Some debug tools (#704)

* machinarium: add machine_get_backtrace*

This functions will fix bugs by printing backtraces

Signed-off-by: rkhapov <[email protected]>

* sources/console.c: clients table improvements

1) rename 'ptr' to 'id' which is more obvious
2) replace useless 'link' with 'ptr' which can be used for debugging
3) add column 'coro' with coroutine id of the client, which can be used for debugging too

Signed-off-by: rkhapov <[email protected]>

---------

Signed-off-by: rkhapov <[email protected]>
Co-authored-by: rkhapov <[email protected]>

sources/console.c

@@ -1339,18 +1339,24 @@ static inline int od_console_show_clients_callback(od_client_t *client,
 	rc = kiwi_be_write_data_row_add(stream, offset, data, data_len);
 	if (rc == NOT_OK_RESPONSE)
 		return NOT_OK_RESPONSE;
-	/* ptr */
+	/* id */
 	data_len =
 		od_snprintf(data, sizeof(data), "%s%.*s", client->id.id_prefix,
 			    (signed)sizeof(client->id.id), client->id.id);
 	rc = kiwi_be_write_data_row_add(stream, offset, data, data_len);
 	if (rc == NOT_OK_RESPONSE)
 		return NOT_OK_RESPONSE;
-	/* link */
-	data_len = od_snprintf(data, sizeof(data), "%s", "");
+	/* ptr */
+	data_len = od_snprintf(data, sizeof(data), "%p", client);
 	rc = kiwi_be_write_data_row_add(stream, offset, data, data_len);
 	if (rc == NOT_OK_RESPONSE)
 		return NOT_OK_RESPONSE;
+	/* coro */
+	data_len = od_snprintf(data, sizeof(data), "%d", client->coroutine_id);
+	rc = kiwi_be_write_data_row_add(stream, offset, data, data_len);
+	if (rc == NOT_OK_RESPONSE) {
+		return NOT_OK_RESPONSE;
+	}
 	/* remote_pid */
 	data_len = od_snprintf(data, sizeof(data), "0");
 	rc = kiwi_be_write_data_row_add(stream, offset, data, data_len);
@@ -1390,10 +1396,10 @@ static inline int od_console_show_clients(od_client_t *client,
 
 	machine_msg_t *msg;
 	msg = kiwi_be_write_row_descriptionf(
-		stream, "ssssssdsdssddssds", "type", "user", "database",
+		stream, "ssssssdsdssddssdds", "type", "user", "database",
 		"state", "storage_user", "addr", "port", "local_addr",
 		"local_port", "connect_time", "request_time", "wait", "wait_us",
-		"ptr", "link", "remote_pid", "tls");
+		"id", "ptr", "coro", "remote_pid", "tls");
 	if (msg == NULL)
 		return NOT_OK_RESPONSE;
 

third_party/machinarium/sources/CMakeLists.txt

@@ -32,6 +32,7 @@ set(machine_src
     close.c
     connect.c
     bind.c
+    backtrace.c
     eventfd.c
     cond.c
     read.c

third_party/machinarium/sources/backtrace.c

@@ -0,0 +1,58 @@
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <machinarium.h>
+
+#include <stdio.h>
+#include <dlfcn.h>
+#include <execinfo.h>
+
+MACHINE_API int machine_get_backtrace(void **entries, int max)
+{
+	return backtrace(entries, max);
+}
+
+#define MM_BACKTRACE_STRING_N_ENTRIES 15
+
+__thread char backtrace_string[MM_BACKTRACE_STRING_N_ENTRIES * 40];
+
+MACHINE_API const char *machine_get_backtrace_string()
+{
+	void *bt[MM_BACKTRACE_STRING_N_ENTRIES];
+	int nentries = machine_get_backtrace(bt, MM_BACKTRACE_STRING_N_ENTRIES);
+
+	if (nentries <= 0) {
+		return NULL;
+	}
+
+	char *wptr = backtrace_string;
+	for (int i = 0; i < nentries; ++i) {
+		wptr += sprintf(wptr, "%p ", bt[i]);
+	}
+
+	wptr += sprintf(wptr, "(");
+
+	for (int i = 0; i < nentries; ++i) {
+		void *addr = bt[i];
+
+		Dl_info info;
+		if (dladdr(addr, &info) == 0) {
+			wptr += sprintf(wptr, "[unknown]");
+		} else {
+			void *calibrated = (void *)((uintptr_t)addr -
+						    (uintptr_t)info.dli_fbase);
+
+			wptr += sprintf(wptr, "%p", calibrated);
+		}
+
+		if (i != nentries - 1) {
+			wptr += sprintf(wptr, " ");
+		}
+	}
+
+	wptr += sprintf(wptr, ")");
+	*wptr = '\0';
+
+	return backtrace_string;
+}

third_party/machinarium/sources/machinarium.h

@@ -295,6 +295,13 @@ MACHINE_API ssize_t machine_tls_cert_hash(
 MACHINE_API char
 machine_compression_choose_alg(char *client_compression_algorithms);
 
+/* debug tools */
+
+// note: backtrace functions are currently slow
+// if you want bt collection to be fast, impl should be rewritten
+MACHINE_API const char *machine_get_backtrace_string();
+MACHINE_API int machine_get_backtrace(void **entries, int max);
+
 #ifdef __cplusplus
 }
 #endif