Got load_brm to work, or at least, not crash.

src/ReadTask.cpp

@@ -23,6 +23,8 @@ ReadTask::~ReadTask()
         return ret; \
     }
 
+#define min(x, y) (x < y ? x : y)
+    
 bool ReadTask::run()
 {
     uint8_t buf[1024] = {0};
@@ -36,38 +38,38 @@ bool ReadTask::run()
     bool success;
     success = read(buf, getLength());
     check_error("ReadTask read cmd", false);
-    cmd_overlay *cmd = (cmd_overlay *) buf;
+    read_cmd *cmd = (read_cmd *) buf;
     
     // read from IOC, write to the socket
     vector<uint8_t> outbuf;
-    outbuf.resize(cmd->count + SM_HEADER_LEN);
+    outbuf.resize(min(cmd->count, 4) + sizeof(sm_msg_resp));
-    uint32_t *outbuf32 = (uint32_t *) &outbuf[0];
+    sm_msg_resp *resp = (sm_msg_resp *) &outbuf[0];
-    outbuf32[0] = SM_MSG_START;
+    
-    outbuf32[1] = cmd->count;
+    resp->type = SM_MSG_START;
+    resp->returnCode = 0;
+    resp->payloadLen = 4;
     
     // todo: do the reading and writing in chunks
-    // todo: need to make this use O_DIRECT
+    // todo: need to make this use O_DIRECT on the IOC side
     ioc->willRead(cmd->filename, cmd->offset, cmd->count);
-    int count = 0, err;
+    int err;
-    while (count < cmd->count)
+    while (resp->returnCode < cmd->count)
     {
-        err = ioc->read(cmd->filename, &outbuf[SM_HEADER_LEN + count], cmd->offset + count, cmd->count - count);
+        err = ioc->read(cmd->filename, &resp->payload[resp->returnCode], cmd->offset + resp->returnCode, 
-        if (err <= 0) {
+          cmd->count - resp->returnCode);
-            if (count > 0)
+        if (err < 0) {
-                outbuf32[1] = count;
+            if (resp->returnCode == 0) {
-            else {
+                resp->payloadLen = 8;
-                int l_errno = errno;
+                resp->returnCode = err;
-                outbuf.resize(16);
+                *((int32_t *) resp->payload) = errno;
-                outbuf32[1] = 8;
-                outbuf32[2] = err;
-                outbuf32[3] = l_errno;
             }
             break;
         }
-        count += err;
+        resp->returnCode += err;
+        resp->payloadLen += err;
     }
     
-    success = write(outbuf);
+    success = write(&outbuf[0], resp->payloadLen + SM_HEADER_LEN);
     return success;
 }
 

src/ReadTask.h

@@ -18,13 +18,6 @@ class ReadTask : public PosixTask
     
     private:
         ReadTask();
-        
-        struct cmd_overlay {
-            size_t count;
-            off_t offset;
-            uint flen;
-            char filename[];
-        };
 };
 
 }

src/SessionManager.cpp

@@ -11,6 +11,7 @@
 #include <errno.h>
 #include <string>
 #include <assert.h>
+#include <iostream>
 using namespace std;
 
 #include <exception>
@@ -223,13 +224,13 @@ int SessionManager::start()
                             }
                             break;
                         }
-
+                        cout << "recv got " << peakLength << " bytes" << endl;
                         endOfData = remainingBytes + peakLength;
                         if (endOfData < 8)
                         {
                             //read this snippet and keep going
-                            len = ::read(fds[socketIncr].fd, &recv_buffer[remainingBytes], peakLength);
                             remainingBytes = endOfData;
+                            len = ::read(fds[socketIncr].fd, &recv_buffer[remainingBytes], peakLength);
                             continue;
                         }
 
@@ -238,10 +239,12 @@ int SessionManager::start()
                         {
                             if (*((uint *) &recv_buffer[i]) == storagemanager::SM_MSG_START)
                             {
-                                //printf("Received SM_MSG_START\n");
+                                printf("Received SM_MSG_START\n");
                                 //found it set msgLength and recvMsgStart offset of SM_MSG_START
                                 recvMsgLength = *((uint *) &recv_buffer[i+4]);
+                                cout << "got length = " << recvMsgLength << endl;
                                 recvMsgStart = i+8;
+                                remainingBytes = 0;
                                 //printf("  recvMsgLength %d recvMsgStart %d endofData %d\n", recvMsgLength,recvMsgStart,endOfData);
                                 // if >= endOfData then the start of the message data is the beginning of next message
                                 if (recvMsgStart >= endOfData)
@@ -253,9 +256,13 @@ int SessionManager::start()
                         // didn't find SM_MSG_START in this message consume the data and loop back through on next message
                         if (recvMsgLength == 0)
                         {
-                            //printf("No SM_MSG_START\n");
+                            printf("No SM_MSG_START\n");
                             len = ::read(fds[socketIncr].fd, &recv_buffer[remainingBytes], peakLength);
-                            remainingBytes = endOfData;
+                            // we know the msg header isn't in position [0, endOfData - 7], so throw that out
+                            // and copy [endOfData - 7, endOfData) to the front of the buffer to be
+                            // checked by the next iteration.
+                            memmove(recv_buffer, &recv_buffer[endOfData - 7], 7);
+                            remainingBytes = 7;
                         }
                         else
                         {
@@ -264,12 +271,14 @@ int SessionManager::start()
                             if (recvMsgStart > 0)
                             {
                                 //printf("SM_MSG_START data is here\n");
-                                len = ::read(fds[socketIncr].fd, &recv_buffer[remainingBytes], peakLength - recvMsgStart);
+                                len = ::read(fds[socketIncr].fd, &recv_buffer[remainingBytes], recvMsgStart);
+                                remainingBytes = 0;
                             }
                             else
                             {
                                 //printf("SM_MSG_START data is next message\n");
                                 len = ::read(fds[socketIncr].fd, &recv_buffer[remainingBytes], peakLength);
+                                remainingBytes = 0;
                             }
                             //Disable polling on this socket
                             fds[socketIncr].events = 0;