Changeset 1038

Timestamp:

04/25/08 13:39:03 (14 years ago)

Author:

ppalmers

Message:

reduce the amount of system time read kernel calls

Files:

• trunk/libffado/config.h.in (modified) (1 diff)
• trunk/libffado/src/libieee1394/cycletimer.h (modified) (1 diff)
• trunk/libffado/src/libieee1394/IsoHandler.cpp (modified) (6 diffs)
• trunk/libffado/src/libieee1394/IsoHandler.h (modified) (1 diff)

trunk/libffado/config.h.in

@@ -81 +81 @@
-
-#define ISOHANDLER_DEATH_DETECT_TIMEOUT_USECS    1000000LL
+
+#define ISOHANDLER_CHECK_CTR_RECONSTRUCTION 0
-
-#define ISOHANDLERMANAGER_MAX_ISO_HANDLERS_PER_PORT         16

trunk/libffado/src/libieee1394/cycletimer.h

@@ -385 +385 @@
-
-/**
+ * @brief Converts a received SYT timestamp to a full timestamp in ticks.
+ *
+ *
+ * @param syt_timestamp The SYT timestamp as present in the packet
+ * @param rcv_ctr The CTR value this timestamp was received on (offset can be 0)
+ * @return
+ */
+static inline uint64_t sytRecvToFullTicks2(uint64_t syt_timestamp, uint32_t rcv_ctr) {
+    uint64_t timestamp;
+
+    debugOutputExtreme(DEBUG_LEVEL_VERY_VERBOSE, "SYT=%04llX RCV_CTR=%08X\n",
+                       syt_timestamp, rcv_ctr);
+
+    // reconstruct the top part of the timestamp using the current cycle number
+    unsigned int rcv_cycle = CYCLE_TIMER_GET_CYCLES(rcv_ctr);
+    unsigned int rcv_cycle_masked = rcv_cycle & 0xF;
+    unsigned int syt_cycle = CYCLE_TIMER_GET_CYCLES(syt_timestamp);
+
+    // if this is true, wraparound has occurred, undo this wraparound
+    if(syt_cycle<rcv_cycle_masked) syt_cycle += 0x10;
+
+    // this is the difference in cycles wrt the cycle the
+    // timestamp was received
+    unsigned int delta_cycles = syt_cycle - rcv_cycle_masked;
+
+    // reconstruct the cycle part of the timestamp
+    rcv_cycle += delta_cycles;
+
+    // if the cycles cause a wraparound of the cycle timer,
+    // perform this wraparound
+    // and convert the timestamp into ticks
+    if(rcv_cycle<8000) {
+        timestamp = rcv_cycle * TICKS_PER_CYCLE;
+    } else {
+        rcv_cycle -= 8000; // wrap around
+#ifdef DEBUG
+        if (rcv_cycle >= 8000) {
+            debugWarning("insufficient unwrapping\n");
+        }
+#endif
+        timestamp  = rcv_cycle * TICKS_PER_CYCLE;
+        // add one second due to wraparound
+        timestamp += TICKS_PER_SECOND;
+    }
+
+    timestamp += CYCLE_TIMER_GET_OFFSET(syt_timestamp);
+
+    timestamp = addTicks(timestamp, CYCLE_TIMER_GET_SECS(rcv_ctr) * TICKS_PER_SECOND);
+
+    #ifdef DEBUG
+        if(( TICKS_TO_CYCLE_TIMER(timestamp) & 0xFFFF) != syt_timestamp) {
+            debugWarning("back-converted timestamp not equal to SYT\n");
+            debugWarning("TS=%011llu TSC=%08lX SYT=%04X\n",
+                  timestamp, TICKS_TO_CYCLE_TIMER(timestamp), syt_timestamp);
+        }
+    #endif
+
+    return timestamp;
+}
+
+/**
- * @brief Converts a transmit SYT timestamp to a full timestamp in ticks.
- *

trunk/libffado/src/libieee1394/IsoHandler.cpp

@@ -91 +91 @@
-   , m_irq_interval( -1 )
-   , m_last_cycle( -1 )
+   , m_last_now( 0xFFFFFFFF )
-   , m_Client( 0 )
-   , m_speed( RAW1394_ISO_SPEED_400 )
@@ -113 +114 @@
-   , m_irq_interval( irq )
-   , m_last_cycle( -1 )
+   , m_last_now( 0xFFFFFFFF )
-   , m_Client( 0 )
-   , m_speed( RAW1394_ISO_SPEED_400 )
@@ -134 +136 @@
-   , m_max_packet_size( max_packet_size )
-   , m_irq_interval( irq )
+   , m_last_cycle( -1 )
+   , m_last_now( 0xFFFFFFFF )
-   , m_Client( 0 )
-   , m_speed( speed )
@@ -186 +190 @@
-        flush();
-#endif
+        m_last_now = m_manager.get1394Service().getCycleTimer();
-        if(raw1394_loop_iterate(m_handle)) {
-            debugError( "IsoHandler (%p): Failed to iterate handler: %s\n",
@@ -363 +368 @@
-                    unsigned int cycle, unsigned int dropped, unsigned int skipped) {
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-
-    debugOutputExtreme(DEBUG_LEVEL_ULTRA_VERBOSE,
@@ -422 +466 @@
-                      int cycle, unsigned int dropped, unsigned int skipped) {
-
-nsigned in
+int32_
-    if (cycle < 0) {
+        // mark invalid
-        pkt_ctr = 0xFFFFFFFF;
-    } else {
-        pkt_ctr = cycle << 12;
+
+#if 0 // we don't need this for xmit
+        // if we assume that one iterate() loop doesn't take longer than 0.5 seconds,
+        // the seconds field won't change while the iterate loop runs
+        // this means that we can preset 'now' before running iterate()
+        uint32_t now_secs = CYCLE_TIMER_GET_SECS(m_last_now);
+        // causality results in the fact that 'now' is always after 'cycle'
+        if(CYCLE_TIMER_GET_CYCLES(m_last_now) > (unsigned int)cycle) {
+            // the cycle field has wrapped, add one second
+            now_secs += 1;
+            // no need for this:
+            //if(now_secs == 128) {
+            //    now_secs = 0;
+            //}
+            // since we mask later on
+        }
+        pkt_ctr |= (now_secs & 0x7F) << 25;
+
+        #if ISOHANDLER_CHECK_CTR_RECONSTRUCTION
+        // add a seconds field
+        uint32_t now = m_manager.get1394Service().getCycleTimer();
+        uint32_t now_secs_ref = CYCLE_TIMER_GET_SECS(now);
+        // causality results in the fact that 'now' is always after 'cycle'
+        if(CYCLE_TIMER_GET_CYCLES(now) > (unsigned int)cycle) {
+            // the cycle field has wrapped, add one second
+            now_secs_ref += 1;
+            // no need for this:
+            //if(now_secs == 128) {
+            //    now_secs = 0;
+            //}
+            // since we mask later on
+        }
+        uint32_t pkt_ctr_ref = cycle << 12;
+        pkt_ctr_ref |= (now_secs_ref & 0x7F) << 25;
+    
+        if(pkt_ctr != pkt_ctr_ref) {
+            debugWarning("reconstructed CTR counter discrepancy\n");
+            pkt_ctr=pkt_ctr_ref;
+        }
+        #endif
+#endif
-    }
-

trunk/libffado/src/libieee1394/IsoHandler.h

@@ -153 +153 @@
-    int             m_irq_interval;
-    int             m_last_cycle;
+    uint32_t        m_last_now;
-
-    Streaming::StreamProcessor *m_Client; // FIXME: implement with functors