1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/runtime/os.cpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,1108 @@
1.4 +/*
1.5 + * Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +# include "incls/_precompiled.incl"
1.29 +# include "incls/_os.cpp.incl"
1.30 +
1.31 +# include <signal.h>
1.32 +
1.33 +OSThread* os::_starting_thread = NULL;
1.34 +address os::_polling_page = NULL;
1.35 +volatile int32_t* os::_mem_serialize_page = NULL;
1.36 +uintptr_t os::_serialize_page_mask = 0;
1.37 +long os::_rand_seed = 1;
1.38 +int os::_processor_count = 0;
1.39 +volatile jlong os::_global_time = 0;
1.40 +volatile int os::_global_time_lock = 0;
1.41 +bool os::_use_global_time = false;
1.42 +size_t os::_page_sizes[os::page_sizes_max];
1.43 +
1.44 +#ifndef PRODUCT
1.45 +int os::num_mallocs = 0; // # of calls to malloc/realloc
1.46 +size_t os::alloc_bytes = 0; // # of bytes allocated
1.47 +int os::num_frees = 0; // # of calls to free
1.48 +#endif
1.49 +
1.50 +// Atomic read of a jlong is assured by a seqlock; see update_global_time()
1.51 +jlong os::read_global_time() {
1.52 +#ifdef _LP64
1.53 + return _global_time;
1.54 +#else
1.55 + volatile int lock;
1.56 + volatile jlong current_time;
1.57 + int ctr = 0;
1.58 +
1.59 + for (;;) {
1.60 + lock = _global_time_lock;
1.61 +
1.62 + // spin while locked
1.63 + while ((lock & 0x1) != 0) {
1.64 + ++ctr;
1.65 + if ((ctr & 0xFFF) == 0) {
1.66 + // Guarantee writer progress. Can't use yield; yield is advisory
1.67 + // and has almost no effect on some platforms. Don't need a state
1.68 + // transition - the park call will return promptly.
1.69 + assert(Thread::current() != NULL, "TLS not initialized");
1.70 + assert(Thread::current()->_ParkEvent != NULL, "sync not initialized");
1.71 + Thread::current()->_ParkEvent->park(1);
1.72 + }
1.73 + lock = _global_time_lock;
1.74 + }
1.75 +
1.76 + OrderAccess::loadload();
1.77 + current_time = _global_time;
1.78 + OrderAccess::loadload();
1.79 +
1.80 + // ratify seqlock value
1.81 + if (lock == _global_time_lock) {
1.82 + return current_time;
1.83 + }
1.84 + }
1.85 +#endif
1.86 +}
1.87 +
1.88 +//
1.89 +// NOTE - Assumes only one writer thread!
1.90 +//
1.91 +// We use a seqlock to guarantee that jlong _global_time is updated
1.92 +// atomically on 32-bit platforms. A locked value is indicated by
1.93 +// the lock variable LSB == 1. Readers will initially read the lock
1.94 +// value, spinning until the LSB == 0. They then speculatively read
1.95 +// the global time value, then re-read the lock value to ensure that
1.96 +// it hasn't changed. If the lock value has changed, the entire read
1.97 +// sequence is retried.
1.98 +//
1.99 +// Writers simply set the LSB = 1 (i.e. increment the variable),
1.100 +// update the global time, then release the lock and bump the version
1.101 +// number (i.e. increment the variable again.) In this case we don't
1.102 +// even need a CAS since we ensure there's only one writer.
1.103 +//
1.104 +void os::update_global_time() {
1.105 +#ifdef _LP64
1.106 + _global_time = timeofday();
1.107 +#else
1.108 + assert((_global_time_lock & 0x1) == 0, "multiple writers?");
1.109 + jlong current_time = timeofday();
1.110 + _global_time_lock++; // lock
1.111 + OrderAccess::storestore();
1.112 + _global_time = current_time;
1.113 + OrderAccess::storestore();
1.114 + _global_time_lock++; // unlock
1.115 +#endif
1.116 +}
1.117 +
1.118 +// Fill in buffer with current local time as an ISO-8601 string.
1.119 +// E.g., yyyy-mm-ddThh:mm:ss-zzzz.
1.120 +// Returns buffer, or NULL if it failed.
1.121 +// This would mostly be a call to
1.122 +// strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
1.123 +// except that on Windows the %z behaves badly, so we do it ourselves.
1.124 +// Also, people wanted milliseconds on there,
1.125 +// and strftime doesn't do milliseconds.
1.126 +char* os::iso8601_time(char* buffer, size_t buffer_length) {
1.127 + // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
1.128 + // 1 2
1.129 + // 12345678901234567890123456789
1.130 + static const char* iso8601_format =
1.131 + "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
1.132 + static const size_t needed_buffer = 29;
1.133 +
1.134 + // Sanity check the arguments
1.135 + if (buffer == NULL) {
1.136 + assert(false, "NULL buffer");
1.137 + return NULL;
1.138 + }
1.139 + if (buffer_length < needed_buffer) {
1.140 + assert(false, "buffer_length too small");
1.141 + return NULL;
1.142 + }
1.143 + // Get the current time
1.144 + jlong milliseconds_since_19700101 = timeofday();
1.145 + const int milliseconds_per_microsecond = 1000;
1.146 + const time_t seconds_since_19700101 =
1.147 + milliseconds_since_19700101 / milliseconds_per_microsecond;
1.148 + const int milliseconds_after_second =
1.149 + milliseconds_since_19700101 % milliseconds_per_microsecond;
1.150 + // Convert the time value to a tm and timezone variable
1.151 + const struct tm *time_struct_temp = localtime(&seconds_since_19700101);
1.152 + if (time_struct_temp == NULL) {
1.153 + assert(false, "Failed localtime");
1.154 + return NULL;
1.155 + }
1.156 + // Save the results of localtime
1.157 + const struct tm time_struct = *time_struct_temp;
1.158 + const time_t zone = timezone;
1.159 +
1.160 + // If daylight savings time is in effect,
1.161 + // we are 1 hour East of our time zone
1.162 + const time_t seconds_per_minute = 60;
1.163 + const time_t minutes_per_hour = 60;
1.164 + const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
1.165 + time_t UTC_to_local = zone;
1.166 + if (time_struct.tm_isdst > 0) {
1.167 + UTC_to_local = UTC_to_local - seconds_per_hour;
1.168 + }
1.169 + // Compute the time zone offset.
1.170 + // localtime(3C) sets timezone to the difference (in seconds)
1.171 + // between UTC and and local time.
1.172 + // ISO 8601 says we need the difference between local time and UTC,
1.173 + // we change the sign of the localtime(3C) result.
1.174 + const time_t local_to_UTC = -(UTC_to_local);
1.175 + // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
1.176 + char sign_local_to_UTC = '+';
1.177 + time_t abs_local_to_UTC = local_to_UTC;
1.178 + if (local_to_UTC < 0) {
1.179 + sign_local_to_UTC = '-';
1.180 + abs_local_to_UTC = -(abs_local_to_UTC);
1.181 + }
1.182 + // Convert time zone offset seconds to hours and minutes.
1.183 + const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
1.184 + const time_t zone_min =
1.185 + ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
1.186 +
1.187 + // Print an ISO 8601 date and time stamp into the buffer
1.188 + const int year = 1900 + time_struct.tm_year;
1.189 + const int month = 1 + time_struct.tm_mon;
1.190 + const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
1.191 + year,
1.192 + month,
1.193 + time_struct.tm_mday,
1.194 + time_struct.tm_hour,
1.195 + time_struct.tm_min,
1.196 + time_struct.tm_sec,
1.197 + milliseconds_after_second,
1.198 + sign_local_to_UTC,
1.199 + zone_hours,
1.200 + zone_min);
1.201 + if (printed == 0) {
1.202 + assert(false, "Failed jio_printf");
1.203 + return NULL;
1.204 + }
1.205 + return buffer;
1.206 +}
1.207 +
1.208 +OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
1.209 +#ifdef ASSERT
1.210 + if (!(!thread->is_Java_thread() ||
1.211 + Thread::current() == thread ||
1.212 + Threads_lock->owned_by_self()
1.213 + || thread->is_Compiler_thread()
1.214 + )) {
1.215 + assert(false, "possibility of dangling Thread pointer");
1.216 + }
1.217 +#endif
1.218 +
1.219 + if (p >= MinPriority && p <= MaxPriority) {
1.220 + int priority = java_to_os_priority[p];
1.221 + return set_native_priority(thread, priority);
1.222 + } else {
1.223 + assert(false, "Should not happen");
1.224 + return OS_ERR;
1.225 + }
1.226 +}
1.227 +
1.228 +
1.229 +OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
1.230 + int p;
1.231 + int os_prio;
1.232 + OSReturn ret = get_native_priority(thread, &os_prio);
1.233 + if (ret != OS_OK) return ret;
1.234 +
1.235 + for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
1.236 + priority = (ThreadPriority)p;
1.237 + return OS_OK;
1.238 +}
1.239 +
1.240 +
1.241 +// --------------------- sun.misc.Signal (optional) ---------------------
1.242 +
1.243 +
1.244 +// SIGBREAK is sent by the keyboard to query the VM state
1.245 +#ifndef SIGBREAK
1.246 +#define SIGBREAK SIGQUIT
1.247 +#endif
1.248 +
1.249 +// sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
1.250 +
1.251 +
1.252 +static void signal_thread_entry(JavaThread* thread, TRAPS) {
1.253 + os::set_priority(thread, NearMaxPriority);
1.254 + while (true) {
1.255 + int sig;
1.256 + {
1.257 + // FIXME : Currently we have not decieded what should be the status
1.258 + // for this java thread blocked here. Once we decide about
1.259 + // that we should fix this.
1.260 + sig = os::signal_wait();
1.261 + }
1.262 + if (sig == os::sigexitnum_pd()) {
1.263 + // Terminate the signal thread
1.264 + return;
1.265 + }
1.266 +
1.267 + switch (sig) {
1.268 + case SIGBREAK: {
1.269 + // Check if the signal is a trigger to start the Attach Listener - in that
1.270 + // case don't print stack traces.
1.271 + if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
1.272 + continue;
1.273 + }
1.274 + // Print stack traces
1.275 + // Any SIGBREAK operations added here should make sure to flush
1.276 + // the output stream (e.g. tty->flush()) after output. See 4803766.
1.277 + // Each module also prints an extra carriage return after its output.
1.278 + VM_PrintThreads op;
1.279 + VMThread::execute(&op);
1.280 + VM_PrintJNI jni_op;
1.281 + VMThread::execute(&jni_op);
1.282 + VM_FindDeadlocks op1(tty);
1.283 + VMThread::execute(&op1);
1.284 + Universe::print_heap_at_SIGBREAK();
1.285 + if (PrintClassHistogram) {
1.286 + VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
1.287 + VMThread::execute(&op1);
1.288 + }
1.289 + if (JvmtiExport::should_post_data_dump()) {
1.290 + JvmtiExport::post_data_dump();
1.291 + }
1.292 + break;
1.293 + }
1.294 + default: {
1.295 + // Dispatch the signal to java
1.296 + HandleMark hm(THREAD);
1.297 + klassOop k = SystemDictionary::resolve_or_null(vmSymbolHandles::sun_misc_Signal(), THREAD);
1.298 + KlassHandle klass (THREAD, k);
1.299 + if (klass.not_null()) {
1.300 + JavaValue result(T_VOID);
1.301 + JavaCallArguments args;
1.302 + args.push_int(sig);
1.303 + JavaCalls::call_static(
1.304 + &result,
1.305 + klass,
1.306 + vmSymbolHandles::dispatch_name(),
1.307 + vmSymbolHandles::int_void_signature(),
1.308 + &args,
1.309 + THREAD
1.310 + );
1.311 + }
1.312 + if (HAS_PENDING_EXCEPTION) {
1.313 + // tty is initialized early so we don't expect it to be null, but
1.314 + // if it is we can't risk doing an initialization that might
1.315 + // trigger additional out-of-memory conditions
1.316 + if (tty != NULL) {
1.317 + char klass_name[256];
1.318 + char tmp_sig_name[16];
1.319 + const char* sig_name = "UNKNOWN";
1.320 + instanceKlass::cast(PENDING_EXCEPTION->klass())->
1.321 + name()->as_klass_external_name(klass_name, 256);
1.322 + if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
1.323 + sig_name = tmp_sig_name;
1.324 + warning("Exception %s occurred dispatching signal %s to handler"
1.325 + "- the VM may need to be forcibly terminated",
1.326 + klass_name, sig_name );
1.327 + }
1.328 + CLEAR_PENDING_EXCEPTION;
1.329 + }
1.330 + }
1.331 + }
1.332 + }
1.333 +}
1.334 +
1.335 +
1.336 +void os::signal_init() {
1.337 + if (!ReduceSignalUsage) {
1.338 + // Setup JavaThread for processing signals
1.339 + EXCEPTION_MARK;
1.340 + klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK);
1.341 + instanceKlassHandle klass (THREAD, k);
1.342 + instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
1.343 +
1.344 + const char thread_name[] = "Signal Dispatcher";
1.345 + Handle string = java_lang_String::create_from_str(thread_name, CHECK);
1.346 +
1.347 + // Initialize thread_oop to put it into the system threadGroup
1.348 + Handle thread_group (THREAD, Universe::system_thread_group());
1.349 + JavaValue result(T_VOID);
1.350 + JavaCalls::call_special(&result, thread_oop,
1.351 + klass,
1.352 + vmSymbolHandles::object_initializer_name(),
1.353 + vmSymbolHandles::threadgroup_string_void_signature(),
1.354 + thread_group,
1.355 + string,
1.356 + CHECK);
1.357 +
1.358 + KlassHandle group(THREAD, SystemDictionary::threadGroup_klass());
1.359 + JavaCalls::call_special(&result,
1.360 + thread_group,
1.361 + group,
1.362 + vmSymbolHandles::add_method_name(),
1.363 + vmSymbolHandles::thread_void_signature(),
1.364 + thread_oop, // ARG 1
1.365 + CHECK);
1.366 +
1.367 + os::signal_init_pd();
1.368 +
1.369 + { MutexLocker mu(Threads_lock);
1.370 + JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
1.371 +
1.372 + // At this point it may be possible that no osthread was created for the
1.373 + // JavaThread due to lack of memory. We would have to throw an exception
1.374 + // in that case. However, since this must work and we do not allow
1.375 + // exceptions anyway, check and abort if this fails.
1.376 + if (signal_thread == NULL || signal_thread->osthread() == NULL) {
1.377 + vm_exit_during_initialization("java.lang.OutOfMemoryError",
1.378 + "unable to create new native thread");
1.379 + }
1.380 +
1.381 + java_lang_Thread::set_thread(thread_oop(), signal_thread);
1.382 + java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
1.383 + java_lang_Thread::set_daemon(thread_oop());
1.384 +
1.385 + signal_thread->set_threadObj(thread_oop());
1.386 + Threads::add(signal_thread);
1.387 + Thread::start(signal_thread);
1.388 + }
1.389 + // Handle ^BREAK
1.390 + os::signal(SIGBREAK, os::user_handler());
1.391 + }
1.392 +}
1.393 +
1.394 +
1.395 +void os::terminate_signal_thread() {
1.396 + if (!ReduceSignalUsage)
1.397 + signal_notify(sigexitnum_pd());
1.398 +}
1.399 +
1.400 +
1.401 +// --------------------- loading libraries ---------------------
1.402 +
1.403 +typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
1.404 +extern struct JavaVM_ main_vm;
1.405 +
1.406 +static void* _native_java_library = NULL;
1.407 +
1.408 +void* os::native_java_library() {
1.409 + if (_native_java_library == NULL) {
1.410 + char buffer[JVM_MAXPATHLEN];
1.411 + char ebuf[1024];
1.412 +
1.413 + // Try to load verify dll first. In 1.3 java dll depends on it and is not always
1.414 + // able to find it when the loading executable is outside the JDK.
1.415 + // In order to keep working with 1.2 we ignore any loading errors.
1.416 + hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "verify");
1.417 + hpi::dll_load(buffer, ebuf, sizeof(ebuf));
1.418 +
1.419 + // Load java dll
1.420 + hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "java");
1.421 + _native_java_library = hpi::dll_load(buffer, ebuf, sizeof(ebuf));
1.422 + if (_native_java_library == NULL) {
1.423 + vm_exit_during_initialization("Unable to load native library", ebuf);
1.424 + }
1.425 + // The JNI_OnLoad handling is normally done by method load in java.lang.ClassLoader$NativeLibrary,
1.426 + // but the VM loads the base library explicitly so we have to check for JNI_OnLoad as well
1.427 + const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
1.428 + JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(JNI_OnLoad_t, hpi::dll_lookup(_native_java_library, onLoadSymbols[0]));
1.429 + if (JNI_OnLoad != NULL) {
1.430 + JavaThread* thread = JavaThread::current();
1.431 + ThreadToNativeFromVM ttn(thread);
1.432 + HandleMark hm(thread);
1.433 + jint ver = (*JNI_OnLoad)(&main_vm, NULL);
1.434 + if (!Threads::is_supported_jni_version_including_1_1(ver)) {
1.435 + vm_exit_during_initialization("Unsupported JNI version");
1.436 + }
1.437 + }
1.438 + }
1.439 + return _native_java_library;
1.440 +}
1.441 +
1.442 +// --------------------- heap allocation utilities ---------------------
1.443 +
1.444 +char *os::strdup(const char *str) {
1.445 + size_t size = strlen(str);
1.446 + char *dup_str = (char *)malloc(size + 1);
1.447 + if (dup_str == NULL) return NULL;
1.448 + strcpy(dup_str, str);
1.449 + return dup_str;
1.450 +}
1.451 +
1.452 +
1.453 +
1.454 +#ifdef ASSERT
1.455 +#define space_before (MallocCushion + sizeof(double))
1.456 +#define space_after MallocCushion
1.457 +#define size_addr_from_base(p) (size_t*)(p + space_before - sizeof(size_t))
1.458 +#define size_addr_from_obj(p) ((size_t*)p - 1)
1.459 +// MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly
1.460 +// NB: cannot be debug variable, because these aren't set from the command line until
1.461 +// *after* the first few allocs already happened
1.462 +#define MallocCushion 16
1.463 +#else
1.464 +#define space_before 0
1.465 +#define space_after 0
1.466 +#define size_addr_from_base(p) should not use w/o ASSERT
1.467 +#define size_addr_from_obj(p) should not use w/o ASSERT
1.468 +#define MallocCushion 0
1.469 +#endif
1.470 +#define paranoid 0 /* only set to 1 if you suspect checking code has bug */
1.471 +
1.472 +#ifdef ASSERT
1.473 +inline size_t get_size(void* obj) {
1.474 + size_t size = *size_addr_from_obj(obj);
1.475 + if (size < 0 )
1.476 + fatal2("free: size field of object #%p was overwritten (%lu)", obj, size);
1.477 + return size;
1.478 +}
1.479 +
1.480 +u_char* find_cushion_backwards(u_char* start) {
1.481 + u_char* p = start;
1.482 + while (p[ 0] != badResourceValue || p[-1] != badResourceValue ||
1.483 + p[-2] != badResourceValue || p[-3] != badResourceValue) p--;
1.484 + // ok, we have four consecutive marker bytes; find start
1.485 + u_char* q = p - 4;
1.486 + while (*q == badResourceValue) q--;
1.487 + return q + 1;
1.488 +}
1.489 +
1.490 +u_char* find_cushion_forwards(u_char* start) {
1.491 + u_char* p = start;
1.492 + while (p[0] != badResourceValue || p[1] != badResourceValue ||
1.493 + p[2] != badResourceValue || p[3] != badResourceValue) p++;
1.494 + // ok, we have four consecutive marker bytes; find end of cushion
1.495 + u_char* q = p + 4;
1.496 + while (*q == badResourceValue) q++;
1.497 + return q - MallocCushion;
1.498 +}
1.499 +
1.500 +void print_neighbor_blocks(void* ptr) {
1.501 + // find block allocated before ptr (not entirely crash-proof)
1.502 + if (MallocCushion < 4) {
1.503 + tty->print_cr("### cannot find previous block (MallocCushion < 4)");
1.504 + return;
1.505 + }
1.506 + u_char* start_of_this_block = (u_char*)ptr - space_before;
1.507 + u_char* end_of_prev_block_data = start_of_this_block - space_after -1;
1.508 + // look for cushion in front of prev. block
1.509 + u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data);
1.510 + ptrdiff_t size = *size_addr_from_base(start_of_prev_block);
1.511 + u_char* obj = start_of_prev_block + space_before;
1.512 + if (size <= 0 ) {
1.513 + // start is bad; mayhave been confused by OS data inbetween objects
1.514 + // search one more backwards
1.515 + start_of_prev_block = find_cushion_backwards(start_of_prev_block);
1.516 + size = *size_addr_from_base(start_of_prev_block);
1.517 + obj = start_of_prev_block + space_before;
1.518 + }
1.519 +
1.520 + if (start_of_prev_block + space_before + size + space_after == start_of_this_block) {
1.521 + tty->print_cr("### previous object: %p (%ld bytes)", obj, size);
1.522 + } else {
1.523 + tty->print_cr("### previous object (not sure if correct): %p (%ld bytes)", obj, size);
1.524 + }
1.525 +
1.526 + // now find successor block
1.527 + u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after;
1.528 + start_of_next_block = find_cushion_forwards(start_of_next_block);
1.529 + u_char* next_obj = start_of_next_block + space_before;
1.530 + ptrdiff_t next_size = *size_addr_from_base(start_of_next_block);
1.531 + if (start_of_next_block[0] == badResourceValue &&
1.532 + start_of_next_block[1] == badResourceValue &&
1.533 + start_of_next_block[2] == badResourceValue &&
1.534 + start_of_next_block[3] == badResourceValue) {
1.535 + tty->print_cr("### next object: %p (%ld bytes)", next_obj, next_size);
1.536 + } else {
1.537 + tty->print_cr("### next object (not sure if correct): %p (%ld bytes)", next_obj, next_size);
1.538 + }
1.539 +}
1.540 +
1.541 +
1.542 +void report_heap_error(void* memblock, void* bad, const char* where) {
1.543 + tty->print_cr("## nof_mallocs = %d, nof_frees = %d", os::num_mallocs, os::num_frees);
1.544 + tty->print_cr("## memory stomp: byte at %p %s object %p", bad, where, memblock);
1.545 + print_neighbor_blocks(memblock);
1.546 + fatal("memory stomping error");
1.547 +}
1.548 +
1.549 +void verify_block(void* memblock) {
1.550 + size_t size = get_size(memblock);
1.551 + if (MallocCushion) {
1.552 + u_char* ptr = (u_char*)memblock - space_before;
1.553 + for (int i = 0; i < MallocCushion; i++) {
1.554 + if (ptr[i] != badResourceValue) {
1.555 + report_heap_error(memblock, ptr+i, "in front of");
1.556 + }
1.557 + }
1.558 + u_char* end = (u_char*)memblock + size + space_after;
1.559 + for (int j = -MallocCushion; j < 0; j++) {
1.560 + if (end[j] != badResourceValue) {
1.561 + report_heap_error(memblock, end+j, "after");
1.562 + }
1.563 + }
1.564 + }
1.565 +}
1.566 +#endif
1.567 +
1.568 +void* os::malloc(size_t size) {
1.569 + NOT_PRODUCT(num_mallocs++);
1.570 + NOT_PRODUCT(alloc_bytes += size);
1.571 +
1.572 + if (size == 0) {
1.573 + // return a valid pointer if size is zero
1.574 + // if NULL is returned the calling functions assume out of memory.
1.575 + size = 1;
1.576 + }
1.577 +
1.578 + NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
1.579 + u_char* ptr = (u_char*)::malloc(size + space_before + space_after);
1.580 +#ifdef ASSERT
1.581 + if (ptr == NULL) return NULL;
1.582 + if (MallocCushion) {
1.583 + for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue;
1.584 + u_char* end = ptr + space_before + size;
1.585 + for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad;
1.586 + for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue;
1.587 + }
1.588 + // put size just before data
1.589 + *size_addr_from_base(ptr) = size;
1.590 +#endif
1.591 + u_char* memblock = ptr + space_before;
1.592 + if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
1.593 + tty->print_cr("os::malloc caught, %lu bytes --> %p", size, memblock);
1.594 + breakpoint();
1.595 + }
1.596 + debug_only(if (paranoid) verify_block(memblock));
1.597 + if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc %lu bytes --> %p", size, memblock);
1.598 + return memblock;
1.599 +}
1.600 +
1.601 +
1.602 +void* os::realloc(void *memblock, size_t size) {
1.603 + NOT_PRODUCT(num_mallocs++);
1.604 + NOT_PRODUCT(alloc_bytes += size);
1.605 +#ifndef ASSERT
1.606 + return ::realloc(memblock, size);
1.607 +#else
1.608 + if (memblock == NULL) {
1.609 + return os::malloc(size);
1.610 + }
1.611 + if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
1.612 + tty->print_cr("os::realloc caught %p", memblock);
1.613 + breakpoint();
1.614 + }
1.615 + verify_block(memblock);
1.616 + NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
1.617 + if (size == 0) return NULL;
1.618 + // always move the block
1.619 + void* ptr = malloc(size);
1.620 + if (PrintMalloc) tty->print_cr("os::remalloc %lu bytes, %p --> %p", size, memblock, ptr);
1.621 + // Copy to new memory if malloc didn't fail
1.622 + if ( ptr != NULL ) {
1.623 + memcpy(ptr, memblock, MIN2(size, get_size(memblock)));
1.624 + if (paranoid) verify_block(ptr);
1.625 + if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
1.626 + tty->print_cr("os::realloc caught, %lu bytes --> %p", size, ptr);
1.627 + breakpoint();
1.628 + }
1.629 + free(memblock);
1.630 + }
1.631 + return ptr;
1.632 +#endif
1.633 +}
1.634 +
1.635 +
1.636 +void os::free(void *memblock) {
1.637 + NOT_PRODUCT(num_frees++);
1.638 +#ifdef ASSERT
1.639 + if (memblock == NULL) return;
1.640 + if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
1.641 + if (tty != NULL) tty->print_cr("os::free caught %p", memblock);
1.642 + breakpoint();
1.643 + }
1.644 + verify_block(memblock);
1.645 + if (PrintMalloc && tty != NULL)
1.646 + // tty->print_cr("os::free %p", memblock);
1.647 + fprintf(stderr, "os::free %p\n", memblock);
1.648 + NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
1.649 + // Added by detlefs.
1.650 + if (MallocCushion) {
1.651 + u_char* ptr = (u_char*)memblock - space_before;
1.652 + for (u_char* p = ptr; p < ptr + MallocCushion; p++) {
1.653 + guarantee(*p == badResourceValue,
1.654 + "Thing freed should be malloc result.");
1.655 + *p = (u_char)freeBlockPad;
1.656 + }
1.657 + size_t size = get_size(memblock);
1.658 + u_char* end = ptr + space_before + size;
1.659 + for (u_char* q = end; q < end + MallocCushion; q++) {
1.660 + guarantee(*q == badResourceValue,
1.661 + "Thing freed should be malloc result.");
1.662 + *q = (u_char)freeBlockPad;
1.663 + }
1.664 + }
1.665 +#endif
1.666 + ::free((char*)memblock - space_before);
1.667 +}
1.668 +
1.669 +void os::init_random(long initval) {
1.670 + _rand_seed = initval;
1.671 +}
1.672 +
1.673 +
1.674 +long os::random() {
1.675 + /* standard, well-known linear congruential random generator with
1.676 + * next_rand = (16807*seed) mod (2**31-1)
1.677 + * see
1.678 + * (1) "Random Number Generators: Good Ones Are Hard to Find",
1.679 + * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
1.680 + * (2) "Two Fast Implementations of the 'Minimal Standard' Random
1.681 + * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
1.682 + */
1.683 + const long a = 16807;
1.684 + const unsigned long m = 2147483647;
1.685 + const long q = m / a; assert(q == 127773, "weird math");
1.686 + const long r = m % a; assert(r == 2836, "weird math");
1.687 +
1.688 + // compute az=2^31p+q
1.689 + unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
1.690 + unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
1.691 + lo += (hi & 0x7FFF) << 16;
1.692 +
1.693 + // if q overflowed, ignore the overflow and increment q
1.694 + if (lo > m) {
1.695 + lo &= m;
1.696 + ++lo;
1.697 + }
1.698 + lo += hi >> 15;
1.699 +
1.700 + // if (p+q) overflowed, ignore the overflow and increment (p+q)
1.701 + if (lo > m) {
1.702 + lo &= m;
1.703 + ++lo;
1.704 + }
1.705 + return (_rand_seed = lo);
1.706 +}
1.707 +
1.708 +// The INITIALIZED state is distinguished from the SUSPENDED state because the
1.709 +// conditions in which a thread is first started are different from those in which
1.710 +// a suspension is resumed. These differences make it hard for us to apply the
1.711 +// tougher checks when starting threads that we want to do when resuming them.
1.712 +// However, when start_thread is called as a result of Thread.start, on a Java
1.713 +// thread, the operation is synchronized on the Java Thread object. So there
1.714 +// cannot be a race to start the thread and hence for the thread to exit while
1.715 +// we are working on it. Non-Java threads that start Java threads either have
1.716 +// to do so in a context in which races are impossible, or should do appropriate
1.717 +// locking.
1.718 +
1.719 +void os::start_thread(Thread* thread) {
1.720 + // guard suspend/resume
1.721 + MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
1.722 + OSThread* osthread = thread->osthread();
1.723 + osthread->set_state(RUNNABLE);
1.724 + pd_start_thread(thread);
1.725 +}
1.726 +
1.727 +//---------------------------------------------------------------------------
1.728 +// Helper functions for fatal error handler
1.729 +
1.730 +void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
1.731 + assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
1.732 +
1.733 + int cols = 0;
1.734 + int cols_per_line = 0;
1.735 + switch (unitsize) {
1.736 + case 1: cols_per_line = 16; break;
1.737 + case 2: cols_per_line = 8; break;
1.738 + case 4: cols_per_line = 4; break;
1.739 + case 8: cols_per_line = 2; break;
1.740 + default: return;
1.741 + }
1.742 +
1.743 + address p = start;
1.744 + st->print(PTR_FORMAT ": ", start);
1.745 + while (p < end) {
1.746 + switch (unitsize) {
1.747 + case 1: st->print("%02x", *(u1*)p); break;
1.748 + case 2: st->print("%04x", *(u2*)p); break;
1.749 + case 4: st->print("%08x", *(u4*)p); break;
1.750 + case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
1.751 + }
1.752 + p += unitsize;
1.753 + cols++;
1.754 + if (cols >= cols_per_line && p < end) {
1.755 + cols = 0;
1.756 + st->cr();
1.757 + st->print(PTR_FORMAT ": ", p);
1.758 + } else {
1.759 + st->print(" ");
1.760 + }
1.761 + }
1.762 + st->cr();
1.763 +}
1.764 +
1.765 +void os::print_environment_variables(outputStream* st, const char** env_list,
1.766 + char* buffer, int len) {
1.767 + if (env_list) {
1.768 + st->print_cr("Environment Variables:");
1.769 +
1.770 + for (int i = 0; env_list[i] != NULL; i++) {
1.771 + if (getenv(env_list[i], buffer, len)) {
1.772 + st->print(env_list[i]);
1.773 + st->print("=");
1.774 + st->print_cr(buffer);
1.775 + }
1.776 + }
1.777 + }
1.778 +}
1.779 +
1.780 +void os::print_cpu_info(outputStream* st) {
1.781 + // cpu
1.782 + st->print("CPU:");
1.783 + st->print("total %d", os::processor_count());
1.784 + // It's not safe to query number of active processors after crash
1.785 + // st->print("(active %d)", os::active_processor_count());
1.786 + st->print(" %s", VM_Version::cpu_features());
1.787 + st->cr();
1.788 +}
1.789 +
1.790 +void os::print_date_and_time(outputStream *st) {
1.791 + time_t tloc;
1.792 + (void)time(&tloc);
1.793 + st->print("time: %s", ctime(&tloc)); // ctime adds newline.
1.794 +
1.795 + double t = os::elapsedTime();
1.796 + // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
1.797 + // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
1.798 + // before printf. We lost some precision, but who cares?
1.799 + st->print_cr("elapsed time: %d seconds", (int)t);
1.800 +}
1.801 +
1.802 +
1.803 +// Looks like all platforms except IA64 can use the same function to check
1.804 +// if C stack is walkable beyond current frame. The check for fp() is not
1.805 +// necessary on Sparc, but it's harmless.
1.806 +bool os::is_first_C_frame(frame* fr) {
1.807 +#ifdef IA64
1.808 + // In order to walk native frames on Itanium, we need to access the unwind
1.809 + // table, which is inside ELF. We don't want to parse ELF after fatal error,
1.810 + // so return true for IA64. If we need to support C stack walking on IA64,
1.811 + // this function needs to be moved to CPU specific files, as fp() on IA64
1.812 + // is register stack, which grows towards higher memory address.
1.813 + return true;
1.814 +#endif
1.815 +
1.816 + // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1.817 + // Check usp first, because if that's bad the other accessors may fault
1.818 + // on some architectures. Ditto ufp second, etc.
1.819 + uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1.820 + // sp on amd can be 32 bit aligned.
1.821 + uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1.822 +
1.823 + uintptr_t usp = (uintptr_t)fr->sp();
1.824 + if ((usp & sp_align_mask) != 0) return true;
1.825 +
1.826 + uintptr_t ufp = (uintptr_t)fr->fp();
1.827 + if ((ufp & fp_align_mask) != 0) return true;
1.828 +
1.829 + uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1.830 + if ((old_sp & sp_align_mask) != 0) return true;
1.831 + if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1.832 +
1.833 + uintptr_t old_fp = (uintptr_t)fr->link();
1.834 + if ((old_fp & fp_align_mask) != 0) return true;
1.835 + if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1.836 +
1.837 + // stack grows downwards; if old_fp is below current fp or if the stack
1.838 + // frame is too large, either the stack is corrupted or fp is not saved
1.839 + // on stack (i.e. on x86, ebp may be used as general register). The stack
1.840 + // is not walkable beyond current frame.
1.841 + if (old_fp < ufp) return true;
1.842 + if (old_fp - ufp > 64 * K) return true;
1.843 +
1.844 + return false;
1.845 +}
1.846 +
1.847 +#ifdef ASSERT
1.848 +extern "C" void test_random() {
1.849 + const double m = 2147483647;
1.850 + double mean = 0.0, variance = 0.0, t;
1.851 + long reps = 10000;
1.852 + unsigned long seed = 1;
1.853 +
1.854 + tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1.855 + os::init_random(seed);
1.856 + long num;
1.857 + for (int k = 0; k < reps; k++) {
1.858 + num = os::random();
1.859 + double u = (double)num / m;
1.860 + assert(u >= 0.0 && u <= 1.0, "bad random number!");
1.861 +
1.862 + // calculate mean and variance of the random sequence
1.863 + mean += u;
1.864 + variance += (u*u);
1.865 + }
1.866 + mean /= reps;
1.867 + variance /= (reps - 1);
1.868 +
1.869 + assert(num == 1043618065, "bad seed");
1.870 + tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1.871 + tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1.872 + const double eps = 0.0001;
1.873 + t = fabsd(mean - 0.5018);
1.874 + assert(t < eps, "bad mean");
1.875 + t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1.876 + assert(t < eps, "bad variance");
1.877 +}
1.878 +#endif
1.879 +
1.880 +
1.881 +// Set up the boot classpath.
1.882 +
1.883 +char* os::format_boot_path(const char* format_string,
1.884 + const char* home,
1.885 + int home_len,
1.886 + char fileSep,
1.887 + char pathSep) {
1.888 + assert((fileSep == '/' && pathSep == ':') ||
1.889 + (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
1.890 +
1.891 + // Scan the format string to determine the length of the actual
1.892 + // boot classpath, and handle platform dependencies as well.
1.893 + int formatted_path_len = 0;
1.894 + const char* p;
1.895 + for (p = format_string; *p != 0; ++p) {
1.896 + if (*p == '%') formatted_path_len += home_len - 1;
1.897 + ++formatted_path_len;
1.898 + }
1.899 +
1.900 + char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1);
1.901 + if (formatted_path == NULL) {
1.902 + return NULL;
1.903 + }
1.904 +
1.905 + // Create boot classpath from format, substituting separator chars and
1.906 + // java home directory.
1.907 + char* q = formatted_path;
1.908 + for (p = format_string; *p != 0; ++p) {
1.909 + switch (*p) {
1.910 + case '%':
1.911 + strcpy(q, home);
1.912 + q += home_len;
1.913 + break;
1.914 + case '/':
1.915 + *q++ = fileSep;
1.916 + break;
1.917 + case ':':
1.918 + *q++ = pathSep;
1.919 + break;
1.920 + default:
1.921 + *q++ = *p;
1.922 + }
1.923 + }
1.924 + *q = '\0';
1.925 +
1.926 + assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1.927 + return formatted_path;
1.928 +}
1.929 +
1.930 +
1.931 +bool os::set_boot_path(char fileSep, char pathSep) {
1.932 +
1.933 + const char* home = Arguments::get_java_home();
1.934 + int home_len = (int)strlen(home);
1.935 +
1.936 + static const char* meta_index_dir_format = "%/lib/";
1.937 + static const char* meta_index_format = "%/lib/meta-index";
1.938 + char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1.939 + if (meta_index == NULL) return false;
1.940 + char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1.941 + if (meta_index_dir == NULL) return false;
1.942 + Arguments::set_meta_index_path(meta_index, meta_index_dir);
1.943 +
1.944 + // Any modification to the JAR-file list, for the boot classpath must be
1.945 + // aligned with install/install/make/common/Pack.gmk. Note: boot class
1.946 + // path class JARs, are stripped for StackMapTable to reduce download size.
1.947 + static const char classpath_format[] =
1.948 + "%/lib/resources.jar:"
1.949 + "%/lib/rt.jar:"
1.950 + "%/lib/sunrsasign.jar:"
1.951 + "%/lib/jsse.jar:"
1.952 + "%/lib/jce.jar:"
1.953 + "%/lib/charsets.jar:"
1.954 + "%/classes";
1.955 + char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1.956 + if (sysclasspath == NULL) return false;
1.957 + Arguments::set_sysclasspath(sysclasspath);
1.958 +
1.959 + return true;
1.960 +}
1.961 +
1.962 +
1.963 +void os::set_memory_serialize_page(address page) {
1.964 + int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1.965 + _mem_serialize_page = (volatile int32_t *)page;
1.966 + // We initialize the serialization page shift count here
1.967 + // We assume a cache line size of 64 bytes
1.968 + assert(SerializePageShiftCount == count,
1.969 + "thread size changed, fix SerializePageShiftCount constant");
1.970 + set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1.971 +}
1.972 +
1.973 +// This method is called from signal handler when SIGSEGV occurs while the current
1.974 +// thread tries to store to the "read-only" memory serialize page during state
1.975 +// transition.
1.976 +void os::block_on_serialize_page_trap() {
1.977 + if (TraceSafepoint) {
1.978 + tty->print_cr("Block until the serialize page permission restored");
1.979 + }
1.980 + // When VMThread is holding the SerializePage_lock during modifying the
1.981 + // access permission of the memory serialize page, the following call
1.982 + // will block until the permission of that page is restored to rw.
1.983 + // Generally, it is unsafe to manipulate locks in signal handlers, but in
1.984 + // this case, it's OK as the signal is synchronous and we know precisely when
1.985 + // it can occur. SerializePage_lock is a transiently-held leaf lock, so
1.986 + // lock_without_safepoint_check should be safe.
1.987 + SerializePage_lock->lock_without_safepoint_check();
1.988 + SerializePage_lock->unlock();
1.989 +}
1.990 +
1.991 +// Serialize all thread state variables
1.992 +void os::serialize_thread_states() {
1.993 + // On some platforms such as Solaris & Linux, the time duration of the page
1.994 + // permission restoration is observed to be much longer than expected due to
1.995 + // scheduler starvation problem etc. To avoid the long synchronization
1.996 + // time and expensive page trap spinning, 'SerializePage_lock' is used to block
1.997 + // the mutator thread if such case is encountered. Since this method is always
1.998 + // called by VMThread during safepoint, lock_without_safepoint_check is used
1.999 + // instead. See bug 6546278.
1.1000 + SerializePage_lock->lock_without_safepoint_check();
1.1001 + os::protect_memory( (char *)os::get_memory_serialize_page(), os::vm_page_size() );
1.1002 + os::unguard_memory( (char *)os::get_memory_serialize_page(), os::vm_page_size() );
1.1003 + SerializePage_lock->unlock();
1.1004 +}
1.1005 +
1.1006 +// Returns true if the current stack pointer is above the stack shadow
1.1007 +// pages, false otherwise.
1.1008 +
1.1009 +bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1.1010 + assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1.1011 + address sp = current_stack_pointer();
1.1012 + // Check if we have StackShadowPages above the yellow zone. This parameter
1.1013 + // is dependant on the depth of the maximum VM call stack possible from
1.1014 + // the handler for stack overflow. 'instanceof' in the stack overflow
1.1015 + // handler or a println uses at least 8k stack of VM and native code
1.1016 + // respectively.
1.1017 + const int framesize_in_bytes =
1.1018 + Interpreter::size_top_interpreter_activation(method()) * wordSize;
1.1019 + int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1.1020 + * vm_page_size()) + framesize_in_bytes;
1.1021 + // The very lower end of the stack
1.1022 + address stack_limit = thread->stack_base() - thread->stack_size();
1.1023 + return (sp > (stack_limit + reserved_area));
1.1024 +}
1.1025 +
1.1026 +size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
1.1027 + uint min_pages)
1.1028 +{
1.1029 + assert(min_pages > 0, "sanity");
1.1030 + if (UseLargePages) {
1.1031 + const size_t max_page_size = region_max_size / min_pages;
1.1032 +
1.1033 + for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
1.1034 + const size_t sz = _page_sizes[i];
1.1035 + const size_t mask = sz - 1;
1.1036 + if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
1.1037 + // The largest page size with no fragmentation.
1.1038 + return sz;
1.1039 + }
1.1040 +
1.1041 + if (sz <= max_page_size) {
1.1042 + // The largest page size that satisfies the min_pages requirement.
1.1043 + return sz;
1.1044 + }
1.1045 + }
1.1046 + }
1.1047 +
1.1048 + return vm_page_size();
1.1049 +}
1.1050 +
1.1051 +#ifndef PRODUCT
1.1052 +void os::trace_page_sizes(const char* str, const size_t region_min_size,
1.1053 + const size_t region_max_size, const size_t page_size,
1.1054 + const char* base, const size_t size)
1.1055 +{
1.1056 + if (TracePageSizes) {
1.1057 + tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1.1058 + " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1.1059 + " size=" SIZE_FORMAT,
1.1060 + str, region_min_size, region_max_size,
1.1061 + page_size, base, size);
1.1062 + }
1.1063 +}
1.1064 +#endif // #ifndef PRODUCT
1.1065 +
1.1066 +// This is the working definition of a server class machine:
1.1067 +// >= 2 physical CPU's and >=2GB of memory, with some fuzz
1.1068 +// because the graphics memory (?) sometimes masks physical memory.
1.1069 +// If you want to change the definition of a server class machine
1.1070 +// on some OS or platform, e.g., >=4GB on Windohs platforms,
1.1071 +// then you'll have to parameterize this method based on that state,
1.1072 +// as was done for logical processors here, or replicate and
1.1073 +// specialize this method for each platform. (Or fix os to have
1.1074 +// some inheritance structure and use subclassing. Sigh.)
1.1075 +// If you want some platform to always or never behave as a server
1.1076 +// class machine, change the setting of AlwaysActAsServerClassMachine
1.1077 +// and NeverActAsServerClassMachine in globals*.hpp.
1.1078 +bool os::is_server_class_machine() {
1.1079 + // First check for the early returns
1.1080 + if (NeverActAsServerClassMachine) {
1.1081 + return false;
1.1082 + }
1.1083 + if (AlwaysActAsServerClassMachine) {
1.1084 + return true;
1.1085 + }
1.1086 + // Then actually look at the machine
1.1087 + bool result = false;
1.1088 + const unsigned int server_processors = 2;
1.1089 + const julong server_memory = 2UL * G;
1.1090 + // We seem not to get our full complement of memory.
1.1091 + // We allow some part (1/8?) of the memory to be "missing",
1.1092 + // based on the sizes of DIMMs, and maybe graphics cards.
1.1093 + const julong missing_memory = 256UL * M;
1.1094 +
1.1095 + /* Is this a server class machine? */
1.1096 + if ((os::active_processor_count() >= (int)server_processors) &&
1.1097 + (os::physical_memory() >= (server_memory - missing_memory))) {
1.1098 + const unsigned int logical_processors =
1.1099 + VM_Version::logical_processors_per_package();
1.1100 + if (logical_processors > 1) {
1.1101 + const unsigned int physical_packages =
1.1102 + os::active_processor_count() / logical_processors;
1.1103 + if (physical_packages > server_processors) {
1.1104 + result = true;
1.1105 + }
1.1106 + } else {
1.1107 + result = true;
1.1108 + }
1.1109 + }
1.1110 + return result;
1.1111 +}
