From: Tomas Mudrunka <tomas@mudrunka.cz>
Date: Tue, 29 Jun 2021 11:15:11 +0000 (+0200)
Subject: Fixed deadlocks in pthread_pause
X-Git-Url: http://git.harvie.cz/?p=mirrors%2FPrograms.git;a=commitdiff_plain;h=24286ba9a7ae3a8c6f5eefe9455e18bd758e742b

Fixed deadlocks in pthread_pause
---

diff --git a/c/pthread_extra/Makefile b/c/pthread_extra/Makefile
index 0b96b41..1197cca 100644
--- a/c/pthread_extra/Makefile
+++ b/c/pthread_extra/Makefile
@@ -1,5 +1,5 @@
 COPT=-g -O2 -flto -ftree-vectorize -ftree-slp-vectorize -fvisibility=hidden -D_FORTIFY_SOURCE=2 -DMG_ENABLE_FS=0 -fstack-protector-strong -fno-delete-null-pointer-checks $(CARCH)
-#COPT=-fvisibility=hidden -DMG_ENABLE_FS=0 -fstack-protector-strong $(CARCH)
+#COPT=-g -fvisibility=hidden -DMG_ENABLE_FS=0 -fstack-protector-strong $(CARCH)
 CDEF=-D_POSIX_C_SOURCE=200809L -D_XOPEN_SOURCE=700 -D_DEFAULT_SOURCE=1 -D_GNU_SOURCE
 CERR=-Wall -Wextra -Werror -pedantic -Werror=date-time -Wformat-security -Wduplicated-cond -Wfloat-equal -Wshadow -Wlogical-not-parentheses -Wnull-dereference
 
diff --git a/c/pthread_extra/README.md b/c/pthread_extra/README.md
index 0824f47..60876f2 100644
--- a/c/pthread_extra/README.md
+++ b/c/pthread_extra/README.md
@@ -5,7 +5,7 @@ Currently will probably only work on Linux. Mostly experimental code.
 
 ### Components
 
+  * pthread_pause - implements suspend/resume functionality for pthreads (no know issues, recently fixed some deadlocks, but not really tested)
   * pthread_msgqueue - implements message queues, more features than POSIX mqueue (no known issues, but not really tested)
   * pthread_user_data - allows user to store and retreive custom data using thread handle as a key (suboptimal, used internaly, not tested)
-  * pthread_multi - lock multiple mutexes at once (might cause deadlocks in complex scenarios)
-  * pthread_pause - implements suspend/resume functionality for pthreads (causes deadlocks under high load)
+  * pthread_multi - lock multiple mutexes at once (might cause deadlocks in complex scenarios???)
diff --git a/c/pthread_extra/pthread_pause.c b/c/pthread_extra/pthread_pause.c
index 662d78f..6df2e3a 100644
--- a/c/pthread_extra/pthread_pause.c
+++ b/c/pthread_extra/pthread_pause.c
@@ -19,7 +19,7 @@ void pthread_pause_handler() {
 	sigset_t sigset;
 	sigfillset(&sigset);
 	sigdelset(&sigset, PTHREAD_XSIG_STOP);
-	while(!pthread_user_data_internal(pthread_self())->running) {
+	if(!pthread_user_data_internal(pthread_self())->running) {
 		sigsuspend(&sigset);
 	}
 }
diff --git a/c/pthread_extra/test_pause.c b/c/pthread_extra/test_pause.c
index 47f2db0..4673289 100644
--- a/c/pthread_extra/test_pause.c
+++ b/c/pthread_extra/test_pause.c
@@ -22,6 +22,22 @@ int main() {
 	//That way you can be sure it is pausable immediately
 	pthread_create(&a, NULL, thread_test, " A");
 	pthread_create(&b, NULL, thread_test, " B");
+	//sleep(1);
+
+	//printf("OK\n");
+	/*
+	for(int32_t i = 1;i>0;i++) {
+		pthread_pause(a);
+		pthread_pause(a);
+		pthread_unpause(a);
+		pthread_unpause(a);
+	}
+	*/
+	/*
+	exit(23);
+	pthread_pause(a);
+	pthread_unpause(b);
+	*/
 
 	while(1) {
 		pthread_pause(b);