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/*
* Copyright (c) 1997, 2023, 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_RUNTIME_OS_HPP
#define SHARE_RUNTIME_OS_HPP
#include "jvm_md.h"
#include "runtime/osInfo.hpp"
#include "utilities/exceptions.hpp"
#include "utilities/ostream.hpp"
#include "utilities/macros.hpp"
#ifdef __APPLE__
# include <mach/mach_time.h>
#endif
class frame;
class JvmtiAgent;
// Rules for using and implementing methods declared in the "os" class
// ===================================================================
//
// The "os" class defines a number of the interfaces for porting HotSpot
// to different operating systems. For example, I/O, memory, timing, etc.
// Note that additional classes such as Semaphore, Mutex, etc., are used for
// porting specific groups of features.
//
// Structure of os*.{cpp, hpp} files
//
// - os.hpp
//
// (This file) declares the entire API of the "os" class.
//
// - os.inline.hpp
//
// To use any of the inline methods declared in the "os" class, this
// header file must be included.
//
// - src/hotspot/os/<os>/os_<os>.hpp
// - src/hotspot/os/posix/os_posix.hpp
//
// These headers declare APIs that should be used only within the
// platform-specific source files for that particular OS.
//
// For example, os_linux.hpp declares the os::Linux class, which provides
// many methods that can be used by files under os/linux/ and os_cpu/linux_*/
//
// os_posix.hpp can be used by platform-specific files for POSIX-like
// OSes such as aix, bsd and linux.
//
// Platform-independent source files should not include these header files
// (although sadly there are some rare exceptions ...)
//
// - os.cpp
//
// Platform-independent methods of the "os" class are defined
// in os.cpp. These are not part of the porting interface, but rather
// can be considered as convenience functions for accessing
// the porting interface. E.g., os::print_function_and_library_name().
//
// The methods declared in os.hpp but not implemented in os.cpp are
// a part the HotSpot Porting APIs. They must be implemented in one of
// the following four files:
//
// - src/hotspot/os/<os>/os_<os>.inline.hpp
// - src/hotspot/os_cpu/<os>_<cpu>/os_<os>_<cpu>.inline.hpp
// - src/hotspot/os/<os>/os_<os>.cpp
// - src/hotspot/os_cpu/<os>_<cpu>/os_<os>_<cpu>.cpp
//
// The Porting APIs declared as "inline" in os.hpp MUST be
// implemented in one of the two .inline.hpp files, depending on
// whether the feature is specific to a particular CPU architecture
// for this OS. These two files are automatically included by
// os.inline.hpp. Platform-independent source files must not include
// these two files directly.
//
// If the full definition of an inline method is too complex to fit in a
// header file, the actual implementation can be deferred to another
// method defined in the .cpp files.
//
// The Porting APIs that are *not* declared as "inline" in os.hpp MUST
// be implemented in one of the two .cpp files above. These files
// also implement OS-specific APIs such as os::Linux, os::Posix, etc.
//
// (Note: on the POSIX-like platforms, some of the Porting APIs are implemented
// in os_posix.cpp instead).
class Thread;
class JavaThread;
class NativeCallStack;
class methodHandle;
class OSThread;
class Mutex;
struct jvmtiTimerInfo;
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
};
enum WXMode {
WXWrite,
WXExec
};
// 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, const methodHandle& method, JavaCallArguments* args, JavaThread* thread);
class MallocTracker;
class os: AllStatic {
friend class VMStructs;
friend class JVMCIVMStructs;
friend class MallocTracker;
#ifdef ASSERT
private:
static bool _mutex_init_done;
public:
static void set_mutex_init_done() { _mutex_init_done = true; }
static bool mutex_init_done() { return _mutex_init_done; }
#endif
public:
// A simple value class holding a set of page sizes (similar to sigset_t)
class PageSizes {
size_t _v; // actually a bitmap.
public:
PageSizes() : _v(0) {}
void add(size_t pagesize);
bool contains(size_t pagesize) const;
// Given a page size, return the next smaller page size in this set, or 0.
size_t next_smaller(size_t pagesize) const;
// Given a page size, return the next larger page size in this set, or 0.
size_t next_larger(size_t pagesize) const;
// Returns the largest page size in this set, or 0 if set is empty.
size_t largest() const;
// Returns the smallest page size in this set, or 0 if set is empty.
size_t smallest() const;
// Prints one line of comma separated, human readable page sizes, "empty" if empty.
void print_on(outputStream* st) const;
};
private:
static OSThread* _starting_thread;
static PageSizes _page_sizes;
static char* pd_reserve_memory(size_t bytes, bool executable);
static char* pd_attempt_reserve_memory_at(char* addr, size_t bytes, bool executable);
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, bool executable);
static bool pd_release_memory(char* addr, size_t bytes);
static char* pd_attempt_map_memory_to_file_at(char* addr, size_t bytes, int file_desc);
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);
static char* pd_reserve_memory_special(size_t size, size_t alignment, size_t page_size,
char* addr, bool executable);
static bool pd_release_memory_special(char* addr, size_t bytes);
static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
// Get summary strings for system information in buffer provided
static void get_summary_cpu_info(char* buf, size_t buflen);
static void get_summary_os_info(char* buf, size_t buflen);
// Returns number of bytes written on success, OS_ERR on failure.
static ssize_t pd_write(int fd, const void *buf, size_t nBytes);
static void initialize_initial_active_processor_count();
LINUX_ONLY(static void pd_init_container_support();)
public:
static void init(void); // Called before command line parsing
static void init_container_support() { // Called during command line parsing.
LINUX_ONLY(pd_init_container_support();)
}
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
// Get environ pointer, platform independently
static char** get_environ();
static bool have_special_privileges();
static jlong javaTimeMillis();
static jlong javaTimeNanos();
static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
static void run_periodic_checks(outputStream* st);
// 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
// returns the elapsed virtual time for the current thread.
static bool supports_vtime();
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);
static struct tm* gmtime_pd (const time_t* clock, struct tm* res);
// "YYYY-MM-DDThh:mm:ss.mmm+zzzz" incl. terminating zero
static const size_t iso8601_timestamp_size = 29;
// Fill in buffer with an ISO-8601 string corresponding to the given javaTimeMillis value
// E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
// Returns buffer, or null if it failed.
static char* iso8601_time(jlong milliseconds_since_19700101, char* buffer,
size_t buffer_length, bool utc = false);
// 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, bool utc = false);
// Interface for detecting multiprocessor system
static inline bool is_MP() {
// During bootstrap if _processor_count is not yet initialized
// we claim to be MP as that is safest. If any platform has a
// stub generator that might be triggered in this phase and for
// which being declared MP when in fact not, is a problem - then
// the bootstrap routine for the stub generator needs to check
// the processor count directly and leave the bootstrap routine
// in place until called after initialization has occurred.
return (_processor_count != 1);
}
// On some platforms there is a distinction between "available" memory and "free" memory.
// For example, on Linux, "available" memory (`MemAvailable` in `/proc/meminfo`) is greater
// than "free" memory (`MemFree` in `/proc/meminfo`) because Linux can free memory
// aggressively (e.g. clear caches) so that it becomes available.
static julong available_memory();
static julong free_memory();
static julong physical_memory();
static bool has_allocatable_memory_limit(size_t* limit);
static bool is_server_class_machine();
// Returns the id of the processor on which the calling thread is currently executing.
// The returned value is guaranteed to be between 0 and (os::processor_count() - 1).
static uint processor_id();
// 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();
// At startup the number of active CPUs this process is allowed to run on.
// This value does not change dynamically. May be different from active_processor_count().
static int initial_active_processor_count() {
assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
return _initial_active_processor_count;
}
// 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.
inline static bool uses_stack_guard_pages();
inline static bool must_commit_stack_guard_pages();
inline static void map_stack_shadow_pages(address sp);
static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp);
private:
// Minimum stack size a thread can be created with (allowing
// the VM to completely create the thread and enter user code).
// The initial values exclude any guard pages (by HotSpot or libc).
// set_minimum_stack_sizes() will add the size required for
// HotSpot guard pages depending on page size and flag settings.
// Libc guard pages are never considered by these values.
static size_t _compiler_thread_min_stack_allowed;
static size_t _java_thread_min_stack_allowed;
static size_t _vm_internal_thread_min_stack_allowed;
static size_t _os_min_stack_allowed;
// Check and sets minimum stack sizes
static jint set_minimum_stack_sizes();
public:
// Find committed memory region within specified range (start, start + size),
// return true if found any
static bool committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size);
// OS interface to Virtual Memory
// Return the default page size.
static size_t vm_page_size() { return OSInfo::vm_page_size(); }
// The set of page sizes which the VM is allowed to use (may be a subset of
// the page sizes actually available on the platform).
static const PageSizes& page_sizes() { return _page_sizes; }
// Returns the page size to use for a region of memory.
// region_size / min_pages will always be greater than or equal to the
// returned value. The returned value will divide region_size.
static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
// Returns the page size to use for a region of memory.
// region_size / min_pages will always be greater than or equal to the
// returned value. The returned value might not divide region_size.
static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
// Return the largest page size that can be used
static size_t max_page_size() { return page_sizes().largest(); }
// Return a lower bound for page sizes. Also works before os::init completed.
static size_t min_page_size() { return 4 * K; }
// Methods for tracing page sizes returned by the above method.
// 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);
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,
const size_t size);
static void trace_page_sizes_for_requested_size(const char* str,
const size_t requested_size,
const size_t page_size,
const size_t alignment,
const char* base,
const size_t size);
static size_t vm_allocation_granularity() { return OSInfo::vm_allocation_granularity(); }
inline static size_t cds_core_region_alignment();
// Reserves virtual memory.
static char* reserve_memory(size_t bytes, bool executable = false, MEMFLAGS flags = mtNone);
// Reserves virtual memory that starts at an address that is aligned to 'alignment'.
static char* reserve_memory_aligned(size_t size, size_t alignment, bool executable = false);
// Attempts to reserve the virtual memory at [addr, addr + bytes).
// Does not overwrite existing mappings.
static char* attempt_reserve_memory_at(char* addr, size_t bytes, bool executable = false);
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, bool executable = false);
static bool release_memory(char* addr, size_t bytes);
// Does the platform support trimming the native heap?
static bool can_trim_native_heap();
// Trim the C-heap. Optionally returns working set size change (RSS+Swap) in *rss_change.
// Note: If trimming succeeded but no size change information could be obtained,
// rss_change.after will contain SIZE_MAX upon return.
struct size_change_t { size_t before; size_t after; };
static bool trim_native_heap(size_change_t* rss_change = nullptr);
// A diagnostic function to print memory mappings in the given range.
static void print_memory_mappings(char* addr, size_t bytes, outputStream* st);
// Prints all mappings
static void print_memory_mappings(outputStream* st);
// Touch memory pages that cover the memory range from start to end
// (exclusive) to make the OS back the memory range with actual memory.
// Other threads may use the memory range concurrently with pretouch.
static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size());
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);
// Helper function to create a new file with template jvmheap.XXXXXX.
// Returns a valid fd on success or else returns -1
static int create_file_for_heap(const char* dir);
// Map memory to the file referred by fd. This function is slightly different from map_memory()
// and is added to be used for implementation of -XX:AllocateHeapAt
static char* map_memory_to_file(size_t size, int fd);
static char* map_memory_to_file_aligned(size_t size, size_t alignment, int fd);
static char* map_memory_to_file(char* base, size_t size, int fd);
static char* attempt_map_memory_to_file_at(char* base, size_t size, int fd);
// Replace existing reserved memory with file mapping
static char* replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd);
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, MEMFLAGS flags = mtNone);
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_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();
static int numa_get_group_id_for_address(const void* address);
static bool numa_get_group_ids_for_range(const void** addresses, int* lgrp_ids, size_t count);
// Page manipulation
struct page_info {
size_t size;
int lgrp_id;
};
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, size_t page_size,
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();
// Check if pointer points to readable memory (by 4-byte read access)
static bool is_readable_pointer(const void* p);
static bool is_readable_range(const void* from, const void* to);
// threads
enum ThreadType {
vm_thread,
gc_thread, // GC thread
java_thread, // Java, JVMTIAgent and Service threads.
compiler_thread,
watcher_thread,
asynclog_thread, // dedicated to flushing logs
os_thread
};
static bool create_thread(Thread* thread,
ThreadType thr_type,
size_t req_stack_size = 0);
// The "main thread", also known as "starting thread", is the thread
// that loads/creates the JVM via JNI_CreateJavaVM.
static bool create_main_thread(JavaThread* thread);
// The primordial thread is the initial process thread. The java
// launcher never uses the primordial thread as the main thread, but
// applications that host the JVM directly may do so. Some platforms
// need special-case handling of the primordial thread if it attaches
// to the VM.
static bool is_primordial_thread(void)
#if defined(_WINDOWS) || defined(BSD)
// No way to identify the primordial thread.
{ return false; }
#else
;
#endif
static bool create_attached_thread(JavaThread* thread);
static void pd_start_thread(Thread* thread);
static void start_thread(Thread* thread);
// Returns true if successful.
static bool signal_thread(Thread* thread, int sig, const char* reason);
static void free_thread(OSThread* osthread);
// thread id on Linux/64bit is 64bit, on Windows it's 32bit
static intx current_thread_id();
static int current_process_id();
// Short standalone OS sleep routines suitable for slow path spin loop.
// Ignores safepoints/suspension/Thread.interrupt() (so keep it short).
// ms/ns = 0, will sleep for the least amount of time allowed by the OS.
// Maximum sleep time is just under 1 second.
static void naked_short_sleep(jlong ms);
static void naked_short_nanosleep(jlong ns);
// Longer standalone OS sleep routine - a convenience wrapper around
// multiple calls to naked_short_sleep. Only for use by non-JavaThreads.
static void naked_sleep(jlong millis);
// Never returns, use with CAUTION
ATTRIBUTE_NORETURN static void infinite_sleep();
static void naked_yield () ;
static OSReturn set_priority(Thread* thread, ThreadPriority priority);
static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
static address fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
static frame fetch_frame_from_context(const void* ucVoid);
static frame fetch_compiled_frame_from_context(const void* ucVoid);
static void breakpoint();
static bool start_debugging(char *buf, int buflen);
static address current_stack_pointer();
static address current_stack_base();
static size_t current_stack_size();
static void verify_stack_alignment() PRODUCT_RETURN;
static bool message_box(const char* title, const char* message);
// run cmd in a separate process and return its exit code; or -1 on failures.
// Note: only safe to use in fatal error situations.
static int fork_and_exec(const char *cmd);
// Call ::exit() on all platforms
ATTRIBUTE_NORETURN static void exit(int num);
// Call ::_exit() on all platforms. Similar semantics to die() except we never
// want a core dump.
ATTRIBUTE_NORETURN 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.
ATTRIBUTE_NORETURN static void abort(bool dump_core, void *siginfo, const void *context);
ATTRIBUTE_NORETURN static void abort(bool dump_core = true);
// Die immediately, no exit hook, no abort hook, no cleanup.
// Dump a core file, if possible, for debugging. os::abort() is the
// preferred means to abort the VM on error. os::die() should only
// be called if something has gone badly wrong. CreateCoredumpOnCrash
// is intentionally not honored by this function.
ATTRIBUTE_NORETURN static void die();
// File i/o operations
static int open(const char *path, int oflag, int mode);
static FILE* fdopen(int fd, const char* mode);
static FILE* fopen(const char* path, const char* mode);
static jlong lseek(int fd, jlong offset, int whence);
static bool file_exists(const char* file);
// This function, on Windows, canonicalizes a given path (see os_windows.cpp for details).
// On Posix, this function is a noop: it does not change anything and just returns
// the input pointer.
static char* native_path(char *path);
static int ftruncate(int fd, jlong length);
static int get_fileno(FILE* fp);
static void flockfile(FILE* fp);
static void funlockfile(FILE* fp);
static int compare_file_modified_times(const char* file1, const char* file2);
static bool same_files(const char* file1, const char* file2);
//File i/o operations
static ssize_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
// Writes the bytes completely. Returns true on success, false otherwise.
static bool write(int fd, const void *buf, size_t nBytes);
// Reading directories.
static DIR* opendir(const char* dirname);
static struct dirent* readdir(DIR* dirp);
static int closedir(DIR* dirp);
static const char* get_temp_directory();
static const char* get_current_directory(char *buf, size_t buflen);
static void prepare_native_symbols();
// Builds the platform-specific name of a library.
// Returns false if the buffer is too small.
static bool dll_build_name(char* buffer, size_t size,
const char* fname);
// Builds a platform-specific full library path given an ld path and
// unadorned library name. Returns true if the buffer contains a full
// path to an existing file, false otherwise. If pathname is empty,
// uses the path to the current directory.
static bool dll_locate_lib(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,
bool demangle = true);
// 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);
// Given an address, attempt to locate both the symbol and the library it
// resides in. If at least one of these steps was successful, prints information
// and returns true.
// - if no scratch buffer is given, stack is used
// - shorten_paths: path is omitted from library name
// - demangle: function name is demangled
// - strip_arguments: arguments are stripped (requires demangle=true)
// On success prints either one of:
// "<function name>+<offset> in <library>"
// "<function name>+<offset>"
// "<address> in <library>+<offset>"
static bool print_function_and_library_name(outputStream* st,
address addr,
char* buf = nullptr, int buflen = 0,
bool shorten_paths = true,
bool demangle = true,
bool strip_arguments = false);
// Used only on PPC.
inline static void* resolve_function_descriptor(void* p);
// 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
// in case of an error null is returned and an error message is stored in ebuf
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);
// Callback for loaded module information
// Input parameters:
// char* module_file_name,
// address module_base_addr,
// address module_top_addr,
// void* param
typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
// Return the handle of this process
static void* get_default_process_handle();
// Check for static linked agent library
static bool find_builtin_agent(JvmtiAgent *agent_lib, const char *syms[],
size_t syms_len);
// Find agent entry point
static void *find_agent_function(JvmtiAgent *agent_lib, bool check_lib,
const char *syms[], size_t syms_len);
// Provide C99 compliant versions of these functions, since some versions
// of some platforms don't.
static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
// Performs snprintf and asserts the result is non-negative (so there was not
// an encoding error) and that the output was not truncated.
static int snprintf_checked(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
// Get host name in buffer provided
static bool get_host_name(char* buf, size_t buflen);
// 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, char* buf, size_t buflen);
static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
static void print_summary_info(outputStream* st, char* buf, size_t buflen);
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);
static void print_context(outputStream* st, const void* context);
static void print_tos_pc(outputStream* st, const void* context);
static void print_tos(outputStream* st, address sp);
static void print_instructions(outputStream* st, address pc, int unitsize = 1);
static void print_register_info(outputStream* st, const void* context, int& continuation);
static void print_register_info(outputStream* st, const void* context);
static bool signal_sent_by_kill(const void* siginfo);
static void print_siginfo(outputStream* st, const void* siginfo);
static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
static void print_user_info(outputStream* st);
static void print_active_locale(outputStream* st);
// helper for output of seconds in days , hours and months
static void print_dhm(outputStream* st, const char* startStr, long sec);
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();
// Send JFR memory info event
static void jfr_report_memory_info() NOT_JFR_RETURN();
// Replacement for strerror().
// Will return the english description of the error (e.g. "File not found", as
// suggested in the POSIX standard.
// Will return "Unknown error" for an unknown errno value.
// Will not attempt to localize the returned string.
// Will always return a valid string which is a static constant.
// Will not change the value of errno.
static const char* strerror(int e);
// Will return the literalized version of the given errno (e.g. "EINVAL"
// for EINVAL).
// Will return "Unknown error" for an unknown errno value.
// Will always return a valid string which is a static constant.
// Will not change the value of errno.
static const char* errno_name(int e);
// 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,
int bytes_per_line, address logical_start);
static void print_hex_dump(outputStream* st, address start, address end, int unitsize) {
print_hex_dump(st, start, end, unitsize, /*bytes_per_line=*/16, /*logical_start=*/start);
}
// 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 the signal number (e.g. 11) for a given signal name (SIGSEGV).
static int get_signal_number(const char* signal_name);
// 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);
// 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);
// 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);
// Retrieve native stack frames.
// Parameter:
// stack: an array to storage stack pointers.
// frames: size of above array.
// toSkip: number of stack frames to skip at the beginning.
// Return: number of stack frames captured.
static int get_native_stack(address* stack, int size, int toSkip = 0);
// General allocation (must be MT-safe)
static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
static void* malloc (size_t size, MEMFLAGS flags);
static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
// handles null pointers
static void free (void *memblock);
static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
// Like strdup, but exit VM when strdup() returns null
static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
// SocketInterface (ex HPI SocketInterface )
static int socket_close(int fd);
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 connect(int fd, struct sockaddr* him, socklen_t len);
// Support for signals
static void initialize_jdk_signal_support(TRAPS);
static void signal_notify(int signal_number);
static int signal_wait();
static void terminate_signal_thread();
static int sigexitnum_pd();
// random number generation
static int random(); // return 32bit pseudorandom number
static int next_random(unsigned int rand_seed); // pure version of random()
static void init_random(unsigned int initval); // initialize random sequence
// Structured OS Exception support
static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, JavaThread* thread);
// On Posix compatible OS it will simply check core dump limits while on Windows
// it will check if dump file can be created. Check or prepare a core dump to be
// taken at a later point in the same thread in os::abort(). Use the caller
// provided buffer as a scratch buffer. The status message which will be written
// into the error log either is file location or a short error message, depending
// on the checking result.
static void check_dump_limit(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.
// Thread CPU Time - return the fast estimate on a platform
// 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);
// Amount beyond the callee frame size that we bang the stack.
static int extra_bang_size_in_bytes();
static char** split_path(const char* path, size_t* elements, size_t file_name_length);
// support for mapping non-volatile memory using MAP_SYNC
static bool supports_map_sync();
public:
// File conventions
static const char* file_separator();
static const char* line_separator();
static const char* path_separator();
// Information about the protection of the page at address '0' on this os.
inline static bool zero_page_read_protected();
static void setup_fpu();
static juint cpu_microcode_revision();
static inline jlong rdtsc();
// Used to register dynamic code cache area with the OS
// Note: Currently only used in 64 bit Windows implementations
inline static bool register_code_area(char *low, char *high);
// Platform-specific code for interacting with individual OSes.
// TODO: This is for compatibility only with current usage of os::Linux, etc.
// We can get rid of the following block if we rename such a class to something
// like ::LinuxUtils
#if defined(AIX)
class Aix;
#elif defined(BSD)
class Bsd;
#elif defined(LINUX)
class Linux;
#elif defined(_WINDOWS)
class win32;
#endif
// Ditto - Posix-specific API. Ideally should be moved to something like ::PosixUtils.
#ifndef _WINDOWS
class Posix;
#endif
// FIXME - some random stuff that was in os_windows.hpp
#ifdef _WINDOWS
// strtok_s is the Windows thread-safe equivalent of POSIX strtok_r
# define strtok_r strtok_s
# define S_ISCHR(mode) (((mode) & _S_IFCHR) == _S_IFCHR)
# define S_ISFIFO(mode) (((mode) & _S_IFIFO) == _S_IFIFO)
#endif
#ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
#define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
#endif
public:
inline static bool platform_print_native_stack(outputStream* st, const void* context,
char *buf, int buf_size, address& lastpc);
// 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
// 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 const char* native_thread_creation_failed_msg() {
return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
}
// 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);
#if defined(__APPLE__) && defined(AARCH64)
// Enables write or execute access to writeable and executable pages.
static void current_thread_enable_wx(WXMode mode);
#endif // __APPLE__ && AARCH64
protected:
static volatile unsigned int _rand_seed; // seed for random number generator
static int _processor_count; // number of processors
static int _initial_active_processor_count; // number of active processors during initialization.
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 bool pd_dll_unload(void* libhandle, char* ebuf, int ebuflen);
};
// 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_RUNTIME_OS_HPP