fix EINTR drop on child pipe read, publish active after memoryMap is populated

src/cross/ElfBug/ElfBug/api/elfbug_api.cpp

@@ -165,9 +165,9 @@ protected:
     void cbCreateProcessEvent(const pid_t pid, const ElfBug::ptr ep) override
     {
         activePid.store(pid, std::memory_order_release);
-        active.store(true, std::memory_order_release);
         entryPoint = ep;
         refreshMemoryMap();
+        active.store(true, std::memory_order_release);
         if(cb.onCreateProcess)
             cb.onCreateProcess(pid, ep, cb.userdata);
     }

src/cross/ElfBug/ElfBug/core/Debugger.Loop.cpp

@@ -34,6 +34,7 @@ namespace ElfBug
         if(mStepPending.load(std::memory_order_acquire) && mThread)
         {
             mStepPending.store(false, std::memory_order_release);
+            // TODO: mPendingSignal is dropped here, decide the policy
             mThread->StepInto();
         }
         else

src/cross/ElfBug/ElfBug/core/Debugger.cpp

@@ -4,6 +4,7 @@
 #include <sys/personality.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <cerrno>
 #include <csignal>
 #include <cstring>
 
@@ -114,9 +115,21 @@ namespace ElfBug
         close(pipeFds[1]);
 
         char errBuf[256] = {};
-        const ssize_t n = read(pipeFds[0], errBuf, sizeof(errBuf) - 1);
+        ssize_t n;
+        do
+        {
+            n = read(pipeFds[0], errBuf, sizeof(errBuf) - 1);
+        } while(n == -1 && errno == EINTR);
         close(pipeFds[0]);
 
+        if(n == -1)
+        {
+            const std::string err = strerror(errno);
+            waitpid(pid, nullptr, 0);
+            cbInternalError("read() from child pipe failed: " + err);
+            return false;
+        }
+
         if(n > 0)
         {
             waitpid(pid, nullptr, 0);