From cb53709f47be43d3f20b1e4866ba6cccead38a2e Mon Sep 17 00:00:00 2001
From: mbdavid <mauricio.david@gmail.com>
Date: Sun, 2 Jul 2017 19:08:52 -0300
Subject: [PATCH] Fix journal initial position

---
 LiteDB.Tests/Concurrency/ProcessTest.cs | 30 ++++++++++++-------------
 LiteDB/Engine/Disks/FileDiskService.cs  |  2 +-
 LiteDB/Engine/Engine/Find.cs            |  2 +-
 LiteDB/Engine/Services/LockService.cs   |  8 +++----
 4 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/LiteDB.Tests/Concurrency/ProcessTest.cs b/LiteDB.Tests/Concurrency/ProcessTest.cs
index 1d7145c93..738a6d06f 100644
--- a/LiteDB.Tests/Concurrency/ProcessTest.cs
+++ b/LiteDB.Tests/Concurrency/ProcessTest.cs
@@ -24,24 +24,24 @@ public void Process_Insert_Test()
                     dbA.EnsureIndex("col", "process", false);
 
                     // insert 1000 x instance=1
-                    //var ta = Task.Factory.StartNew(() =>
-                    //{
-                        for (var i = 0; i < 1000; i++)
-                        {
-                            dbA.Insert("col", new BsonDocument { { "process", 1 } });
-                        }
-                    //});
+                    var ta = Task.Factory.StartNew(() =>
+                    {
+                      for (var i = 0; i < 1000; i++)
+                      {
+                          dbA.Insert("col", new BsonDocument { { "process", 1 } });
+                      }
+                    });
 
                     // insert 700 x instance=2
-                    //var tb = Task.Factory.StartNew(() =>
-                    //{
-                        for (var i = 0; i < 700; i++)
-                        {
-                            dbB.Insert("col", new BsonDocument { { "process", 2 } });
-                        }
-                    //});
+                    var tb = Task.Factory.StartNew(() =>
+                    {
+                      for (var i = 0; i < 700; i++)
+                      {
+                          dbB.Insert("col", new BsonDocument { { "process", 2 } });
+                      }
+                    });
 
-                    //Task.WaitAll(ta, tb);
+                    Task.WaitAll(ta, tb);
 
                     Assert.AreEqual(1000, dbA.Count("col", Query.EQ("process", 1)));
                     Assert.AreEqual(700, dbA.Count("col", Query.EQ("process", 2)));
diff --git a/LiteDB/Engine/Disks/FileDiskService.cs b/LiteDB/Engine/Disks/FileDiskService.cs
index 112dd4646..a1afbe672 100644
--- a/LiteDB/Engine/Disks/FileDiskService.cs
+++ b/LiteDB/Engine/Disks/FileDiskService.cs
@@ -169,7 +169,7 @@ public void WriteJournal(ICollection<byte[]> pages, uint lastPageID)
                 BasePage.GetSizeOfPages(pages.Count));
 
             // go to initial file position (after lastPageID)
-            _stream.Seek(lastPageID + 1, SeekOrigin.Begin);
+            _stream.Seek(BasePage.GetSizeOfPages(lastPageID + 1), SeekOrigin.Begin);
 
             foreach(var buffer in pages)
             {
diff --git a/LiteDB/Engine/Engine/Find.cs b/LiteDB/Engine/Engine/Find.cs
index 213105e2a..6498ba6d3 100644
--- a/LiteDB/Engine/Engine/Find.cs
+++ b/LiteDB/Engine/Engine/Find.cs
@@ -9,7 +9,7 @@ public partial class LiteEngine
         /// <summary>
         /// Find for documents in a collection using Query definition
         /// </summary>
-        public IEnumerable<BsonDocument> Find(string collection, Query query, int skip = 0, int limit = int.MaxValue, int bufferSize = 10)
+        public IEnumerable<BsonDocument> Find(string collection, Query query, int skip = 0, int limit = int.MaxValue)
         {
             if (collection.IsNullOrWhiteSpace()) throw new ArgumentNullException("collection");
             if (query == null) throw new ArgumentNullException("query");
diff --git a/LiteDB/Engine/Services/LockService.cs b/LiteDB/Engine/Services/LockService.cs
index 9a40f83ac..0f6701dc1 100644
--- a/LiteDB/Engine/Services/LockService.cs
+++ b/LiteDB/Engine/Services/LockService.cs
@@ -55,7 +55,7 @@ public LockControl Shared()
                 }
 
                 // try enter in read mode
-                if (_thread.TryEnterReadLock(_timeout))
+                if (!_thread.TryEnterReadLock(_timeout))
                 {
                     throw LiteException.LockTimeout(_timeout);
                 }
@@ -91,15 +91,15 @@ public LockControl Exclusive()
         {
             lock (_disk)
             {
-                // if are locked in shared, throw invalid operation
-                if (_state == LockState.Shared) throw new InvalidOperationException("Call exit shared lock before call exclusive");
-
                 // if already in exclusive, do nothing
                 if (_state == LockState.Exclusive)
                 {
                     return new LockControl(() => { });
                 }
 
+                // if are locked in shared, exit read to enter in write
+                if (_state == LockState.Shared) throw new NotSupportedException("Lock are in exclusive mode");
+
                 // try enter in write mode (thread)
                 if (!_thread.TryEnterWriteLock(_timeout))
                 {