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fix for two-byte enhanced transfer polling, fix unnecessary buffer allocation, fix skip for invalid protocol bytes

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This commit is contained in:
john30
2020-01-25 19:44:41 +01:00
parent b8658f8f2c
commit a82ef6631f
2 changed files with 60 additions and 49 deletions
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src/lib/ebus/device.cpp
+58 -48
View File
@@ -183,58 +183,68 @@ result_t Device::recv(unsigned int timeout, symbol_t* value, ArbitrationState* a
if (!isValid()) {
return RESULT_ERR_DEVICE;
}
bool isAvailable = available();
if (!isAvailable && timeout > 0) {
int ret;
struct timespec tdiff;
bool repeat = false;
bool repeated = false;
ArbitrationState prevState = *arbitrationState;
do {
repeat = false;
bool isAvailable = available();
if (!isAvailable && timeout > 0) {
int ret;
struct timespec tdiff;
// set select timeout
tdiff.tv_sec = timeout/1000000;
tdiff.tv_nsec = (timeout%1000000)*1000;
// set select timeout
tdiff.tv_sec = timeout/1000000;
tdiff.tv_nsec = (timeout%1000000)*1000;
#ifdef HAVE_PPOLL
nfds_t nfds = 1;
struct pollfd fds[nfds];
nfds_t nfds = 1;
struct pollfd fds[nfds];
memset(fds, 0, sizeof(fds));
memset(fds, 0, sizeof(fds));
fds[0].fd = m_fd;
fds[0].events = POLLIN | POLLERR | POLLHUP | POLLRDHUP;
ret = ppoll(fds, nfds, &tdiff, nullptr);
if (ret >= 0 && fds[0].revents & (POLLERR | POLLHUP | POLLRDHUP)) {
ret = -1;
}
fds[0].fd = m_fd;
fds[0].events = POLLIN | POLLERR | POLLHUP | POLLRDHUP;
ret = ppoll(fds, nfds, &tdiff, nullptr);
if (ret >= 0 && fds[0].revents & (POLLERR | POLLHUP | POLLRDHUP)) {
ret = -1;
}
#else
#ifdef HAVE_PSELECT
fd_set readfds, exceptfds;
fd_set readfds, exceptfds;
FD_ZERO(&readfds);
FD_ZERO(&exceptfds);
FD_SET(m_fd, &readfds);
FD_ZERO(&readfds);
FD_ZERO(&exceptfds);
FD_SET(m_fd, &readfds);
ret = pselect(m_fd + 1, &readfds, nullptr, &exceptfds, &tdiff, nullptr);
if (ret >= 1 && FD_ISSET(m_fd, &exceptfds)) {
ret = -1;
}
ret = pselect(m_fd + 1, &readfds, nullptr, &exceptfds, &tdiff, nullptr);
if (ret >= 1 && FD_ISSET(m_fd, &exceptfds)) {
ret = -1;
}
#else
ret = 1; // ignore timeout if neither ppoll nor pselect are available
ret = 1; // ignore timeout if neither ppoll nor pselect are available
#endif
#endif
if (ret == -1) {
close();
return RESULT_ERR_DEVICE;
if (ret == -1) {
close();
return RESULT_ERR_DEVICE;
}
if (ret == 0) {
return RESULT_ERR_TIMEOUT;
}
}
if (ret == 0) {
// directly read byte from device
bool incomplete = false;
if (!read(value, isAvailable, arbitrationState, &incomplete)) {
if (!isAvailable && incomplete && !repeated) {
// for a two-byte transfer another poll is needed
repeat = true;
continue;
}
return RESULT_ERR_TIMEOUT;
}
}
ArbitrationState prevState = *arbitrationState;
// directly read byte from device
if (!read(value, isAvailable, arbitrationState)) {
close();
return RESULT_ERR_DEVICE;
}
} while (repeat);
if (m_enhancedProto || *value != SYN || m_arbitrationMaster == SYN) {
if (m_listener != nullptr) {
m_listener->notifyDeviceData(*value, true);
@@ -316,12 +326,16 @@ bool Device::available() {
if ((ch&ENH_BYTE_MASK) == ENH_BYTE1) {
return pos+1 < m_bufLen;
}
// TODO check protocol error
// TODO protocol error
// skip byte from erroneous protocol
m_bufPos = (m_bufPos+1)%m_bufSize;
m_bufLen--;
pos--;
}
return false;
}
bool Device::read(symbol_t* value, bool isAvailable, ArbitrationState* arbitrationState) {
bool Device::read(symbol_t* value, bool isAvailable, ArbitrationState* arbitrationState, bool* incomplete) {
if (!isAvailable) {
if (m_bufLen > 0 && m_bufPos != 0) {
if (m_bufLen > m_bufSize / 2) {
@@ -350,6 +364,9 @@ bool Device::read(symbol_t* value, bool isAvailable, ArbitrationState* arbitrati
m_bufLen += size;
}
if (!available()) {
if (incomplete) {
*incomplete = m_enhancedProto && m_bufLen > 0;
}
return false;
}
if (!m_enhancedProto) {
@@ -377,11 +394,11 @@ bool Device::read(symbol_t* value, bool isAvailable, ArbitrationState* arbitrati
}
// kind is ENH_BYTE1
symbol_t ch2 = m_buffer[m_bufPos];
m_bufPos = (m_bufPos + 1) % m_bufSize;
m_bufLen--;
if ((ch2 & ENH_BYTE_MASK) != ENH_BYTE2) {
return false; // TODO protocol error
}
m_bufPos = (m_bufPos + 1) % m_bufSize;
m_bufLen--;
ch2 = (symbol_t)(((ch&0x03)<<6) | (ch2&0x3f));
ch = (ch>>2)&0xf;
switch (ch) {
@@ -577,13 +594,6 @@ result_t NetworkDevice::open() {
close();
return RESULT_ERR_GENERIC_IO;
}
if (m_bufSize == 0) {
m_bufSize = MAX_LEN+1;
m_buffer = reinterpret_cast<symbol_t*>(malloc(m_bufSize));
if (!m_buffer) {
m_bufSize = 0;
}
}
m_bufLen = 0;
if (m_initialSend && !write(ESC)) {
return RESULT_ERR_SEND;
src/lib/ebus/device.h
+2 -1
View File
@@ -199,9 +199,10 @@ class Device {
* @param value the reference in which the read byte value is stored.
* @param isAvailable the result of the immediately preceding call to @a available().
* @param arbitrationState the variable in which to store the received arbitration state (mandatory for enhanced proto).
* @param incomplete the variable in which to store when a partial transfer needs another poll.
* @return true on success, false on error.
*/
virtual bool read(symbol_t* value, bool isAvailable, ArbitrationState* arbitrationState=nullptr);
virtual bool read(symbol_t* value, bool isAvailable, ArbitrationState* arbitrationState=nullptr, bool* incomplete=nullptr);
/** the device name (e.g. "/dev/ttyUSB0" for serial, "127.0.0.1:1234" for network). */
const char* m_name;