diff options
| -rw-r--r-- | src/corelib/tools/qregularexpression.cpp | 31 |
1 files changed, 24 insertions, 7 deletions
diff --git a/src/corelib/tools/qregularexpression.cpp b/src/corelib/tools/qregularexpression.cpp index 7faa907e35..0252a30c89 100644 --- a/src/corelib/tools/qregularexpression.cpp +++ b/src/corelib/tools/qregularexpression.cpp @@ -773,7 +773,7 @@ struct QRegularExpressionPrivate : QSharedData void cleanCompiledPattern(); void compilePattern(); void getPatternInfo(); - void optimizePattern(); + pcre16_extra *optimizePattern(); QRegularExpressionMatchPrivate *doMatch(const QString &subject, int offset, @@ -1006,15 +1006,30 @@ static bool isJitEnabled() /*! \internal + + The purpose of the function is to call pcre16_study (which allows some + optimizations to be performed, including JIT-compiling the pattern), and + setting the studyData member variable to the result of the study. It gets + called by doMatch() every time a match is performed. As of now, the + optimizations on the pattern are performed after a certain number of usages + (i.e. the OPTIMIZE_AFTER_USE_COUNT constant). + + Notice that although the method is protected by a mutex, one thread may + invoke this function and return immediately (i.e. not study the pattern, + leaving studyData to NULL); but before calling pcre16_exec to perform the + match, another thread performs the studying and sets studyData to something + else. Although the assignment to studyData is itself atomic, the release of + the memory pointed by studyData isn't. Therefore, the current studyData + value is returned and used by doMatch. */ -void QRegularExpressionPrivate::optimizePattern() +pcre16_extra *QRegularExpressionPrivate::optimizePattern() { Q_ASSERT(compiledPattern); QMutexLocker lock(&mutex); if (studyData || (++usedCount != OPTIMIZE_AFTER_USE_COUNT)) - return; + return studyData; static const bool enableJit = isJitEnabled(); @@ -1027,6 +1042,8 @@ void QRegularExpressionPrivate::optimizePattern() if (!studyData && err) qWarning("QRegularExpressionPrivate::optimizePattern(): pcre_study failed: %s", err); + + return studyData; } /*! @@ -1089,7 +1106,7 @@ QRegularExpressionMatchPrivate *QRegularExpressionPrivate::doMatch(const QString capturingCount); // this is mutex protected - const_cast<QRegularExpressionPrivate *>(this)->optimizePattern(); + const pcre16_extra *currentStudyData = const_cast<QRegularExpressionPrivate *>(this)->optimizePattern(); int pcreOptions = convertToPcreOptions(matchOptions); @@ -1113,12 +1130,12 @@ QRegularExpressionMatchPrivate *QRegularExpressionPrivate::doMatch(const QString int result; if (!previousMatchWasEmpty) { - result = pcre16_exec(compiledPattern, studyData, + result = pcre16_exec(compiledPattern, currentStudyData, subjectUtf16, subjectLength, offset, pcreOptions, captureOffsets, captureOffsetsCount); } else { - result = pcre16_exec(compiledPattern, studyData, + result = pcre16_exec(compiledPattern, currentStudyData, subjectUtf16, subjectLength, offset, pcreOptions | PCRE_NOTEMPTY_ATSTART | PCRE_ANCHORED, captureOffsets, captureOffsetsCount); @@ -1136,7 +1153,7 @@ QRegularExpressionMatchPrivate *QRegularExpressionPrivate::doMatch(const QString ++offset; } - result = pcre16_exec(compiledPattern, studyData, + result = pcre16_exec(compiledPattern, currentStudyData, subjectUtf16, subjectLength, offset, pcreOptions, captureOffsets, captureOffsetsCount); |