Now keeping track of unused shared objects and maybe unloading them

6 files changed, 102 insertions, 14 deletions

diff --git a/synth/.depend b/synth/.depend
index fb0d8aa..ba430bb 100644
--- a/synth/.depend
+++ b/synth/.depend
@@ -9,12 +9,12 @@ filter.o: filter.cpp filter.h fixed.h defines.h globals.h programs.h \
 globals.o: globals.cpp globals.h programs.h fixed.h note_funcs.h \
   channel.h note_skel.h defines.h util.h
 jack.o: jack.cpp defines.h globals.h programs.h fixed.h note_funcs.h \
-  channel.h note_skel.h util.h jack.h
+  channel.h note_skel.h util.h jack.h communication.h
 load.o: load.cpp util.h programs.h fixed.h note_funcs.h globals.h \
-  channel.h note_skel.h defines.h
-main.o: main.cpp jack.h load.h cli.h parser.h fixed.h programs.h \
-  note_funcs.h channel.h note_skel.h defines.h util.h globals.h \
-  note_loader.h
+  channel.h note_skel.h defines.h parser.h note_loader.h
+main.o: main.cpp jack.h load.h programs.h fixed.h note_funcs.h cli.h \
+  channel.h note_skel.h defines.h util.h globals.h in_synth_cli.h \
+  communication.h note_loader.h
 note.o: note.cpp note.h programs.h fixed.h note_funcs.h envelope.h \
   filter.h note_skel.h globals.h channel.h defines.h util.h
 note_skel.o: note_skel.cpp note_skel.h programs.h fixed.h note_funcs.h \
@@ -22,10 +22,17 @@ note_skel.o: note_skel.cpp note_skel.h programs.h fixed.h note_funcs.h \
 parser.o: parser.cpp parser.h fixed.h programs.h note_funcs.h defines.h \
   globals.h channel.h note_skel.h util.h readwave.h
 programs.o: programs.cpp programs.h fixed.h note_funcs.h globals.h \
-  channel.h note_skel.h defines.h util.h
+  channel.h note_skel.h defines.h util.h shared_object_manager.h
 readwave.o: readwave.cpp readwave.h programs.h fixed.h note_funcs.h \
   util.h
 util.o: util.cpp util.h programs.h fixed.h note_funcs.h globals.h \
   channel.h note_skel.h defines.h
 note_loader.o: note_loader.cpp note_loader.h programs.h fixed.h \
-  note_funcs.h globals.h channel.h note_skel.h defines.h util.h
+  note_funcs.h globals.h channel.h note_skel.h defines.h util.h \
+  shared_object_manager.h
+in_synth_cli.o: in_synth_cli.cpp in_synth_cli.h util.h programs.h fixed.h \
+  note_funcs.h communication.h globals.h channel.h note_skel.h defines.h \
+  load.h
+communication.o: communication.cpp communication.h
+shared_object_manager.o: shared_object_manager.cpp util.h programs.h \
+  fixed.h note_funcs.h shared_object_manager.h
diff --git a/synth/Makefile b/synth/Makefile
index 2f16297..8109bc8 100644
--- a/synth/Makefile
+++ b/synth/Makefile
@@ -3,7 +3,7 @@ CFLAGS=-Wall -g
 CXXFLAGS=$(CFLAGS)
 LDFLAGS=-lm `pkg-config --cflags --libs jack`
 
-OBJ=channel.o cli.o defines.o envelope.o filter.o globals.o jack.o load.o main.o note.o note_skel.o parser.o programs.o readwave.o util.o note_loader.o in_synth_cli.o communication.o
+OBJ=channel.o cli.o defines.o envelope.o filter.o globals.o jack.o load.o main.o note.o note_skel.o parser.o programs.o readwave.o util.o note_loader.o in_synth_cli.o communication.o shared_object_manager.o
 BIN=synth
 
 DEPENDFILE = .depend
diff --git a/synth/note_loader.cpp b/synth/note_loader.cpp
index 28613b9..d322552 100644
--- a/synth/note_loader.cpp
+++ b/synth/note_loader.cpp
@@ -6,6 +6,7 @@
 #include "programs.h"
 #include "note_funcs.h"
 #include "globals.h"
+#include "shared_object_manager.h"
 
 using namespace std;
 
@@ -13,10 +14,7 @@ void load_note_from_so(string file, program_t &prog)
 {
 	void *handle;
 	
-	handle = dlopen(file.c_str(), RTLD_LAZY);
-	
-	if (handle==NULL)
-		throw string("could not open shared object (")+string(dlerror())+string(")");
+	handle = my_dlopen(file);
 	
 	try
 	{
@@ -38,7 +36,7 @@ void load_note_from_so(string file, program_t &prog)
 	{
 		prog.create_func=NULL;
 		prog.dl_handle=NULL;
-		dlclose(handle);
+		dlref_dec(handle);
 		throw err;
 	}
 }
@@ -47,7 +45,7 @@ void maybe_unload_note(program_t &prog)
 {
 	if (prog.dl_handle)
 	{
-		dlclose(prog.dl_handle);
+		dlref_dec(prog.dl_handle);
 		prog.dl_handle=NULL;
 		prog.create_func=NULL;
 	}
diff --git a/synth/programs.cpp b/synth/programs.cpp
index 094f209..b896a06 100644
--- a/synth/programs.cpp
+++ b/synth/programs.cpp
@@ -1,8 +1,10 @@
 #include <string>
 #include <cstring>
+#include <dlfcn.h>
 
 #include "programs.h"
 #include "globals.h"
+#include "shared_object_manager.h"
 
 using namespace std;
 
@@ -78,6 +80,12 @@ void program_t::cleanup()
 			delete [] pfactor.fm[i];
 		delete [] pfactor.fm;
 	}
+
+	if (dl_handle)
+		dlref_dec(dl_handle);
+	
+	dl_handle=NULL;
+	create_func=NULL;
 }
 
 program_t& program_t::operator=(const program_t &that)
@@ -121,6 +129,8 @@ program_t& program_t::operator=(const program_t &that)
 		
 		this->create_func=that.create_func;
 		this->dl_handle=that.dl_handle;
+		if (dl_handle)
+			dlref_inc(dl_handle);
 		
 		return *this;
 	}
diff --git a/synth/shared_object_manager.cpp b/synth/shared_object_manager.cpp
new file mode 100644
index 0000000..045f409
--- /dev/null
+++ b/synth/shared_object_manager.cpp
@@ -0,0 +1,65 @@
+#include <dlfcn.h>
+#include <map>
+#include <string>
+
+#include "util.h"
+#include "shared_object_manager.h"
+
+using namespace std;
+
+map<void*, int> dl_ref_count;
+
+void* my_dlopen(string file)
+{
+	void* handle;
+	
+	if (file.find('/')==string::npos)
+		file="./"+file;
+	
+	handle=dlopen(file.c_str(),RTLD_NOW);
+
+	if (handle==NULL)
+		throw string("could not open shared object (")+string(dlerror())+string(")");
+	
+	if (dl_ref_count[handle]!=0) //the library is already opened
+	{
+		output_verbose("the requested shared object '"+file+"' is already opened, reusing the handle #"+IntToStr(int(handle)));
+		dlclose(handle); //we don't need it opened twice
+	}
+	else
+	{
+		output_verbose("the requested shared object '"+file+"' has been loaded with handle #"+IntToStr(int(handle)));
+	}
+	
+	dl_ref_count[handle]++;
+	
+	return handle;
+}
+
+void dlref_inc(void* handle)
+{
+	if (handle==NULL)
+		throw string("dlref_inc: tried to increment the ref-count for NULL");
+	
+	if (dl_ref_count[handle]==0)
+		throw string("dlref_inc: tried to increment the ref-count for a nonexistent handle");
+		
+	dl_ref_count[handle]++;
+}
+
+void dlref_dec(void* handle)
+{
+	if (handle==NULL)
+		throw string("dlref_inc: tried to increment the ref-count for NULL");
+	
+	if (dl_ref_count[handle]==0)
+		throw string("dlref_inc: tried to decrement the ref-count for a nonexistent handle");
+	
+	dl_ref_count[handle]--;
+	
+	if (dl_ref_count[handle]==0)
+	{
+		output_verbose("noone uses dl-handle "+IntToStr(int(handle))+", unloading the shared object...");
+		dlclose(handle);
+	}
+}
diff --git a/synth/shared_object_manager.h b/synth/shared_object_manager.h
new file mode 100644
index 0000000..5927408
--- /dev/null
+++ b/synth/shared_object_manager.h
@@ -0,0 +1,8 @@
+#ifndef __SHARED_OBJECT_MANAGER__
+#define __SHARED_OBJECT_MANAGER__
+
+void* my_dlopen(string file);
+void dlref_inc(void* handle);
+void dlref_dec(void* handle);
+
+#endif