1818#include " llvm/Support/Path.h"
1919#include " llvm/Support/Program.h"
2020#include " llvm/Support/SystemUtils.h"
21+ #include " llvm/Support/Threading.h"
2122
23+ #include < list>
2224#include < vector>
2325
2426using namespace llvm ;
@@ -69,6 +71,17 @@ static cl::opt<std::string> OutIncrement{
6971 " pass."
7072 cl::init (" " cl::value_desc (" R"
7173
74+ static cl::opt<unsigned int > JobsInParallel{
75+ " jobs"
76+ cl::Optional,
77+ cl::init (1 ),
78+ cl::desc (" Specify the number of threads for launching input commands in "
79+ " parallel mode"
80+ };
81+
82+ static cl::alias JobsInParallelShort{" j" cl::desc (" Alias for --jobs"
83+ cl::aliasopt (JobsInParallel)};
84+
7285static void error (const Twine &Msg) {
7386 errs () << " llvm-foreach: " ' \n '
7487 exit (1 );
@@ -79,6 +92,32 @@ static void error(std::error_code EC, const Twine &Prefix) {
7992 error (Prefix + " : " message ());
8093}
8194
95+ // With BlockingWait=false this function just goes through the all
96+ // submitted jobs to check if some of them have finished.
97+ int checkIfJobsAreFinished (std::list<sys::ProcessInfo> &JobsSubmitted,
98+ bool BlockingWait = true ) {
99+ std::string ErrMsg;
100+ auto It = JobsSubmitted.begin ();
101+ while (It != JobsSubmitted.end ()) {
102+ sys::ProcessInfo WaitResult =
103+ sys::Wait (*It, 0 , /* WaitUntilTerminates*/
104+
105+ // Check if the job has finished (PID will be 0 if it's not).
106+ if (!BlockingWait && !WaitResult.Pid ) {
107+ It++;
108+ continue ;
109+ }
110+ assert (BlockingWait || WaitResult.Pid );
111+ It = JobsSubmitted.erase (It);
112+
113+ if (WaitResult.ReturnCode != 0 ) {
114+ errs () << " llvm-foreach: " ' \n '
115+ return WaitResult.ReturnCode ;
116+ }
117+ }
118+ return 0 ;
119+ }
120+
82121int main (int argc, char **argv) {
83122 cl::ParseCommandLineOptions (
84123 argc, argv,
@@ -160,6 +199,16 @@ int main(int argc, char **argv) {
160199 PrevNumOfLines = FileLists[i].size ();
161200 }
162201
202+ if (!JobsInParallel)
203+ error (" Number of parallel threads should be a positive integer"
204+
205+ size_t MaxSafeNumThreads = optimal_concurrency ().compute_thread_count ();
206+ if (JobsInParallel > MaxSafeNumThreads) {
207+ JobsInParallel = MaxSafeNumThreads;
208+ outs () << " llvm-foreach: adjusted number of threads to "
209+ << MaxSafeNumThreads << " (max safe available).\n "
210+ }
211+
163212 std::error_code EC;
164213 raw_fd_ostream OS{OutputFileList, EC, sys::fs::OpenFlags::OF_None};
165214 if (!OutputFileList.empty ())
@@ -170,6 +219,7 @@ int main(int argc, char **argv) {
170219 std::string IncOutArg;
171220 std::vector<std::string> ResInArgs (InReplaceArgs.size ());
172221 std::string ResFileList = " "
222+ std::list<sys::ProcessInfo> JobsSubmitted;
173223 for (size_t j = 0 ; j != FileLists[0 ].size (); ++j) {
174224 for (size_t i = 0 ; i < InReplaceArgs.size (); ++i) {
175225 ArgumentReplace CurReplace = InReplaceArgs[i];
@@ -221,17 +271,23 @@ int main(int argc, char **argv) {
221271 Args[OutIncrementArg.ArgNum ] = IncOutArg;
222272 }
223273
224- std::string ErrMsg;
225- // TODO: Add possibility to execute commands in parallel .
226- int Result =
227- sys::ExecuteAndWait (Prog, Args, /* Env= */ None, /* Redirects= */ None,
228- /* SecondsToWait= */ 0 , /* MemoryLimit= */ 0 , &ErrMsg);
229- if (Result != 0 ) {
230- errs () << " llvm-foreach: " << ErrMsg << ' \n ' ;
231- Res = Result;
232- }
274+ // Do not start execution of a new job until previous one(s) are finished,
275+ // if the maximum number of parallel workers is reached .
276+ while (JobsSubmitted. size () == JobsInParallel)
277+ if ( int Result =
278+ checkIfJobsAreFinished (JobsSubmitted , /* BlockingWait */ false ))
279+ Res = Result;
280+
281+ JobsSubmitted. emplace_back ( sys::ExecuteNoWait (
282+ Prog, Args, /* Env= */ None, /* Redirects= */ None, /* MemoryLimit= */ 0 ));
233283 }
234284
285+ // Wait for all commands to be executed.
286+ while (!JobsSubmitted.empty ())
287+ if (int Result =
288+ checkIfJobsAreFinished (JobsSubmitted, /* BlockingWait*/ true ))
289+ Res = Result;
290+
235291 if (!OutputFileList.empty ()) {
236292 OS.close ();
237293 }
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