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authorJohn Denker <jsd@av8n.com>2012-07-23 21:31:05 (GMT)
committerJohn Denker <jsd@av8n.com>2012-07-23 21:31:05 (GMT)
commit263260498e0d8b12d5d539f9e8244ac4e5b1ba9c (patch)
tree23529961555fa0afd56e68ad16eeb1d0f3e2e883 /tools/hi-q.c
parentfdaeef07dffa8894672da5e51f63d467d452c7c9 (diff)
finally () get smart about not leaving stray FDs lying around;
also get smart about blocking fd0 and fd1 for later use.
Diffstat (limited to 'tools/hi-q.c')
-rw-r--r--tools/hi-q.c119
1 files changed, 92 insertions, 27 deletions
diff --git a/tools/hi-q.c b/tools/hi-q.c
index 5ee7688..3d654c5 100644
--- a/tools/hi-q.c
+++ b/tools/hi-q.c
@@ -22,10 +22,15 @@ using namespace std;
#include <fstream>
#include <sstream>
#include <string>
+#include <list>
#include <vector>
#include <sstream>
#include <map>
+#include <sys/types.h> /* for fstat */
+#include <sys/stat.h> /* .. */
+#include <unistd.h> /* .. */
+
// error exit codes, mostly as stated in qmail.c
#define bar \
foo(good, 0) ;\
@@ -63,6 +68,13 @@ foo_sa(NOPERM, 77, "permission denied") ;\
foo_sa(CONFIG, 78, "configuration error") ;\
foo_sa(TOOBIG, 98, "message was too big to process (see --max-size)"
+string progname;
+pid_t mypid;
+string progid;
+
+extern char** environ;
+const int rEnd(0); // end of a pipe for reading
+const int wEnd(1); // end of a pipe for writing
typedef enum {MSG, ENV} channeler;
@@ -204,7 +216,9 @@ void slurp(const int inch, const int ouch){
break;
}
if (got < 0) {
- fprintf(stderr, "hi-q: input error: ");
+ cerr << progid
+ << " slurp: input error on fd " << inch
+ << " : ";
perror(0);
exeunt(ex_comerr);
}
@@ -214,7 +228,9 @@ void slurp(const int inch, const int ouch){
ssize_t sent = write(ouch, buf, todo);
//xx cerr << "slurp: write returns " << sent << endl;
if (sent < 0 && errno != EINTR) {
- fprintf(stderr, "hi-q: output error on fd%d : ", ouch);
+ cerr << progid
+ << " slurp: output rror on fd " << ouch
+ << " : ";
perror(0);
exeunt(ex_comerr);
}
@@ -261,10 +277,6 @@ void usage() {
// we have data coming in on fd 0.
// and envelope / control information coming in on fd 1.
-string progname;
-pid_t mypid;
-string progid;
-
void dump(const string var){
char* str = getenv(var.c_str());
cerr << progid << var;
@@ -277,7 +289,39 @@ int xclose(int arg){
return close(arg);
}
-extern char** environ;
+typedef list<int> LI;
+void block_fd(const LI todo){
+ int blocker(-1);
+ int inplace(0);
+
+ for (LI::const_iterator ptr = todo.begin();
+ ptr != todo.end(); ptr++) {
+ int fd = *ptr;
+ struct stat statbuf;
+ int rslt = fstat(fd, &statbuf);
+ if (rslt) {
+ if (0) {
+ cerr << "definitely needed to block_fd unit " << fd << " : ";
+ perror(0);
+ }
+ if (blocker < 0) {
+ int blockex[2];
+ pipe(blockex);
+ close(blockex[rEnd]);
+ blocker = blockex[wEnd];
+ }
+ if (blocker != fd){
+ dup2(blocker, fd);
+ close(blocker);
+ } else {
+ inplace++;
+ }
+ } else {
+ if (0) cerr << "unit " << fd << " already blocked" << endl;
+ }
+ }
+ if (!inplace) close(blocker);
+}
string basename(const string path){
size_t where = path.rfind("/");
@@ -286,7 +330,7 @@ string basename(const string path){
}
void attach(const int pipe_end, const int fd, const int kidno){
- cerr << "attaching current pipe_end " << pipe_end
+ cerr << "attaching current pipe_end " << pipe_end
<< " to " << fd
<< " for " << kidno << endl;
if (pipe_end != fd) {
@@ -298,7 +342,7 @@ void attach(const int pipe_end, const int fd, const int kidno){
}
close(pipe_end);
}
-
+
}
int main(int argc, char** argv) {
@@ -397,8 +441,6 @@ bar
vector<pid_t> kidpid(nkids); // indexed by kid number
- const int rEnd(0); // end of a pipe for reading
- const int wEnd(1); // end of a pipe for writing
int sync[2];
int resync[2];
if (pipe(sync) != 0) cerr << "sync pipe failed" << endl;
@@ -419,19 +461,30 @@ bar
int slurp_read(1); // our original non-standard input
int slurp_write = -1; // effectively next_write[ENV];
map<channeler,int> current_read;
- map<channeler,int> cur_write; // current kid writes here
- cur_write[MSG] = -1;
- cur_write[ENV] = -1;
+ map<channeler,int> current_write; // current kid writes here
+ current_write[MSG] = -1;
+ current_write[ENV] = -1;
+ list<int> blockme;
+ blockme.push_back(0);
+ blockme.push_back(1);
// important loop to start all kids
for (unsigned int ii=0; ii < nkids; ii++){ /* loop starting all kids */
+ string kidid;
+ {
+ stringstream foo;
+ foo << ii
+ << " mode " << filter[ii].mode
+ << " " << filter[ii].cmd[0];
+ kidid = foo.str();
+ }
current_read = next_read;
cerr << "top of loop: "
- << " cr.MSG: " << current_read[MSG]
+ << " cr.MSG: " << current_read[MSG]
<< " cr.ENV: " << current_read[ENV]
- << " w.MSG: " << cur_write[MSG]
- << " w.ENV: " << cur_write[ENV]
+ << " w.MSG: " << current_write[MSG]
+ << " w.ENV: " << current_write[ENV]
<< " for " << ii << endl;
if (current_read[MSG] > 20) exit(99);
if (current_read[ENV] > 20) exit(99);
@@ -452,6 +505,7 @@ bar
// this child's output to the next child's input ...
// except for the special kid, which reads both fd0 and fd1,
// while writing nothing.
+ block_fd(blockme);
rslt = pipe(datapipe);
if (rslt < 0) {
fprintf(stderr, "hi-q: could not create datapipe: ");
@@ -473,10 +527,13 @@ bar
}
// figure out the intended bindings:
+ int pardang1(-1), pardang2(-1); // used by current kid,
+ // but dangling, from parent's point of view
switch (filter[ii].mode) {
case sa:
case series:
- cur_write[MSG] = datapipe[wEnd];
+ pardang1 = current_write[MSG] = datapipe[wEnd];
+ pardang2 = current_read[MSG];
next_read[MSG] = datapipe[rEnd];
break;
case qq:
@@ -484,11 +541,11 @@ bar
cerr << "???? multiple qq jobs?" << endl;
}
slurp_write= datapipe[wEnd];
- current_read[ENV] = datapipe[rEnd];
+ pardang1 = current_read[ENV] = datapipe[rEnd];
next_read[ENV] = -1;
next_read[MSG] = -1;
- cur_write[ENV] = -1;
- cur_write[MSG] = -1;
+ current_write[ENV] = -1;
+ current_write[MSG] = -1;
break;
case postspam:
case stub:
@@ -561,7 +618,7 @@ bar
case sa:
case series:
attach(current_read[MSG], 0, ii);
- attach(cur_write[MSG], 1, ii);
+ attach(current_write[MSG], 1, ii);
break;
case stub:
case postspam:
@@ -612,8 +669,16 @@ bar
}
// these tricks are for kid:
- close(cur_write[MSG]);
- close(cur_write[ENV]);
+ close(current_write[MSG]);
+ close(current_write[ENV]);
+ close(current_read[ENV]);
+ if (0) cerr << "closing " << pardang1
+ << " for parent of " << kidid << endl;
+
+ close(pardang1);
+ if (0) cerr << "closing " << pardang2
+ << " for parent of " << kidid << endl;
+ close(pardang2);
// Let kid #0 run a little ways:
if (ii==0) {
@@ -770,10 +835,10 @@ bar
// Now it is safe to transfer the envelope information:
if (0) cerr << "about to slurp: "
- << " cr.MSG: " << current_read[MSG]
+ << " cr.MSG: " << current_read[MSG]
<< " cr.ENV: " << current_read[ENV]
- << " w.MSG: " << cur_write[MSG]
- << " w.ENV: " << cur_write[ENV]
+ << " w.MSG: " << current_write[MSG]
+ << " w.ENV: " << current_write[ENV]
<< " slurp_read: " << slurp_read
<< " slurp_write: " << slurp_write
<< endl;