Merge pull request #171 from luke-jr/icarus_longpoll

Icarus: Abandon a scanhash early when work restart requested

configure.ac

@@ -301,6 +301,8 @@ if test "x$bitforce" != xno; then
 fi
 AM_CONDITIONAL([HAVE_LIBUDEV], [test x$libudev != xno])
 
+AC_CHECK_HEADERS([sys/epoll.h])
+
 PKG_PROG_PKG_CONFIG()
 
 PKG_CHECK_MODULES([LIBCURL], [libcurl >= 7.15.6], [AC_DEFINE([CURL_HAS_SOCKOPT], [1], [Defined if version of curl supports sockopts.])],

driver-icarus.c

@@ -46,11 +46,17 @@
   #include <windows.h>
   #include <io.h>
 #endif
+#ifdef HAVE_SYS_EPOLL_H
+  #include <sys/epoll.h>
+  #define HAVE_EPOLL
+#endif
 
 #include "elist.h"
 #include "miner.h"
 
-#define ICARUS_READ_FAULT_COUNT	(8)
+// 8 second timeout
+#define ICARUS_READ_FAULT_DECISECONDS (1)
+#define ICARUS_READ_FAULT_COUNT	(80)
 
 struct device_api icarus_api;
 
@@ -87,7 +93,7 @@ static int icarus_open(const char *devpath)
 				ISTRIP | INLCR | IGNCR | ICRNL | IXON);
 	my_termios.c_oflag &= ~OPOST;
 	my_termios.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
-	my_termios.c_cc[VTIME] = 10; /* block 1 second */
+	my_termios.c_cc[VTIME] = ICARUS_READ_FAULT_DECISECONDS;
 	my_termios.c_cc[VMIN] = 0;
 	tcsetattr(serialfd, TCSANOW, &my_termios);
 
@@ -108,12 +114,31 @@ static int icarus_open(const char *devpath)
 #endif
 }
 
-static int icarus_gets(unsigned char *buf, size_t bufLen, int fd)
+static int icarus_gets(unsigned char *buf, size_t bufLen, int fd, volatile unsigned long *wr)
 {
 	ssize_t ret = 0;
 	int rc = 0;
+	int epollfd = -1;
+
+#ifdef HAVE_EPOLL
+	struct epoll_event ev, evr;
+	epollfd = epoll_create(1);
+	if (epollfd != -1) {
+		ev.events = EPOLLIN;
+		ev.data.fd = fd;
+		if (-1 == epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev)) {
+			close(epollfd);
+			epollfd = -1;
+		}
+	}
+#endif
 
 	while (bufLen) {
+#ifdef HAVE_EPOLL
+		if (epollfd != -1 && epoll_wait(epollfd, &evr, 1, ICARUS_READ_FAULT_DECISECONDS * 100) != 1)
+			ret = 0;
+		else
+#endif
 		ret = read(fd, buf, 1);
 		if (ret == 1) {
 			bufLen--;
@@ -122,13 +147,20 @@ static int icarus_gets(unsigned char *buf, size_t bufLen, int fd)
 		}
 
 		rc++;
+		if (*wr)
+			return 1;
 		if (rc == ICARUS_READ_FAULT_COUNT) {
+			if (epollfd != -1)
+				close(epollfd);
 			applog(LOG_DEBUG,
-			       "Icarus Read: No data in %d seconds", rc);
+			       "Icarus Read: No data in %d seconds", rc * ICARUS_READ_FAULT_DECISECONDS / 10);
 			return 1;
 		}
 	}
 
+	if (epollfd != -1)
+		close(epollfd);
+
 	return 0;
 }
 
@@ -172,7 +204,8 @@ static bool icarus_detect_one(const char *devpath)
 	icarus_write(fd, ob_bin, sizeof(ob_bin));
 
 	memset(nonce_bin, 0, sizeof(nonce_bin));
-	icarus_gets(nonce_bin, sizeof(nonce_bin), fd);
+	volatile unsigned long wr = 0;
+	icarus_gets(nonce_bin, sizeof(nonce_bin), fd, &wr);
 
 	icarus_close(fd);
 
@@ -243,6 +276,8 @@ static bool icarus_prepare(struct thr_info *thr)
 static uint64_t icarus_scanhash(struct thr_info *thr, struct work *work,
 				__maybe_unused uint64_t max_nonce)
 {
+	volatile unsigned long *wr = &work_restart[thr->id].restart;
+
 	struct cgpu_info *icarus;
 	int fd;
 	int ret;
@@ -278,7 +313,7 @@ static uint64_t icarus_scanhash(struct thr_info *thr, struct work *work,
 
 	/* Icarus will return 8 bytes nonces or nothing */
 	memset(nonce_bin, 0, sizeof(nonce_bin));
-	ret = icarus_gets(nonce_bin, sizeof(nonce_bin), fd);
+	ret = icarus_gets(nonce_bin, sizeof(nonce_bin), fd, wr);
 
 	nonce_hex = bin2hex(nonce_bin, sizeof(nonce_bin));
 	if (nonce_hex) {

sha256_4way.c

@@ -111,8 +111,6 @@ bool ScanHash_4WaySSE2(int thr_id, const unsigned char *pmidstate,
 
 	pdata += 64;
 
-    work_restart[thr_id].restart = 0;
-
     for (;;)
     {
         unsigned int thash[9][NPAR] __attribute__((aligned(128)));

sha256_altivec_4way.c

@@ -84,8 +84,6 @@ bool ScanHash_altivec_4way(int thr_id, const unsigned char *pmidstate,
 
 	pdata += 64;
 
-    work_restart[thr_id].restart = 0;
-
     for (;;)
     {
         unsigned int thash[9][NPAR] __attribute__((aligned(128)));

sha256_cryptopp.c

@@ -589,8 +589,6 @@ bool scanhash_asm32(int thr_id, const unsigned char *midstate,
 
 	data += 64;
 
-	work_restart[thr_id].restart = 0;
-
 	while (1) {
 		n++;
 		*nonce = n;

sha256_generic.c

@@ -251,8 +251,6 @@ bool scanhash_c(int thr_id, const unsigned char *midstate, unsigned char *data,
 
 	data += 64;
 
-	work_restart[thr_id].restart = 0;
-
 	while (1) {
 		n++;
 		*nonce = n;

sha256_sse2_amd64.c

@@ -65,8 +65,6 @@ bool scanhash_sse2_64(int thr_id, const unsigned char *pmidstate,
 
 	pdata += 64;
 
-    work_restart[thr_id].restart = 0;
-
     /* For debugging */
     union {
         __m128i m;

sha256_sse2_i386.c

@@ -65,8 +65,6 @@ bool scanhash_sse2_32(int thr_id, const unsigned char *pmidstate,
 
 	pdata += 64;
 
-    work_restart[thr_id].restart = 0;
-
     /* Message expansion */
     memcpy(m_midstate, pmidstate, sizeof(m_midstate));
     memcpy(m_w, pdata, sizeof(m_w)); /* The 2nd half of the data */

sha256_sse4_amd64.c

@@ -62,8 +62,6 @@ bool scanhash_sse4_64(int thr_id, const unsigned char *pmidstate,
 
 	pdata += 64;
 
-    work_restart[thr_id].restart = 0;
-
     /* For debugging */
     union {
         __m128i m;

sha256_via.c

@@ -35,8 +35,6 @@ bool scanhash_via(int thr_id, const unsigned char *pmidstate,
 	unsigned long stat_ctr = 0;
 	int i;
 
-	work_restart[thr_id].restart = 0;
-
 	/* bitcoin gives us big endian input, but via wants LE,
 	 * so we reverse the swapping bitcoin has already done (extra work)
 	 * in order to permit the hardware to swap everything