Mercurial > hg > graal-compiler
view src/share/vm/runtime/os.hpp @ 2212:d9e4d0aefc90
Small clean up to reduce delta to OpenJDK.
author | Thomas Wuerthinger <thomas.wuerthinger@gmail.com> |
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date | Mon, 21 Feb 2011 19:28:35 +0100 |
parents | 63d374c54045 |
children | 850b2295a494 da091bb67459 |
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/* * Copyright (c) 1997, 2011, 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" #endif #ifdef TARGET_OS_FAMILY_solaris # include "jvm_solaris.h" #endif #ifdef TARGET_OS_FAMILY_windows # include "jvm_windows.h" #endif // 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 }; // Typedef for structured exception handling support typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread); class os: AllStatic { 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 } public: static void init(void); // Called before command line parsing static jint init_2(void); // Called after command line parsing 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; } static julong available_memory(); static julong physical_memory(); static julong allocatable_physical_memory(julong size); 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); // 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); // Method 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 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* 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 = false); static bool commit_memory(char* addr, size_t size, size_t alignment_hint, bool executable = false); 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 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); 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, char* addr = NULL, bool executable = false); static bool release_memory_special(char* addr, size_t bytes); static bool 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(); 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 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 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, int buflen); // Builds a platform-specific full library path given a ld path and lib name static void 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 returned as offset. // If function name is not found, buf[0] is set to '\0' and offset is // set to -1. 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 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. 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); // 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_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); // 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); // General allocation (must be MT-safe) static void* malloc (size_t size); static void* realloc (void *memblock, size_t size); static void free (void *memblock); static bool check_heap(bool force = false); // verify C heap integrity static char* strdup(const char *); // Like strdup #ifndef PRODUCT static int num_mallocs; // # of calls to malloc/realloc static size_t alloc_bytes; // # of bytes allocated static int num_frees; // # of calls to free #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, int nBytes, int flags); static int send(int fd, char *buf, int nBytes, int flags); static int raw_send(int fd, char *buf, int nBytes, int flags); static int timeout(int fd, long timeout); static int listen(int fd, int count); static int connect(int fd, struct sockaddr *him, int len); static int bind(int fd, struct sockaddr *him, int len); static int accept(int fd, struct sockaddr *him, int *len); static int recvfrom(int fd, char *buf, int nbytes, int flags, struct sockaddr *from, int *fromlen); static int get_sock_name(int fd, struct sockaddr *him, int *len); static int sendto(int fd, char *buf, int len, int flags, struct sockaddr *to, int tolen); static int socket_available(int fd, jint *pbytes); static int get_sock_opt(int fd, int level, int optname, char *optval, int* optlen); static int set_sock_opt(int fd, int level, int optname, const char *optval, int optlen); static int get_host_name(char* name, int namelen); static struct hostent* get_host_by_name(char* name); // Printing 64 bit integers static const char* jlong_format_specifier(); static const char* julong_format_specifier(); // 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); // 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); // Platform dependent stuff #ifdef TARGET_OS_FAMILY_linux # include "os_linux.hpp" #endif #ifdef TARGET_OS_FAMILY_solaris # include "os_solaris.hpp" #endif #ifdef TARGET_OS_FAMILY_windows # include "os_windows.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 // 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[MaxPriority + 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(); 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 () ; extern "C" int SafeFetch32 (int * adr, int errValue) ; extern "C" intptr_t SafeFetchN (intptr_t * adr, intptr_t errValue) ; #endif // SHARE_VM_RUNTIME_OS_HPP