The Tor Browser: storage/test/test_deadlock_detector.cpp@97036ab72558 (annotated)

storage/test/test_deadlock_detector.cpp@97036ab72558 (annotated)

storage/test/test_deadlock_detector.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
  * vim: sw=4 ts=4 et :
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 /**
  * 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,
 );
 }
 #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
     int32_t 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),
 
         };
         // 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,
 , // 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(uint32_t aWaitMs)
     {
         PR_Close(mStdinfd);
         PRPollDesc pollfds[2];
         int32_t nfds;
         bool stdoutOpen = true, stderrOpen = true;
         char buf[4096];
         int32_t 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;
             }
             int32_t 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 (int32_t 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;
             int32_t 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;
     int32_t 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.
 int
 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",
 
     };
     if (CheckForDeadlock("Sanity", tokens)) {
         PASS();
     } else {
         FAIL("deadlock not detected");
     }
 }
 // Slightly less stupid deadlock.
 int
 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",
 
     };
     if (CheckForDeadlock("Sanity2", tokens)) {
         PASS();
     } else {
         FAIL("deadlock not detected");
     }
 }
 int
 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",
 
     };
     if (CheckForDeadlock("Sanity3", tokens)) {
         PASS();
     } else {
         FAIL("deadlock not detected");
     }
 }
 int
 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",
 
     };
     if (CheckForDeadlock("Sanity4", tokens)) {
         PASS();
     } else {
         FAIL("deadlock not detected");
     }
 }
 //-----------------------------------------------------------------------------
 // Multithreaded tests
 TestMutex* ttM1;
 TestMutex* ttM2;
 static void
 TwoThreads_thread(void* arg)
 {
     int32_t 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();
     }
 }
 int
 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",
 
     };
     if (CheckForDeadlock("TwoThreads", tokens)) {
         PASS();
     } else {
         FAIL("deadlock not detected");
     }
 }
 TestMutex* cndMs[4];
 const uint32_t K = 100000;
 static void
 ContentionNoDeadlock_thread(void* arg)
 {
     int32_t starti = NS_PTR_TO_INT32(arg);
     for (uint32_t k = 0; k < K; ++k) {
         for (int32_t i = starti; i < (int32_t) ArrayLength(cndMs); ++i)
             cndMs[i]->Lock();
         // comment out the next two lines for deadlocking fun!
         for (int32_t i = ArrayLength(cndMs) - 1; i >= starti; --i)
             cndMs[i]->Unlock();
         starti = (starti + 1) % 3;
     }
 }
 int
 ContentionNoDeadlock_Child()
 {
     PRThread* threads[3];
     for (uint32_t i = 0; i < ArrayLength(cndMs); ++i)
         cndMs[i] = new TestMutex("dd.cnd.ms");
     for (int32_t i = 0; i < (int32_t) ArrayLength(threads); ++i)
         threads[i] = spawn(ContentionNoDeadlock_thread, NS_INT32_TO_PTR(i));
     for (uint32_t i = 0; i < ArrayLength(threads); ++i)
         PR_JoinThread(threads[i]);
     for (uint32_t 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("%s | %s - unknown child test", __FILE__, __FUNCTION__);
         return 1;
     }
     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;
 }

The Tor Browser / annotate

storage/test/test_deadlock_detector.cpp@97036ab72558 (annotated)

storage/test/test_deadlock_detector.cpp