------------------------------------------------------------
revno: 12380
revision-id: squid3@treenet.co.nz-20121110040252-njww6vm5k04c87nc
parent: squid3@treenet.co.nz-20121110035744-ytrkuj55aj9vt0f8
fixes bug(s): http://bugs.squid-cache.org/show_bug.cgi?id=3189
committer: Amos Jeffries <squid3@treenet.co.nz>
branch nick: 3.3
timestamp: Fri 2012-11-09 21:02:52 -0700
message:
  Bug 3189: AIO thread race on pipe() initialization
------------------------------------------------------------
# Bazaar merge directive format 2 (Bazaar 0.90)
# revision_id: squid3@treenet.co.nz-20121110040252-njww6vm5k04c87nc
# target_branch: http://bzr.squid-cache.org/bzr/squid3/3.3
# testament_sha1: 8bc61e1cb96eb428703b1b3d7f90a6ccffcf7d7c
# timestamp: 2012-11-10 04:03:37 +0000
# source_branch: http://bzr.squid-cache.org/bzr/squid3/3.3
# base_revision_id: squid3@treenet.co.nz-20121110035744-\
#   ytrkuj55aj9vt0f8
# 
# Begin patch
=== modified file 'src/DiskIO/DiskThreads/CommIO.cc'
--- src/DiskIO/DiskThreads/CommIO.cc	2012-08-31 16:57:39 +0000
+++ src/DiskIO/DiskThreads/CommIO.cc	2012-11-10 04:02:52 +0000
@@ -39,19 +39,22 @@
 #include "globals.h"
 
 void
-CommIO::Initialise()
+CommIO::Initialize()
 {
+    if (CommIO::Initialized)
+        return;
+
     /* Initialize done pipe signal */
     int DonePipe[2];
     if (pipe(DonePipe)) {}
     DoneFD = DonePipe[1];
     DoneReadFD = DonePipe[0];
-    fd_open(DoneReadFD, FD_PIPE, "async-io completetion event: main");
-    fd_open(DoneFD, FD_PIPE, "async-io completetion event: threads");
+    fd_open(DoneReadFD, FD_PIPE, "async-io completion event: main");
+    fd_open(DoneFD, FD_PIPE, "async-io completion event: threads");
     commSetNonBlocking(DoneReadFD);
     commSetNonBlocking(DoneFD);
     Comm::SetSelect(DoneReadFD, COMM_SELECT_READ, NULLFDHandler, NULL, 0);
-    Initialised = true;
+    Initialized = true;
 }
 
 void
@@ -63,10 +66,10 @@
     close(DoneReadFD);
     fd_close(DoneFD);
     fd_close(DoneReadFD);
-    Initialised = false;
+    Initialized = false;
 }
 
-bool CommIO::Initialised = false;
+bool CommIO::Initialized = false;
 bool CommIO::DoneSignalled = false;
 int CommIO::DoneFD = -1;
 int CommIO::DoneReadFD = -1;

=== modified file 'src/DiskIO/DiskThreads/CommIO.h'
--- src/DiskIO/DiskThreads/CommIO.h	2012-08-28 13:00:30 +0000
+++ src/DiskIO/DiskThreads/CommIO.h	2012-11-10 04:02:52 +0000
@@ -10,24 +10,25 @@
 public:
     static inline void NotifyIOCompleted();
     static void ResetNotifications();
-    static void Initialise();
+    static void Initialize();
     static void NotifyIOClose();
 
 private:
     static void NULLFDHandler(int, void *);
     static void FlushPipe();
-    static bool Initialised;
+    static bool Initialized;
     static bool DoneSignalled;
     static int DoneFD;
     static int DoneReadFD;
 };
 
-/* Inline code. TODO: make structued approach to inlining */
+/* Inline code. TODO: make structured approach to inlining */
 void
 CommIO::NotifyIOCompleted()
 {
-    if (!Initialised)
-        Initialise();
+    if (!Initialized) {
+        fatalf("Disk Threads I/O pipes not initialized before first use.");
+    }
 
     if (!DoneSignalled) {
         DoneSignalled = true;

=== modified file 'src/DiskIO/DiskThreads/aiops.cc'
--- src/DiskIO/DiskThreads/aiops.cc	2012-10-03 17:32:57 +0000
+++ src/DiskIO/DiskThreads/aiops.cc	2012-11-10 04:02:52 +0000
@@ -306,6 +306,10 @@
 
     done_queue.blocked = 0;
 
+    // Initialize the thread I/O pipes before creating any threads
+    // see bug 3189 comment 5 about race conditions.
+    CommIO::Initialize();
+
     /* Create threads and get them to sit in their wait loop */
     squidaio_thread_pool = memPoolCreate("aio_thread", sizeof(squidaio_thread_t));