Attachment #232317 for bug #133421

View Details Raw Unified Return to Bug 133421



2014-05-31  Anders Carlsson  <andersca@apple.com>

        Don't use std::mutex::try_lock to check if we own a mutex
        https://bugs.webkit.org/show_bug.cgi?id=133421

        Reviewed by NOBODY (OOPS!).

        According the C++ standard, calling try_lock on a mutex that's already owned by the current thread
        is undefined behavior, so don't do that.

        * Modules/webdatabase/DatabaseBackendBase.cpp:
        (WebCore::guidToVersionMap):
        (WebCore::updateGuidVersionMap):
        (WebCore::guidToDatabaseMap):
        (WebCore::guidForOriginAndName):

2014-05-30  Enrica Casucci  <enrica@apple.com>

        REGRESSION (WebKit2): space space to insert period doesn't work in web forms.



typedef HashMap<DatabaseGuid, String> GuidVersionMap;
static GuidVersionMap& guidToVersionMap()
{
    // Ensure the the mutex is locked.
    ASSERT(!guidMutex().try_lock());

    static NeverDestroyed<GuidVersionMap> map;
    return map;
}

// NOTE: Caller must lock guidMutex().
static inline void updateGuidVersionMap(DatabaseGuid guid, String newVersion)
{
    // Ensure the the mutex is locked.
    ASSERT(!guidMutex().try_lock());

    // Note: It is not safe to put an empty string into the guidToVersionMap() map.
    // That's because the map is cross-thread, but empty strings are per-thread.
    // The copy() function makes a version of the string you can use on the current


static GuidDatabaseMap& guidToDatabaseMap()
{
    // Ensure the the mutex is locked.
    ASSERT(!guidMutex().try_lock());

    static NeverDestroyed<GuidDatabaseMap> map;
    return map;
}

static DatabaseGuid guidForOriginAndName(const String& origin, const String& name)
{
    // Ensure the the mutex is locked.
    ASSERT(!guidMutex().try_lock());

    String stringID = origin + "/" + name;

    typedef HashMap<String, int> IDGuidMap;

Return to Bug 133421

Lines 153-161 static std::mutex& guidMutex() a/Source/WebCore/Modules/webdatabase/DatabaseBackendBase.cpp_sec1
- a/Source/WebCore/Modules/webdatabase/DatabaseBackendBase.cpp -12 lines
153	typedef HashMap<DatabaseGuid, String> GuidVersionMap;	153	typedef HashMap<DatabaseGuid, String> GuidVersionMap;
154	static GuidVersionMap& guidToVersionMap()	154	static GuidVersionMap& guidToVersionMap()
155	{	155	{
156	// Ensure the the mutex is locked.
157	ASSERT(!guidMutex().try_lock());
158
159	static NeverDestroyed<GuidVersionMap> map;	156	static NeverDestroyed<GuidVersionMap> map;
160	return map;	157	return map;
161	}	158	}
Lines 163-171 static GuidVersionMap& guidToVersionMap() a/Source/WebCore/Modules/webdatabase/DatabaseBackendBase.cpp_sec2
163	// NOTE: Caller must lock guidMutex().	160	// NOTE: Caller must lock guidMutex().
164	static inline void updateGuidVersionMap(DatabaseGuid guid, String newVersion)	161	static inline void updateGuidVersionMap(DatabaseGuid guid, String newVersion)
165	{	162	{
166	// Ensure the the mutex is locked.
167	ASSERT(!guidMutex().try_lock());
168
169	// Note: It is not safe to put an empty string into the guidToVersionMap() map.	163	// Note: It is not safe to put an empty string into the guidToVersionMap() map.
170	// That's because the map is cross-thread, but empty strings are per-thread.	164	// That's because the map is cross-thread, but empty strings are per-thread.
171	// The copy() function makes a version of the string you can use on the current	165	// The copy() function makes a version of the string you can use on the current
Lines 180-197 typedef HashMap<DatabaseGuid, std::unique_ptr<HashSet<DatabaseBackendBase*>>> Gu a/Source/WebCore/Modules/webdatabase/DatabaseBackendBase.cpp_sec3
180		174
181	static GuidDatabaseMap& guidToDatabaseMap()	175	static GuidDatabaseMap& guidToDatabaseMap()
182	{	176	{
183	// Ensure the the mutex is locked.
184	ASSERT(!guidMutex().try_lock());
185
186	static NeverDestroyed<GuidDatabaseMap> map;	177	static NeverDestroyed<GuidDatabaseMap> map;
187	return map;	178	return map;
188	}	179	}
189		180
190	static DatabaseGuid guidForOriginAndName(const String& origin, const String& name)	181	static DatabaseGuid guidForOriginAndName(const String& origin, const String& name)
191	{	182	{
192	// Ensure the the mutex is locked.
193	ASSERT(!guidMutex().try_lock());
194
195	String stringID = origin + "/" + name;	183	String stringID = origin + "/" + name;
196		184
197	typedef HashMap<String, int> IDGuidMap;	185	typedef HashMap<String, int> IDGuidMap;

Lines 1-3 a/Source/WebCore/ChangeLog_sec1
- a/Source/WebCore/ChangeLog +16 lines
		1	2014-05-31 Anders Carlsson <andersca@apple.com>
		2
		3	Don't use std::mutex::try_lock to check if we own a mutex
		4	https://bugs.webkit.org/show_bug.cgi?id=133421
		5
		6	Reviewed by NOBODY (OOPS!).
		7
		8	According the C++ standard, calling try_lock on a mutex that's already owned by the current thread
		9	is undefined behavior, so don't do that.
		10
		11	* Modules/webdatabase/DatabaseBackendBase.cpp:
		12	(WebCore::guidToVersionMap):
		13	(WebCore::updateGuidVersionMap):
		14	(WebCore::guidToDatabaseMap):
		15	(WebCore::guidForOriginAndName):
		16
1	2014-05-30 Enrica Casucci <enrica@apple.com>	17	2014-05-30 Enrica Casucci <enrica@apple.com>
2		18
3	REGRESSION (WebKit2): space space to insert period doesn't work in web forms.	19	REGRESSION (WebKit2): space space to insert period doesn't work in web forms.