From e865f5920d4c6a53ee12cc1dc5c939f7d6414f93 Mon Sep 17 00:00:00 2001
From: Zoltan Varga <vargaz@gmail.com>
Date: Thu, 31 Oct 2019 01:33:50 -0400
Subject: [PATCH] [runtime] Add a --enable-minimal=threads configure option to
 disable threading support. Use it on wasm. (mono/mono#17611)

Commit migrated from https://github.com/mono/mono/commit/dc76a95aa9d266c0c9611408b00e63dfeca214b5
---
 src/mono/configure.ac                 |  7 +++-
 src/mono/mono/utils/mono-coop-mutex.h | 79 ++++++++++++++++++++++++++++++++++-
 src/mono/mono/utils/mono-os-mutex.h   | 42 +++++++++++++++++++
 3 files changed, 126 insertions(+), 2 deletions(-)

diff --git a/src/mono/configure.ac b/src/mono/configure.ac
index 7ab5aa4..12c7048 100644
--- a/src/mono/configure.ac
+++ b/src/mono/configure.ac
@@ -1752,7 +1752,7 @@ AM_CONDITIONAL(ENABLE_STATIC_GCC_LIBS, test "x$enable_static_gcc_libs" = "xyes")
 AC_ARG_ENABLE(minimal, [  --enable-minimal=LIST      drop support for LIST subsystems.
      LIST is a comma-separated list from: aot, profiler, decimal, pinvoke, debug, appdomains, verifier, dllmap,
      reflection_emit, reflection_emit_save, large_code, logging, com, ssa, generics, attach, jit, interpreter, simd, soft_debug, perfcounters, normalization, desktop_loader, shared_perfcounters, remoting,
-	 security, lldb, mdb, assert_messages, cleanup, sgen_marksweep_conc, sgen_split_nursery, sgen_gc_bridge, sgen_debug_helpers, sockets, gac.],
+	 security, lldb, mdb, assert_messages, cleanup, sgen_marksweep_conc, sgen_split_nursery, sgen_gc_bridge, sgen_debug_helpers, sockets, gac, threads.],
 [
 	for feature in `echo "$enable_minimal" | sed -e "s/,/ /g"`; do
 		eval "mono_feature_disable_$feature='yes'"
@@ -1969,6 +1969,11 @@ if test "x$mono_feature_disable_dllmap" = "xyes"; then
     AC_MSG_NOTICE([Disabled DllMap in the loader.])
 fi
 
+if test "x$mono_feature_disable_threads" = "xyes"; then
+	AC_DEFINE(DISABLE_THREADS, 1, [Disable Threads])
+	AC_MSG_NOTICE([Disabled threading support])
+fi
+
 AC_ARG_ENABLE(executables, [  --disable-executables disable the build of the runtime executables], enable_executables=$enableval, enable_executables=yes)
 AM_CONDITIONAL(DISABLE_EXECUTABLES, test x$enable_executables = xno)
 
diff --git a/src/mono/mono/utils/mono-coop-mutex.h b/src/mono/mono/utils/mono-coop-mutex.h
index 2aa9bc6..61b62ac 100644
--- a/src/mono/mono/utils/mono-coop-mutex.h
+++ b/src/mono/mono/utils/mono-coop-mutex.h
@@ -15,11 +15,14 @@
  * we use mono_os_(mutex|cond|sem)_... on MonoCoop(Mutex|Cond|Sem) structures */
 
 typedef struct _MonoCoopMutex MonoCoopMutex;
+typedef struct _MonoCoopCond MonoCoopCond;
+
+#ifndef DISABLE_THREADS
+
 struct _MonoCoopMutex {
 	mono_mutex_t m;
 };
 
-typedef struct _MonoCoopCond MonoCoopCond;
 struct _MonoCoopCond {
 	mono_cond_t c;
 };
@@ -130,4 +133,78 @@ mono_coop_cond_broadcast (MonoCoopCond *cond)
 	MONO_EXIT_GC_SAFE;
 }
 
+#else /* DISABLE_THREADS */
+
+struct _MonoCoopMutex {
+	int dummy;
+};
+
+struct _MonoCoopCond {
+	int dummy;
+};
+
+static inline void
+mono_coop_mutex_init (MonoCoopMutex *mutex)
+{
+}
+
+static inline void
+mono_coop_mutex_init_recursive (MonoCoopMutex *mutex)
+{
+}
+
+static inline void
+mono_coop_mutex_destroy (MonoCoopMutex *mutex)
+{
+}
+
+static inline void
+mono_coop_mutex_lock (MonoCoopMutex *mutex)
+{
+}
+
+static inline gint
+mono_coop_mutex_trylock (MonoCoopMutex *mutex)
+{
+	return 0;
+}
+
+static inline void
+mono_coop_mutex_unlock (MonoCoopMutex *mutex)
+{
+}
+
+static inline void
+mono_coop_cond_init (MonoCoopCond *cond)
+{
+}
+
+static inline void
+mono_coop_cond_destroy (MonoCoopCond *cond)
+{
+}
+
+static inline void
+mono_coop_cond_wait (MonoCoopCond *cond, MonoCoopMutex *mutex)
+{
+}
+
+static inline gint
+mono_coop_cond_timedwait (MonoCoopCond *cond, MonoCoopMutex *mutex, guint32 timeout_ms)
+{
+	return 0;
+}
+
+static inline void
+mono_coop_cond_signal (MonoCoopCond *cond)
+{
+}
+
+static inline void
+mono_coop_cond_broadcast (MonoCoopCond *cond)
+{
+}
+
+#endif /* DISABLE_THREADS */
+
 #endif /* __MONO_COOP_MUTEX_H__ */
diff --git a/src/mono/mono/utils/mono-os-mutex.h b/src/mono/mono/utils/mono-os-mutex.h
index d2a466e..f26e9d8 100644
--- a/src/mono/mono/utils/mono-os-mutex.h
+++ b/src/mono/mono/utils/mono-os-mutex.h
@@ -43,6 +43,8 @@
 typedef pthread_mutex_t mono_mutex_t;
 typedef pthread_cond_t mono_cond_t;
 
+#ifndef DISABLE_THREADS
+
 static inline void
 mono_os_mutex_init_type (mono_mutex_t *mutex, int type)
 {
@@ -127,6 +129,46 @@ mono_os_mutex_unlock (mono_mutex_t *mutex)
 		g_error ("%s: pthread_mutex_unlock failed with \"%s\" (%d)", __func__, g_strerror (res), res);
 }
 
+#else /* DISABLE_THREADS */
+
+static inline void
+mono_os_mutex_init_type (mono_mutex_t *mutex, int type)
+{
+}
+
+static inline void
+mono_os_mutex_init (mono_mutex_t *mutex)
+{
+}
+
+static inline void
+mono_os_mutex_init_recursive (mono_mutex_t *mutex)
+{
+}
+
+static inline void
+mono_os_mutex_destroy (mono_mutex_t *mutex)
+{
+}
+
+static inline void
+mono_os_mutex_lock (mono_mutex_t *mutex)
+{
+}
+
+static inline int
+mono_os_mutex_trylock (mono_mutex_t *mutex)
+{
+	return 0;
+}
+
+static inline void
+mono_os_mutex_unlock (mono_mutex_t *mutex)
+{
+}
+
+#endif /* DISABLE_THREADS */
+
 static inline void
 mono_os_cond_init (mono_cond_t *cond)
 {
-- 
2.7.4