From 540c683f9702a0e27a593d29019e125304a6ea7a Mon Sep 17 00:00:00 2001 From: Kyotaro Horiguchi Date: Tue, 10 Sep 2019 17:28:48 +0900 Subject: [PATCH v6 3/4] Remove globals readSegNo, readOff, readLen These global variables is functionally duplicated with them in XLogReaderState. Remove the globals. --- src/backend/access/transam/xlog.c | 77 ++++++++++++++++++--------------------- src/include/access/xlogreader.h | 2 +- 2 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 34ab4ea359..c20d3b1418 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -783,14 +783,10 @@ static XLogSegNo openLogSegNo = 0; * These variables are used similarly to the ones above, but for reading * the XLOG. Note, however, that readOff generally represents the offset * of the page just read, not the seek position of the FD itself, which - * will be just past that page. readLen indicates how much of the current - * page has been read into readBuf, and readSource indicates where we got - * the currently open file from. + * will be just past that page. readSource indicates where we got the + * currently open file from. */ static int readFile = -1; -static XLogSegNo readSegNo = 0; -static uint32 readOff = 0; -static uint32 readLen = 0; static XLogSource readSource = 0; /* XLOG_FROM_* code */ /* @@ -877,10 +873,12 @@ static bool InstallXLogFileSegment(XLogSegNo *segno, char *tmppath, static int XLogFileRead(XLogSegNo segno, int emode, TimeLineID tli, int source, bool notfoundOk); static int XLogFileReadAnyTLI(XLogSegNo segno, int emode, int source); -static bool XLogPageRead(XLogReaderState *xlogreader, +static bool XLogPageRead(XLogReaderState *state, bool fetching_ckpt, int emode, bool randAccess); static bool WaitForWALToBecomeAvailable(XLogRecPtr RecPtr, bool randAccess, - bool fetching_ckpt, XLogRecPtr tliRecPtr); + bool fetching_ckpt, + XLogRecPtr tliRecPtr, + XLogSegNo readSegNo); static int emode_for_corrupt_record(int emode, XLogRecPtr RecPtr); static void XLogFileClose(void); static void PreallocXlogFiles(XLogRecPtr endptr); @@ -7494,7 +7492,8 @@ StartupXLOG(void) XLogRecPtr pageBeginPtr; pageBeginPtr = EndOfLog - (EndOfLog % XLOG_BLCKSZ); - Assert(readOff == XLogSegmentOffset(pageBeginPtr, wal_segment_size)); + Assert(XLogSegmentOffset(xlogreader->readPagePtr, wal_segment_size) == + XLogSegmentOffset(pageBeginPtr, wal_segment_size)); firstIdx = XLogRecPtrToBufIdx(EndOfLog); @@ -11514,14 +11513,15 @@ CancelBackup(void) * sleep and retry. */ static bool -XLogPageRead(XLogReaderState *xlogreader, +XLogPageRead(XLogReaderState *state, bool fetching_ckpt, int emode, bool randAccess) { - char *readBuf = xlogreader->readBuf; - XLogRecPtr targetPagePtr = xlogreader->readPagePtr; - int reqLen = xlogreader->readLen; - XLogRecPtr targetRecPtr = xlogreader->ReadRecPtr; - TimeLineID *readTLI = &xlogreader->readPageTLI; + char *readBuf = state->readBuf; + XLogRecPtr targetPagePtr = state->readPagePtr; + int reqLen = state->readLen; + int readLen = 0; + XLogRecPtr targetRecPtr = state->ReadRecPtr; + TimeLineID *readTLI = &state->readPageTLI; uint32 targetPageOff; XLogSegNo targetSegNo PG_USED_FOR_ASSERTS_ONLY; int r; @@ -11534,7 +11534,7 @@ XLogPageRead(XLogReaderState *xlogreader, * is not in the currently open one. */ if (readFile >= 0 && - !XLByteInSeg(targetPagePtr, readSegNo, wal_segment_size)) + !XLByteInSeg(targetPagePtr, state->readSegNo, wal_segment_size)) { /* * Request a restartpoint if we've replayed too much xlog since the @@ -11542,10 +11542,10 @@ XLogPageRead(XLogReaderState *xlogreader, */ if (bgwriterLaunched) { - if (XLogCheckpointNeeded(readSegNo)) + if (XLogCheckpointNeeded(state->readSegNo)) { (void) GetRedoRecPtr(); - if (XLogCheckpointNeeded(readSegNo)) + if (XLogCheckpointNeeded(state->readSegNo)) RequestCheckpoint(CHECKPOINT_CAUSE_XLOG); } } @@ -11555,7 +11555,7 @@ XLogPageRead(XLogReaderState *xlogreader, readSource = 0; } - XLByteToSeg(targetPagePtr, readSegNo, wal_segment_size); + XLByteToSeg(targetPagePtr, state->readSegNo, wal_segment_size); retry: /* See if we need to retrieve more data */ @@ -11564,17 +11564,14 @@ retry: receivedUpto < targetPagePtr + reqLen)) { if (!WaitForWALToBecomeAvailable(targetPagePtr + reqLen, - randAccess, - fetching_ckpt, - targetRecPtr)) + randAccess, fetching_ckpt, + targetRecPtr, state->readSegNo)) { if (readFile >= 0) close(readFile); readFile = -1; - readLen = 0; readSource = 0; - - xlogreader->readLen = -1; + state->readLen = -1; return false; } } @@ -11602,37 +11599,33 @@ retry: else readLen = XLOG_BLCKSZ; - /* Read the requested page */ - readOff = targetPageOff; - pgstat_report_wait_start(WAIT_EVENT_WAL_READ); - r = pg_pread(readFile, readBuf, XLOG_BLCKSZ, (off_t) readOff); + r = pg_pread(readFile, readBuf, XLOG_BLCKSZ, (off_t) targetPageOff); if (r != XLOG_BLCKSZ) { char fname[MAXFNAMELEN]; int save_errno = errno; pgstat_report_wait_end(); - XLogFileName(fname, curFileTLI, readSegNo, wal_segment_size); + XLogFileName(fname, curFileTLI, state->readSegNo, wal_segment_size); if (r < 0) { errno = save_errno; ereport(emode_for_corrupt_record(emode, targetPagePtr + reqLen), (errcode_for_file_access(), errmsg("could not read from log segment %s, offset %u: %m", - fname, readOff))); + fname, targetPageOff))); } else ereport(emode_for_corrupt_record(emode, targetPagePtr + reqLen), (errcode(ERRCODE_DATA_CORRUPTED), errmsg("could not read from log segment %s, offset %u: read %d of %zu", - fname, readOff, r, (Size) XLOG_BLCKSZ))); + fname, targetPageOff, r, (Size) XLOG_BLCKSZ))); goto next_record_is_invalid; } pgstat_report_wait_end(); - Assert(targetSegNo == readSegNo); - Assert(targetPageOff == readOff); + Assert(targetSegNo == state->readSegNo); Assert(reqLen <= readLen); *readTLI = curFileTLI; @@ -11663,15 +11656,15 @@ retry: * Validating the page header is cheap enough that doing it twice * shouldn't be a big deal from a performance point of view. */ - if (!XLogReaderValidatePageHeader(xlogreader, targetPagePtr, readBuf)) + if (!XLogReaderValidatePageHeader(state, targetPagePtr, readBuf)) { - /* reset any error XLogReaderValidatePageHeader() might have set */ - xlogreader->errormsg_buf[0] = '\0'; + /* reset any error StateValidatePageHeader() might have set */ + state->errormsg_buf[0] = '\0'; goto next_record_is_invalid; } - Assert(xlogreader->readPagePtr == targetPagePtr); - xlogreader->readLen = readLen; + Assert(state->readPagePtr == targetPagePtr); + state->readLen = readLen; return true; next_record_is_invalid: @@ -11680,14 +11673,13 @@ next_record_is_invalid: if (readFile >= 0) close(readFile); readFile = -1; - readLen = 0; readSource = 0; /* In standby-mode, keep trying */ if (StandbyMode) goto retry; - xlogreader->readLen = -1; + state->readLen = -1; return false; } @@ -11719,7 +11711,8 @@ next_record_is_invalid: */ static bool WaitForWALToBecomeAvailable(XLogRecPtr RecPtr, bool randAccess, - bool fetching_ckpt, XLogRecPtr tliRecPtr) + bool fetching_ckpt, XLogRecPtr tliRecPtr, + XLogSegNo readSegNo) { static TimestampTz last_fail_time = 0; TimestampTz now; diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h index 11ae82b96d..aca15be216 100644 --- a/src/include/access/xlogreader.h +++ b/src/include/access/xlogreader.h @@ -122,6 +122,7 @@ struct XLogReaderState * read by reader, which must be larger than * the request, or -1 on error */ TimeLineID readPageTLI; /* TLI for data currently in readBuf */ + XLogSegNo readSegNo; /* Segment # for data currently in readBuf */ char *readBuf; /* buffer to store data */ /* ---------------------------------------- @@ -152,7 +153,6 @@ struct XLogReaderState /* last read segment and segment offset for data currently in readBuf */ bool page_verified; bool record_verified; - XLogSegNo readSegNo; /* * beginning of prior page read, and its TLI. Doesn't necessarily -- 2.16.3