DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (a81015259a98)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: sw=4 ts=4 et :
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Mozilla Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2009
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Chris Jones <jones.chris.g@gmail.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/**
 * Note: This file is a copy of xpcom/tests/TestDeadlockDetector.cpp, but all
 *       mutexes were turned into SQLiteMutexes.
 */

#include "prenv.h"
#include "prerror.h"
#include "prio.h"
#include "prproces.h"

#include "nsMemory.h"

#include "mozilla/CondVar.h"
#include "mozilla/ReentrantMonitor.h"
#include "SQLiteMutex.h"

#include "TestHarness.h"

using namespace mozilla;

/**
 * Helper class to allocate a sqlite3_mutex for our SQLiteMutex.  Also makes
 * keeping the test files in sync easier.
 */
class TestMutex : public mozilla::storage::SQLiteMutex
{
public:
    TestMutex(const char* aName)
    : mozilla::storage::SQLiteMutex(aName)
    , mInner(sqlite3_mutex_alloc(SQLITE_MUTEX_FAST))
    {
        NS_ASSERTION(mInner, "could not allocate a sqlite3_mutex");
        initWithMutex(mInner);
    }

    ~TestMutex()
    {
        sqlite3_mutex_free(mInner);
    }

    void Lock()
    {
        lock();
    }

    void Unlock()
    {
        unlock();
    }
private:
  sqlite3_mutex *mInner;
};

static PRThread*
spawn(void (*run)(void*), void* arg)
{
    return PR_CreateThread(PR_SYSTEM_THREAD,
                           run,
                           arg,
                           PR_PRIORITY_NORMAL,
                           PR_GLOBAL_THREAD,
                           PR_JOINABLE_THREAD,
                           0);
}

#define PASS()                                  \
    do {                                        \
        passed(__FUNCTION__);                   \
        return NS_OK;                           \
    } while (0)

#define FAIL(why)                               \
    do {                                        \
        fail("%s | %s - %s", __FILE__, __FUNCTION__, why); \
        return NS_ERROR_FAILURE;                \
    } while (0)

//-----------------------------------------------------------------------------

static const char* sPathToThisBinary;
static const char* sAssertBehaviorEnv = "XPCOM_DEBUG_BREAK=abort";

class Subprocess
{
public:
    // not available until process finishes
    PRInt32 mExitCode;
    nsCString mStdout;
    nsCString mStderr;

    Subprocess(const char* aTestName) {
        // set up stdio redirection
        PRFileDesc* readStdin;  PRFileDesc* writeStdin;
        PRFileDesc* readStdout; PRFileDesc* writeStdout;
        PRFileDesc* readStderr; PRFileDesc* writeStderr;
        PRProcessAttr* pattr = PR_NewProcessAttr();

        NS_ASSERTION(pattr, "couldn't allocate process attrs");

        NS_ASSERTION(PR_SUCCESS == PR_CreatePipe(&readStdin, &writeStdin),
                     "couldn't create child stdin pipe");
        NS_ASSERTION(PR_SUCCESS == PR_SetFDInheritable(readStdin, true),
                     "couldn't set child stdin inheritable");
        PR_ProcessAttrSetStdioRedirect(pattr, PR_StandardInput, readStdin);

        NS_ASSERTION(PR_SUCCESS == PR_CreatePipe(&readStdout, &writeStdout),
                     "couldn't create child stdout pipe");
        NS_ASSERTION(PR_SUCCESS == PR_SetFDInheritable(writeStdout, true),
                     "couldn't set child stdout inheritable");
        PR_ProcessAttrSetStdioRedirect(pattr, PR_StandardOutput, writeStdout);

        NS_ASSERTION(PR_SUCCESS == PR_CreatePipe(&readStderr, &writeStderr),
                     "couldn't create child stderr pipe");
        NS_ASSERTION(PR_SUCCESS == PR_SetFDInheritable(writeStderr, true),
                     "couldn't set child stderr inheritable");
        PR_ProcessAttrSetStdioRedirect(pattr, PR_StandardError, writeStderr);

        // set up argv with test name to run
        char* const newArgv[3] = {
            strdup(sPathToThisBinary),
            strdup(aTestName),
            0
        };

        // make sure the child will abort if an assertion fails
        NS_ASSERTION(PR_SUCCESS == PR_SetEnv(sAssertBehaviorEnv),
                     "couldn't set XPCOM_DEBUG_BREAK env var");

        PRProcess* proc;
        NS_ASSERTION(proc = PR_CreateProcess(sPathToThisBinary,
                                             newArgv,
                                             0, // inherit environment
                                             pattr),
                     "couldn't create process");
        PR_Close(readStdin);
        PR_Close(writeStdout);
        PR_Close(writeStderr);

        mProc = proc;
        mStdinfd = writeStdin;
        mStdoutfd = readStdout;
        mStderrfd = readStderr;

        free(newArgv[0]);
        free(newArgv[1]);
        PR_DestroyProcessAttr(pattr);
    }

    void RunToCompletion(PRUint32 aWaitMs)
    {
        PR_Close(mStdinfd);

        PRPollDesc pollfds[2];
        PRInt32 nfds;
        bool stdoutOpen = true, stderrOpen = true;
        char buf[4096];
        PRInt32 len;

        PRIntervalTime now = PR_IntervalNow();
        PRIntervalTime deadline = now + PR_MillisecondsToInterval(aWaitMs);

        while ((stdoutOpen || stderrOpen) && now < deadline) {
            nfds = 0;
            if (stdoutOpen) {
                pollfds[nfds].fd = mStdoutfd;
                pollfds[nfds].in_flags = PR_POLL_READ;
                pollfds[nfds].out_flags = 0;
                ++nfds;
            }
            if (stderrOpen) {
                pollfds[nfds].fd = mStderrfd;
                pollfds[nfds].in_flags = PR_POLL_READ;
                pollfds[nfds].out_flags = 0;
                ++nfds;
            }

            PRInt32 rv = PR_Poll(pollfds, nfds, deadline - now);
            NS_ASSERTION(0 <= rv, PR_ErrorToName(PR_GetError()));

            if (0 == rv) {      // timeout
                fputs("(timed out!)\n", stderr);
                Finish(false); // abnormal
                return;
            }

            for (PRInt32 i = 0; i < nfds; ++i) {
                if (!pollfds[i].out_flags)
                    continue;

                bool isStdout = mStdoutfd == pollfds[i].fd;
                
                if (PR_POLL_READ & pollfds[i].out_flags) {
                    len = PR_Read(pollfds[i].fd, buf, sizeof(buf) - 1);
                    NS_ASSERTION(0 <= len, PR_ErrorToName(PR_GetError()));
                }
                else if (PR_POLL_HUP & pollfds[i].out_flags) {
                    len = 0;
                }
                else {
                    NS_ERROR(PR_ErrorToName(PR_GetError()));
                }

                if (0 < len) {
                    buf[len] = '\0';
                    if (isStdout)
                        mStdout += buf;
                    else
                        mStderr += buf;
                }
                else if (isStdout) {
                    stdoutOpen = false;
                }
                else {
                    stderrOpen = false;
                }
            }

            now = PR_IntervalNow();
        }

        if (stdoutOpen)
            fputs("(stdout still open!)\n", stderr);
        if (stderrOpen)
            fputs("(stderr still open!)\n", stderr);
        if (now > deadline)
            fputs("(timed out!)\n", stderr);

        Finish(!stdoutOpen && !stderrOpen && now <= deadline);
    }

private:
    void Finish(bool normalExit) {
        if (!normalExit) {
            PR_KillProcess(mProc);
            mExitCode = -1;
            PRInt32 dummy;
            PR_WaitProcess(mProc, &dummy);
        }
        else {
            PR_WaitProcess(mProc, &mExitCode); // this had better not block ...
        }

        PR_Close(mStdoutfd);
        PR_Close(mStderrfd);
    }

    PRProcess* mProc;
    PRFileDesc* mStdinfd;         // writeable
    PRFileDesc* mStdoutfd;        // readable
    PRFileDesc* mStderrfd;        // readable
};

//-----------------------------------------------------------------------------
// Harness for checking detector errors
bool
CheckForDeadlock(const char* test, const char* const* findTokens)
{
    Subprocess proc(test);
    proc.RunToCompletion(5000);

    if (0 == proc.mExitCode)
        return false;

    PRInt32 idx = 0;
    for (const char* const* tp = findTokens; *tp; ++tp) {
        const char* const token = *tp;
#ifdef MOZILLA_INTERNAL_API
        idx = proc.mStderr.Find(token, false, idx);
#else
        nsCString tokenCString(token);
        idx = proc.mStderr.Find(tokenCString, idx);
#endif
        if (-1 == idx) {
            printf("(missed token '%s' in output)\n", token);
            puts("----------------------------------\n");
            puts(proc.mStderr.get());
            puts("----------------------------------\n");
            return false;
        }
        idx += strlen(token);
    }

    return true;
}

//-----------------------------------------------------------------------------
// Single-threaded sanity tests

// Stupidest possible deadlock.
nsresult
Sanity_Child()
{
    TestMutex m1("dd.sanity.m1");
    m1.Lock();
    m1.Lock();
    return 0;                  // not reached
}

nsresult
Sanity()
{
    const char* const tokens[] = {
        "###!!! ERROR: Potential deadlock detected",
        "=== Cyclical dependency starts at\n--- Mutex : dd.sanity.m1",
        "=== Cycle completed at\n--- Mutex : dd.sanity.m1",
        "###!!! Deadlock may happen NOW!", // better catch these easy cases...
        "###!!! ASSERTION: Potential deadlock detected",
        0
    };
    if (CheckForDeadlock("Sanity", tokens)) {
        PASS();
    } else {
        FAIL("deadlock not detected");
    }
}

// Slightly less stupid deadlock.
nsresult
Sanity2_Child()
{
    TestMutex m1("dd.sanity2.m1");
    TestMutex m2("dd.sanity2.m2");
    m1.Lock();
    m2.Lock();
    m1.Lock();
    return 0;                  // not reached
}

nsresult
Sanity2()
{
    const char* const tokens[] = {
        "###!!! ERROR: Potential deadlock detected",
        "=== Cyclical dependency starts at\n--- Mutex : dd.sanity2.m1",
        "--- Next dependency:\n--- Mutex : dd.sanity2.m2",
        "=== Cycle completed at\n--- Mutex : dd.sanity2.m1",
        "###!!! Deadlock may happen NOW!", // better catch these easy cases...
        "###!!! ASSERTION: Potential deadlock detected",
        0
    };
    if (CheckForDeadlock("Sanity2", tokens)) {
        PASS();
    } else {
        FAIL("deadlock not detected");
    }
}


nsresult
Sanity3_Child()
{
    TestMutex m1("dd.sanity3.m1");
    TestMutex m2("dd.sanity3.m2");
    TestMutex m3("dd.sanity3.m3");
    TestMutex m4("dd.sanity3.m4");

    m1.Lock();
    m2.Lock();
    m3.Lock();
    m4.Lock();
    m4.Unlock();
    m3.Unlock();
    m2.Unlock();
    m1.Unlock();

    m4.Lock();
    m1.Lock();
    return 0;
}

nsresult
Sanity3()
{
    const char* const tokens[] = {
        "###!!! ERROR: Potential deadlock detected",
        "=== Cyclical dependency starts at\n--- Mutex : dd.sanity3.m1",
        "--- Next dependency:\n--- Mutex : dd.sanity3.m2",
        "--- Next dependency:\n--- Mutex : dd.sanity3.m3",
        "--- Next dependency:\n--- Mutex : dd.sanity3.m4",
        "=== Cycle completed at\n--- Mutex : dd.sanity3.m1",
        "###!!! ASSERTION: Potential deadlock detected",
        0
    };
    if (CheckForDeadlock("Sanity3", tokens)) {
        PASS();
    } else {
        FAIL("deadlock not detected");
    }
}


nsresult
Sanity4_Child()
{
    mozilla::ReentrantMonitor m1("dd.sanity4.m1");
    TestMutex m2("dd.sanity4.m2");
    m1.Enter();
    m2.Lock();
    m1.Enter();
    return 0;
}

nsresult
Sanity4()
{
    const char* const tokens[] = {
        "Re-entering ReentrantMonitor after acquiring other resources",
        "###!!! ERROR: Potential deadlock detected",
        "=== Cyclical dependency starts at\n--- ReentrantMonitor : dd.sanity4.m1",
        "--- Next dependency:\n--- Mutex : dd.sanity4.m2",
        "=== Cycle completed at\n--- ReentrantMonitor : dd.sanity4.m1",
        "###!!! ASSERTION: Potential deadlock detected",
        0
    };
    if (CheckForDeadlock("Sanity4", tokens)) {
        PASS();
    } else {
        FAIL("deadlock not detected");
    }
}

//-----------------------------------------------------------------------------
// Multithreaded tests

TestMutex* ttM1;
TestMutex* ttM2;

static void
TwoThreads_thread(void* arg)
{
    PRInt32 m1First = NS_PTR_TO_INT32(arg);
    if (m1First) {
        ttM1->Lock();
        ttM2->Lock();
        ttM2->Unlock();
        ttM1->Unlock();
    }
    else {
        ttM2->Lock();
        ttM1->Lock();
        ttM1->Unlock();
        ttM2->Unlock();
    }
}

nsresult
TwoThreads_Child()
{
    ttM1 = new TestMutex("dd.twothreads.m1");
    ttM2 = new TestMutex("dd.twothreads.m2");
    if (!ttM1 || !ttM2)
        NS_RUNTIMEABORT("couldn't allocate mutexes");

    PRThread* t1 = spawn(TwoThreads_thread, (void*) 0);
    PR_JoinThread(t1);

    PRThread* t2 = spawn(TwoThreads_thread, (void*) 1);
    PR_JoinThread(t2);

    return 0;
}

nsresult
TwoThreads()
{
    const char* const tokens[] = {
        "###!!! ERROR: Potential deadlock detected",
        "=== Cyclical dependency starts at\n--- Mutex : dd.twothreads.m2",
        "--- Next dependency:\n--- Mutex : dd.twothreads.m1",
        "=== Cycle completed at\n--- Mutex : dd.twothreads.m2",
        "###!!! ASSERTION: Potential deadlock detected",
        0
    };

    if (CheckForDeadlock("TwoThreads", tokens)) {
        PASS();
    } else {
        FAIL("deadlock not detected");
    }
}


TestMutex* cndMs[4];
const PRUint32 K = 100000;

static void
ContentionNoDeadlock_thread(void* arg)
{
    PRInt32 starti = NS_PTR_TO_INT32(arg);

    for (PRUint32 k = 0; k < K; ++k) {
        for (PRInt32 i = starti; i < (PRInt32) ArrayLength(cndMs); ++i)
            cndMs[i]->Lock();
        // comment out the next two lines for deadlocking fun!
        for (PRInt32 i = ArrayLength(cndMs) - 1; i >= starti; --i)
            cndMs[i]->Unlock();

        starti = (starti + 1) % 3;
    }
}

nsresult
ContentionNoDeadlock_Child()
{
    PRThread* threads[3];

    for (PRUint32 i = 0; i < ArrayLength(cndMs); ++i)
        cndMs[i] = new TestMutex("dd.cnd.ms");

    for (PRInt32 i = 0; i < (PRInt32) ArrayLength(threads); ++i)
        threads[i] = spawn(ContentionNoDeadlock_thread, NS_INT32_TO_PTR(i));

    for (PRUint32 i = 0; i < ArrayLength(threads); ++i)
        PR_JoinThread(threads[i]);

    for (PRUint32 i = 0; i < ArrayLength(cndMs); ++i)
        delete cndMs[i];

    return 0;
}

nsresult
ContentionNoDeadlock()
{
    const char * func = __func__;
    Subprocess proc(func);
    proc.RunToCompletion(60000);
    if (0 != proc.mExitCode) {
        printf("(expected 0 == return code, got %d)\n", proc.mExitCode);
        puts("(output)\n----------------------------------\n");
        puts(proc.mStdout.get());
        puts("----------------------------------\n");
        puts("(error output)\n----------------------------------\n");
        puts(proc.mStderr.get());
        puts("----------------------------------\n");

        FAIL("deadlock");
    }
    PASS();
}



//-----------------------------------------------------------------------------

int
main(int argc, char** argv)
{
    if (1 < argc) {
        // XXX can we run w/o scoped XPCOM?
        const char* test = argv[1];
        ScopedXPCOM xpcom(test);
        if (xpcom.failed())
            return 1;

        // running in a spawned process.  call the specificed child function.
        if (!strcmp("Sanity", test))
            return Sanity_Child();
        if (!strcmp("Sanity2", test))
            return Sanity2_Child();
        if (!strcmp("Sanity3", test))
            return Sanity3_Child();
        if (!strcmp("Sanity4", test))
            return Sanity4_Child();

        if (!strcmp("TwoThreads", test))
            return TwoThreads_Child();
        if (!strcmp("ContentionNoDeadlock", test))
            return ContentionNoDeadlock_Child();

        FAIL("unknown child test");
    }

    ScopedXPCOM xpcom("Storage deadlock detector correctness (" __FILE__ ")");
    if (xpcom.failed())
        return 1;

    // in the first invocation of this process.  we will be the "driver".
    int rv = 0;

    sPathToThisBinary = argv[0];

    if (NS_FAILED(Sanity()))
        rv = 1;
    if (NS_FAILED(Sanity2()))
        rv = 1;
    if (NS_FAILED(Sanity3()))
        rv = 1;
    if (NS_FAILED(Sanity4()))
        rv = 1;

    if (NS_FAILED(TwoThreads()))
        rv = 1;
    if (NS_FAILED(ContentionNoDeadlock()))
        rv = 1;

    return rv;
}