Add an option to run mostly synchronously for profiling

flatgeobuf.cpp

@@ -302,7 +302,7 @@ void fgbRunQueue() {
 	}
 
 	for (size_t i = 0; i < CPUS; i++) {
-		if (pthread_create(&pthreads[i], NULL, fgb_run_parse_feature, &qra[i]) != 0) {
+		if (pthread_create_wrap(&pthreads[i], NULL, fgb_run_parse_feature, &qra[i]) != 0) {
 			perror("pthread_create");
 			exit(EXIT_FAILURE);
 		}

geobuf.cpp

@@ -464,7 +464,7 @@ void runQueue() {
 	}
 
 	for (size_t i = 0; i < CPUS; i++) {
-		if (pthread_create(&pthreads[i], NULL, run_parse_feature, &qra[i]) != 0) {
+		if (pthread_create_wrap(&pthreads[i], NULL, run_parse_feature, &qra[i]) != 0) {
 			perror("pthread_create");
 			exit(EXIT_FAILURE);
 		}

main.cpp

@@ -468,7 +468,7 @@ void do_read_parallel(char *map, long long len, long long initial_offset, const
 	}
 
 	for (size_t i = 0; i < CPUS; i++) {
-		if (pthread_create(&pthreads[i], NULL, run_parse_json, &pja[i]) != 0) {
+		if (pthread_create_wrap(&pthreads[i], NULL, run_parse_json, &pja[i]) != 0) {
 			perror("pthread_create");
 			exit(EXIT_FAILURE);
 		}
@@ -682,7 +682,7 @@ void start_parsing(int fd, STREAM *fp, long long offset, long long len, std::ato
 	rpa->want_dist = want_dist;
 	rpa->filters = filters;
 
-	if (pthread_create(parallel_parser, NULL, run_read_parallel, rpa) != 0) {
+	if (pthread_create_wrap(parallel_parser, NULL, run_read_parallel, rpa) != 0) {
 		perror("pthread_create");
 		exit(EXIT_FAILURE);
 	}
@@ -877,7 +877,7 @@ void radix1(int *geomfds_in, int *indexfds_in, int inputs, int prefix, int split
 				}
 
 				for (size_t a = 0; a < CPUS; a++) {
-					if (pthread_create(&pthreads[a], NULL, run_sort, &args[a]) != 0) {
+					if (pthread_create_wrap(&pthreads[a], NULL, run_sort, &args[a]) != 0) {
 						perror("pthread_create");
 						exit(EXIT_FAILURE);
 					}
@@ -2789,6 +2789,7 @@ int main(int argc, char **argv) {
 		{"check-polygons", no_argument, &additional[A_DEBUG_POLYGON], 1},
 		{"no-polygon-splitting", no_argument, &prevent[P_POLYGON_SPLIT], 1},
 		{"prefer-radix-sort", no_argument, &additional[A_PREFER_RADIX_SORT], 1},
+		{"single-threaded", no_argument, &prevent[P_THREADS], 1},
 		{"help", no_argument, 0, 'H'},
 
 		{0, 0, 0, 0},
@@ -3451,3 +3452,16 @@ bool progress_time() {
 		return false;
 	}
 }
+
+static void *donothing(void *arg) {
+	return arg;
+}
+
+int pthread_create_wrap(pthread_t *thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg) {
+	if (prevent[P_THREADS]) {
+		void *ret = start_routine(arg);
+		return pthread_create(thread, attr, donothing, ret);
+	} else {
+		return pthread_create(thread, attr, start_routine, arg);
+	}
+}

main.hpp

@@ -72,4 +72,6 @@ bool progress_time();
 
 #define MAX_ZOOM 24
 
+int pthread_create_wrap(pthread_t *thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg);
+
 #endif

options.hpp

@@ -44,6 +44,7 @@
 #define P_REVERSE_SOURCE_POLYGON_WINDING ((int) 'W')
 #define P_EMPTY_CSV_COLUMNS ((int) 'e')
 #define P_BASEZOOM_ABOVE_MAXZOOM ((int) 'b')
+#define P_THREADS ((int) 'T')
 
 extern int prevent[256];
 extern int additional[256];

text.cpp

@@ -141,6 +141,10 @@ std::string format_commandline(int argc, char **argv) {
 	std::string out;
 
 	for (int i = 0; i < argc; i++) {
+		if (std::string(argv[i]) == "-pT") {
+			continue;
+		}
+
 		bool need_quote = false;
 		for (char *cp = argv[i]; *cp != '\0'; cp++) {
 			if (!isalpha(*cp) && !isdigit(*cp) &&

tile.cpp

@@ -2225,8 +2225,8 @@ long long write_tile(FILE *geoms, std::atomic<long long> *geompos_in, char *meta
 			args[i].shared_nodes = &shared_nodes;
 
 			if (tasks > 1) {
-				if (pthread_create(&pthreads[i], NULL, partial_feature_worker, &args[i]) != 0) {
+				if (pthread_create_wrap(&pthreads[i], NULL, partial_feature_worker, &args[i]) != 0) {
-					perror("pthread_create");
+					perror("pthread_create_wrap");
 					exit(EXIT_FAILURE);
 				}
 			} else {
@@ -2980,8 +2980,8 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 				args[thread].still_dropping = false;
 				args[thread].strategy = &strategy;
 
-				if (pthread_create(&pthreads[thread], NULL, run_thread, &args[thread]) != 0) {
+				if (pthread_create_wrap(&pthreads[thread], NULL, run_thread, &args[thread]) != 0) {
-					perror("pthread_create");
+					perror("pthread_create_wrap");
 					exit(EXIT_FAILURE);
 				}
 			}