Diff: USBSerialBuffered/USBSerialBuffered.cpp

Revision:

3:bddd92cd3a17

Child:

4:b6be2a43cb85

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/USBSerialBuffered/USBSerialBuffered.cpp	Thu Feb 22 12:18:45 2018 +0100
@@ -0,0 +1,126 @@
+/*
+ * $Id: bulkserial.h,v 1.3 2018/02/23 15:04:29 grimrath Exp $
+ * This is an unpublished work copyright (c) 2017 HELIOS Software GmbH
+ * 30827 Garbsen, Germany
+ */
+
+#include <algorithm>
+#include <mbed.h>
+// #include "arch.h"
+
+#ifdef FEATURE_USBSERIAL
+
+#include "USBSerial.h"
+#include "USBSerialBuffered.h"
+
+USBSerialBuffered::USBSerialBuffered(int MaxBuffSize, uint16_t vendor_id, uint16_t product_id, uint16_t product_release, bool connect_blocking)
+: USBSerial(vendor_id, product_id, product_release, connect_blocking)
+, mFullBuffSize(MaxBuffSize)
+{
+    ASSERT(mFullBuffSize > CorkBuffSize && "FullBuff must be larger than CorkBuff");
+    m_buff = new char[mFullBuffSize];
+    m_irq_buffused = 0;
+    POISONMEM(m_buff, mFullBuffSize);
+}
+
+USBSerialBuffered::~USBSerialBuffered() {
+    delete[] m_buff;
+}
+
+//-----------------------------------------------------------------------------
+
+int USBSerialBuffered::irqbuff_acquire() {
+    core_util_critical_section_enter();
+    return help_atomic_load_relaxed(&m_irq_buffused);
+}
+
+void USBSerialBuffered::irqbuff_release(int buffused) {
+    help_atomic_store_relaxed(&m_irq_buffused, buffused);
+    irq_barrier();
+    core_util_critical_section_exit();
+}
+
+//-----------------------------------------------------------------------------
+
+int USBSerialBuffered::printf_irqsafe(const char *fmt, ...) {
+    std::va_list va;
+    va_start(va, fmt);
+    int nchars = vprintf_irqsafe(fmt, va);
+    va_end(va);
+    return nchars;
+}
+
+int USBSerialBuffered::vprintf_irqsafe(const char *fmt, std::va_list va) {
+    if (RunningInInterrupt()) {
+        int buffused = irqbuff_acquire();
+        int bspc = mFullBuffSize - buffused;
+        ASSERT(bspc >= 0);
+        int nchars = vsnprintf(m_buff + buffused, bspc, fmt, va);
+        if (nchars >= bspc) {
+            memcpy(m_buff + mFullBuffSize - 4, "...\n", 4);
+            buffused = mFullBuffSize;
+        } else {
+            buffused += nchars;
+        }
+        irqbuff_release(buffused);
+        return nchars;
+    } else {
+        return USBSerial::vprintf(fmt, va);
+    }
+}
+
+//-----------------------------------------------------------------------------
+
+void USBSerialBuffered::flush() {
+    int flushedbytes = 0;
+    int buffused = 0;
+    while (1) {
+        bool wasequal = help_atomic_compare_and_swap(&m_irq_buffused, buffused, 0);
+        if (wasequal)
+            break;
+        //
+        // This only works because @ref print_irq always _increases_ @c m_irq_buffused (but never(!) decreases this variable)
+        //
+        buffused = help_atomic_load_relaxed(&m_irq_buffused);   // __sync_* implementation requires this refetch
+        while (buffused != flushedbytes) {
+            int towrite = std::min(buffused - flushedbytes, static_cast<int>(CorkBuffSize));
+            if (connected()) {
+                writeBlock(reinterpret_cast<uint8_t *>(m_buff + flushedbytes), towrite);
+            }
+            flushedbytes += towrite;
+        }
+    }
+}
+
+void USBSerialBuffered::putc_normal(int c) {
+    while (1) {
+        int buffused = help_atomic_load_relaxed(&m_irq_buffused);
+        if (buffused >= CorkBuffSize) {
+            flush();
+        } else {
+//             static bool TESTonce;
+//             if (! TESTonce) {
+//                 printf_irqsafe("ppp");
+//                 TESTonce = true;
+//             }
+            ASSERT(buffused + 1 <= CorkBuffSize);
+            bool wasequal = help_atomic_compare_and_swap(&m_irq_buffused, buffused, buffused + 1);
+            if (wasequal) {
+                m_buff[buffused] = c;   // alloc successful
+                return;
+            } else {
+                // An irq extended m_irq_buffused, start over
+            }
+        }
+    }
+}
+
+int USBSerialBuffered::_putc(int c) {
+    putc_normal(c);
+    if (c == '\n') {
+        flush();
+    }
+    return connected() ? 1 : 0;
+}
+
+#endif