annotate src/hotspot/os/posix/os_posix.hpp @ 56947:36abd263dca2

Automatic merge with records-and-sealed
author mcimadamore
date Thu, 18 Jul 2019 21:05:42 +0000
parents 3086f9259e97
children
rev   line source
nloodin@12735 1 /*
coleenp@54304 2 * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
nloodin@12735 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
nloodin@12735 4 *
nloodin@12735 5 * This code is free software; you can redistribute it and/or modify it
nloodin@12735 6 * under the terms of the GNU General Public License version 2 only, as
nloodin@12735 7 * published by the Free Software Foundation.
nloodin@12735 8 *
nloodin@12735 9 * This code is distributed in the hope that it will be useful, but WITHOUT
nloodin@12735 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
nloodin@12735 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
nloodin@12735 12 * version 2 for more details (a copy is included in the LICENSE file that
nloodin@12735 13 * accompanied this code).
nloodin@12735 14 *
nloodin@12735 15 * You should have received a copy of the GNU General Public License version
nloodin@12735 16 * 2 along with this work; if not, write to the Free Software Foundation,
nloodin@12735 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
nloodin@12735 18 *
nloodin@12735 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
nloodin@12735 20 * or visit www.oracle.com if you need additional information or have any
nloodin@12735 21 * questions.
nloodin@12735 22 *
nloodin@12735 23 */
nloodin@12735 24
goetz@25468 25 #include "runtime/os.hpp"
goetz@25468 26
coleenp@54304 27 #ifndef OS_POSIX_OS_POSIX_HPP
coleenp@54304 28 #define OS_POSIX_OS_POSIX_HPP
goetz@25468 29
goetz@25468 30 // File conventions
goetz@25468 31 static const char* file_separator() { return "/"; }
goetz@25468 32 static const char* line_separator() { return "\n"; }
goetz@25468 33 static const char* path_separator() { return ":"; }
goetz@25468 34
nloodin@12735 35 class Posix {
nloodin@12735 36 friend class os;
nloodin@12735 37
nloodin@12735 38 protected:
nloodin@12735 39 static void print_distro_info(outputStream* st);
nloodin@12735 40 static void print_rlimit_info(outputStream* st);
nloodin@12735 41 static void print_uname_info(outputStream* st);
nloodin@12735 42 static void print_libversion_info(outputStream* st);
nloodin@12735 43 static void print_load_average(outputStream* st);
nloodin@12735 44
rdurbin@41070 45 // Minimum stack size a thread can be created with (allowing
goetz@42906 46 // the VM to completely create the thread and enter user code).
goetz@42906 47 // The initial values exclude any guard pages (by HotSpot or libc).
goetz@42906 48 // set_minimum_stack_sizes() will add the size required for
goetz@42906 49 // HotSpot guard pages depending on page size and flag settings.
goetz@42906 50 // Libc guard pages are never considered by these values.
rdurbin@41070 51 static size_t _compiler_thread_min_stack_allowed;
rdurbin@41070 52 static size_t _java_thread_min_stack_allowed;
rdurbin@41070 53 static size_t _vm_internal_thread_min_stack_allowed;
rdurbin@41070 54
goetz@22826 55 public:
dholmes@46507 56 static void init(void); // early initialization - no logging available
dholmes@46507 57 static void init_2(void);// later initialization - logging available
dholmes@46507 58
rdurbin@41070 59 // Return default stack size for the specified thread type
rdurbin@41070 60 static size_t default_stack_size(os::ThreadType thr_type);
rdurbin@41070 61 // Check and sets minimum stack sizes
rdurbin@41070 62 static jint set_minimum_stack_sizes();
rdurbin@41070 63 static size_t get_initial_stack_size(ThreadType thr_type, size_t req_stack_size);
goetz@22826 64
goetz@22826 65 // Returns true if signal is valid.
goetz@22826 66 static bool is_valid_signal(int sig);
coleenp@50761 67 static bool is_sig_ignored(int sig);
goetz@22826 68
goetz@22826 69 // Helper function, returns a string (e.g. "SIGILL") for a signal.
goetz@22826 70 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
goetz@22826 71 static const char* get_signal_name(int sig, char* out, size_t outlen);
goetz@22826 72
stuefe@34621 73 // Helper function, returns a signal number for a given signal name, e.g. 11
stuefe@34621 74 // for "SIGSEGV". Name can be given with or without "SIG" prefix, so both
stuefe@34621 75 // "SEGV" or "SIGSEGV" work. Name must be uppercase.
stuefe@34621 76 // Returns -1 for an unknown signal name.
stuefe@34621 77 static int get_signal_number(const char* signal_name);
stuefe@34621 78
goetz@22826 79 // Returns one-line short description of a signal set in a user provided buffer.
goetz@22826 80 static const char* describe_signal_set_short(const sigset_t* set, char* buffer, size_t size);
goetz@22826 81
goetz@22826 82 // Prints a short one-line description of a signal set.
goetz@22826 83 static void print_signal_set_short(outputStream* st, const sigset_t* set);
goetz@22826 84
sebastian@34305 85 // unblocks the signal masks for current thread
sebastian@34305 86 static int unblock_thread_signal_mask(const sigset_t *set);
sebastian@34305 87
goetz@22826 88 // Writes a one-line description of a combination of sigaction.sa_flags
goetz@22826 89 // into a user provided buffer. Returns that buffer.
goetz@22826 90 static const char* describe_sa_flags(int flags, char* buffer, size_t size);
goetz@22826 91
goetz@22826 92 // Prints a one-line description of a combination of sigaction.sa_flags.
goetz@22826 93 static void print_sa_flags(outputStream* st, int flags);
goetz@22826 94
stuefe@35077 95 static address ucontext_get_pc(const ucontext_t* ctx);
sebastian@34305 96 // Set PC into context. Needed for continuation after signal.
sebastian@34305 97 static void ucontext_set_pc(ucontext_t* ctx, address pc);
stuefe@36355 98
stuefe@36355 99 // Helper function; describes pthread attributes as short string. String is written
stuefe@36355 100 // to buf with len buflen; buf is returned.
stuefe@36355 101 static char* describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr);
stuefe@36355 102
stuefe@46331 103 // A safe implementation of realpath which will not cause a buffer overflow if the resolved path
stuefe@46331 104 // is longer than PATH_MAX.
stuefe@46331 105 // On success, returns 'outbuf', which now contains the path.
stuefe@46331 106 // On error, it will return NULL and set errno. The content of 'outbuf' is undefined.
stuefe@46331 107 // On truncation error ('outbuf' too small), it will return NULL and set errno to ENAMETOOLONG.
stuefe@46331 108 static char* realpath(const char* filename, char* outbuf, size_t outbuflen);
dtitov@50937 109
dtitov@50937 110 // Returns true if given uid is root.
dtitov@50937 111 static bool is_root(uid_t uid);
dtitov@50937 112
dtitov@50937 113 // Returns true if given uid is effective or root uid.
dtitov@50937 114 static bool matches_effective_uid_or_root(uid_t uid);
dtitov@50937 115
dtitov@50937 116 // Returns true if either given uid is effective uid and given gid is
dtitov@50937 117 // effective gid, or if given uid is root.
dtitov@50937 118 static bool matches_effective_uid_and_gid_or_root(uid_t uid, gid_t gid);
dholmes@52818 119
aoqi@55327 120 static struct sigaction *get_preinstalled_handler(int);
aoqi@55327 121 static void save_preinstalled_handler(int, struct sigaction&);
aoqi@55327 122
mbaesken@53553 123 static void print_umask(outputStream* st, mode_t umsk);
mbaesken@53553 124
mbaesken@53553 125 static void print_user_info(outputStream* st);
mbaesken@53553 126
dholmes@52818 127 #ifdef SUPPORTS_CLOCK_MONOTONIC
dholmes@52818 128
dholmes@54771 129 private:
dholmes@54771 130 // These need to be members so we can access them from inline functions
dholmes@54771 131 static int (*_clock_gettime)(clockid_t, struct timespec *);
dholmes@54771 132 static int (*_clock_getres)(clockid_t, struct timespec *);
dholmes@54771 133 public:
dholmes@52818 134 static bool supports_monotonic_clock();
dholmes@52818 135 static int clock_gettime(clockid_t clock_id, struct timespec *tp);
dholmes@52818 136 static int clock_getres(clockid_t clock_id, struct timespec *tp);
dholmes@52818 137
dholmes@52818 138 #else
dholmes@52818 139
dholmes@52818 140 static bool supports_monotonic_clock() { return false; }
dholmes@52818 141
dholmes@52818 142 #endif
dholmes@54542 143
dholmes@54542 144 static void to_RTC_abstime(timespec* abstime, int64_t millis);
nloodin@12735 145 };
nloodin@12735 146
rbackman@18943 147 /*
rbackman@18943 148 * Crash protection for the watcher thread. Wrap the callback
rbackman@18943 149 * with a sigsetjmp and in case of a SIGSEGV/SIGBUS we siglongjmp
rbackman@18943 150 * back.
rbackman@18943 151 * To be able to use this - don't take locks, don't rely on destructors,
rbackman@18943 152 * don't make OS library calls, don't allocate memory, don't print,
rbackman@18943 153 * don't call code that could leave the heap / memory in an inconsistent state,
rbackman@18943 154 * or anything else where we are not in control if we suddenly jump out.
rbackman@18943 155 */
rehn@46644 156 class ThreadCrashProtection : public StackObj {
rbackman@18943 157 public:
rehn@46644 158 static bool is_crash_protected(Thread* thr) {
rehn@46644 159 return _crash_protection != NULL && _protected_thread == thr;
rehn@46644 160 }
rehn@46644 161
rehn@46644 162 ThreadCrashProtection();
rbackman@18943 163 bool call(os::CrashProtectionCallback& cb);
rbackman@18943 164
rbackman@18943 165 static void check_crash_protection(int signal, Thread* thread);
rbackman@18943 166 private:
rehn@46644 167 static Thread* _protected_thread;
rehn@46644 168 static ThreadCrashProtection* _crash_protection;
rehn@46644 169 static volatile intptr_t _crash_mux;
rbackman@18943 170 void restore();
rbackman@18943 171 sigjmp_buf _jmpbuf;
rbackman@18943 172 };
nloodin@12735 173
dholmes@46507 174 #ifndef SOLARIS
dholmes@46507 175
dholmes@46507 176 /*
dholmes@46507 177 * This is the platform-specific implementation underpinning
dholmes@46507 178 * the ParkEvent class, which itself underpins Java-level monitor
dholmes@46507 179 * operations. See park.hpp for details.
dholmes@46507 180 * These event objects are type-stable and immortal - we never delete them.
dholmes@46507 181 * Events are associated with a thread for the lifetime of the thread.
dholmes@46507 182 */
zgu@55030 183 class PlatformEvent : public CHeapObj<mtSynchronizer> {
dholmes@46507 184 private:
dholmes@46507 185 double cachePad[4]; // Increase odds that _mutex is sole occupant of cache line
dholmes@46507 186 volatile int _event; // Event count/permit: -1, 0 or 1
dholmes@46507 187 volatile int _nParked; // Indicates if associated thread is blocked: 0 or 1
dholmes@46507 188 pthread_mutex_t _mutex[1]; // Native mutex for locking
dholmes@46507 189 pthread_cond_t _cond[1]; // Native condition variable for blocking
dholmes@46507 190 double postPad[2];
dholmes@46507 191
dholmes@46507 192 protected: // TODO-FIXME: make dtor private
dholmes@46507 193 ~PlatformEvent() { guarantee(false, "invariant"); } // immortal so can't delete
dholmes@46507 194
dholmes@46507 195 public:
dholmes@46507 196 PlatformEvent();
dholmes@46507 197 void park();
dholmes@46507 198 int park(jlong millis);
dholmes@46507 199 void unpark();
dholmes@46507 200
dholmes@46507 201 // Use caution with reset() and fired() -- they may require MEMBARs
dholmes@46507 202 void reset() { _event = 0; }
dholmes@46507 203 int fired() { return _event; }
dholmes@46507 204 };
dholmes@46507 205
dholmes@46507 206 // JSR166 support
dholmes@46507 207 // PlatformParker provides the platform dependent base class for the
dholmes@46507 208 // Parker class. It basically provides the internal data structures:
dholmes@46507 209 // - mutex and convars
dholmes@46507 210 // which are then used directly by the Parker methods defined in the OS
dholmes@46507 211 // specific implementation files.
dholmes@46507 212 // There is significant overlap between the funcionality supported in the
dholmes@46507 213 // combination of Parker+PlatformParker and PlatformEvent (above). If Parker
dholmes@46507 214 // were more like ObjectMonitor we could use PlatformEvent in both (with some
dholmes@46507 215 // API updates of course). But Parker methods use fastpaths that break that
dholmes@46507 216 // level of encapsulation - so combining the two remains a future project.
dholmes@46507 217
zgu@55030 218 class PlatformParker : public CHeapObj<mtSynchronizer> {
dholmes@46507 219 protected:
dholmes@46507 220 enum {
dholmes@46507 221 REL_INDEX = 0,
dholmes@46507 222 ABS_INDEX = 1
dholmes@46507 223 };
dholmes@46507 224 int _cur_index; // which cond is in use: -1, 0, 1
dholmes@46507 225 pthread_mutex_t _mutex[1];
dholmes@46507 226 pthread_cond_t _cond[2]; // one for relative times and one for absolute
dholmes@46507 227
dholmes@46507 228 public: // TODO-FIXME: make dtor private
dholmes@46507 229 ~PlatformParker() { guarantee(false, "invariant"); }
dholmes@46507 230
dholmes@46507 231 public:
dholmes@46507 232 PlatformParker();
dholmes@46507 233 };
dholmes@46507 234
kbarrett@55452 235 // Workaround for a bug in macOSX kernel's pthread support (fixed in Mojave?).
kbarrett@55452 236 // Avoid ever allocating a pthread_mutex_t at the same address as one of our
kbarrett@55452 237 // former pthread_cond_t, by using a freelist of mutex/condvar pairs.
kbarrett@55452 238 // Conditional to avoid extra indirection and padding loss on other platforms.
kbarrett@55452 239 #ifdef __APPLE__
kbarrett@55452 240 #define PLATFORM_MONITOR_IMPL_INDIRECT 1
kbarrett@55452 241 #else
kbarrett@55452 242 #define PLATFORM_MONITOR_IMPL_INDIRECT 0
kbarrett@55452 243 #endif
kbarrett@55452 244
pchilanomate@54763 245 // Platform specific implementation that underpins VM Monitor/Mutex class
zgu@55030 246 class PlatformMonitor : public CHeapObj<mtSynchronizer> {
kbarrett@55452 247 class Impl : public CHeapObj<mtSynchronizer> {
kbarrett@55452 248 public:
kbarrett@55452 249 pthread_mutex_t _mutex;
kbarrett@55452 250 pthread_cond_t _cond;
kbarrett@55452 251 Impl* _next;
kbarrett@55452 252
kbarrett@55452 253 Impl();
kbarrett@55452 254 ~Impl();
kbarrett@55452 255 };
kbarrett@55452 256
kbarrett@55452 257 #if PLATFORM_MONITOR_IMPL_INDIRECT
kbarrett@55452 258
kbarrett@55452 259 Impl* _impl;
kbarrett@55452 260
kbarrett@55452 261 pthread_mutex_t* mutex() { return &(_impl->_mutex); }
kbarrett@55452 262 pthread_cond_t* cond() { return &(_impl->_cond); }
kbarrett@55452 263
kbarrett@55452 264 class WithFreeListLocked;
kbarrett@55452 265 static pthread_mutex_t _freelist_lock;
kbarrett@55452 266 static Impl* _freelist;
pchilanomate@54763 267
pchilanomate@54763 268 public:
kbarrett@55452 269 PlatformMonitor(); // Use freelist allocation of impl.
pchilanomate@54763 270 ~PlatformMonitor();
kbarrett@55452 271
kbarrett@55452 272 static void init(); // Initialize the freelist.
kbarrett@55452 273
kbarrett@55452 274 #else
kbarrett@55452 275
kbarrett@55452 276 Impl _impl;
kbarrett@55452 277
kbarrett@55452 278 pthread_mutex_t* mutex() { return &(_impl._mutex); }
kbarrett@55452 279 pthread_cond_t* cond() { return &(_impl._cond); }
kbarrett@55452 280
kbarrett@55452 281 public:
kbarrett@55452 282 static void init() {} // Nothing needed for the non-indirect case.
kbarrett@55452 283
kbarrett@55452 284 // Default constructor and destructor.
kbarrett@55452 285
kbarrett@55452 286 #endif // PLATFORM_MONITOR_IMPL_INDIRECT
kbarrett@55452 287
kbarrett@55452 288 public:
pchilanomate@54763 289 void lock();
pchilanomate@54763 290 void unlock();
pchilanomate@54763 291 bool try_lock();
pchilanomate@54763 292 int wait(jlong millis);
pchilanomate@54763 293 void notify();
pchilanomate@54763 294 void notify_all();
pchilanomate@54763 295 };
pchilanomate@54763 296
dholmes@46507 297 #endif // !SOLARIS
dholmes@46507 298
coleenp@54304 299 #endif // OS_POSIX_OS_POSIX_HPP