From 7a0134204ebf3fe03ce670348c326521ae48f2ed Mon Sep 17 00:00:00 2001
From: Lukas Fleischer <lfleischer@calcurse.org>
Date: Fri, 8 Sep 2017 20:34:37 +0200
Subject: Use a shared input/output mutex

Replace the save mutex with a common mutex, which is locked whenever
read or write operations on the data files are performed. Also, since
this mutex is an implementation detail, mark the locking functions
static and remove them from the header file.

Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>
---
 src/io.c | 37 +++++++++++++++++++++++--------------
 1 file changed, 23 insertions(+), 14 deletions(-)

(limited to 'src/io.c')

diff --git a/src/io.c b/src/io.c
index 0cefa9c..600993b 100644
--- a/src/io.c
+++ b/src/io.c
@@ -286,16 +286,16 @@ void io_extract_data(char *dst_data, const char *org, int len)
 	*dst_data = '\0';
 }
 
-static pthread_mutex_t io_save_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t io_mutex = PTHREAD_MUTEX_INITIALIZER;
 
-void io_save_mutex_lock(void)
+static void io_mutex_lock(void)
 {
-	pthread_mutex_lock(&io_save_mutex);
+	pthread_mutex_lock(&io_mutex);
 }
 
-void io_save_mutex_unlock(void)
+static void io_mutex_unlock(void)
 {
-	pthread_mutex_unlock(&io_save_mutex);
+	pthread_mutex_unlock(&io_mutex);
 }
 
 /* Print all appointments and events to stdout. */
@@ -434,10 +434,10 @@ static void io_merge_data(void)
 	asprintf(&path_apts_new, "%s%s", path_apts, new_ext);
 	asprintf(&path_todo_new, "%s%s", path_todo, new_ext);
 
-	io_save_mutex_lock();
+	io_mutex_lock();
 	io_save_apts(path_apts_new);
 	io_save_todo(path_todo_new);
-	io_save_mutex_unlock();
+	io_mutex_unlock();
 
 	/*
 	 * We do not directly write to the data files here; however, the
@@ -504,22 +504,29 @@ static int io_check_data_files_modified()
 {
 	FILE *fp;
 	char sha1_new[SHA1_DIGESTLEN * 2 + 1];
+	int ret = 1;
+
+	io_mutex_lock();
 
 	if ((fp = fopen(path_apts, "r"))) {
 		sha1_stream(fp, sha1_new);
 		fclose(fp);
 		if (strncmp(sha1_new, apts_sha1, SHA1_DIGESTLEN * 2) != 0)
-			return 1;
+			goto cleanup;
 	}
 
 	if ((fp = fopen(path_todo, "r"))) {
 		sha1_stream(fp, sha1_new);
 		fclose(fp);
 		if (strncmp(sha1_new, todo_sha1, SHA1_DIGESTLEN * 2) != 0)
-			return 1;
+			goto cleanup;
 	}
 
-	return 0;
+	ret = 0;
+
+cleanup:
+	io_mutex_unlock();
+	return ret;
 }
 
 /* Save the calendar data */
@@ -538,7 +545,7 @@ void io_save_cal(enum save_display display)
 		return;
 
 	run_hook("pre-save");
-	pthread_mutex_lock(&io_save_mutex);
+	io_mutex_lock();
 
 	show_bar = 0;
 	if (ui_mode == UI_CURSES && display == IO_SAVE_DISPLAY_BAR
@@ -574,7 +581,7 @@ void io_save_cal(enum save_display display)
 		keys_wait_for_any_key(win[KEY].p);
 	}
 
-	pthread_mutex_unlock(&io_save_mutex);
+	io_mutex_unlock();
 	run_hook("post-save");
 }
 
@@ -865,8 +872,10 @@ void io_load_todo(struct item_filter *filter)
 void io_load_data(struct item_filter *filter)
 {
 	run_hook("pre-load");
+	io_mutex_lock();
 	io_load_app(filter);
 	io_load_todo(filter);
+	io_mutex_unlock();
 	run_hook("post-load");
 }
 
@@ -1495,10 +1504,10 @@ void io_stop_psave_thread(void)
 		return;
 
 	/* Lock the mutex to avoid cancelling the thread during saving. */
-	io_save_mutex_lock();
+	io_mutex_lock();
 	pthread_cancel(io_t_psave);
 	pthread_join(io_t_psave, NULL);
-	io_save_mutex_unlock();
+	io_mutex_unlock();
 }
 
 /*
-- 
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