From 44b5b659f273cac7e2808a88b932715d4174d3db Mon Sep 17 00:00:00 2001
From: Kristofer Berggren <kristofer.berggren@gmail.com>
Date: Sat, 6 Jul 2024 16:45:40 +0800
Subject: [PATCH] fix full sync hang for large mailboxes

---
 src/imapmanager.cpp | 53 ++++++++++++++++++++++++++-------------------
 src/imapmanager.h   |  2 ++
 src/nmail.1         |  2 +-
 src/version.cpp     |  2 +-
 4 files changed, 35 insertions(+), 24 deletions(-)

diff --git a/src/imapmanager.cpp b/src/imapmanager.cpp
index 71599cf..2164285 100644
--- a/src/imapmanager.cpp
+++ b/src/imapmanager.cpp
@@ -70,7 +70,7 @@ ImapManager::~ImapManager()
     }
 
     m_Running = false;
-    LOG_IF_NOT_EQUAL(write(m_Pipe[1], "1", 1), 1);
+    PipeWriteOne(m_Pipe);
 
     if (m_ExitedCond.wait_for(lock, std::chrono::seconds(3)) != std::cv_status::timeout)
     {
@@ -103,7 +103,7 @@ ImapManager::~ImapManager()
     std::unique_lock<std::mutex> lock(m_ExitedCacheCondMutex);
 
     m_CacheRunning = false;
-    LOG_IF_NOT_EQUAL(write(m_CachePipe[1], "1", 1), 1);
+    PipeWriteOne(m_CachePipe);
 
     if (m_ExitedCacheCond.wait_for(lock, std::chrono::seconds(2)) != std::cv_status::timeout)
     {
@@ -151,14 +151,14 @@ void ImapManager::AsyncRequest(const ImapManager::Request& p_Request)
   {
     std::lock_guard<std::mutex> lock(m_CacheQueueMutex);
     m_CacheRequests.push_front(p_Request);
-    LOG_IF_NOT_EQUAL(write(m_CachePipe[1], "1", 1), 1);
+    PipeWriteOne(m_CachePipe);
   }
 
   if (m_Connecting || m_OnceConnected)
   {
     std::lock_guard<std::mutex> lock(m_QueueMutex);
     m_Requests.push_front(p_Request);
-    LOG_IF_NOT_EQUAL(write(m_Pipe[1], "1", 1), 1);
+    PipeWriteOne(m_Pipe);
     ProgressCountRequestAdd(p_Request, false /* p_IsPrefetch */);
   }
   else
@@ -173,7 +173,7 @@ void ImapManager::PrefetchRequest(const ImapManager::Request& p_Request)
   {
     std::lock_guard<std::mutex> lock(m_QueueMutex);
     m_PrefetchRequests[p_Request.m_PrefetchLevel].push_front(p_Request);
-    LOG_IF_NOT_EQUAL(write(m_Pipe[1], "1", 1), 1);
+    PipeWriteOne(m_Pipe);
     ProgressCountRequestAdd(p_Request, true /* p_IsPrefetch */);
   }
   else
@@ -188,7 +188,7 @@ void ImapManager::AsyncAction(const ImapManager::Action& p_Action)
   {
     std::lock_guard<std::mutex> lock(m_QueueMutex);
     m_Actions.push_front(p_Action);
-    LOG_IF_NOT_EQUAL(write(m_Pipe[1], "1", 1), 1);
+    PipeWriteOne(m_Pipe);
   }
   else
   {
@@ -519,15 +519,8 @@ void ImapManager::Process()
     else if (m_Running && !authRefreshNeeded &&
              ((selrv > 0) || !isQueueEmpty))
     {
-      int len = 0;
-      ioctl(m_Pipe[0], FIONREAD, &len);
-      if (len > 0)
-      {
-        std::vector<char> buf(len);
-        LOG_IF_NOT_EQUAL(read(m_Pipe[0], &buf[0], len), len);
-      }
-
       m_QueueMutex.lock();
+      PipeReadAll(m_Pipe);
 
       while (m_Running && !authRefreshNeeded &&
              m_OnceConnected &&
@@ -817,15 +810,8 @@ void ImapManager::CacheProcess()
 
     if ((selrv != 0) && FD_ISSET(m_CachePipe[0], &fds))
     {
-      int len = 0;
-      ioctl(m_CachePipe[0], FIONREAD, &len);
-      if (len > 0)
-      {
-        std::vector<char> buf(len);
-        LOG_IF_NOT_EQUAL(read(m_CachePipe[0], &buf[0], len), len);
-      }
-
       m_CacheQueueMutex.lock();
+      PipeReadAll(m_CachePipe);
 
       while (m_CacheRunning && !m_CacheRequests.empty())
       {
@@ -1106,3 +1092,26 @@ float ImapManager::GetProgressPercentage(const Request& p_Request, bool p_IsPref
 
   return progress;
 }
+
+void ImapManager::PipeWriteOne(int p_Fds[2])
+{
+  const int readFd = p_Fds[0];
+  int len = 0;
+  ioctl(readFd, FIONREAD, &len);
+  if (len > 0) return; // bail out if already signaled
+
+  const int writeFd = p_Fds[1];
+  LOG_IF_NOT_EQUAL(write(writeFd, "1", 1), 1);
+}
+
+void ImapManager::PipeReadAll(int p_Fds[2])
+{
+  const int readFd = p_Fds[0];
+  int len = 0;
+  ioctl(readFd, FIONREAD, &len);
+  if (len > 0)
+  {
+    std::vector<char> buf(len);
+    LOG_IF_NOT_EQUAL(read(readFd, &buf[0], len), len);
+  }
+}
diff --git a/src/imapmanager.h b/src/imapmanager.h
index 8abfaba..419aaa2 100644
--- a/src/imapmanager.h
+++ b/src/imapmanager.h
@@ -168,6 +168,8 @@ class ImapManager
   void ProgressCountRequestDone(const Request& p_Request, bool p_IsPrefetch);
   void ProgressCountReset(bool p_IsPrefetch);
   float GetProgressPercentage(const Request& p_Request, bool p_IsPrefetch);
+  void PipeWriteOne(int p_Fds[2]);
+  void PipeReadAll(int p_Fds[2]);
 
 private:
   Imap m_Imap;
diff --git a/src/nmail.1 b/src/nmail.1
index b8c575e..ca085bf 100644
--- a/src/nmail.1
+++ b/src/nmail.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man.
-.TH NMAIL "1" "June 2024" "nmail 5.1.2" "User Commands"
+.TH NMAIL "1" "July 2024" "nmail 5.1.3" "User Commands"
 .SH NAME
 nmail \- ncurses mail
 .SH SYNOPSIS
diff --git a/src/version.cpp b/src/version.cpp
index 8f3d83b..629ccd3 100644
--- a/src/version.cpp
+++ b/src/version.cpp
@@ -7,7 +7,7 @@
 
 #include "version.h"
 
-#define NMAIL_VERSION "5.1.2"
+#define NMAIL_VERSION "5.1.3"
 
 std::string Version::GetBuildOs()
 {