_file_offset(int fd);
static jlong seek_to_file_offset(int fd, jlong offset);
// Thread Local Storage
static int allocate_thread_local_storage();
static void thread_local_storage_at_put(int index, void* value);
static void* thread_local_storage_at(int index);
static void free_thread_local_storage(int index);
// Stack walk
static address get_caller_pc(int n = 0);
// General allocation (must be MT-safe)
static void* malloc (size_t size, MEMFLAGS flags, address caller_pc = 0);
static void* realloc (void *memblock, size_t size, MEMFLAGS flags, address caller_pc = 0);
static void free (void *memblock, MEMFLAGS flags = mtNone);
static bool check_heap(bool force = false); // verify C heap integrity
static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
#ifndef PRODUCT
static julong num_mallocs; // # of calls to malloc/realloc
static julong alloc_bytes; // # of bytes allocated
static julong num_frees; // # of calls to free
static julong free_bytes; // # of bytes freed
#endif
// SocketInterface (ex HPI SocketInterface )
static int socket(int domain, int type, int protocol);
static int socket_close(int fd);
static int socket_shutdown(int fd, int howto);
static int recv(int fd, char* buf, size_t nBytes, uint flags);
static int send(int fd, char* buf, size_t nBytes, uint flags);
static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
static int timeout(int fd, long timeout);
static int listen(int fd, int count);
static int connect(int fd, struct sockaddr* him, socklen_t len);
static int bind(int fd, struct sockaddr* him, socklen_t len);
static int accept(int fd, struct sockaddr* him, socklen_t* len);
static int recvfrom(int fd, char* buf, size_t nbytes, uint flags,
struct sockaddr* from, socklen_t* fromlen);
static int get_sock_name(int fd, struct sockaddr* him, socklen_t* len);
static int sendto(int fd, char* buf, size_t len, uint flags,
struct sockaddr* to, socklen_t tolen);
static int socket_available(int fd, jint* pbytes);
static int get_sock_opt(int fd, int level, int optname,
char* optval, socklen_t* optlen);
static int set_sock_opt(int fd, int level, int optname,
const char* optval, socklen_t optlen);
static int get_host_name(char* name, int namelen);
static struct hostent* get_host_by_name(char* name);
// Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
static void signal_init();
static void signal_init_pd();
static void signal_notify(int signal_number);
static void* signal(int signal_number, void* handler);
static void signal_raise(int signal_number);
static int signal_wait();
static int signal_lookup();
static void* user_handler();
static void terminate_signal_thread();
static int sigexitnum_pd();
// random number generation
static long random(); // return 32bit pseudorandom number
static void init_random(long initval); // initialize random sequence
// Structured OS Exception support
static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
// On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
// Get the default path to the core file
// Returns the length of the string
static int get_core_path(char* buffer, size_t bufferSize);
// JVMTI & JVM monitoring and management support
// The thread_cpu_time() and current_thread_cpu_time() are only
// supported if is_thread_cpu_time_supported() returns true.
// They are not supported on Solaris T1.
// Thread CPU Time - return the fast estimate on a platform
// On Solaris - call gethrvtime (fast) - user time only
// On Linux - fast clock_gettime where available - user+sys
// - otherwise: very slow /proc fs - user+sys
// On Windows - GetThreadTimes - user+sys
static jlong current_thread_cpu_time();
static jlong thread_cpu_time(Thread* t);
// Thread CPU Time with user_sys_cpu_time parameter.
//
// If user_sys_cpu_time is true, user+sys time is returned.
// Otherwise, only user time is returned
static jlong current_thread_cpu_time(bool user_sys_cpu_time);
static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
// Return a bunch of info about the timers.
// Note that the returned info for these two functions may be different
// on some platforms
static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
static bool is_thread_cpu_time_supported();
// System loadavg support. Returns -1 if load average cannot be obtained.
static int loadavg(double loadavg[], int nelem);
// Hook for os specific jvm options that we don't want to abort on seeing
static bool obsolete_option(const JavaVMOption *option);
// Extensions
#include "runtime/os_ext.hpp"
public:
class CrashProtectionCallback : public StackObj {
public:
virtual void call() = 0;
};
// Platform dependent stuff
#ifdef TARGET_OS_FAMILY_linux
# include "os_linux.hpp"
# include "os_posix.hpp"
#endif
#ifdef TARGET_OS_FAMILY_solaris
# include "os_solaris.hpp"
# include "os_posix.hpp"
#endif
#ifdef TARGET_OS_FAMILY_windows
# include "os_windows.hpp"
#endif
#ifdef TARGET_OS_FAMILY_bsd
# include "os_posix.hpp"
# include "os_bsd.hpp"
#endif
#ifdef TARGET_OS_ARCH_linux_x86
# include "os_linux_x86.hpp"
#endif
#ifdef TARGET_OS_ARCH_linux_sparc
# include "os_linux_sparc.hpp"
#endif
#ifdef TARGET_OS_ARCH_linux_zero
# include "os_linux_zero.hpp"
#endif
#ifdef TARGET_OS_ARCH_solaris_x86
# include "os_solaris_x86.hpp"
#endif
#ifdef TARGET_OS_ARCH_solaris_sparc
# include "os_solaris_sparc.hpp"
#endif
#ifdef TARGET_OS_ARCH_windows_x86
# include "os_windows_x86.hpp"
#endif
#ifdef TARGET_OS_ARCH_linux_arm
# include "os_linux_arm.hpp"
#endif
#ifdef TARGET_OS_ARCH_linux_ppc
# include "os_linux_ppc.hpp"
#endif
#ifdef TARGET_OS_ARCH_bsd_x86
# include "os_bsd_x86.hpp"
#endif
#ifdef TARGET_OS_ARCH_bsd_zero
# include "os_bsd_zero.hpp"
#endif
public:
#ifndef PLATFORM_PRINT_NATIVE_STACK
// No platform-specific code for printing the native stack.
static bool platform_print_native_stack(outputStream* st, void* context,
char *buf, int buf_size) {
return false;
}
#endif
// debugging support (mostly used by debug.cpp but also fatal error handler)
static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
static bool dont_yield(); // when true, JVM_Yield() is nop
static void print_statistics();
// Thread priority helpers (implemented in OS-specific part)
static OSReturn set_native_priority(Thread* thread, int native_prio);
static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
static int java_to_os_priority[CriticalPriority + 1];
// Hint to the underlying OS that a task switch would not be good.
// Void return because it's a hint and can fail.
static void hint_no_preempt();
// Used at creation if requested by the diagnostic flag PauseAtStartup.
// Causes the VM to wait until an external stimulus has been applied
// (for Unix, that stimulus is a signal, for Windows, an external
// ResumeThread call)
static void pause();
// Builds a platform dependent Agent_OnLoad_<libname> function name
// which is used to find statically linked in agents.
static char* build_agent_function_name(const char *sym, const char *cname,
bool is_absolute_path);
class SuspendedThreadTaskContext {
public:
SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
Thread* thread() const { return _thread; }
void* ucontext() const { return _ucontext; }
private:
Thread* _thread;
void* _ucontext;
};
class SuspendedThreadTask {
public:
SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
virtual ~SuspendedThreadTask() {}
void run();
bool is_done() { return _done; }
virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
protected:
private:
void internal_do_task();
Thread* _thread;
bool _done;
};
#ifndef TARGET_OS_FAMILY_windows
// Suspend/resume support
// Protocol:
//
// a thread starts in SR_RUNNING
//
// SR_RUNNING can go to
// * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
// SR_SUSPEND_REQUEST can go to
// * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
// * SR_SUSPENDED if the stopped thread receives the signal and switches state
// SR_SUSPENDED can go to
// * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
// SR_WAKEUP_REQUEST can go to
// * SR_RUNNING when the stopped thread receives the signal
// * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
class SuspendResume {
public:
enum State {
SR_RUNNING,
SR_SUSPEND_REQUEST,
SR_SUSPENDED,
SR_WAKEUP_REQUEST
};
private:
volatile State _state;
private:
/* try to switch state from state "from" to state "to"
* returns the state set after the method is complete
*/
State switch_state(State from, State to);
public:
SuspendResume() : _state(SR_RUNNING) { }
State state() const { return _state; }
State request_suspend() {
return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
}
State cancel_suspend() {
return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
}
State suspended() {
return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
}
State request_wakeup() {
return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
}
State running() {
return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
}
bool is_running() const {
return _state == SR_RUNNING;
}
bool is_suspend_request() const {
return _state == SR_SUSPEND_REQUEST;
}
bool is_suspended() const {
return _state == SR_SUSPENDED;
}
};
#endif
protected:
static long _rand_seed; // seed for random number generator
static int _processor_count; // number of processors
static char* format_boot_path(const char* format_string,
const char* home,
int home_len,
char fileSep,
char pathSep);
static bool set_boot_path(char fileSep, char pathSep);
static char** split_path(const char* path, int* n);
};
// Note that "PAUSE" is almost always used with synchronization
// so arguably we should provide Atomic::SpinPause() instead
// of the global SpinPause() with C linkage.
// It'd also be eligible for inlining on many platforms.
extern "C" int SpinPause();
#endif // SHARE_VM_RUNTIME_OS_HPP
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