races

1 files changed, 38 insertions, 15 deletions

diff --git a/coroutine.c b/coroutine.c
index f138fcf..12d4a25 100644
--- a/coroutine.c
+++ b/coroutine.c
@@ -154,10 +154,11 @@ enum coroutine_state {
  */
 
 struct coroutine {
-	enum coroutine_state state;
-	jmp_buf              env;
-	size_t               stack_size;
-	void                *stack;
+	volatile enum coroutine_state  state;
+	volatile bool                  sig_unpause;
+	jmp_buf                        env;
+	size_t                         stack_size;
+	void                          *stack;
 };
 
 static struct coroutine coroutine_table[CONFIG_COROUTINE_NUM] = {0};
@@ -213,8 +214,10 @@ static void call_with_stack(void *stack, cr_fn_t fn, void *args) {
 static const uint8_t stack_pattern[] = {0x1e, 0x15, 0x16, 0x0a, 0xcc, 0x52, 0x7e, 0xb7};
 #endif
 
+static void inline assert_cid(cid_t cid) {
+	assert(cid > 0);
+	assert(cid <= CONFIG_COROUTINE_NUM);
 #if CONFIG_COROUTINE_PROTECT_STACK
-void assert_stack_protection(cid_t cid) {
 	assert(coroutine_table[cid-1].stack_size);
 	assert(coroutine_table[cid-1].stack);
 	for (size_t i = 0; i < sizeof(stack_pattern); i++) {
@@ -222,16 +225,12 @@ void assert_stack_protection(cid_t cid) {
 		assert(((uint8_t*)coroutine_table[cid-1].stack)[i] == stack_pattern[i]);
 		assert(((uint8_t*)coroutine_table[cid-1].stack)[j] == stack_pattern[j%sizeof(stack_pattern)]);
 	}
-}
-#else
-#  define assert_stack_protection(cid) ((void)0)
 #endif
+}
 
 #define assert_cid_state(cid, opstate) do {                     \
-		assert((cid) > 0);                              \
-		assert((cid) <= CONFIG_COROUTINE_NUM);          \
+		assert_cid(cid);                                \
 		assert(coroutine_table[(cid)-1].state opstate); \
-		assert_stack_protection(cid);                   \
 	} while (0)
 
 cid_t coroutine_add_with_stack_size(size_t stack_size, cr_fn_t fn, void *args) {
@@ -344,7 +343,6 @@ void cr_begin(void) {
 }
 
 static inline void _cr_transition(enum coroutine_state state) {
-	assert_cid_state(coroutine_running, == CR_RUNNING);
 	debugf("cid=%zu: transition %i->%i\n", coroutine_running, coroutine_table[coroutine_running-1].state, state);
 
 	coroutine_table[coroutine_running-1].state = state;
@@ -352,8 +350,19 @@ static inline void _cr_transition(enum coroutine_state state) {
 		longjmp(coroutine_main_env, 1); /* jump to point=b */
 }
 
-void cr_yield(void)           { _cr_transition(CR_RUNNABLE); }
-void cr_pause_and_yield(void) { _cr_transition(CR_PAUSED); }
+void cr_yield(void) {
+	assert_cid_state(coroutine_running, == CR_RUNNING);
+	_cr_transition(CR_RUNNABLE);
+}
+
+void cr_pause_and_yield(void) {
+	assert_cid_state(coroutine_running, == CR_RUNNING);
+	if (coroutine_table[cid-1].sig_unpause)
+		_cr_transition(CR_RUNNABLE);
+	else
+		_cr_transition(CR_PAUSED);
+	coroutine_table[cid-1].sig_unpause = false;
+}
 
 void cr_exit(void) {
 	assert_cid_state(coroutine_running, == CR_RUNNING);
@@ -367,7 +376,21 @@ void cr_unpause(cid_t cid) {
 	assert_cid_state(cid, == CR_PAUSED);
 	debugf("cr_unpause(%zu)\n", cid);
 
-	coroutine_table[cid-1].state = CR_RUNNABLE;
+	coroutine_table[cid-1].sig_unpause = false;
+	coroutine_table[cid-1].state       = CR_RUNNABLE;
+}
+
+void cr_unpause_from_sighandler(cid_t cid) {
+	assert_cid(cid);
+
+	switch (coroutine_table[cid-1].state) {
+	case CR_RUNNING:
+		coroutine_table[cid-1].sig_unpause = true;
+	case CR_PAUSED:
+		coroutine_table[cid-1].state = CR_RUNNABLE;
+	default:
+		assert(false);
+	}
 }
 
 cid_t cr_getcid(void) {