| /* |
| * Copyright (c) 1999, 2017, 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. |
| * |
| */ |
| |
| #include "runtime/os.hpp" |
| |
| #ifndef OS_POSIX_VM_OS_POSIX_HPP |
| #define OS_POSIX_VM_OS_POSIX_HPP |
| |
| // File conventions |
| static const char* file_separator() { return "/"; } |
| static const char* line_separator() { return "\n"; } |
| static const char* path_separator() { return ":"; } |
| |
| class Posix { |
| friend class os; |
| |
| protected: |
| static void print_distro_info(outputStream* st); |
| static void print_rlimit_info(outputStream* st); |
| static void print_uname_info(outputStream* st); |
| static void print_libversion_info(outputStream* st); |
| static void print_load_average(outputStream* st); |
| |
| // 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; |
| |
| public: |
| static void init(void); // early initialization - no logging available |
| static void init_2(void);// later initialization - logging available |
| |
| // Return default stack size for the specified thread type |
| static size_t default_stack_size(os::ThreadType thr_type); |
| // Check and sets minimum stack sizes |
| static jint set_minimum_stack_sizes(); |
| static size_t get_initial_stack_size(ThreadType thr_type, size_t req_stack_size); |
| |
| // Returns true if signal is valid. |
| static bool is_valid_signal(int sig); |
| |
| // Helper function, returns a string (e.g. "SIGILL") for a signal. |
| // Returned string is a constant. For unknown signals "UNKNOWN" is returned. |
| static const char* get_signal_name(int sig, char* out, size_t outlen); |
| |
| // Helper function, returns a signal number for a given signal name, e.g. 11 |
| // for "SIGSEGV". Name can be given with or without "SIG" prefix, so both |
| // "SEGV" or "SIGSEGV" work. Name must be uppercase. |
| // Returns -1 for an unknown signal name. |
| static int get_signal_number(const char* signal_name); |
| |
| // Returns one-line short description of a signal set in a user provided buffer. |
| static const char* describe_signal_set_short(const sigset_t* set, char* buffer, size_t size); |
| |
| // Prints a short one-line description of a signal set. |
| static void print_signal_set_short(outputStream* st, const sigset_t* set); |
| |
| // unblocks the signal masks for current thread |
| static int unblock_thread_signal_mask(const sigset_t *set); |
| |
| // Writes a one-line description of a combination of sigaction.sa_flags |
| // into a user provided buffer. Returns that buffer. |
| static const char* describe_sa_flags(int flags, char* buffer, size_t size); |
| |
| // Prints a one-line description of a combination of sigaction.sa_flags. |
| static void print_sa_flags(outputStream* st, int flags); |
| |
| static address ucontext_get_pc(const ucontext_t* ctx); |
| // Set PC into context. Needed for continuation after signal. |
| static void ucontext_set_pc(ucontext_t* ctx, address pc); |
| |
| // Helper function; describes pthread attributes as short string. String is written |
| // to buf with len buflen; buf is returned. |
| static char* describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr); |
| |
| // A safe implementation of realpath which will not cause a buffer overflow if the resolved path |
| // is longer than PATH_MAX. |
| // On success, returns 'outbuf', which now contains the path. |
| // On error, it will return NULL and set errno. The content of 'outbuf' is undefined. |
| // On truncation error ('outbuf' too small), it will return NULL and set errno to ENAMETOOLONG. |
| static char* realpath(const char* filename, char* outbuf, size_t outbuflen); |
| }; |
| |
| // On POSIX platforms the signal handler is global so we just do the write. |
| static void write_memory_serialize_page_with_handler(JavaThread* thread) { |
| write_memory_serialize_page(thread); |
| } |
| |
| /* |
| * Crash protection for the watcher thread. Wrap the callback |
| * with a sigsetjmp and in case of a SIGSEGV/SIGBUS we siglongjmp |
| * back. |
| * To be able to use this - don't take locks, don't rely on destructors, |
| * don't make OS library calls, don't allocate memory, don't print, |
| * don't call code that could leave the heap / memory in an inconsistent state, |
| * or anything else where we are not in control if we suddenly jump out. |
| */ |
| class ThreadCrashProtection : public StackObj { |
| public: |
| static bool is_crash_protected(Thread* thr) { |
| return _crash_protection != NULL && _protected_thread == thr; |
| } |
| |
| ThreadCrashProtection(); |
| bool call(os::CrashProtectionCallback& cb); |
| |
| static void check_crash_protection(int signal, Thread* thread); |
| private: |
| static Thread* _protected_thread; |
| static ThreadCrashProtection* _crash_protection; |
| static volatile intptr_t _crash_mux; |
| void restore(); |
| sigjmp_buf _jmpbuf; |
| }; |
| |
| #ifndef SOLARIS |
| |
| /* |
| * This is the platform-specific implementation underpinning |
| * the ParkEvent class, which itself underpins Java-level monitor |
| * operations. See park.hpp for details. |
| * These event objects are type-stable and immortal - we never delete them. |
| * Events are associated with a thread for the lifetime of the thread. |
| */ |
| class PlatformEvent : public CHeapObj<mtInternal> { |
| private: |
| double cachePad[4]; // Increase odds that _mutex is sole occupant of cache line |
| volatile int _event; // Event count/permit: -1, 0 or 1 |
| volatile int _nParked; // Indicates if associated thread is blocked: 0 or 1 |
| pthread_mutex_t _mutex[1]; // Native mutex for locking |
| pthread_cond_t _cond[1]; // Native condition variable for blocking |
| double postPad[2]; |
| |
| protected: // TODO-FIXME: make dtor private |
| ~PlatformEvent() { guarantee(false, "invariant"); } // immortal so can't delete |
| |
| public: |
| PlatformEvent(); |
| void park(); |
| int park(jlong millis); |
| void unpark(); |
| |
| // Use caution with reset() and fired() -- they may require MEMBARs |
| void reset() { _event = 0; } |
| int fired() { return _event; } |
| }; |
| |
| // JSR166 support |
| // PlatformParker provides the platform dependent base class for the |
| // Parker class. It basically provides the internal data structures: |
| // - mutex and convars |
| // which are then used directly by the Parker methods defined in the OS |
| // specific implementation files. |
| // There is significant overlap between the funcionality supported in the |
| // combination of Parker+PlatformParker and PlatformEvent (above). If Parker |
| // were more like ObjectMonitor we could use PlatformEvent in both (with some |
| // API updates of course). But Parker methods use fastpaths that break that |
| // level of encapsulation - so combining the two remains a future project. |
| |
| class PlatformParker : public CHeapObj<mtInternal> { |
| protected: |
| enum { |
| REL_INDEX = 0, |
| ABS_INDEX = 1 |
| }; |
| int _cur_index; // which cond is in use: -1, 0, 1 |
| pthread_mutex_t _mutex[1]; |
| pthread_cond_t _cond[2]; // one for relative times and one for absolute |
| |
| public: // TODO-FIXME: make dtor private |
| ~PlatformParker() { guarantee(false, "invariant"); } |
| |
| public: |
| PlatformParker(); |
| }; |
| |
| #endif // !SOLARIS |
| |
| #endif // OS_POSIX_VM_OS_POSIX_HPP |