Add mutex (#69)

ChangeLog

@@ -1,3 +1,7 @@
+2022-06-18  Alex Kotov  <kotovalexarian@gmail.com>
+
+	* include/kernaux/mutex.h: Added
+
 2022-06-17  Alex Kotov  <kotovalexarian@gmail.com>
 
 	* configure.ac: Added package "alloc"

Makefile.am

@@ -21,7 +21,7 @@ libc/libc.la:
 
 lib_LTLIBRARIES = libkernaux.la
 
-libkernaux_la_SOURCES = src/libc.h src/assert.c
+libkernaux_la_SOURCES = src/libc.h src/assert.c src/mutex.c
 libkernaux_la_LIBADD =
 
 if ASM_I386

README.md

@@ -44,6 +44,7 @@ zero). Work-in-progress APIs can change at any time.
     * [Example: Assert](/examples/assert.c)
     * [Example: Panic](/examples/panic.c)
   * Stack trace *(planned)*
+  * [Mutex](/include/kernaux/mutex.h) (*non-breaking since* **?.?.?**)
   * [Input/output](/include/kernaux/io.h) (*work in progress*)
   * Architecture-specific code (*work in progress*)
     * [Declarations](/include/kernaux/arch/)

include/Makefile.am

@@ -4,6 +4,7 @@ nobase_include_HEADERS = \
 	kernaux/arch/riscv64.h \
 	kernaux/arch/x86_64.h \
 	kernaux/assert.h \
+	kernaux/mutex.h \
 	kernaux/version.h
 
 if ASM_I386

include/kernaux.h.in

@@ -4,6 +4,7 @@
 */
 
 #include <kernaux/assert.h>
+#include <kernaux/mutex.h>
 #include <kernaux/version.h>
 
 @comment_line_alloc@#include <kernaux/alloc.h>

include/kernaux/mutex.h

@@ -0,0 +1,26 @@
+#ifndef KERNAUX_INCLUDED_MUTEX
+#define KERNAUX_INCLUDED_MUTEX
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define KERNAUX_MUTEX_EXTRA_DATA_SIZE (32)
+
+typedef void (*KernAux_Mutex_Lock  )(void *extra_data);
+typedef void (*KernAux_Mutex_Unlock)(void *extra_data);
+
+typedef struct KernAux_Mutex {
+    KernAux_Mutex_Lock lock;
+    KernAux_Mutex_Unlock unlock;
+    char extra_data[KERNAUX_MUTEX_EXTRA_DATA_SIZE];
+} *KernAux_Mutex;
+
+void KernAux_Mutex_lock  (KernAux_Mutex mutex);
+void KernAux_Mutex_unlock(KernAux_Mutex mutex);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

src/mutex.c

@@ -0,0 +1,22 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <kernaux/assert.h>
+#include <kernaux/mutex.h>
+
+void KernAux_Mutex_lock(const KernAux_Mutex mutex)
+{
+    KERNAUX_ASSERT(mutex);
+    KERNAUX_ASSERT(mutex->lock);
+
+    mutex->lock(mutex->extra_data);
+}
+
+void KernAux_Mutex_unlock(const KernAux_Mutex mutex)
+{
+    KERNAUX_ASSERT(mutex);
+    KERNAUX_ASSERT(mutex->unlock);
+
+    mutex->unlock(mutex->extra_data);
+}