From a1160bb5b12b273f44860ccd4f028cb22c4f5e4d Mon Sep 17 00:00:00 2001
From: Scott Worley <scottworley@scottworley.com>
Date: Wed, 13 Sep 2023 14:51:07 -0700
Subject: [PATCH] test: Try writing to flock-locked files

---
 tl-append-test.c | 43 ++++++++++++++++++++++++++++---------------
 1 file changed, 28 insertions(+), 15 deletions(-)

diff --git a/tl-append-test.c b/tl-append-test.c
index 20ae7fb..04c679e 100644
--- a/tl-append-test.c
+++ b/tl-append-test.c
@@ -10,6 +10,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/file.h>
 #include <time.h>
 #include <unistd.h>
 
@@ -195,19 +196,23 @@ static void test_encode_time() {
   assert(encoded[19] == '\0');
 }
 
-static FILE *take_lock() {
-  FILE *f = fopen(FILENAME, "a");
-  if (f == NULL)
-    die_err("Couldn't open file for locking");
+static FILE *take_lock(FILE *f, char *lock_type) {
   int fd = fileno(f);
   if (fd == -1)
     die_err("Couldn't get file descriptor for locking");
-  if (fcntl(fd, F_SETLK,
-            &(struct flock){.l_type = F_WRLCK,
-                            .l_whence = SEEK_SET,
-                            .l_start = 0,
-                            .l_len = 0}) == -1)
-    die_err("Couldn't take lock");
+  if (strcmp(lock_type, "fcntl") == 0) {
+    if (fcntl(fd, F_SETLK,
+              &(struct flock){.l_type = F_WRLCK,
+                              .l_whence = SEEK_SET,
+                              .l_start = 0,
+                              .l_len = 0}) == -1)
+      die_err("Couldn't take fcntl lock");
+  } else if (strcmp(lock_type, "flock") == 0) {
+    if (flock(fd, LOCK_EX) == -1)
+      die_err("Couldn't take flock lock");
+  } else {
+    die("Bad lock type");
+  }
   return f;
 }
 
@@ -217,7 +222,7 @@ static void release_lock(FILE *f) {
 }
 
 static void *release_lock_after_delay(void *f) {
-  sleep(2);
+  sleep(1);
   release_lock((FILE *)f);
   return NULL;
 }
@@ -247,13 +252,17 @@ static void write_and_read_two_lines() {
   verify_log_contents((ex_t[]){e1, e2, END});
 }
 
-static void write_to_locked_log() {
+static void write_to_locked_log(char *lock_types[]) {
   remove_logfile();
   ex_t e1 = write_to_tl_append("begin\n");
-  FILE *lock = take_lock();
+  FILE *f = fopen(FILENAME, "a");
+  if (f == NULL)
+    die_err("Couldn't open file for locking");
+  for (int i = 0; lock_types[i]; i++)
+    take_lock(f, lock_types[0]);
   pthread_t unlock_thread;
   int create_ret =
-      pthread_create(&unlock_thread, NULL, &release_lock_after_delay, lock);
+      pthread_create(&unlock_thread, NULL, &release_lock_after_delay, f);
   if (create_ret != 0) {
     errno = create_ret;
     die_err("Couldn't start thread");
@@ -301,6 +310,10 @@ int main() {
   test_encode_time();
   write_and_read_line();
   write_and_read_two_lines();
-  write_to_locked_log();
+  write_to_locked_log((char *[]){NULL});
+  write_to_locked_log((char *[]){"fcntl", NULL});
+  write_to_locked_log((char *[]){"flock", NULL});
+  write_to_locked_log((char *[]){"flock", "fcntl", NULL});
+  write_to_locked_log((char *[]){"fcntl", "flock", NULL});
   write_concurrently();
 }
-- 
2.44.1