Implement timeout for the deadlock of traverse & transactions.

[ccan] / ccan / tdb / tools / replay_trace.c

diff --git a/ccan/tdb/tools/replay_trace.c b/ccan/tdb/tools/replay_trace.c
index 8fc0ce52a63379cdf325ee4fd2ced797afb8edb0..bd4b8aa804eeaca2c11626cd659d4c7345ec73f4 100644 (file)
--- a/ccan/tdb/tools/replay_trace.c
+++ b/ccan/tdb/tools/replay_trace.c
@@ -22,7 +22,7 @@
 /* Avoid mod by zero */
 static unsigned int total_keys = 1;
 
 /* Avoid mod by zero */
 static unsigned int total_keys = 1;
 

-#define DEBUG_DEPS 1
+/* #define DEBUG_DEPS 1 */

 
 /* Traversals block transactions in the current implementation. */
 #define TRAVERSALS_TAKE_TRANSACTION_LOCK 1
 
 /* Traversals block transactions in the current implementation. */
 #define TRAVERSALS_TAKE_TRANSACTION_LOCK 1


@@ -425,9 +425,10 @@ static void dump_pre(char *filename[], struct op *op[],
 }
 
 /* We simply read/write pointers, since we all are children. */
 }
 
 /* We simply read/write pointers, since we all are children. */

-static void do_pre(struct tdb_context *tdb,
+static bool do_pre(struct tdb_context *tdb,

                   char *filename[], struct op *op[],
                   char *filename[], struct op *op[],

-                  unsigned int file, int pre_fd, unsigned int i)
+                  unsigned int file, int pre_fd, unsigned int i,
+                  bool backoff)

 {
        while (!list_empty(&op[file][i].pre)) {
                struct depend *dep;
 {
        while (!list_empty(&op[file][i].pre)) {
                struct depend *dep;


@@ -436,9 +437,17 @@ static void do_pre(struct tdb_context *tdb,
                printf("%s:%u:waiting for pre\n", filename[file], i+1);
                fflush(stdout);
 #endif
                printf("%s:%u:waiting for pre\n", filename[file], i+1);
                fflush(stdout);
 #endif

-               alarm(10);
+               if (backoff)
+                       alarm(2);
+               else
+                       alarm(10);

                while (read(pre_fd, &dep, sizeof(dep)) != sizeof(dep)) {
                        if (errno == EINTR) {
                while (read(pre_fd, &dep, sizeof(dep)) != sizeof(dep)) {
                        if (errno == EINTR) {

+                               if (backoff) {
+                                       warnx("%s:%u:avoiding deadlock",
+                                             filename[file], i+1);
+                                       return false;
+                               }

                                dump_pre(filename, op, file, i);
                                exit(1);
                        } else
                                dump_pre(filename, op, file, i);
                                exit(1);
                        } else


@@ -455,6 +464,7 @@ static void do_pre(struct tdb_context *tdb,
                /* This could be any op, not just this one. */
                talloc_free(dep);
        }
                /* This could be any op, not just this one. */
                talloc_free(dep);
        }

+       return true;

 }
 
 static void do_post(char *filename[], struct op *op[],
 }
 
 static void do_post(char *filename[], struct op *op[],


@@ -484,7 +494,8 @@ static unsigned run_ops(struct tdb_context *tdb,
                        char *filename[],
                        struct op *op[],
                        unsigned int file,
                        char *filename[],
                        struct op *op[],
                        unsigned int file,

-                       unsigned int start, unsigned int stop);
+                       unsigned int start, unsigned int stop,
+                       bool backoff);

 
 struct traverse_info {
        struct op **op;
 
 struct traverse_info {
        struct op **op;


@@ -502,6 +513,7 @@ static int nontrivial_traverse(struct tdb_context *tdb,
 {
        struct traverse_info *tinfo = _tinfo;
        unsigned int trav_len = tinfo->op[tinfo->file][tinfo->start].group_len;
 {
        struct traverse_info *tinfo = _tinfo;
        unsigned int trav_len = tinfo->op[tinfo->file][tinfo->start].group_len;

+       bool avoid_deadlock = false;

 
        if (tinfo->i == tinfo->start + trav_len) {
                /* This can happen if traverse expects to be empty. */
 
        if (tinfo->i == tinfo->start + trav_len) {
                /* This can happen if traverse expects to be empty. */


@@ -515,11 +527,17 @@ static int nontrivial_traverse(struct tdb_context *tdb,
                fail(tinfo->filename[tinfo->file], tinfo->start + 1,
                     "%s:%u:traverse terminated early");
 
                fail(tinfo->filename[tinfo->file], tinfo->start + 1,
                     "%s:%u:traverse terminated early");
 

+#if TRAVERSALS_TAKE_TRANSACTION_LOCK
+       avoid_deadlock = true;
+#endif
+

        /* Run any normal ops. */
        tinfo->i = run_ops(tdb, tinfo->pre_fd, tinfo->filename, tinfo->op,
        /* Run any normal ops. */
        tinfo->i = run_ops(tdb, tinfo->pre_fd, tinfo->filename, tinfo->op,

-                          tinfo->file, tinfo->i+1, tinfo->start + trav_len);
+                          tinfo->file, tinfo->i+1, tinfo->start + trav_len,
+                          avoid_deadlock);

 
 

-       if (tinfo->i == tinfo->start + trav_len)
+       /* We backed off, or we hit OP_TDB_TRAVERSE_END. */
+       if (tinfo->op[tinfo->file][tinfo->i].op != OP_TDB_TRAVERSE)

                return 1;
 
        return 0;
                return 1;
 
        return 0;


@@ -548,7 +566,8 @@ static unsigned op_traverse(struct tdb_context *tdb,
                else
                        tinfo.i = run_ops(tdb, pre_fd, filename, op, file,
                                          tinfo.i,
                else
                        tinfo.i = run_ops(tdb, pre_fd, filename, op, file,
                                          tinfo.i,

-                                         start + op[file][start].group_len);
+                                         start + op[file][start].group_len,
+                                         false);

        }
 
        return tinfo.i;
        }
 
        return tinfo.i;


@@ -564,7 +583,8 @@ unsigned run_ops(struct tdb_context *tdb,
                 char *filename[],
                 struct op *op[],
                 unsigned int file,
                 char *filename[],
                 struct op *op[],
                 unsigned int file,

-                unsigned int start, unsigned int stop)
+                unsigned int start, unsigned int stop,
+                bool backoff)

 {
        unsigned int i;
        struct sigaction sa;
 {
        unsigned int i;
        struct sigaction sa;


@@ -574,7 +594,8 @@ unsigned run_ops(struct tdb_context *tdb,
 
        sigaction(SIGALRM, &sa, NULL);
        for (i = start; i < stop; i++) {
 
        sigaction(SIGALRM, &sa, NULL);
        for (i = start; i < stop; i++) {

-               do_pre(tdb, filename, op, file, pre_fd, i);
+               if (!do_pre(tdb, filename, op, file, pre_fd, i, backoff))
+                       return i;

 
                switch (op[file][i].op) {
                case OP_TDB_LOCKALL:
 
                switch (op[file][i].op) {
                case OP_TDB_LOCKALL:


@@ -1453,7 +1474,8 @@ int main(int argc, char *argv[])
                printf("Single threaded run...");
                fflush(stdout);
 
                printf("Single threaded run...");
                fflush(stdout);
 

-               run_ops(tdb, pipes[0].fd[0], argv+2, op, 0, 1, num_ops[0]);
+               run_ops(tdb, pipes[0].fd[0], argv+2, op, 0, 1, num_ops[0],
+                       false);

                check_deps(argv[2], op[0], num_ops[0]);
 
                printf("done\n");
                check_deps(argv[2], op[0], num_ops[0]);
 
                printf("done\n");


@@ -1481,7 +1503,7 @@ int main(int argc, char *argv[])
                        if (read(fds[0], &c, 1) != 1)
                                exit(1);
                        run_ops(tdb, pipes[i].fd[0], argv+2, op, i, 1,
                        if (read(fds[0], &c, 1) != 1)
                                exit(1);
                        run_ops(tdb, pipes[i].fd[0], argv+2, op, i, 1,

-                               num_ops[i]);
+                               num_ops[i], false);

                        check_deps(argv[2+i], op[i], num_ops[i]);
                        exit(0);
                default:
                        check_deps(argv[2+i], op[i], num_ops[i]);
                        exit(0);
                default: