diff options
author | Andy Schwerin <schwerin@10gen.com> | 2013-07-12 18:05:35 -0400 |
---|---|---|
committer | Andy Schwerin <schwerin@10gen.com> | 2013-07-12 18:08:19 -0400 |
commit | 6e3ccc5649d16fd9940bc8fd1b490556d5767bf8 (patch) | |
tree | 6485289521af46ae932edb12a54c39737bea03f4 /src/mongo | |
parent | 15333b2a308fd26c28448810780b06407328a795 (diff) | |
download | mongo-6e3ccc5649d16fd9940bc8fd1b490556d5767bf8.tar.gz |
SERVER-10172 Refactor RamLog to make it thread-safe.
Also prevent accidental creation of duplicate ramlogs of the same name.
Diffstat (limited to 'src/mongo')
-rw-r--r-- | src/mongo/db/commands/server_status.cpp | 18 | ||||
-rw-r--r-- | src/mongo/db/db.cpp | 4 | ||||
-rw-r--r-- | src/mongo/db/dbcommands_generic.cpp | 14 | ||||
-rw-r--r-- | src/mongo/db/dbwebserver.cpp | 14 | ||||
-rw-r--r-- | src/mongo/db/initialize_server_global_state.cpp | 5 | ||||
-rw-r--r-- | src/mongo/db/repl/health.cpp | 2 | ||||
-rw-r--r-- | src/mongo/logger/ramlog.cpp | 108 | ||||
-rw-r--r-- | src/mongo/logger/ramlog.h | 105 | ||||
-rw-r--r-- | src/mongo/s/d_migrate.cpp | 4 | ||||
-rw-r--r-- | src/mongo/s/server.cpp | 3 | ||||
-rw-r--r-- | src/mongo/util/log.cpp | 4 |
11 files changed, 189 insertions, 92 deletions
diff --git a/src/mongo/db/commands/server_status.cpp b/src/mongo/db/commands/server_status.cpp index 689dac9aac2..2059ddeb551 100644 --- a/src/mongo/db/commands/server_status.cpp +++ b/src/mongo/db/commands/server_status.cpp @@ -141,20 +141,16 @@ namespace mongo { // --- some hard coded global things hard to pull out { - RamLog* rl = RamLog::get( "warnings" ); - massert(15880, "no ram log for warnings?" , rl); - - if (rl->lastWrite() >= time(0)-(10*60)){ // only show warnings from last 10 minutes - vector<const char*> lines; - rl->get( lines ); - - BSONArrayBuilder arr( result.subarrayStart( "warnings" ) ); - for ( unsigned i=std::max(0,(int)lines.size()-10); i<lines.size(); i++ ) - arr.append( lines[i] ); + RamLog::LineIterator rl(RamLog::get("warnings")); + if (rl.lastWrite() >= time(0)-(10*60)){ // only show warnings from last 10 minutes + BSONArrayBuilder arr(result.subarrayStart("warnings")); + while (rl.more()) { + arr.append(rl.next()); + } arr.done(); } } - + timeBuilder.appendNumber( "at end" , Listener::getElapsedTimeMillis() - start ); if ( Listener::getElapsedTimeMillis() - start > 1000 ) { BSONObj t = timeBuilder.obj(); diff --git a/src/mongo/db/db.cpp b/src/mongo/db/db.cpp index 448b631dec0..8bd7efb37fb 100644 --- a/src/mongo/db/db.cpp +++ b/src/mongo/db/db.cpp @@ -581,10 +581,6 @@ namespace mongo { Client::initThread("initandlisten"); - logger::globalLogDomain()->attachAppender( - logger::MessageLogDomain::AppenderAutoPtr( - new RamLogAppender(new RamLog("global")))); - bool is32bit = sizeof(int*) == 4; { diff --git a/src/mongo/db/dbcommands_generic.cpp b/src/mongo/db/dbcommands_generic.cpp index 1a78890a971..22666d7a5c5 100644 --- a/src/mongo/db/dbcommands_generic.cpp +++ b/src/mongo/db/dbcommands_generic.cpp @@ -354,20 +354,18 @@ namespace mongo { result.appendArray( "names" , arr.arr() ); } else { - RamLog* rl = RamLog::get( p ); - if ( ! rl ) { + RamLog* ramlog = RamLog::getIfExists(p); + if ( ! ramlog ) { errmsg = str::stream() << "no RamLog named: " << p; return false; } + RamLog::LineIterator rl(ramlog); - result.appendNumber( "totalLinesWritten", rl->getTotalLinesWritten() ); - - vector<const char*> lines; - rl->get( lines ); + result.appendNumber( "totalLinesWritten", rl.getTotalLinesWritten() ); BSONArrayBuilder arr( result.subarrayStart( "log" ) ); - for ( unsigned i=0; i<lines.size(); i++ ) - arr.append( lines[i] ); + while (rl.more()) + arr.append(rl.next()); arr.done(); } return true; diff --git a/src/mongo/db/dbwebserver.cpp b/src/mongo/db/dbwebserver.cpp index 4754d2a57ad..506945575fe 100644 --- a/src/mongo/db/dbwebserver.cpp +++ b/src/mongo/db/dbwebserver.cpp @@ -324,21 +324,15 @@ namespace mongo { vector<WebStatusPlugin*> * WebStatusPlugin::_plugins = 0; - // -- basic statuc plugins -- + // -- basic status plugins -- class LogPlugin : public WebStatusPlugin { public: LogPlugin() : WebStatusPlugin( "Log" , 100 ), _log(0) { _log = RamLog::get( "global" ); - if ( ! _log ) { - _log = new RamLog("global"); - logger::globalLogDomain()->attachAppender(logger::MessageLogDomain::AppenderAutoPtr( - new RamLogAppender(_log))); - } } - virtual void init() { - } + virtual void init() {} virtual void run( stringstream& ss ) { _log->toHTML( ss ); @@ -346,9 +340,7 @@ namespace mongo { RamLog * _log; }; - MONGO_INITIALIZER_GENERAL(WebStatusLogPlugin, ("ServerLogRedirection"), ("default"))( - InitializerContext*) { - + MONGO_INITIALIZER(WebStatusLogPlugin)(InitializerContext*) { if (cmdLine.isHttpInterfaceEnabled) { new LogPlugin; } diff --git a/src/mongo/db/initialize_server_global_state.cpp b/src/mongo/db/initialize_server_global_state.cpp index 084109d11b7..71798bcc238 100644 --- a/src/mongo/db/initialize_server_global_state.cpp +++ b/src/mongo/db/initialize_server_global_state.cpp @@ -35,6 +35,7 @@ #include "mongo/logger/logger.h" #include "mongo/logger/message_event.h" #include "mongo/logger/message_event_utf8_encoder.h" +#include "mongo/logger/ramlog.h" #include "mongo/logger/rotatable_file_appender.h" #include "mongo/logger/rotatable_file_manager.h" #include "mongo/logger/rotatable_file_writer.h" @@ -264,6 +265,10 @@ namespace mongo { } } + logger::globalLogDomain()->attachAppender( + logger::MessageLogDomain::AppenderAutoPtr( + new RamLogAppender(RamLog::get("global")))); + return Status::OK(); } diff --git a/src/mongo/db/repl/health.cpp b/src/mongo/db/repl/health.cpp index 3a2681128f8..7dd9f528d27 100644 --- a/src/mongo/db/repl/health.cpp +++ b/src/mongo/db/repl/health.cpp @@ -46,7 +46,7 @@ namespace mongo { using namespace mongoutils::html; using namespace bson; - static RamLog * _rsLog = new RamLog( "rs" ); + static RamLog * _rsLog = RamLog::get("rs"); Tee *rsLog = _rsLog; extern bool replSetBlind; // for testing diff --git a/src/mongo/logger/ramlog.cpp b/src/mongo/logger/ramlog.cpp index 6bb8e9df40d..d2a5f507e76 100644 --- a/src/mongo/logger/ramlog.cpp +++ b/src/mongo/logger/ramlog.cpp @@ -19,43 +19,39 @@ #include "mongo/logger/ramlog.h" +#include "mongo/base/init.h" +#include "mongo/base/status.h" #include "mongo/logger/message_event_utf8_encoder.h" #include "mongo/util/mongoutils/html.h" +#include "mongo/util/map_util.h" #include "mongo/util/mongoutils/str.h" namespace mongo { +namespace { + typedef std::map<string,RamLog*> RM; + mongo::mutex* _namedLock = NULL; + RM* _named = NULL; + +} // namespace using namespace mongoutils; RamLog::RamLog( const std::string& name ) : _name(name), _totalLinesWritten(0), _lastWrite(0) { - h = 0; n = 0; + h = 0; + n = 0; for( int i = 0; i < N; i++ ) lines[i][C-1] = 0; - - if ( name.size() ) { - - if ( ! _namedLock ) - _namedLock = new mongo::mutex("RamLog::_namedLock"); - - scoped_lock lk( *_namedLock ); - if ( ! _named ) - _named = new RM(); - (*_named)[name] = this; - } - } - RamLog::~RamLog() { - - } + RamLog::~RamLog() {} void RamLog::write(const std::string& str) { - boost::unique_lock<boost::mutex> lk(_mutex); + boost::lock_guard<boost::mutex> lk(_mutex); _lastWrite = time(0); _totalLinesWritten++; char *p = lines[(h+n)%N]; - + unsigned sz = str.size(); if (0 == sz) return; if( sz < C ) { @@ -74,20 +70,18 @@ namespace mongo { else h = (h+1) % N; } - time_t RamLog::lastWrite() { - boost::unique_lock<boost::mutex> lk(_mutex); - return _lastWrite; + time_t RamLog::LineIterator::lastWrite() { + return _ramlog->_lastWrite; } - long long RamLog::getTotalLinesWritten() { - boost::unique_lock<boost::mutex> lk(_mutex); - return _totalLinesWritten; + long long RamLog::LineIterator::getTotalLinesWritten() { + return _ramlog->_totalLinesWritten; } - void RamLog::get( std::vector<const char*>& v) { - boost::unique_lock<boost::mutex> lk(_mutex); - for( unsigned x=0, i=h; x++ < n; i=(i+1)%N ) - v.push_back(lines[i]); + const char* RamLog::getLine_inlock(unsigned lineNumber) const { + if (lineNumber >= n) + return ""; + return lines[(lineNumber + h) % N]; // h = 0 unless n == N, hence modulo N. } int RamLog::repeats(const std::vector<const char *>& v, int i) { @@ -143,8 +137,10 @@ namespace mongo { } void RamLog::toHTML(std::stringstream& s) { + LineIterator iter(this); std::vector<const char*> v; - get( v ); + while (iter.more()) + v.push_back(iter.next()); s << "<pre>\n"; for( int i = 0; i < (int)v.size(); i++ ) { @@ -173,6 +169,12 @@ namespace mongo { s << "</pre>\n"; } + RamLog::LineIterator::LineIterator(RamLog* ramlog) : + _ramlog(ramlog), + _lock(ramlog->_mutex), + _nextLineIndex(0) { + } + RamLogAppender::RamLogAppender(RamLog* ramlog) : _ramlog(ramlog) {} RamLogAppender::~RamLogAppender() {} @@ -188,15 +190,31 @@ namespace mongo { // static things // --------------- - RamLog* RamLog::get( const std::string& name ) { - if ( ! _named ) - return 0; + RamLog* RamLog::get(const std::string& name) { + if (!_namedLock) { + // Guaranteed to happen before multi-threaded operation. + _namedLock = new mongo::mutex("RamLog::_namedLock"); + } scoped_lock lk( *_namedLock ); - RM::iterator i = _named->find( name ); - if ( i == _named->end() ) - return 0; - return i->second; + if (!_named) { + // Guaranteed to happen before multi-threaded operation. + _named = new RM(); + } + + RamLog* result = mapFindWithDefault(*_named, name, static_cast<RamLog*>(NULL)); + if (!result) { + result = new RamLog(name); + (*_named)[name] = result; + } + return result; + } + + RamLog* RamLog::getIfExists(const std::string& name) { + if (!_named) + return NULL; + scoped_lock lk(*_namedLock); + return mapFindWithDefault(*_named, name, static_cast<RamLog*>(NULL)); } void RamLog::getNames( std::vector<string>& names ) { @@ -210,6 +228,20 @@ namespace mongo { } } - mongo::mutex* RamLog::_namedLock; - RamLog::RM* RamLog::_named = 0; + /** + * Ensures that RamLog::get() is called at least once during single-threaded operation, + * ensuring that _namedLock and _named are initialized safely. + */ + MONGO_INITIALIZER(RamLogCatalog)(InitializerContext*) { + if (!_namedLock) { + if (_named) { + return Status(ErrorCodes::InternalError, + "Inconsistent intiailization of RamLogCatalog."); + } + _namedLock = new mongo::mutex("RamLog::_namedLock"); + _named = new RM(); + } + + return Status::OK(); + } } diff --git a/src/mongo/logger/ramlog.h b/src/mongo/logger/ramlog.h index 2b78d91daaa..16263055c38 100644 --- a/src/mongo/logger/ramlog.h +++ b/src/mongo/logger/ramlog.h @@ -17,7 +17,6 @@ #pragma once -#include <map> #include <sstream> #include <string> #include <vector> @@ -32,23 +31,61 @@ namespace mongo { + /** + * Fixed-capacity log of line-oriented messages. + * + * Holds up to RamLog::N lines of up to RamLog::C bytes, each. + * + * RamLogs are stored in a global registry, accessed via RamLog::get() and + * RamLog::getIfExists(). + * + * RamLogs and their registry are self-synchronizing. See documentary comments. + * To read a RamLog, instantiate a RamLog::LineIterator, documented below. + */ class RamLog : public logger::Tee { MONGO_DISALLOW_COPYING(RamLog); public: - RamLog( const std::string& name ); + class LineIterator; + friend class RamLog::LineIterator; + + /** + * Returns a pointer to the ramlog named "name", creating one if it did not already exist. + * + * Synchronizes on the RamLog catalog lock, _namedLock. + */ + static RamLog* get(const std::string& name); + + /** + * Returns a pointer to the ramlog named "name", or NULL if no such ramlog exists. + * + * Synchronizes on the RamLog catalog lock, _namedLock. + */ + static RamLog* getIfExists(const std::string& name); + + /** + * Writes the names of all existing ramlogs into "names". + * + * Synchronizes on the RamLog catalog lock, _namedLock. + */ + static void getNames( std::vector<std::string>& names ); + /** + * Writes "str" as a line into the RamLog. If "str" is longer than the maximum + * line size, RamLog::C, truncates the line to the first C bytes. If "str" + * is shorter than RamLog::C and has a terminal '\n', it omits that character. + * + * Synchronized on the instance's own mutex, _mutex. + */ void write(const std::string& str); - void get( std::vector<const char*>& v); + /** + * Writes an HTML representation of the log to "s". + * + * Synchronized on the instance's own mutex, _mutex. + */ void toHTML(std::stringstream& s); - static RamLog* get( const std::string& name ); - static void getNames( std::vector<std::string>& names ); - - time_t lastWrite(); - long long getTotalLinesWritten(); - private: static int repeats(const std::vector<const char *>& v, int i); static string clean(const std::vector<const char *>& v, int i, string line=""); @@ -57,6 +94,7 @@ namespace mongo { /* turn http:... into an anchor */ static string linkify(const char *s); + explicit RamLog( const std::string& name ); ~RamLog(); // want this private as we want to leak so we can use them till the very end enum { @@ -64,6 +102,8 @@ namespace mongo { C = 512 // max size of line }; + const char* getLine_inlock(unsigned lineNumber) const; + boost::mutex _mutex; // Guards all non-static data. char lines[N][C]; unsigned h; // current position @@ -71,12 +111,53 @@ namespace mongo { string _name; long long _totalLinesWritten; - typedef std::map<string,RamLog*> RM; - static mongo::mutex* _namedLock; - static RM* _named; time_t _lastWrite; }; + /** + * Iterator over the lines of a RamLog. + * + * Also acts as a means of inspecting other properites of a ramlog consistently. + * + * Instances of LineIterator hold the lock for the underlying RamLog for their whole lifetime, + * and so should not be kept around. + */ + class RamLog::LineIterator { + MONGO_DISALLOW_COPYING(LineIterator); + public: + explicit LineIterator(RamLog* ramlog); + + /** + * Returns true if there are more lines available to return by calls to next(). + */ + bool more() const { return _nextLineIndex < _ramlog->n; } + + /** + * Returns the next line and advances the iterator. + */ + const char* next() { + return _ramlog->getLine_inlock(_nextLineIndex++); // Postfix increment. + } + + /** + * Returns the time of the last write to the ramlog. + */ + time_t lastWrite(); + + /** + * Returns the total number of lines ever written to the ramlog. + */ + long long getTotalLinesWritten(); + + private: + const RamLog* _ramlog; + boost::lock_guard<boost::mutex> _lock; + unsigned _nextLineIndex; + }; + + /** + * Appender for appending MessageEvents to a RamLog. + */ class RamLogAppender : public logger::Appender<logger::MessageEventEphemeral> { public: explicit RamLogAppender(RamLog* ramlog); diff --git a/src/mongo/s/d_migrate.cpp b/src/mongo/s/d_migrate.cpp index 27b238c921c..04122d23008 100644 --- a/src/mongo/s/d_migrate.cpp +++ b/src/mongo/s/d_migrate.cpp @@ -54,6 +54,7 @@ #include "mongo/db/repl/rs.h" #include "mongo/db/repl/rs_config.h" #include "mongo/db/repl/write_concern.h" +#include "mongo/logger/ramlog.h" #include "mongo/s/chunk.h" #include "mongo/s/chunk_version.h" #include "mongo/s/config.h" @@ -64,14 +65,13 @@ #include "mongo/util/elapsed_tracker.h" #include "mongo/util/processinfo.h" #include "mongo/util/queue.h" -#include "mongo/util/ramlog.h" #include "mongo/util/startup_test.h" using namespace std; namespace mongo { - Tee* migrateLog = new RamLog( "migrate" ); + Tee* migrateLog = RamLog::get("migrate"); class MoveTimingHelper { public: diff --git a/src/mongo/s/server.cpp b/src/mongo/s/server.cpp index 1d90c204ac1..58995b63055 100644 --- a/src/mongo/s/server.cpp +++ b/src/mongo/s/server.cpp @@ -228,9 +228,6 @@ namespace mongo { void init() { serverID.init(); - - logger::globalLogDomain()->attachAppender( - logger::MessageLogDomain::AppenderAutoPtr(new RamLogAppender(new RamLog("global")))); } void start( const MessageServer::Options& opts ) { diff --git a/src/mongo/util/log.cpp b/src/mongo/util/log.cpp index 34421f3aecb..b778b8cc006 100644 --- a/src/mongo/util/log.cpp +++ b/src/mongo/util/log.cpp @@ -137,7 +137,7 @@ namespace mongo { LogIndentLevel::~LogIndentLevel() { } - Tee* const warnings = new RamLog("warnings"); // Things put here go in serverStatus - Tee* const startupWarningsLog = new RamLog("startupWarnings"); // intentionally leaked + Tee* const warnings = RamLog::get("warnings"); // Things put here go in serverStatus + Tee* const startupWarningsLog = RamLog::get("startupWarnings"); // intentionally leaked } // namespace mongo |