New option allowing processing using multiple threads

Introduces new option NUM_PROC_THREADS.
It specifies the number threads doxygen is allowed to use during
processing. When set to 0 doxygen will based this on the number of cores
available in the system. You can set it explicitly to a value larger than 0
to get more control over the balance between CPU load and processing speed.

At this moment only the input processing can be done using multiple threads.
I plan to extend this with more parallel processing in the future.

Since this is still an experimental feature the default is set to 1,
which efficively disables parallel processing. Please report any issues you
encounter that appear when changing the default.

Note that generating dot graphs in parallel is still controlled separately
by the DOT_NUM_THREADS setting.

1 files changed, 0 insertions, 10 deletions

diff --git a/src/message.cpp b/src/message.cpp
index 96c54a1..37204f5 100644
--- a/src/message.cpp
+++ b/src/message.cpp
@@ -35,9 +35,7 @@ static const char *error_str = "error: ";
 static FILE *warnFile = stderr;
 
 
-#if MULTITHREADED_INPUT
 static std::mutex g_mutex;
-#endif
 
 void initWarningFormat()
 {
@@ -112,9 +110,7 @@ void msg(const char *fmt, ...)
 {
   if (!Config_getBool(QUIET))
   {
-#if MULTITHREADED_INPUT
     std::unique_lock<std::mutex> lock(g_mutex);
-#endif
     if (Debug::isFlagSet(Debug::Time))
     {
       printf("%.3f sec: ",((double)Debug::elapsedTime()));
@@ -155,9 +151,7 @@ static void format_warn(const char *file,int line,const char *text)
   msgText += '\n';
 
   {
-#if MULTITHREADED_INPUT
     std::unique_lock<std::mutex> lock(g_mutex);
-#endif
     // print resulting message
     fwrite(msgText.data(),1,msgText.length(),warnFile);
   }
@@ -257,9 +251,7 @@ extern void err_full(const char *file,int line,const char *fmt, ...)
 void term(const char *fmt, ...)
 {
   {
-#if MULTITHREADED_INPUT
     std::unique_lock<std::mutex> lock(g_mutex);
-#endif
     va_list args;
     va_start(args, fmt);
     vfprintf(warnFile, (QCString(error_str) + fmt).data(), args);
@@ -284,9 +276,7 @@ void printlex(int dbg, bool enter, const char *lexName, const char *fileName)
     enter_txt_uc = "Finished";
   }
 
-#if MULTITHREADED_INPUT
   std::unique_lock<std::mutex> lock(g_mutex);
-#endif
   if (dbg)
   {
     if (fileName)