AMD64 build fixes and parallelism tweaks

TODO: figure out how to autodetect lib vs lib64.

These changes were made some time ago (can't remember when) but didn't
get committed until now.  (Yes, naughty me, but perhaps I was in a rush.)

Makefile

@@ -1,16 +1,17 @@
 .PHONY: clean install
 
-CS_PATH=/usr
+CS_PATH ?= /usr
 MY_CFLAGS+=-I$(CS_PATH)/include/ClearSilver $(CFLAGS)
 MY_CFLAGS+=$(shell Wand-config --cflags --cppflags)
 MY_LDFLAGS+=$(shell Wand-config --ldflags --libs) $(LDFLAGS)
 
 MY_CFLAGS+=$(shell pkg-config --cflags json)
 MY_LDFLAGS+=$(shell pkg-config --libs json)
+MY_LDFLAGS+=-ljpeg
 OBJS=obj/main.o obj/util.o obj/galleries.o obj/gallery.o obj/varray.o \
 	obj/photo.o obj/hdf-json.o obj/jpeg.o \
-	$(CS_PATH)/lib/libneo_cgi.a $(CS_PATH)/lib/libneo_cs.a \
+	$(CS_PATH)/lib64/libneo_cgi.a $(CS_PATH)/lib64/libneo_cs.a \
-	$(CS_PATH)/lib/libneo_utl.a
+	$(CS_PATH)/lib64/libneo_utl.a
 
 VERSIONSTAMP=$(shell if [ -d .git ]; then git describe; else cat version; fi)
 COMPILESTAMP=$(shell date "+%Y-%m-%d %H:%M:%S %z" )
@@ -23,7 +24,7 @@ obj:
 obj/%.o:	src/%.c include/%.h obj
 	$(CC) -DCOMPILESTAMP='"$(COMPILESTAMP)"' \
 		-DVERSIONSTAMP='"$(VERSIONSTAMP)"' \
-		$(MY_CFLAGS) -I include -o $@ -c $<
+		$(MY_CFLAGS) -I include $(CPPFLAGS) -o $@ -c $<
 
 clean:
 	rm -fr obj gallery.cgi

include/util.h

@@ -179,4 +179,14 @@ void sort_str_array( char** array, size_t length, int case_insensitive );
 void sort_array( void** array, size_t length,
 				int (*compare)( const void*, const void* ) );
 
+/*!
+ * Pause if the server load is too high.
+ * This causes the CGI script to sleep for a second if the load average is
+ * above MAX_CPU_LOAD.
+ */
+void wait_cpu_load();
+#ifndef MAX_CPU_LOAD
+#define MAX_CPU_LOAD	(2.0)
+#endif
+
 #endif

src/photo.c

@@ -463,21 +463,25 @@ char* resize_photo(	struct photo_meta* dest,
 		}
 	}
 
+#ifndef NO_SEMAPHORE
 	/*
 	 * Check for semaphore... if it exists, wait for it to disappear.
 	 * For this, we use the open() syscall with O_CREAT|O_EXCL, which
 	 * will fail if the file already exists.
 	 */
-	char* sem_file = construct_path( "s/s/s", get_cgidir(),
+	char* sem_file = construct_path( "s/ss", get_cgidir(),
-						CACHEDIR, "semaphore" );
+						cache_file, ".sem" );
 	int fd = open( sem_file, O_CREAT|O_EXCL, S_IRUSR|S_IWUSR );
 	while( fd == -1 ) {
 		sleep(1);
 		fd = open( sem_file, O_CREAT|O_EXCL, S_IRUSR|S_IWUSR );
+		fprintf( stderr, "resize_photo: waiting for semaphore %s (fd: %d)\n",
+			sem_file, fd );
 		dprintf( "resize_photo: waiting for semaphore %s (fd: %d)\n",
 			sem_file, fd );
 	}
 	close(fd);
+#endif
 	
 	MagickWand* wand = NewMagickWand();
 	dprintf( "resize_photo: wand created at %p\n", wand);
@@ -486,11 +490,12 @@ char* resize_photo(	struct photo_meta* dest,
 		char* description=MagickGetException(wand,&severity);
 		dprintf("%s %s %ld %s\n",GetMagickModule(),description);
 		gcfree( cache_file );
-	
+
+#ifndef NO_SEMAPHORE
 		/* Get rid of the semaphore */
 		unlink( sem_file );
 		gcfree( sem_file );
-
+#endif
 		return NULL;
 	}
 	
@@ -521,9 +526,11 @@ char* resize_photo(	struct photo_meta* dest,
 		char* description=MagickGetException(wand,&severity);
 		dprintf("%s %s %ld %s\n",GetMagickModule(),description);
 	
+#ifndef NO_SEMAPHORE
 		/* Get rid of the semaphore */
 		unlink( sem_file );
 		gcfree( sem_file );
+#endif
 
 		gcfree( cache_file );
 		cache_file = NULL;
@@ -531,9 +538,11 @@ char* resize_photo(	struct photo_meta* dest,
 
 	DestroyMagickWand( wand );
 	
+#ifndef NO_SEMAPHORE
 	/* Get rid of the semaphore */
 	unlink( sem_file );
 	gcfree( sem_file );
+#endif
 
 	gcfree( cache_path );
 	dprintf( "resize_photo: resized photo at %s (%p)\n", cache_file, cache_file );

src/util.c

@@ -6,6 +6,8 @@
 #include <errno.h>
 #include <dprintf.h>
 
+#include <unistd.h>
+
 /* Memory management -- helpers */
 #ifdef MEMALLOC_TRACK
 struct mem_chunk* gc_find_chunk( void* ptr ) {
@@ -678,3 +680,19 @@ void sort_str_array( char** array, size_t length, int case_insensitive ) {
 	else
 		quicksort_main( (void**)array, 0, length-1, &void_strcmp );
 }
+
+
+void wait_load() {
+#ifndef NO_MAX_LOAD
+	double avg;
+	if (getloadavg(&avg,1) < 0)
+		return;
+	while(avg >= MAX_CPU_LOAD) {
+		dprintf("Waiting for CPU load %f to drop below %f\n",
+			avg, MAX_CPU_LOAD);
+		sleep(1);
+		if (getloadavg(&avg,1) < 0)
+			return;
+	}
+#endif
+}