- Revert r3187, which only masked an underlying bug and caused double columns in views

 - In SPTableStructureDelete, don't request the encoding if the table is reloading; this prevents multithreaded data fetches and race conditions causing Issue #974.
 - Alter SPTableData to use thread mutexes instead of a boolean to prevent threading issues, which also fixes Issue #974 in a different way.  Alter race condition checks to block their threads instead of returning bogus information to prevent state issues.
 - Alter table loading to no longer load trigger information until required, speeding up use of other views and cleaning up the console log.

6 files changed, 90 insertions, 87 deletions

diff --git a/Source/SPDatabaseViewController.m b/Source/SPDatabaseViewController.m
index 03153230..a6600d3f 100644
--- a/Source/SPDatabaseViewController.m
+++ b/Source/SPDatabaseViewController.m
@@ -280,7 +280,7 @@
 		[tableSourceInstance loadTable:nil];
 		[tableContentInstance loadTable:nil];
 		[[extendedTableInfoInstance onMainThread] loadTable:nil];
-		[[tableTriggersInstance onMainThread] loadTriggers];
+		[[tableTriggersInstance onMainThread] resetInterface];
 		structureLoaded = NO;
 		contentLoaded = NO;
 		statusLoaded = NO;
@@ -393,8 +393,12 @@
 	// Update the window title
 	[self updateWindowTitle:self];
 
-	// Reset table information caches
+	// Reset table information caches and mark that all loaded views require their data reloading
 	[tableDataInstance resetAllData];
+	structureLoaded = NO;
+	contentLoaded = NO;
+	statusLoaded = NO;
+	triggersLoaded = NO;
 
 	// Ensure status and details are fetched using UTF8
 	NSString *previousEncoding = [mySQLConnection encoding];
@@ -408,7 +412,8 @@
 	[tableDataInstance updateStatusInformationForCurrentTable];
 
 	// Check the current encoding against the table encoding to see whether
-	// an encoding change and reset is required
+	// an encoding change and reset is required.  This also caches table information on
+	// the working thread.
 	if( selectedTableType == SPTableTypeView || selectedTableType == SPTableTypeTable) {
 
 		// tableEncoding == nil indicates that there was an error while retrieving table data
@@ -426,24 +431,12 @@
 
 	if (changeEncoding) [mySQLConnection restoreStoredEncoding];
 
-	// Cache table information on the working thread
-	if (selectedTableType == SPTableTypeView)
-		[tableDataInstance updateInformationForCurrentView];
-	else
-		[tableDataInstance updateInformationForCurrentTable];
-
 	// Notify listeners of the table change now that the state is fully set up.
 	[[NSNotificationCenter defaultCenter] postNotificationOnMainThreadWithName:SPTableChangedNotification object:self];
 
 	// Restore view states as appropriate
 	[spHistoryControllerInstance restoreViewStates];
 
-	// Mark that all loaded views require their data reloading
-	structureLoaded = NO;
-	contentLoaded = NO;
-	statusLoaded = NO;
-	triggersLoaded = NO;
-
 	// Load the currently selected view if looking at a table or view
 	if (tableEncoding && (selectedTableType == SPTableTypeView || selectedTableType == SPTableTypeTable))
 	{
@@ -475,7 +468,7 @@
 	if (!structureLoaded) [tableSourceInstance loadTable:nil];
 	if (!contentLoaded) [tableContentInstance loadTable:nil];
 	if (!statusLoaded) [[extendedTableInfoInstance onMainThread] loadTable:nil];
-	if (!triggersLoaded) [[tableTriggersInstance onMainThread] loadTriggers];
+	if (!triggersLoaded) [[tableTriggersInstance onMainThread] resetInterface];
 
 	// Update the "Show Create Syntax" window if it's already opened
 	// according to the selected table/view/proc/func
diff --git a/Source/SPTableData.h b/Source/SPTableData.h
index cb24d51f..4503bd03 100644
--- a/Source/SPTableData.h
+++ b/Source/SPTableData.h
@@ -41,9 +41,9 @@
 	
 	MCPConnection *mySQLConnection;
 
-	BOOL isWorking;
-	BOOL tableHasAutoIncrementField;
+	pthread_mutex_t dataProcessingLock;
 
+	BOOL tableHasAutoIncrementField;
 }
 
 @property (readwrite, assign) BOOL isWorking;
diff --git a/Source/SPTableData.m b/Source/SPTableData.m
index 28717864..c63d10ff 100644
--- a/Source/SPTableData.m
+++ b/Source/SPTableData.m
@@ -31,11 +31,13 @@
 #import "RegexKitLite.h"
 #import "SPServerSupport.h"
 
+@interface SPTableData (PrivateAPI)
+- (void)_loopWhileWorking;
+@end
+
 @implementation SPTableData
 
-@synthesize isWorking;
 @synthesize tableHasAutoIncrementField;
-;
 
 /**
  * Init class.
@@ -52,9 +54,9 @@
 		tableEncoding = nil;
 		tableCreateSyntax = nil;
 		mySQLConnection = nil;
-		isWorking = NO;
 		tableHasAutoIncrementField = NO;
 
+		pthread_mutex_init(&dataProcessingLock, NULL);
 	}
 
 	return self;
@@ -79,8 +81,8 @@
 - (NSString *) tableEncoding
 {
 
-	// Return if CREATE SYNTAX is being parsed
-	if(isWorking) return nil;
+	// If processing is already in action, wait for it to complete
+	[self _loopWhileWorking];
 
 	if (tableEncoding == nil) {
 		if ([tableListInstance tableType] == SPTableTypeView) {
@@ -98,8 +100,8 @@
 - (NSString *) tableCreateSyntax
 {
 
-	// Return if CREATE SYNTAX is being parsed
-	if(isWorking) return nil;
+	// If processing is already in action, wait for it to complete
+	[self _loopWhileWorking];
 
 	if (tableCreateSyntax == nil) {
 		if ([tableListInstance tableType] == SPTableTypeView) {
@@ -123,8 +125,8 @@
 - (NSArray *) columns
 {
 
-	// Return if CREATE SYNTAX is being parsed
-	if(isWorking) return [NSArray array];
+	// If processing is already in action, wait for it to complete
+	[self _loopWhileWorking];
 
 	if ([columns count] == 0) {
 		if ([tableListInstance tableType] == SPTableTypeView) {
@@ -149,9 +151,8 @@
  */
 - (NSArray *) triggers
 {
-	// Return if CREATE SYNTAX is being parsed
-	if (isWorking) return [NSArray array];
-	
+	// If processing is already in action, wait for it to complete
+	[self _loopWhileWorking];	
 
 	// If triggers is nil, the triggers need to be loaded - if a table is selected on MySQL >= 5.0.2
 	if (!triggers) {
@@ -173,10 +174,8 @@
  */
 - (NSDictionary *) columnWithName:(NSString *)colName
 {
-
-	// Return if CREATE SYNTAX is being parsed
-	if(isWorking) return nil;
-	
+	// If processing is already in action, wait for it to complete
+	[self _loopWhileWorking];
 
 	if ([columns count] == 0) {
 		if ([tableListInstance tableType] == SPTableTypeView) {
@@ -196,10 +195,8 @@
  */
 - (NSArray *) columnNames
 {
-
-	// Return if CREATE SYNTAX is being parsed
-	if(isWorking) return [NSArray array];
-	
+	// If processing is already in action, wait for it to complete
+	[self _loopWhileWorking];
 
 	if ([columnNames count] == 0) {
 		if ([tableListInstance tableType] == SPTableTypeView) {
@@ -219,9 +216,8 @@
  */
 - (NSDictionary *) columnAtIndex:(NSInteger)index
 {
-
-	// Return if CREATE SYNTAX is being parsed
-	if(isWorking) return nil;
+	// If processing is already in action, wait for it to complete
+	[self _loopWhileWorking];
 
 	if ([columns count] == 0) {
 		if ([tableListInstance tableType] == SPTableTypeView) {
@@ -242,9 +238,8 @@
 
 - (BOOL) columnIsBlobOrText:(NSString *)colName
 {
-
-	// Return if CREATE SYNTAX is being parsed
-	if(isWorking) return YES; // to be at the safe side
+	// If processing is already in action, wait for it to complete
+	[self _loopWhileWorking];
 
 	if ([columns count] == 0) {
 		if ([tableListInstance tableType] == SPTableTypeView) {
@@ -266,9 +261,8 @@
 
 - (BOOL) columnIsGeometry:(NSString *)colName
 {
-
-	// Return if CREATE SYNTAX is being parsed
-	if(isWorking) return YES; // to be at the safe side
+	// If processing is already in action, wait for it to complete
+	[self _loopWhileWorking];
 
 	if ([columns count] == 0) {
 		if ([tableListInstance tableType] == SPTableTypeView) {
@@ -289,9 +283,8 @@
  */
 - (NSString *) statusValueForKey:(NSString *)aKey
 {
-
-	// Return if CREATE SYNTAX is being parsed
-	if(isWorking) return nil;
+	// If processing is already in action, wait for it to complete
+	[self _loopWhileWorking];
 
 	if ([status count] == 0) {
 		[self updateStatusInformationForCurrentTable];
@@ -318,9 +311,8 @@
  */
 - (NSDictionary *) statusValues
 {
-
-	// Return if CREATE SYNTAX is being parsed
-	if(isWorking) return nil;
+	// If processing is already in action, wait for it to complete
+	[self _loopWhileWorking];
 
 	if ([status count] == 0) {
 		[self updateStatusInformationForCurrentTable];
@@ -380,7 +372,7 @@
  */
 - (BOOL) updateInformationForCurrentTable
 {
-	isWorking = YES;
+	pthread_mutex_lock(&dataProcessingLock);
 
 	NSDictionary *tableData = nil;
 	NSDictionary *columnData;
@@ -396,7 +388,7 @@
 	}
 
 	if (tableData == nil ) {
-		isWorking = NO;
+		pthread_mutex_unlock(&dataProcessingLock);
 		return FALSE;
 	}
 
@@ -412,7 +404,7 @@
 	}
 	tableEncoding = [[NSString alloc] initWithString:[tableData objectForKey:@"encoding"]];
 
-	isWorking = NO;
+	pthread_mutex_unlock(&dataProcessingLock);
 
 	return TRUE;
 }
@@ -423,8 +415,7 @@
  */
 - (BOOL) updateInformationForCurrentView
 {
-
-	isWorking = YES;
+	pthread_mutex_lock(&dataProcessingLock);
 
 	NSDictionary *viewData = [self informationForView:[tableListInstance tableName]];
 	NSDictionary *columnData;
@@ -436,7 +427,7 @@
 		[columns removeAllObjects];
 		[columnNames removeAllObjects];
 		[constraints removeAllObjects];
-		isWorking = NO;
+		pthread_mutex_unlock(&dataProcessingLock);
 		return FALSE;
 	}
 
@@ -452,7 +443,7 @@
 	}
 	tableEncoding = [[NSString alloc] initWithString:[viewData objectForKey:@"encoding"]];
 
-	isWorking = NO;
+	pthread_mutex_unlock(&dataProcessingLock);
 
 	return TRUE;
 }
@@ -476,10 +467,6 @@
 	unichar quoteCharacter;
 	BOOL changeEncoding = ![[mySQLConnection encoding] isEqualToString:@"utf8"];
 
-	[columns removeAllObjects];
-	[columnNames removeAllObjects];
-	[constraints removeAllObjects];
-
 	// Catch unselected tables and return nil
 	if ([tableName isEqualToString:@""] || !tableName) return nil;
 
@@ -925,14 +912,13 @@
  */
 - (BOOL)updateStatusInformationForCurrentTable
 {
-
-	isWorking = YES;
+	pthread_mutex_lock(&dataProcessingLock);
 
 	BOOL changeEncoding = ![[mySQLConnection encoding] isEqualToString:@"utf8"];
 
 	// Catch unselected tables and return false
 	if ([[tableListInstance tableName] isEqualToString:@""] || ![tableListInstance tableName]) {
-		isWorking = NO;
+		pthread_mutex_unlock(&dataProcessingLock);
 		return FALSE;
 	}
 
@@ -979,7 +965,7 @@
 					   [mySQLConnection getLastErrorMessage]]);
 			if (changeEncoding) [mySQLConnection restoreStoredEncoding];
 		}
-		isWorking = NO;
+		pthread_mutex_unlock(&dataProcessingLock);
 		return FALSE;
 	}
 
@@ -997,7 +983,7 @@
 		if ([[status objectForKey:@"Engine"] isNSNull]) {
 			[status setDictionary:[NSDictionary dictionaryWithObjectsAndKeys:@"Error", @"Engine", [NSString stringWithFormat:NSLocalizedString(@"An error occurred retrieving table information.  MySQL said: %@", @"MySQL table info retrieval error message"), [status objectForKey:@"Comment"]], @"Comment", [tableListInstance tableName], @"Name", nil]];
 			if (changeEncoding) [mySQLConnection restoreStoredEncoding];
-			isWorking = NO;
+			pthread_mutex_unlock(&dataProcessingLock);
 			return FALSE;
 		}
 
@@ -1032,7 +1018,7 @@
 
 	if (changeEncoding) [mySQLConnection restoreStoredEncoding];
 
-	isWorking = NO;
+	pthread_mutex_unlock(&dataProcessingLock);
 
 	return TRUE;
 }
@@ -1042,8 +1028,7 @@
  */
 - (BOOL) updateTriggersForCurrentTable
 {
-
-	isWorking = YES;
+	pthread_mutex_lock(&dataProcessingLock);
 
 	// Ensure queries are made in UTF8
 	BOOL changeEncoding = ![[mySQLConnection encoding] isEqualToString:@"utf8"];
@@ -1067,7 +1052,7 @@
 			if (changeEncoding) [mySQLConnection restoreStoredEncoding];
 		}
 
-		isWorking = NO;
+		pthread_mutex_unlock(&dataProcessingLock);
 		return NO;
 	}
 
@@ -1079,7 +1064,7 @@
 
 	if (changeEncoding) [mySQLConnection restoreStoredEncoding];
 
-	isWorking = NO;
+	pthread_mutex_unlock(&dataProcessingLock);
 
 	return YES;
 }
@@ -1364,7 +1349,18 @@
 	if (tableCreateSyntax) [tableCreateSyntax release];
 	if (mySQLConnection) [mySQLConnection release];
 
+	pthread_mutex_destroy(&dataProcessingLock);
+
 	[super dealloc];
 }
 
-@end
+#pragma mark -
+#pragma mark Private API
+
+- (void)_loopWhileWorking
+{
+	while (pthread_mutex_trylock(&dataProcessingLock)) usleep(10000);
+	pthread_mutex_unlock(&dataProcessingLock);
+}
+
+@end
\ No newline at end of file
diff --git a/Source/SPTableStructureDelegate.m b/Source/SPTableStructureDelegate.m
index 17ad817d..729091d6 100644
--- a/Source/SPTableStructureDelegate.m
+++ b/Source/SPTableStructureDelegate.m
@@ -49,7 +49,10 @@
 			NSInteger end = [enc length] - start - 1;
 			collations = [databaseDataInstance getDatabaseCollationsForEncoding:[enc substringWithRange:NSMakeRange(start, end)]];
 		} else {
-			if([tableDataInstance tableEncoding] != nil) {
+
+			// If the structure has loaded (not still loading!) and the table encoding
+			// is set, use the appropriate collations.
+			if([tableDocumentInstance structureLoaded] && [tableDataInstance tableEncoding] != nil) {
 				collations = [databaseDataInstance getDatabaseCollationsForEncoding:[tableDataInstance tableEncoding]];
 			} else {
 				collations = [NSArray array];
diff --git a/Source/SPTableTriggers.h b/Source/SPTableTriggers.h
index 0dfd6f30..70eeeb2e 100644
--- a/Source/SPTableTriggers.h
+++ b/Source/SPTableTriggers.h
@@ -65,6 +65,7 @@
 @property (readwrite, assign) MCPConnection *connection;
 
 - (void)loadTriggers;
+- (void)resetInterface;
 
 // IB action methods
 - (IBAction)addTrigger:(id)sender;
diff --git a/Source/SPTableTriggers.m b/Source/SPTableTriggers.m
index 44a17549..6462a43f 100644
--- a/Source/SPTableTriggers.m
+++ b/Source/SPTableTriggers.m
@@ -111,17 +111,7 @@ static const NSString *SPTriggerSQLMode    = @"TriggerSQLMode";
 {
 	BOOL enableInteraction = ((![[tableDocumentInstance selectedToolbarItemIdentifier] isEqualToString:SPMainToolbarTableTriggers]) || (![tableDocumentInstance isWorking]));
 
-	// Disable all interface elements by default
-	[addTriggerButton setEnabled:NO];
-	[refreshTriggersButton setEnabled:NO];
-	[triggersTableView setEnabled:NO];
-	[labelTextField setStringValue:@""];
-
-	// Show a warning if the version of MySQL is too low to support triggers
-	if (![[tableDocumentInstance serverSupport] supportsTriggers]) {
-		[labelTextField setStringValue:NSLocalizedString(@"This version of MySQL does not support triggers. Support for triggers was added in MySQL 5.0.2", @"triggers not supported label")];
-		return;
-	}
+	[self resetInterface];
 
 	// If no item is selected, or the item selected is not a table, return.
 	if (![tablesListInstance tableName] || [tablesListInstance tableType] != SPTableTypeTable)
@@ -139,6 +129,26 @@ static const NSString *SPTriggerSQLMode    = @"TriggerSQLMode";
 	[self _refreshTriggerDataForcingCacheRefresh:NO];
 }
 
+/**
+ * Reset the trigger interface, as for no selected table.
+ */
+- (void)resetInterface
+{
+	[triggerData removeAllObjects];
+	[triggersTableView noteNumberOfRowsChanged];
+
+	// Disable all interface elements by default
+	[addTriggerButton setEnabled:NO];
+	[refreshTriggersButton setEnabled:NO];
+	[triggersTableView setEnabled:NO];
+	[labelTextField setStringValue:@""];
+
+	// Show a warning if the version of MySQL is too low to support triggers
+	if (![[tableDocumentInstance serverSupport] supportsTriggers]) {
+		[labelTextField setStringValue:NSLocalizedString(@"This version of MySQL does not support triggers. Support for triggers was added in MySQL 5.0.2", @"triggers not supported label")];
+	}
+}
+
 #pragma mark -
 #pragma mark IB action methods