Pass timeout to optimistic_yield, add cont_can_yield check

cores/esp8266/Arduino.h

@@ -38,9 +38,6 @@ extern "C" {
 #include "esp8266_peri.h"
 #include "twi.h"
 
-void yield(void);
-void optimistic_yield(void);
-
 #define HIGH 0x1
 #define LOW  0x0
 
@@ -207,6 +204,9 @@ void detachInterrupt(uint8_t);
 void setup(void);
 void loop(void);
 
+void yield(void);
+void optimistic_yield(uint32_t interval_us);
+
 // Get the bit location within the hardware port of the given virtual pin.
 // This comes from the pins_*.c file for the active board configuration.
 #define digitalPinToPort(pin)       (0)

cores/esp8266/HardwareSerial.cpp

@@ -559,7 +559,7 @@ int HardwareSerial::available(void) {
     }
 
     if (!result) {
-        optimistic_yield();
+        optimistic_yield(USD(_uart->uart_nr) / 128);
     }
 
     return result;

cores/esp8266/cont.S

@@ -109,6 +109,9 @@ cont_norm:
     l32i    a2,    a1, 4
     /* sp <- cont_ctx.sp_ret */
     l32i    a1, a2, 4
+    /* 0 -> cont_ctx.pc_ret */
+    movi    a4, 0
+    s32i    a4, a2, 0
 
 cont_ret:
     /* restore registers */

cores/esp8266/cont.h

@@ -21,6 +21,8 @@
 #ifndef CONT_H_
 #define CONT_H_
 
+#include <stdbool.h>
+
 #ifndef CONT_STACKSIZE
 #define CONT_STACKSIZE 4096
 #endif
@@ -58,4 +60,8 @@ void cont_yield(cont_t*);
 // return 1 if guard bytes were overwritten.
 int cont_check(cont_t* cont);
 
+// Check if yield() may be called. Returns true if we are running inside
+// continuation stack
+bool cont_can_yield(cont_t* cont);
+
 #endif /* CONT_H_ */

cores/esp8266/cont_util.c

@@ -19,6 +19,9 @@
  */
 
 #include "cont.h"
+#include <stddef.h>
+#include "ets_sys.h"
+
 
 #define CONT_STACKGUARD 0xfeefeffe
 
@@ -34,3 +37,8 @@ int cont_check(cont_t* cont) {
 
     return 0;
 }
+
+bool cont_can_yield(cont_t* cont) {
+    return !ETS_INTR_WITHINISR() &&
+           cont->pc_ret != 0 && cont->pc_yield == 0;
+}

cores/esp8266/core_esp8266_main.cpp

@@ -64,16 +64,16 @@ extern void (*__init_array_end)(void);
 cont_t g_cont __attribute__ ((aligned (16)));
 static os_event_t g_loop_queue[LOOP_QUEUE_SIZE];
 
-static uint32_t g_micros_at_last_task_yield;
+static uint32_t g_micros_at_task_start;
 
 
 extern "C" void abort() {
-    while(1) {
+    do {
-    }
+        *((int*)0) = 0;
+    } while(true);
 }
 
 extern "C" void esp_yield() {
-    g_micros_at_last_task_yield = system_get_time();
     cont_yield(&g_cont);
 }
 
@@ -82,16 +82,22 @@ extern "C" void esp_schedule() {
 }
 
 extern "C" void __yield() {
+    if (cont_can_yield(&g_cont)) {
         esp_schedule();
         esp_yield();
     }
+    else {
+        abort();
+    }
+}
+
 extern "C" void yield(void) __attribute__ ((weak, alias("__yield")));
 
-extern "C" void optimistic_yield(void) {
+extern "C" void optimistic_yield(uint32_t interval_us) {
-    if (!ETS_INTR_WITHINISR() && 
+    if (cont_can_yield(&g_cont) &&
-        (system_get_time() - g_micros_at_last_task_yield) > OPTIMISTIC_YIELD_TIME_US)
+        (system_get_time() - g_micros_at_task_start) > interval_us)
     {
-        __yield();
+        yield();
     }
 }
 
@@ -107,10 +113,10 @@ static void loop_wrapper() {
 }
 
 static void loop_task(os_event_t *events) {
-    g_micros_at_last_task_yield = system_get_time();
+    g_micros_at_task_start = system_get_time();
     cont_run(&g_cont, &loop_wrapper);
     if(cont_check(&g_cont) != 0) {
-        ets_printf("\r\nheap collided with sketch stack\r\n");
+        ets_printf("\r\nsketch stack overflow detected\r\n");
         abort();
     }
 }
@@ -127,13 +133,11 @@ void init_done() {
     esp_schedule();
 }
 
-extern "C" {
+
-void user_init(void) {
+extern "C" void user_init(void) {
     struct rst_info *rtc_info_ptr = system_get_rst_info();
-
     memcpy((void *) &resetInfo, (void *) rtc_info_ptr, sizeof(resetInfo));
 
-
     uart_div_modify(0, UART_CLK_FREQ / (115200));
 
     init();
@@ -148,5 +152,3 @@ void user_init(void) {
 
     system_init_done_cb(&init_done);
 }
-}
-

libraries/ESP8266WiFi/src/ESP8266WiFi.cpp

@@ -653,7 +653,7 @@ bool ESP8266WiFiClass::beginWPSConfig(void) {
 
     disconnect();
 
-    DEBUGV("wps begin: %d\n", wps_type);
+    DEBUGV("wps begin\n");
 
     if(!wifi_wps_disable()) {
         DEBUGV("wps disable faild\n");

libraries/ESP8266WiFi/src/WiFiClient.cpp

@@ -179,14 +179,13 @@ size_t WiFiClient::write(const uint8_t *buf, size_t size)
 
 int WiFiClient::available()
 {
-    int result = 0;
+    if (!_client)
+        return false;
 
-    if (_client) {
+    int result = _client->getSize();
-        result = _client->getSize();
-    }
 
     if (!result) {
-        optimistic_yield();
+        optimistic_yield(100);
     }
     return result;
 }

libraries/ESP8266WiFi/src/WiFiServer.cpp

@@ -99,7 +99,7 @@ WiFiClient WiFiServer::available(byte* status)
         return result;
     }
 
-    optimistic_yield();
+    optimistic_yield(1000);
 
     return WiFiClient();
 }
@@ -161,4 +161,3 @@ void WiFiServer::_s_discard(void* server, ClientContext* ctx)
 {
     reinterpret_cast<WiFiServer*>(server)->_discard(ctx);
 }
-

libraries/ESP8266WiFi/src/WiFiUdp.cpp

@@ -122,10 +122,6 @@ int WiFiUDP::available() {
         result = static_cast<int>(_ctx->getSize());
     }
 
-    if (!result) {
-        optimistic_yield();
-    }
-
     return result;
 }
 
@@ -207,8 +203,12 @@ int WiFiUDP::parsePacket()
 {
     if (!_ctx)
         return 0;
-    if (!_ctx->next())
+
+    if (!_ctx->next()) {
+        optimistic_yield(100);
         return 0;
+    }
+
     return _ctx->getSize();
 }
 
@@ -284,4 +284,3 @@ void WiFiUDP::stopAll()
         it->stop();
     }
 }
-

tools/sdk/include/ets_sys.h

@@ -65,8 +65,8 @@ inline bool ETS_INTR_WITHINISR()
 {
     uint32_t ps;
     __asm__ __volatile__("rsr %0,ps":"=a" (ps));
-    // PS.EXCM and PS.UM bit checks
+    // PS.EXCM bit check
-    return ((ps & ((1 << 4) | (1 << 5))) > 0);
+    return ((ps & (1 << 4)) != 0);
 }
 
 inline uint32_t ETS_INTR_ENABLED(void)