Add exhaustive_gen_retry, fix infinite loop, add retry limit to exhaustive gen

5 files changed, 49 insertions, 10 deletions

diff --git a/src/exhaustive/exhaustive.c b/src/exhaustive/exhaustive.c
index 3b16349..42c174f 100644
--- a/src/exhaustive/exhaustive.c
+++ b/src/exhaustive/exhaustive.c
@@ -99,15 +99,19 @@ void exhaustive_ainit(arg_t **argss, config_t *cfg) {
 	}
 }
 
-int exhaustive_gen(curve_t *curve, config_t *cfg, gen_t generators[],
-                   arg_t *argss[], int start_offset, int end_offset) {
+int exhaustive_gen_retry(curve_t *curve, config_t *cfg, gen_t generators[],
+                         arg_t *argss[], int start_offset, int end_offset,
+                         int retry) {
 	if (start_offset == end_offset) {
 		return 1;
 	}
 	if (start_offset > end_offset) {
-		return 0;
+		return -1;
 	}
-	pari_sp tops[end_offset - start_offset];
+	int num_gens = end_offset - start_offset;
+	pari_sp tops[num_gens];
+	int tries[num_gens];
+	memset(tries, 0, sizeof(int) * num_gens);
 
 	int state = start_offset;
 	while (state < end_offset) {
@@ -115,9 +119,19 @@ int exhaustive_gen(curve_t *curve, config_t *cfg, gen_t generators[],
 
 		int diff = generators[state](curve, cfg, argss ? argss[state] : NULL);
 		if (diff == INT_MIN) {
-			fprintf(stderr, "Error generating a curve. %i\n", state);
+			fprintf(stderr, "Error generating a curve. state = %i\n", state);
 			return 0;
 		}
+		if (diff == 0) {
+			int tried = ++tries[state - start_offset];
+			if (retry && tried >= retry) {
+				fprintf(stderr, "Reached retry limit: %i, state = %i\n", retry,
+				        state);
+				return 0;
+			}
+		} else if (diff > 0) {
+			tries[state - start_offset] = 0;
+		}
 		state += diff;
 
 		if (diff <= 0) {
@@ -141,6 +155,12 @@ int exhaustive_gen(curve_t *curve, config_t *cfg, gen_t generators[],
 	return 1;
 }
 
+int exhaustive_gen(curve_t *curve, config_t *cfg, gen_t generators[],
+                   arg_t *argss[], int start_offset, int end_offset) {
+	return exhaustive_gen_retry(curve, cfg, generators, argss, start_offset,
+	                            end_offset, 0);
+}
+
 void exhaustive_quit(arg_t *argss[]) {
 	equation_quit();
 	for (size_t i = 0; i < OFFSET_END; ++i) {
@@ -158,8 +178,8 @@ int exhaustive_do(config_t *cfg) {
 
 	for (long i = 0; i < cfg->count; ++i) {
 		curve_t *curve = curve_new();
-		if (!exhaustive_gen(curve, cfg, generators, argss, OFFSET_SEED,
-		                    OFFSET_END)) {
+		if (!exhaustive_gen_retry(curve, cfg, generators, argss, OFFSET_SEED,
+		                          OFFSET_END, 10)) {
 			curve_free(&curve);
 			return 1;
 		}
diff --git a/src/exhaustive/exhaustive.h b/src/exhaustive/exhaustive.h
index ee81874..76e8000 100644
--- a/src/exhaustive/exhaustive.h
+++ b/src/exhaustive/exhaustive.h
@@ -13,6 +13,21 @@
 /**
  *
  * @param curve
+ * @param cfg
+ * @param generators
+ * @param argss
+ * @param start_offset
+ * @param end_offset
+ * @param retry
+ * @return
+ */
+int exhaustive_gen_retry(curve_t *curve, config_t *cfg, gen_t generators[],
+                         arg_t *argss[], int start_offset, int end_offset,
+                         int retry);
+
+/**
+ *
+ * @param curve
  * @param config
  * @param generators
  * @param argss
diff --git a/src/invalid/invalid.c b/src/invalid/invalid.c
index 98052fd..c882b79 100644
--- a/src/invalid/invalid.c
+++ b/src/invalid/invalid.c
@@ -201,7 +201,8 @@ int invalid_do(config_t *cfg) {
 	invalid_ginit(gen, cfg);
 
 	// actually generate the curve
-	if (!exhaustive_gen(curve, cfg, gen, argss, OFFSET_FIELD, OFFSET_POINTS)) {
+	if (!exhaustive_gen_retry(curve, cfg, gen, argss, OFFSET_FIELD,
+	                          OFFSET_POINTS, 1)) {
 		curve_free(&curve);
 		return 1;
 	}
diff --git a/src/io/input.c b/src/io/input.c
index 4697d05..348302d 100644
--- a/src/io/input.c
+++ b/src/io/input.c
@@ -18,6 +18,9 @@ GEN input_i(const char *prompt, long bits) {
 	size_t n = 0;
 
 	ssize_t len = getdelim(&line, &n, delim, in);
+	if (len <= 0) {
+		return gen_m1;
+	}
 	if (len == 1) {
 		free(line);
 		return gen_m1;
@@ -26,7 +29,7 @@ GEN input_i(const char *prompt, long bits) {
 		;
 
 	pari_sp ltop = avma;
-	if (len <= 3 || line[0] != '0' && (line[1] != 'x' || line[1] != 'X')) {
+	if (len <= 3 || (line[0] != '0' && (line[1] != 'x' || line[1] != 'X'))) {
 		char *new_line = realloc(line, (size_t)(len + 2));
 		if (!new_line) {
 			perror("Couldn't alloc.");
diff --git a/src/math/order.c b/src/math/order.c
index e7abf56..1bcbb3e 100644
--- a/src/math/order.c
+++ b/src/math/order.c
@@ -17,7 +17,7 @@ int order_smallfact(curve_t *curve, config_t *cfg, arg_t *args) {
 	pari_ulong smallfact = *(pari_ulong *)args->args;
 	pari_sp ltop = avma;
 	GEN fact = mpfact(smallfact);
-	if  (lgefint(fact) > 3) {
+	if (lgefint(fact) > 3) {
 		smallfact = 0;
 	} else {
 		smallfact = itou(fact);