perf_counter tools: add in basic glue from Git

First very raw version at having a central 'perf' command and
a list of subcommands:

  perf top
  perf stat
  perf record
  perf report
  ...

This is done by picking up Git's collection of utility functions,
and hacking them to build fine in this new environment.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 93 insertions, 0 deletions

diff --git a/Documentation/perf_counter/run-command.h b/Documentation/perf_counter/run-command.h
new file mode 100644
index 000000000000..328289f23669
--- /dev/null
+++ b/Documentation/perf_counter/run-command.h
@@ -0,0 +1,93 @@
+#ifndef RUN_COMMAND_H
+#define RUN_COMMAND_H
+
+enum {
+        ERR_RUN_COMMAND_FORK = 10000,
+        ERR_RUN_COMMAND_EXEC,
+        ERR_RUN_COMMAND_PIPE,
+        ERR_RUN_COMMAND_WAITPID,
+        ERR_RUN_COMMAND_WAITPID_WRONG_PID,
+        ERR_RUN_COMMAND_WAITPID_SIGNAL,
+        ERR_RUN_COMMAND_WAITPID_NOEXIT,
+};
+#define IS_RUN_COMMAND_ERR(x) (-(x) >= ERR_RUN_COMMAND_FORK)
+
+struct child_process {
+        const char **argv;
+        pid_t pid;
+        /*
+         * Using .in, .out, .err:
+         * - Specify 0 for no redirections (child inherits stdin, stdout,
+         *   stderr from parent).
+         * - Specify -1 to have a pipe allocated as follows:
+         *     .in: returns the writable pipe end; parent writes to it,
+         *          the readable pipe end becomes child's stdin
+         *     .out, .err: returns the readable pipe end; parent reads from
+         *          it, the writable pipe end becomes child's stdout/stderr
+         *   The caller of start_command() must close the returned FDs
+         *   after it has completed reading from/writing to it!
+         * - Specify > 0 to set a channel to a particular FD as follows:
+         *     .in: a readable FD, becomes child's stdin
+         *     .out: a writable FD, becomes child's stdout/stderr
+         *     .err > 0 not supported
+         *   The specified FD is closed by start_command(), even in case
+         *   of errors!
+         */
+        int in;
+        int out;
+        int err;
+        const char *dir;
+        const char *const *env;
+        unsigned no_stdin:1;
+        unsigned no_stdout:1;
+        unsigned no_stderr:1;
+        unsigned perf_cmd:1; /* if this is to be perf sub-command */
+        unsigned stdout_to_stderr:1;
+        void (*preexec_cb)(void);
+};
+
+int start_command(struct child_process *);
+int finish_command(struct child_process *);
+int run_command(struct child_process *);
+
+extern int run_hook(const char *index_file, const char *name, ...);
+
+#define RUN_COMMAND_NO_STDIN 1
+#define RUN_PERF_CMD         2  /*If this is to be perf sub-command */
+#define RUN_COMMAND_STDOUT_TO_STDERR 4
+int run_command_v_opt(const char **argv, int opt);
+
+/*
+ * env (the environment) is to be formatted like environ: "VAR=VALUE".
+ * To unset an environment variable use just "VAR".
+ */
+int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);
+
+/*
+ * The purpose of the following functions is to feed a pipe by running
+ * a function asynchronously and providing output that the caller reads.
+ *
+ * It is expected that no synchronization and mutual exclusion between
+ * the caller and the feed function is necessary so that the function
+ * can run in a thread without interfering with the caller.
+ */
+struct async {
+        /*
+         * proc writes to fd and closes it;
+         * returns 0 on success, non-zero on failure
+         */
+        int (*proc)(int fd, void *data);
+        void *data;
+        int out;        /* caller reads from here and closes it */
+#ifndef __MINGW32__
+        pid_t pid;
+#else
+        HANDLE tid;
+        int fd_for_proc;
+#endif
+};
+
+int start_async(struct async *async);
+int finish_async(struct async *async);
+
+#endif