xpcom/base/nsMemoryImpl.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
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   8  * http://www.mozilla.org/MPL/
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  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is mozilla.org code.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 1998
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *
  24  * Alternatively, the contents of this file may be used under the terms of
  25  * either of the GNU General Public License Version 2 or later (the "GPL"),
  26  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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  36  * ***** END LICENSE BLOCK ***** */
  37
  38 #include "nsXPCOM.h"
  39 #include "nsMemoryImpl.h"
  40 #include "nsThreadUtils.h"
  41
  42 #include "nsIObserverService.h"
  43 #include "nsIServiceManager.h"
  44 #include "nsISupportsArray.h"
  45
  46 #include "prmem.h"
  47 #include "prcvar.h"
  48 #include "pratom.h"
  49
  50 #include "nsAlgorithm.h"
  51 #include "nsAutoLock.h"
  52 #include "nsCOMPtr.h"
  53 #include "nsString.h"
  54
  55 #if defined(XP_WIN)
  56 #include <windows.h>
  57 #define NS_MEMORY_FLUSHER
  58 #elif defined (NS_OSSO)
  59 #include <osso-mem.h>
  60 #include <fcntl.h>
  61 #include <unistd.h>
  62 const char* kHighMark = "/sys/kernel/high_watermark";
  63 #else
  64 // Need to implement the nsIMemory::IsLowMemory() predicate
  65 #undef NS_MEMORY_FLUSHER
  66 #endif
  67
  68 #ifdef NS_MEMORY_FLUSHER
  69 #include "nsITimer.h"
  70 #endif
  71
  72 ////////////////////////////////////////////////////////////////////////////////
  73 // Define NS_OUT_OF_MEMORY_TESTER if you want to force memory failures
  74
  75 #ifdef DEBUG_xwarren
  76 #define NS_OUT_OF_MEMORY_TESTER
  77 #endif
  78
  79 #ifdef NS_OUT_OF_MEMORY_TESTER
  80
  81 // flush memory one in this number of times:
  82 #define NS_FLUSH_FREQUENCY        100000
  83
  84 // fail allocation one in this number of flushes:
  85 #define NS_FAIL_FREQUENCY         10
  86
  87 PRUint32 gFlushFreq = 0;
  88 PRUint32 gFailFreq = 0;
  89
  90 static void*
  91 mallocator(PRSize size, PRUint32& counter, PRUint32 max)
  92 {
  93     if (counter++ >= max) {
  94         counter = 0;
  95         NS_ASSERTION(0, "about to fail allocation... watch out");
  96         return nsnull;
  97     }
  98     return PR_Malloc(size);
  99 }
 100
 101 static void*
 102 reallocator(void* ptr, PRSize size, PRUint32& counter, PRUint32 max)
 103 {
 104     if (counter++ >= max) {
 105         counter = 0;
 106         NS_ASSERTION(0, "about to fail reallocation... watch out");
 107         return nsnull;
 108     }
 109     return PR_Realloc(ptr, size);
 110 }
 111
 112 #define MALLOC1(s)       mallocator(s, gFlushFreq, NS_FLUSH_FREQUENCY)
 113 #define REALLOC1(p, s)   reallocator(p, s, gFlushFreq, NS_FLUSH_FREQUENCY)
 114
 115 #else
 116
 117 #define MALLOC1(s)       PR_Malloc(s)
 118 #define REALLOC1(p, s)   PR_Realloc(p, s)
 119
 120 #endif // NS_OUT_OF_MEMORY_TESTER
 121
 122 #if defined(XDEBUG_waterson)
 123 #define NS_TEST_MEMORY_FLUSHER
 124 #endif
 125
 126 #ifdef NS_MEMORY_FLUSHER
 127 /**
 128  * A class that is used to periodically check the status of the system,
 129  * determine if too much memory is in use, and if so, trigger a "memory flush".
 130  */
 131 class MemoryFlusher : public nsITimerCallback
 132 {
 133 public:
 134     // We don't use the generic macros because we are a special static object
 135     NS_IMETHOD QueryInterface(REFNSIID aIID, void** aResult);
 136     NS_IMETHOD_(nsrefcnt) AddRef(void) { return 2; }
 137     NS_IMETHOD_(nsrefcnt) Release(void) { return 1; }
 138
 139     NS_DECL_NSITIMERCALLBACK
 140
 141     nsresult Init();
 142     void StopAndJoin();
 143
 144 private:
 145     static PRIntervalTime sTimeout;
 146     static PRLock*        sLock;
 147     static PRCondVar*     sCVar;
 148
 149     enum {
 150         kTimeout = 60000 // milliseconds
 151     };
 152 };
 153
 154 static MemoryFlusher sGlobalMemoryFlusher;
 155
 156 #endif // NS_MEMORY_FLUSHER
 157
 158 static nsMemoryImpl sGlobalMemory;
 159
 160 NS_IMPL_QUERY_INTERFACE1(nsMemoryImpl, nsIMemory)
 161
 162 NS_IMETHODIMP_(void*)
 163 nsMemoryImpl::Alloc(PRSize size)
 164 {
 165     return NS_Alloc(size);
 166 }
 167
 168 NS_IMETHODIMP_(void*)
 169 nsMemoryImpl::Realloc(void* ptr, PRSize size)
 170 {
 171     return NS_Realloc(ptr, size);
 172 }
 173
 174 NS_IMETHODIMP_(void)
 175 nsMemoryImpl::Free(void* ptr)
 176 {
 177     NS_Free(ptr);
 178 }
 179
 180 NS_IMETHODIMP
 181 nsMemoryImpl::HeapMinimize(PRBool aImmediate)
 182 {
 183     return FlushMemory(NS_LITERAL_STRING("heap-minimize").get(), aImmediate);
 184 }
 185
 186 NS_IMETHODIMP
 187 nsMemoryImpl::IsLowMemory(PRBool *result)
 188 {
 189 #if defined(WINCE)
 190     MEMORYSTATUS stat;
 191     GlobalMemoryStatus(&stat);
 192     *result = ((float)stat.dwAvailPhys / stat.dwTotalPhys) < 0.1;
 193 #elif defined(XP_WIN)
 194     MEMORYSTATUS stat;
 195     GlobalMemoryStatus(&stat);
 196     *result = ((float)stat.dwAvailPageFile / stat.dwTotalPageFile) < 0.1;
 197 #elif defined(NS_OSSO)
 198     int fd = open (kHighMark, O_RDONLY);
 199     if (fd == -1) {
 200         *result = PR_FALSE;
 201         return NS_OK;
 202     }
 203     int c = 0;
 204     read (fd, &c, 1);
 205     close(fd);
 206     *result = (c == '1');
 207 #else
 208     *result = PR_FALSE;
 209 #endif
 210     return NS_OK;
 211 }
 212
 213
 214 /*static*/ nsresult
 215 nsMemoryImpl::InitFlusher()
 216 {
 217 #ifdef NS_MEMORY_FLUSHER
 218     return sGlobalMemoryFlusher.Init();
 219 #else
 220     return NS_OK;
 221 #endif
 222 }
 223
 224 /*static*/ nsresult
 225 nsMemoryImpl::Create(nsISupports* outer, const nsIID& aIID, void **aResult)
 226 {
 227     NS_ENSURE_NO_AGGREGATION(outer);
 228     return sGlobalMemory.QueryInterface(aIID, aResult);
 229 }
 230
 231 nsresult
 232 nsMemoryImpl::FlushMemory(const PRUnichar* aReason, PRBool aImmediate)
 233 {
 234     nsresult rv;
 235
 236     if (aImmediate) {
 237         // They've asked us to run the flusher *immediately*. We've
 238         // got to be on the UI main thread for us to be able to do
 239         // that...are we?
 240         if (!NS_IsMainThread()) {
 241             NS_ERROR("can't synchronously flush memory: not on UI thread");
 242             return NS_ERROR_FAILURE;
 243         }
 244     }
 245
 246     PRInt32 lastVal = PR_AtomicSet(&sIsFlushing, 1);
 247     if (lastVal)
 248         return NS_OK;
 249
 250     // Run the flushers immediately if we can; otherwise, proxy to the
 251     // UI thread an run 'em asynchronously.
 252     if (aImmediate) {
 253         rv = RunFlushers(aReason);
 254     }
 255     else {
 256         sFlushEvent.mReason = aReason;
 257         rv = NS_DispatchToMainThread(&sFlushEvent, NS_DISPATCH_NORMAL);
 258     }
 259
 260     return rv;
 261 }
 262
 263 nsresult
 264 nsMemoryImpl::RunFlushers(const PRUnichar* aReason)
 265 {
 266     nsCOMPtr<nsIObserverService> os = do_GetService("@mozilla.org/observer-service;1");
 267     if (os) {
 268         os->NotifyObservers(this, "memory-pressure", aReason);
 269     }
 270
 271     sIsFlushing = 0;
 272     return NS_OK;
 273 }
 274
 275 // XXX need NS_IMPL_STATIC_ADDREF/RELEASE
 276 NS_IMETHODIMP_(nsrefcnt) nsMemoryImpl::FlushEvent::AddRef() { return 2; }
 277 NS_IMETHODIMP_(nsrefcnt) nsMemoryImpl::FlushEvent::Release() { return 1; }
 278 NS_IMPL_QUERY_INTERFACE1(nsMemoryImpl::FlushEvent, nsIRunnable)
 279
 280 NS_IMETHODIMP
 281 nsMemoryImpl::FlushEvent::Run()
 282 {
 283     sGlobalMemory.RunFlushers(mReason);
 284     return NS_OK;
 285 }
 286
 287 PRInt32
 288 nsMemoryImpl::sIsFlushing = 0;
 289
 290 nsMemoryImpl::FlushEvent
 291 nsMemoryImpl::sFlushEvent;
 292
 293 XPCOM_API(void*)
 294 NS_Alloc(PRSize size)
 295 {
 296     void* result = MALLOC1(size);
 297     if (! result) {
 298         // Request an asynchronous flush
 299         sGlobalMemory.FlushMemory(NS_LITERAL_STRING("alloc-failure").get(), PR_FALSE);
 300     }
 301     return result;
 302 }
 303
 304 XPCOM_API(void*)
 305 NS_Realloc(void* ptr, PRSize size)
 306 {
 307     void* result = REALLOC1(ptr, size);
 308     if (! result && size != 0) {
 309         // Request an asynchronous flush
 310         sGlobalMemory.FlushMemory(NS_LITERAL_STRING("alloc-failure").get(), PR_FALSE);
 311     }
 312     return result;
 313 }
 314
 315 XPCOM_API(void)
 316 NS_Free(void* ptr)
 317 {
 318     PR_Free(ptr);
 319 }
 320
 321 #ifdef NS_MEMORY_FLUSHER
 322
 323 NS_IMPL_QUERY_INTERFACE1(MemoryFlusher, nsITimerCallback)
 324
 325 NS_IMETHODIMP
 326 MemoryFlusher::Notify(nsITimer *timer)
 327 {
 328     PRBool isLowMemory;
 329     sGlobalMemory.IsLowMemory(&isLowMemory);
 330
 331 #ifdef NS_TEST_MEMORY_FLUSHER
 332     // Fire the flusher *every* time
 333     isLowMemory = PR_TRUE;
 334 #endif
 335
 336     if (isLowMemory)
 337         sGlobalMemory.FlushMemory(NS_LITERAL_STRING("low-memory").get(),
 338                                   PR_FALSE);
 339     return NS_OK;
 340 }
 341
 342 nsresult
 343 MemoryFlusher::Init()
 344 {
 345     nsCOMPtr<nsITimer> timer = do_CreateInstance(NS_TIMER_CONTRACTID);
 346     NS_ENSURE_STATE(timer);
 347
 348     // There is no need to keep a reference to the timer object because we
 349     // don't need to kill the timer.  It will be killed automatically when
 350     // XPCOM is shutdown.
 351
 352     return timer->InitWithCallback(this, kTimeout,
 353                                    nsITimer::TYPE_REPEATING_SLACK);
 354 }
 355
 356 #endif // NS_MEMORY_FLUSHER
 357
 358 nsresult
 359 NS_GetMemoryManager(nsIMemory* *result)
 360 {
 361     return sGlobalMemory.QueryInterface(NS_GET_IID(nsIMemory), (void**) result);
 362 }