xpcom/base/nsMemoryImpl.cpp

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