wiredtiger_prepare_conflict.h

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#pragma once

#include "mongo/db/curop.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/storage/wiredtiger/wiredtiger_record_store.h"
#include "mongo/db/storage/wiredtiger/wiredtiger_recovery_unit.h"
#include "mongo/util/fail_point_service.h"

namespace mongo {

// When set, returns simulates returning WT_PREPARE_CONFLICT on WT cursor read operations.
MONGO_FAIL_POINT_DECLARE(WTPrepareConflictForReads);

void wiredTigerPrepareConflictLog(int attempt);

template <typename F>
int wiredTigerPrepareConflictRetry(OperationContext* opCtx, F&& f) {
    invariant(opCtx);

    auto recoveryUnit = WiredTigerRecoveryUnit::get(opCtx);
    int attempts = 0;
    while (true) {
        attempts++;
        // If the failpoint is enabled, don't call the function, just simulate a conflict.
        int ret =
            MONGO_FAIL_POINT(WTPrepareConflictForReads) ? WT_PREPARE_CONFLICT : WT_READ_CHECK(f());

        if (ret != WT_PREPARE_CONFLICT)
            return ret;

        ++CurOp::get(opCtx)->debug().prepareReadConflicts;
        wiredTigerPrepareConflictLog(attempts);
        // Wait on the session cache to signal that a unit of work has been committed or aborted.
        recoveryUnit->getSessionCache()->waitUntilPreparedUnitOfWorkCommitsOrAborts(opCtx);
    }
}
}  // namespace mongo